Moparts
Possible to lessen choppy idle due to cam?
Posted By: larrymopar360
Possible to lessen choppy idle due to cam? - 08/24/14 01:36 AM
Love the power my 410 smallblock makes, but the idle is pretty choppy and I'd prefer it be as smooth as possible (kind of a sleeper car). Assuming the carb is set properly, and I believe mechanic has it spot on, are there ways to smooth it out? Adding a vacuum canister (I don't know the proper terminology but I have seen them) that holds vacuum help? The power brakes are fine. The pedal does get a little hard after back to back use, but I can live with that. This engine is in my '89 Diplomat Police car so choppy idle isn't exactly "appropriate". Now if it were a Duster or Demon, etc......
It is a brand new engine so I don't want to change out the cam. Just wondering if there is a simpler solution that might lessen the choppiness. Thanks.
Posted By: 70AARcuda
Re: Possible to lessen choppy idle due to cam? - 08/24/14 02:04 AM
More initial timing you can crank into to it the smoother it will idle...and then you have to limit the mechanical advance in the distributor to keep total around 35 degrees...
Posted By: ademon
Re: Possible to lessen choppy idle due to cam? - 08/24/14 02:05 AM
Rhodes lifters,
Posted By: radar
Re: Possible to lessen choppy idle due to cam? - 08/24/14 03:31 AM
Turn up the idle to a slightly higher rpm and keep it quiet with good mufflers
Posted By: Curt
Re: Possible to lessen choppy idle due to cam? - 08/24/14 03:52 AM
I ran crane variable duration lifters over 2 decades ago...... Doubled my idle vacuum from 2" to 4" and helped smooth out off idle running as well.
Curt
Posted By: Kern Dog
Re: Possible to lessen choppy idle due to cam? - 08/24/14 08:21 AM
Holy crap ! TWO inches of idle vacuum???
Posted By: 451Mopar
Re: Possible to lessen choppy idle due to cam? - 08/24/14 10:04 AM
More timing at idle really helps. I found that out when I installed the EFI system. You might be able to adjust the vacuum advance to pull in at a lower vacuum level and then connect the vacuum advance to full time vacuum source.
Another option could use an ignition retard module triggered with a microswitch on the carb, like a nitrous setup. At idle you could run alot of ignition advance, then when you hit the throttle, the ignition would retard and advance with the distrubitors advance curve.
Posted By: Red 79
Re: Possible to lessen choppy idle due to cam? - 08/24/14 02:21 PM
The more initial timing you can run the better it will idle. I used to run 12 degrees at idle with a choppy solid lifter in 360 cu and since have changed to 19 degree at idle (still 35 total). The difference in idle quality is much better and still starts just as easy as before. For me it was worth the effort and time it took to modify to mechanical advance.
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/24/14 11:38 PM
I did bring up the idle setting just a bit and that helped a little. Still very choppy though. I noticed install mechanic has the vacuum advance plugged. I know total timing is set at 36 per the engine builder. I will check with him on initial timing, thanks.
I don't want to change out anything right now. It is a brand new internally balanced engine, and I sprung for the roller cam upgrade and other goodies, so I really can't afford nor want to start unbolting and replacing parts. Hoping for a simpler solution but am ignorant on the subject of choppy idling cams. I know there may not be a simple one, but I will definitely talk with mechanic about initial timing. Thanks again.
Posted By: RobX4406
Re: Possible to lessen choppy idle due to cam? - 08/24/14 11:48 PM
Total might be OK at 36, but if that dist has 28* of mechanical in it, it's going to idle like bullcrap. Total timing method is horrible way to time a car that's street driven and good idle quality is desired. Put a distributor out of the box that isn't set up for the engine and you'll get junky idle and low speed manners.
Put a light on it at idle and see where it's timed.
I wouldn't have any less than 15 minimum in most any case.
It may take some work to get it right.
Posted By: bonefish
Re: Possible to lessen choppy idle due to cam? - 08/25/14 12:56 AM
Quote:
Turn up the idle to a slightly higher rpm and keep it quiet with good mufflers
thats all thats going to help without changing parts.i usually just tell people when they say somthing about the cam."naw,i just need to get that carb dialed in and it,ll smooth rite out" 
Posted By: 70AARcuda
Re: Possible to lessen choppy idle due to cam? - 08/25/14 01:07 AM
turn up the idle speed...then lose your mixture screws adjustifiability....fix the timing...then adjust carb...
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/25/14 01:32 AM
I will definitely discuss all the timing settings with install mechanic. He is a great mechanic...not a Mopar guy, but still great mechanic. I am certain he had a light on it and vacuum gauge, but this distributor is a Mopar performance with the orange box, so maybe other changes will help? I would be willing to spring for new ignition if it would help alot, and at least that wouldn't require getting into internals of new engine.
I'd love it if tweaking the carb adjustments brought it down some! I think maybe the timing is a little off of the suggestions of builder. We shall see!
Posted By: 70Cuda383
Re: Possible to lessen choppy idle due to cam? - 08/25/14 03:06 AM
The only way you'll smooth out the idle, is to increase the RPM. Even the choppiest of race engines 'smooth out' in sound as RPM goes up, and the tamest if engines will sound like wild race motors if you dial the rpm down to 350 at idle.
Now, don't cheat and just turn your idle speed screw. Need to tune for max vacuum at idle by increasing timing. Then set dustributir to limit total timing to 36-38. If its still too choppy, get a big, single exhaust snd large muffler. Combining exhaust into 1 system helps mellow out the pulses from each other. And finally, if its still not enough, bump RPM by 150 via idle speed screw.
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/25/14 03:29 AM
Quote:
The only way you'll smooth out the idle, is to increase the RPM. Even the choppiest of race engines 'smooth out' in sound as RPM goes up, and the tamest if engines will sound like wild race motors if you dial the rpm down to 350 at idle.
Now, don't cheat and just turn your idle speed screw. Need to tune for max vacuum at idle by increasing timing. Then set dustributir to limit total timing to 36-38. If its still too choppy, get a big, single exhaust snd large muffler. Combining exhaust into 1 system helps mellow out the pulses from each other. And finally, if its still not enough, bump RPM by 150 via idle speed screw.
I am taking notes. I just spent big on the exhaust too though. Mandrel bent 2.5 dual exhausts. H or X pipe make a considerable difference?
I did turn up idle a bit and it helped a bit but not enough. Thanks.
Posted By: bonefish
Re: Possible to lessen choppy idle due to cam? - 08/25/14 02:03 PM
it sounds like the motor you built,SOUNDS like the motor you built.it needs to breath and thats going to keep it choppy.
Posted By: skicker
Re: Possible to lessen choppy idle due to cam? - 08/25/14 03:20 PM
Installing an X pipe will smooth it out a lot. Its not a cheap solution but it does work well and will add performance. I just went through some of this with my 340. I run an MSD ignition and after changing the bushings to limit the advance my motor sounded a little tamer than before. My initial timing is now advanced to 20* with total being right at 38*. Your distributor can be modified to do what you want, it's just so much easier with the MSD because the adjustments were built in when it was designed.
Posted By: dogdays
Re: Possible to lessen choppy idle due to cam? - 08/25/14 04:40 PM
Wht's the duration at 50 lift and the lobe separation angle?
Where is the intake centerline?
These questions MUST be answered before any kind of intelligent answer can be found.
I have a feeling you and your mechanic have different ideas of what a "streetable" cam is. Eventually you're going to replace or regrind the cam , is my bet. You may be able to advance the cam, which closes the intake valve sooner, which can cut down somewhat on the choppy idle.
But answer the questions first. And if your mechanic can't tell you where he installed the cam, he's not much of a mechanic. And "lined up the dots" doesn't count as an answer.
R.
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/25/14 10:17 PM
Quote:
Installing an X pipe will smooth it out a lot. Its not a cheap solution but it does work well and will add performance. I just went through some of this with my 340. I run an MSD ignition and after changing the bushings to limit the advance my motor sounded a little tamer than before. My initial timing is now advanced to 20* with total being right at 38*. Your distributor can be modified to do what you want, it's just so much easier with the MSD because the adjustments were built in when it was designed.
Thanks for the tips.
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/25/14 10:25 PM
It is possible "streetable" has different definition to me. A lot of people like a choppy idle on their street cars. I did explain to engine builder the use of the car, weight, rear gear, trans, tire size, etc. In their defense, it does have enough vacuum to run power brakes. The builder was Muscle Motors, who came very recommended on this forum when I was asking around. The dyno run sheet shows total timing of 36. I don't think it has initial timing. My mechanic did the install, and I have as much confidence in him and his abilities as I do in any mechanic. He does excellent work and is very knowledgable. That doesn't mean the timing or something else doesn't need to be tweaked though, or that the addition of something like an X pipe as suggested wouldn't help. I hadn't thought of an X pipe. I want to have some info written down when I talked to him so I don't waste any of his time. I will see what he has to say. Today I checked the firing order just to be sure. there wasn't a loose wire or crossed wires (I doubted it but easy to check). I figured it runs too good to have that issue, but it idles like it might have. Thx.
Posted By: RobX4406
Re: Possible to lessen choppy idle due to cam? - 08/25/14 10:38 PM
Quote:
It is possible "streetable" has different definition to me. A lot of people like a choppy idle on their street cars. I did explain to engine builder the use of the car, weight, rear gear, trans, tire size, etc. In their defense, it does have enough vacuum to run power brakes. The builder was Muscle Motors, who came very recommended on this forum when I was asking around. The dyno run sheet shows total timing of 36. I don't think it has initial timing. My mechanic did the install, and I have as much confidence in him and his abilities as any mechanic. Super good. That doesn't mean the timing or something else doesn't need to be tweaked to, or adding something like an X pipe as suggested. I hadn't thought of that. I want to have some info written down when I talked to him so I don't waste any of his time. I will see what he has to say. Today I checked the firing order just to be sure. there wasn't a loose wire or crossed wires (I doubted it but easy to check). I figured it runs too good to have that issue, but it idles like it might have. Thx.
What camshaft is in this thing?
What distributor?
There is a very good chance that 36 is fine for total, but if that distributor has 24+ of mechanical advance built in it, it's going to run like junk at idle and off idle. This is the "WORK" part of the program.
Unfortunately, sometimes parts get tossed at engines with no desire to get them sorted out properly. Dynos shops and most operators run for one thing in general, max HP/TQ. They don't usually worry about idle quality.
Put a timing light on it and see where you are.
A very easy test, find where it's set now. Warm it up, loosen the dist clamp and give a little twist CCW to the housing, did it pick up RPM? If so it wants the timing and the distributor mechanical advance will need adjusting. If you aren't going to fix it right then, reset it to where it was before the test and know that the initial timing setting is not correct for your engine.
Posted By: mikemee1331
Re: Possible to lessen choppy idle due to cam? - 08/25/14 11:17 PM
Quote:
Rhodes lifters,
X2 
work great for me. no "lump-a-lump"!
Posted By: dogdays
Re: Possible to lessen choppy idle due to cam? - 08/25/14 11:22 PM
Rhoads.
I believe he said it was a roller cam.
OP, nothing wrong with Muscle Motors. But, you really need the cam specs and where it was installed. It should be in the paperwork or give them a call. It's vital.
For example, If the cam you're running has 252 degrees @ 50 lift, you can bandaid it all day and it won't be smooth.
R.
Posted By: AndyF
Re: Possible to lessen choppy idle due to cam? - 08/25/14 11:57 PM
As others have said the easiest solution is to add more ignition advance. Another fairly easy solution is to add some lash. Check with the cam mfg to see what the maximum lash is. Adding lash makes the cam seem smaller. You can also play with the cam timing but that is more involved, especially on a small block.
You'll also want to inspect the engine carefully for any vacuum leaks. Maybe plug the PCV if it is hooked up to see if that helps. Double check the AF ratio to make sure that he carb is properly adjusted. A wide band is the best way to go. If the carb is lean or rich then it can cause misfiring at idle which makes things worse.
Posted By: mikemee1331
Re: Possible to lessen choppy idle due to cam? - 08/26/14 12:32 AM
Quote:
Rhoads.
I believe he said it was a roller cam.
not seeing where that was said. 
Posted By: dogdays
Re: Possible to lessen choppy idle due to cam? - 08/26/14 01:48 AM
His second or third post, he said, "It is a brand new internally balanced engine, and I sprung for the roller cam upgrade and other goodies, so I really can't afford nor want to start unbolting and replacing parts."
All this leads me to believe that it's a Muscle Motors crate engine. It could be a hydraulic roller, even.
MM's website isn't very specific about the camshafts.
The fact that it idles with quite a bit of vacuum tells me that it's probably not too big and the rest of you are probably on the right track with suggestions about timing, or else the carb is out of adjustment, something like that.
I'd still like to know what the cam is, though.
R.
Posted By: mikemee1331
Re: Possible to lessen choppy idle due to cam? - 08/26/14 02:26 AM
Quote:
His second or third post, he said, "It is a brand new internally balanced engine, and I sprung for the roller cam upgrade and other goodies, so I really can't afford nor want to start unbolting and replacing parts."
All this leads me to believe that it's a Muscle Motors crate engine. It could be a hydraulic roller, even.
MM's website isn't very specific about the camshafts.
The fact that it idles with quite a bit of vacuum tells me that it's probably not too big and the rest of you are probably on the right track with suggestions about timing, or else the carb is out of adjustment, something like that.
I'd still like to know what the cam is, though.
R.
re-read it again and you're right, also right about it probably being hydraulic roller and I agree, probably timing or carb tweek. 
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/26/14 03:29 AM
I am so grateful for all the information, and I am listening. Yes, turning the idle up a bit did help but still choppy/shaky.
Yes, it is a hydraulic roller cam upgrade. I did ask for the cam specifics when first shopping, and was told their builds are proprietorial. I think this engine is called their Killer Street Krate, with the hyd/roller cam and windage tray upgrade.
I am going to do my best to get specifics on the cam. I am hearing what you are saying, and that will be a help in making a decision on what to try. Then I will call install mechanic and see when I can go by and talk to him about all the timing and carb settings. I feel like the carb is set right, but if anything, maybe a little lean by the smell of the exhaust. I know that isn't exactly scientific. Carb was set on dyno. Really everything in this engine is new and designed to work together, except the MP electronic ignition (distributor too) with orange box. I am very strongly considering replacing that, then having mechanic work on timing and possible carb mixture. Thanks again to all.
Posted By: NachoRT74
Re: Possible to lessen choppy idle due to cam? - 08/26/14 07:52 AM
I'm wondering why nobody have adviced to advance the camshaft some degrees. I'm still into the HOW A CAMSHAFT SPEC AFFECTS EVERYTHING ignorance world, specially talking about centerline instalation and all related ( duration and lift is really clear ), but I have know installing an advanced camshaft makes more "streetable" the engine
Posted By: Sxrxrnr
Re: Possible to lessen choppy idle due to cam? - 08/26/14 11:01 AM
Several things of some importance I have not seen, or am I missing them.
1. Auto or manual transmission?
2. Current idle speed?
3. Current vacuum reading at idle?
4. Does car have AC
5. Any other conditions causing rough idle,,,carb issue(running rich or lean)spark plug/wire misfiring, Vacuum leaks, etc.
6. Current timing initial advance?
7. Solid or hydraulic lifters,,,I got the roller part.
8. What is meant by rough idle,,,there are different types. Hurky/jerky, lopping like big rpm swings or sense that engine is searching or wants to die,,,etc.
Posted By: dogdays
Re: Possible to lessen choppy idle due to cam? - 08/26/14 04:20 PM
Well, Nacho, I did say, " You may be able to advance the cam, which closes the intake valve sooner, which can cut down somewhat on the choppy idle." a while ago on the page.
This poor guy spent a lot of money on this engine and expected it to run right out of the box. That's what a crate engine from a specialty shop is supposed to do. Muscle Motors' reluctance to give the specs on their camshaft is understandable if they spent money to develop it, but now that a customer is having trouble with it, they should pitch in and help.
OP, have you talked to MM about your situation?
R.
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/26/14 07:00 PM
Quote:
Several things of some importance I have not seen, or am I missing them.
1. Auto or manual transmission?
2. Current idle speed?
3. Current vacuum reading at idle?
4. Does car have AC
5. Any other conditions causing rough idle,,,carb issue(running rich or lean)spark plug/wire misfiring, Vacuum leaks, etc.
6. Current timing initial advance?
7. Solid or hydraulic lifters,,,I got the roller part.
8. What is meant by rough idle,,,there are different types. Hurky/jerky, lopping like big rpm swings or sense that engine is searching or wants to die,,,etc.
Trans is an HD 727. I can't tell you what the vacuum is at idle or intial timing. As mentioned, I have to get with install mechanic soon and am taking notes on what to discuss with him as to not waste any of his time. NO a/c. No vacuum leaks. No misfires. New plugs and 8mm wires. Hydraulic lifters. I would call it choppy idle more than rough. No doesn't want to stall. RPM swings I guess is a good discription, along with shaking.
I am sure it's a big cam. Just didn't know if there were tricks to lessen the signs of such.
Yes, I spent big money. Looking at 10 grand right now. It's complete from carb ($700 Quick Fuel) to oil pan (Milodon 8qt), with all the best parts (ARP, Felpro, etc), Kb Hyp. pistons, scat parts (heard Eagle is having issues, braided fuel line, windage tray/roller setup upgrade, RPM air gap intake, and other good stuff like filter relocation, BM Super Engine Oil Cooler all with braided 10AN steel hose. Had it all painted black for stealthy-ness. Also paid an additional $700 for Dyno Test and Tune so that I wouldn't (presumably) have to wonder where to have mechanic set everything from carb to timing.
I WILL get cam specs today. I am so grateful for the outpouring of help.
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/26/14 08:07 PM
Ok, got it. Cam is a Comp Cam Hydraulic Roller with;
Lift .541 intake .537 exhaust
Duration .230 intake .236 exhaust
Compression is 10.1
Posted By: RobX4406
Re: Possible to lessen choppy idle due to cam? - 08/26/14 08:53 PM
Quote:
Ok, got it. Cam is a Comp Cam Hydraulic Roller with;
Lift .541 intake .537 exhaust
Duration .230 intake .236 exhaust
Compression is 10.1
Proprietary??? That's a XR280HR
They may have cut it on a LSA tigher than the shelf 110* to make it "custom".
That thing shouldn't idle real choppy.
Look at the initial timing FIRST! Use a vacuum gauge or just turn the housing CCW and see if it picks up RPM. You'll likely need to work on the mechanical advance to clean it up. My guess, 18-22 initial timing and 14-18 in the mechanical advance.
It should idle easily at 800-850rpm, with very little chop to it. Shouldn't smell like a fuel truck out the tailpipes either.
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/26/14 11:31 PM
Quote:
Quote:
Ok, got it. Cam is a Comp Cam Hydraulic Roller with;
Lift .541 intake .537 exhaust
Duration .230 intake .236 exhaust
Compression is 10.1
Proprietary??? That's a XR280HR
They may have cut it on a LSA tigher than the shelf 110* to make it "custom".
That thing shouldn't idle real choppy.
Look at the initial timing FIRST! Use a vacuum gauge or just turn the housing CCW and see if it picks up RPM. You'll likely need to work on the mechanical advance to clean it up. My guess, 18-22 initial timing and 14-18 in the mechanical advance.
It should idle easily at 800-850rpm, with very little chop to it. Shouldn't smell like a fuel truck out the tailpipes either.
Ok, thanks! I think the proprietary part he spoke of was the combination of parts to make the build, but I don't know. I appreciate the info though and you can bet I (actually mechanic) will be tinkering with the timing/distributor. What ignition system would you recommend if I decide to spend just a little more and replace the MP orange box/distributor/ballast resistor system i have now? MSD?
Posted By: mikemee1331
Re: Possible to lessen choppy idle due to cam? - 08/26/14 11:36 PM
Quote:
What ignition system would you recommend if I decide to spend just a little more and replace the MP orange box/distributor/ballast resistor system i have now? MSD?
just suggestion but take of one problem at a time. what you have should work just fine to get it running good. start a different thread on the ignition upgrade. just my 
Posted By: RobX4406
Re: Possible to lessen choppy idle due to cam? - 08/26/14 11:37 PM
The MP can work fine.
If it has a bronze colored tower where the rotor plugs on, it's a mallory unit and easy to adjust with basic tools and some drill bit shanks. Iron colored it requires some welding. The slot lengths are on the site and other places to set mechanical advance.
IMO, get it hot and see how much initial timing the engine will stand before kicking back or dragging on the starter. Once you find that point, you can dial in the rest.
It should run a lot better once you get the idle sorted out. I had a 360 with a similar cam, 20 initial 14 mechanical. Idled like a nice sleeper car.
Posted By: dogdays
Re: Possible to lessen choppy idle due to cam? - 08/27/14 01:27 AM
We might be getting somewhere here. It's a brand-new engine. My assumption is that the distributor is the newest MP (mallory) unit that E-berg and others have said has a really hard time keeping timing stable at idle.
https://board.moparts.org/ubbthreads/show...rue#Post8230660Go back and read some of the posts about this, or email E-berg and ask him directly, he sometimes answers posts.
The camshaft at 230 intake duration is not that big, it is ground 4 degrees advanced, so intake centerline is 106 on a 110 LSA.
Check the ignition first. There's nothing wrong with the MP electronics, but the distributor thing might be the culprit. That'd be the one with the bronze colored shaft end (where the rotor goes.) If so, swapping on any other distributor, even one out of a 1974 Dart, should make a real difference.
Then you would indeed buy and put in an MSD electronic distribut or Firecore, you can hook it to the MP box or use the MSD-6 or whatever.
For example:
https://www.customwiresets.com/product.php?productid=16293&cat=252&page=1 R.
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/27/14 01:48 AM
I am so glad to have this information! The distributor in it came with the kit and I bought the kit probably 3 years ago now. I will look at the color of the shaft as soon as I get home later tonight. What would I do without this forum???!!! Such a wealth of knowledge here.
Eherenberg has answered some questions for me, so I may shoot him an email and a couple dollars for his "divorce fund" I think he calls it. First I will check the color of the distributor shaft.
Posted By: 70AARcuda
Re: Possible to lessen choppy idle due to cam? - 08/27/14 03:24 AM
MP switched to the Mallory based Distributor in the late 90s or early 2000s..I have a MP distributor with a 2001 date on it..and it is a Mallory...Hard to believe anything bought new in the last couple of years would not be a Mallory unit.
Posted By: 1fastrunner
Re: Possible to lessen choppy idle due to cam? - 08/27/14 05:21 AM
I have to ask why?
I got my cam for the lumpy idle. With it kicking in at 3000 RPM"s, I ask why did I get this cam?
But I still love the lumpy idle
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/27/14 07:42 PM
Ok I check distributor shaft, and it is silver, not brass colored.
I am trying to write down the highlights of this and go speak with mechanic in next day or two.
What I have taken from this is to see where initial timing is and shoot for 20 degrees or so, with a total of 36.
My MP distributor should be ok if adjusted properly.
Turn idle speed higher (already done).
One thing I read and don't understand is the suggestion to adjust idle vacuum to 4". Not sure what that means. Does that mean set idle where I have that vacuum and not at certain RPM. I guess the mechanic will know, but I am curious.
I will try to have a resolution soon and not drag this out any longer than necessary.
Like I mentioned earlier; mechanic is excellent but not a Mopar guy. I wonder if I should just spring for a Mallory or MSD system that is more easily tuned and familiar to him?
Posted By: dogdays
Re: Possible to lessen choppy idle due to cam? - 08/27/14 10:01 PM
There was NO suggestion to tune to 4" of vacuum. Someone else was telling you about his situation.
The following is with vacuum advance disconnected and plugged:
In general, the suggestion was to increase initial advance until the vacuum at idle was at maximum. Then try starting the car with the engine warm and see if the engine "kicks back" against the starter. If that is so decrease initial advance by 2 degrees or so. This may take more than one iteration. When you have finally gotten the initial advance figured out, adjust the distributor to have no more than 36 degrees total advance, all in by 3000 or so rpm. This may mean shortening some slots or installing a bushing to limit total advance.
One thing for sure, the advance at idle should be rock-steady, the timing light showing the mark being still.
Once you have the initial set, and the total advance limited to the 35 or 36 degrees, then you reconnect the vacuum advance to the "ported vacuum" port on the carb. This should have no vacuum advance at idle, and when you open the throttle a little the vacuum advance works.
R.
Posted By: RobX4406
Re: Possible to lessen choppy idle due to cam? - 08/27/14 11:20 PM
You can get a lot of useful info to make a decision before spending another penny on parts.
Find the correct initial timing setting and go from there. Find where it's set now as well.
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/28/14 03:21 AM
Ok, DogDays and RobX, got it. That is what I will do. Going to make an appointment to leave it with mechanic, and discuss issues and suggestions.
You reminded me of a couple of things that happened, but only once. Once when starting, it was slow to turn over for a second then turned over quickly and started right up. Kind of what I believe is the sound of the timing being off. Then, for the first time, today when I shut it off at work, it sounded like it ran-on for a second after key was off. I guess these indicate timing issues, along with the crappy idle. The car really does idle like there is a miss the more I drive it.
Will call mechanic tomorrow and hope he can take it on Monday. Thanks to all. I won't spend any money on parts yet.
Posted By: mikemee1331
Re: Possible to lessen choppy idle due to cam? - 08/28/14 01:39 PM
[quote Like I mentioned earlier; mechanic is excellent but not a Mopar guy.
and if he does know his stuff, he doesn't need to a 'mopar' guy. everything that has been suggested to you here is basic engine tuning. good luck! 
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/28/14 02:57 PM
Quote:
[quote Like I mentioned earlier; mechanic is excellent but not a Mopar guy.
and if he does know his stuff, he doesn't need to a 'mopar' guy. everything that has been suggested to you here is basic engine tuning. good luck!
Thanks. I think that the job was a big one and he was juggling all his regular customers at the same time that the fine tuning was left behind. He did a great job on everything though. Setting up a filter relocation and cooler, dual exhausts (didn't come with duals), and all the other stuff were done so perfectly.
Posted By: scratchnfotraction
Re: Possible to lessen choppy idle due to cam? - 08/28/14 04:06 PM
good info here Larry,
not your average engine swap on a M-body cop car adding those huge pipes under there. they did look like like a top notch shop when I picked the 318 up.
I need to get over there on a weekend again for the 'ride'
Posted By: JohnRR
Re: Possible to lessen choppy idle due to cam? - 08/28/14 04:22 PM
Quote:
Quote:
Rhoads.
I believe he said it was a roller cam.
not seeing where that was said.
Quote:
I don't want to change out anything right now. It is a brand new internally balanced engine, and I sprung for the roller cam upgrade and other goodies, so I really can't afford nor want to start unbolting and replacing parts.
He also said he has an MP distributor , which one , new or old , was this what it had when it came from Muscle motors and a POS ORANGE BOX ....
Fix the ignition first then throw other parts at it .
Posted By: mikemee1331
Re: Possible to lessen choppy idle due to cam? - 08/28/14 05:07 PM
Quote:
Quote:
Quote:
Rhoads.
I believe he said it was a roller cam.
not seeing where that was said.
Quote:
I don't want to change out anything right now. It is a brand new internally balanced engine, and I sprung for the roller cam upgrade and other goodies, so I really can't afford nor want to start unbolting and replacing parts.
He also said he has an MP distributor , which one , new or old , was this what it had when it came from Muscle motors and a POS ORANGE BOX ....
Fix the ignition first then throw other parts at it .
I saw that John on my 2nd re-read and my 'spanking' from dogdays! I also aSSumed it was the same ignition system. that too was probably a mistake!
Posted By: JohnRR
Re: Possible to lessen choppy idle due to cam? - 08/28/14 06:23 PM
Quote:
Quote:
Quote:
Quote:
Rhoads.
I believe he said it was a roller cam.
not seeing where that was said.
Quote:
I don't want to change out anything right now. It is a brand new internally balanced engine, and I sprung for the roller cam upgrade and other goodies, so I really can't afford nor want to start unbolting and replacing parts.
He also said he has an MP distributor , which one , new or old , was this what it had when it came from Muscle motors and a POS ORANGE BOX ....
Fix the ignition first then throw other parts at it .
I saw that John on my 2nd re-read and my 'spanking' from dogdays! I also aSSumed it was the same ignition system. that too was probably a mistake!
I missed a bunch , he has an OLD MP distributor , he said he bought it 3 yrs ago but doesn't say if it was new or used , currnet or NOS, but we know it's an old one.
I ASSuME he put that on after he received the engine from MM as I doubt they would have let it leave the shop without it being setup for both inital and max advance ?????
Anyway Larry if you are going to buy a new ignition I would Look at the latest and greatest from MSD , the plug and play that has built in rev limiter and other features ... I wish they would make this one for Low decks 
....
Posted By: Magnum
Re: Possible to lessen choppy idle due to cam? - 08/29/14 04:06 AM
I tried power reading each reply but did you determine the initial timing?
Higher timing at idle will reduce the choppy idle.
Why stop at 15? because of your starter? Run it higher. I read you have enough vacuum for power brakes. How much vacuum are you pulling.
Running manifold vacuum advance is another way for achieving big timing numbers at idle.
How about a looser torque convertor?
A bigger exhaust system is another way to mash the sound.
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/29/14 09:11 PM
Magnum: I know there is ALOT to read on this one. I don't know any of the timing settings except that install mechanic said he set it to total of 36 as recommended by engine builder (muscle motors). I bought the ignition system new about 3 years ago and was using it on another one of my cars with a 360, and it was working fine. It does not have the brass colored shaft, so I am told that makes it the Mallory unit. I have not found out what the other timing settings are. I haven't had a chance to make appt. with mechanic. I want to drive by and when I don't see a bunch of cars there I am going to stop by and chat. I hate to bug him because I know he has people stopping his progress all day. Took a drive by earlier and he was real busy. I have to drive one of my other cars in the mean time. Can't take the shaking and choppy idle. I am noticing more and more times when I go to start it turns over slow the first time then cranks fast and starts. Must be initial timing I guess.
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/29/14 10:19 PM
Just went and saw the mechanic. He says he set the initial timing around 22 and total at 36. He said he didn't want to go any higher with initial or car wouldn't start. I already have a little bit of slow turn over on first crank, then it cranks and starts. I asked about something that retards the timing at start and he said I could spend money on that but he doesn't think it's really going to smooth out idle. He believes it's in the cam. I asked about the duration specs and as to whether it should be so choppy with these specs. He said something about advertised and overlap and that may have something to do with it. Greek to me. He said easier than changing out the cam is changing the rocker arms to lower ratio, like a 1.5 and it probably would smooth it a little, but I don't want to start that kind of spending, and can't after putting 10 grand into now. So I guess it is drive it and hope to get used to it.
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/30/14 02:17 AM
I would appreciate some opinions on this ignition from MSD. Pricey! But maybe beneficial to my engine.
http://www.summitracing.com/parts/msd-8388/overview/make/dodgeEdit; i started a new thread on recommendations. Thanks.
Posted By: dogdays
Re: Possible to lessen choppy idle due to cam? - 08/30/14 07:06 PM
You basically have two threads running on the same topic.
We finally got enough information and it seems to me that your ignition is set up right. Your mechanic is good.
Spend the money on a new camshaft, the next smaller one, I believe it's a 274, has 224 @ 50 on the intake.
R.
Posted By: BSB67
Re: Possible to lessen choppy idle due to cam? - 08/30/14 07:29 PM
At some point you need to own all of the aspects to this hobby, or commit a bunch more money to it. It is a bit of a hands on hobby. Spending $10,000 on the motor is just the beginning.
You should start educating yourself on ignitions, carburetors, cam shafts and tuning and start doing things yourself if you want any hope for success. Otherwise there will always be a little something not right, a thousand opinions on what is wrong, and regular trips to the mechanic. And if your not paying him, he'll be done with you pretty quick.
People here will help you all day long, but at some point you need to flip wrenches and get dirty.
Just some advice.
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/30/14 07:33 PM
Quote:
You basically have two threads running on the same topic.
We finally got enough information and it seems to me that your ignition is set up right. Your mechanic is good.
Spend the money on a new camshaft, the next smaller one, I believe it's a 274, has 224 @ 50 on the intake.
R.
Someone recommended I start a new thread on ignition recommendations, so I did so. As mentioned earlier, I really don't want to start pulling parts off this engine. The labor alone would be very costly (I cannot change cams myself). I am going to try a different ignition. Maybe it'll help, maybe it won't, but it's probably a good upgrade anyhow. Thanks.
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/30/14 07:38 PM
Quote:
At some point you need to own all of the aspects to this hobby, or commit a bunch more money to it. It is a bit of a hands on hobby. Spending $10,000 on the motor is just the beginning.
You should start educating yourself on ignitions, carburetors, cam shafts and tuning and start doing things yourself if you want any hope for success. Otherwise there will always be a little something not right, a thousand opinions on what is wrong, and regular trips to the mechanic. And if your not paying him, he'll be done with you pretty quick.
People here will help you all day long, but at some point you need to flip wrenches and get dirty.
Just some advice.
I am most definitely paying the mechanic. I do get a little dirty. I change oil, pulled diff cover and replace gear oil and gasket, replace water pump, radiator, thermostat, brake jobs, pulled a K frame out of a car, and alot of other stuff. Problem is I work alot, have a small single car garage, and limited tools because only so much will fit in garage along with a car. I subscribe to the two big Mopar mags and try and learn what I can. I don't have a vacuum gauge. I do have a timing light. I just find I don't have enough time and want things done right. So I try and learn, but have realized the hard way that some things are better left to the expert. If I had a big garage and a little more time, I'd be in heaven. I loved Mopars all my life and never owned anything but. My opinion is you don't have to know everything, but you have to know the right people to ask. So when I am overmatched, I come here. When I am retired, assuming I will ever be able to, it will be a different story.
Posted By: BSB67
Re: Possible to lessen choppy idle due to cam? - 08/30/14 07:52 PM
Sounds like you have the right attitude. Maybe slow down, do some reading and research in your spare time and let the car sit a little. Right now would be a good time to acquire the literature on your ignition, pull the distributer, play with it until you understand it, then put it together and time it and check advance at several rpm. If you do that, you will have that knowledge forever. Good luck.
Posted By: autoxcuda
Re: Possible to lessen choppy idle due to cam? - 08/30/14 08:38 PM
Quote:
You basically have two threads running on the same topic.
We finally got enough information and it seems to me that your ignition is set up right. Your mechanic is good.
Spend the money on a new camshaft, the next smaller one, I believe it's a 274, has 224 @ 50 on the intake.
R.
Yep.
Hitting a number on a Dyno is not that hard nowdays. It's objective goal that everyone understands.
Idle sound, idle quality, exhaust loudness at cruise, etc are all subjective things. They mean different thing to different people and they are hard to measure and predict.
You got racers who unload their cars of the trailers at the track who think anything not needing earplugs is tame. Then guys who consider their cars "daily drivers" that drive them 3 miles to the local cruise-in.
I have an out of the box XE274 in a 419" stoker. It's not bad, but I wouldn't mind if it idled quieter. Having it custom ground on a 112* lobe seperation would help too. MRL Performance uses that can with that custom centerline on many of his stroker builds.
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/30/14 11:22 PM
I agree AutoxCuda. I think alot is because "choppy" and "lopey" are subjective terms. I have never owned anything other than smooth idling engines. The most powerful I have had have been my Charger SRT8 and the Mopar Performance 360 in my '89. It is quite impressive. I wish Mopar still made them but they don't have the 360 block anymore. It is so strong and torquey, yet idles very smooth. But I live and learn. I believe I am already getting used to the idle a bit, and if some of the suggestions I have received help bring it down a little smoother, all the better.
Thanks all.
Posted By: mikemee1331
Re: Possible to lessen choppy idle due to cam? - 08/30/14 11:29 PM
Someone recommended I start a new thread on ignition recommendations, so I did so.
actually my recommendation was to sort out the first problem and THEN start a new thread on upgrading the ignition. the last thing you want to do is get 2 separate issues going on your motor. there's nothing wrong with what you have right now..
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/30/14 11:36 PM
Quote:
Someone recommended I start a new thread on ignition recommendations, so I did so.
actually my recommendation was to sort out the first problem and THEN start a new thread on upgrading the ignition. the last thing you want to do is get 2 separate issues going on your motor. there's nothing wrong with what you have right now..
I gotch ya. I think everything is fine with what I got now. I still want to upgrade the ignition, even though I really shouldn't spend the money. Thanks.
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/30/14 11:38 PM
Quote:
good info here Larry, not your average engine swap on a M-body cop car adding those huge pipes under there. they did look like like a top notch shop when I picked the 318 up.
I need to get over there on a weekend again for the 'ride'
The ride? You mean the drive. You will be driving it!
Posted By: autoxcuda
Re: Possible to lessen choppy idle due to cam? - 08/31/14 01:22 AM
Quote:
I agree AutoxCuda. I think alot is because "choppy" and "lopey" are subjective terms. I have never owned anything other than smooth idling engines. The most powerful I have had have been my Charger SRT8 and the Mopar Performance 360 in my '89. It is quite impressive. I wish Mopar still made them but they don't have the 360 block anymore. It is so strong and torquey, yet idles very smooth. But I live and learn. I believe I am already getting used to the idle a bit, and if some of the suggestions I have received help bring it down a little smoother, all the better.
Thanks all.
That old MP 360 with 300 HP is a whole different animal than a 410 with an XR280HR-10 that should be 450HP/500TQ +++.
So how does the performance compare between 410" XR280HR-10 cammed Dippy compared to your crate MP 360 Dippy??
I'm thinking the first one is downright Dippy-Trippy.
Posted By: larrymopar360
Re: Possible to lessen choppy idle due to cam? - 08/31/14 01:47 AM
Quote:
Quote:
I agree AutoxCuda. I think alot is because "choppy" and "lopey" are subjective terms. I have never owned anything other than smooth idling engines. The most powerful I have had have been my Charger SRT8 and the Mopar Performance 360 in my '89. It is quite impressive. I wish Mopar still made them but they don't have the 360 block anymore. It is so strong and torquey, yet idles very smooth. But I live and learn. I believe I am already getting used to the idle a bit, and if some of the suggestions I have received help bring it down a little smoother, all the better.
Thanks all.
That old MP 360 with 300 HP is a whole different animal than a 410 with an XR280HR-10 that should be 450HP/500TQ +++.
So how does the performance compare between 410" XR280HR-10 cammed Dippy compared to your crate MP 360 Dippy??
I'm thinking the first one is downright Dippy-Trippy.
I haven't really wound out the 410 yet. It is real strong, I can feel that. It's going to take a few hard runs for me to really tell. But what I can say is I am even more impressed with the MP 360 than I already was. There was probably some sloppy assembly on some of them, but as far as the combination of parts and cost when they were making them, really very hard to beat!
I can tell in the 410, even with rolling starts it will smoke the tires. The 360 will smoke them too, but not in a rolling start. Both have 2.94 gears and same stock rims and 235/70/15 tires.
Posted By: autoxcuda
Re: Possible to lessen choppy idle due to cam? - 08/31/14 02:15 AM
Quote:
Quote:
Quote:
I agree AutoxCuda. I think alot is because "choppy" and "lopey" are subjective terms. I have never owned anything other than smooth idling engines. The most powerful I have had have been my Charger SRT8 and the Mopar Performance 360 in my '89. It is quite impressive. I wish Mopar still made them but they don't have the 360 block anymore. It is so strong and torquey, yet idles very smooth. But I live and learn. I believe I am already getting used to the idle a bit, and if some of the suggestions I have received help bring it down a little smoother, all the better.
Thanks all.
That old MP 360 with 300 HP is a whole different animal than a 410 with an XR280HR-10 that should be 450HP/500TQ +++.
So how does the performance compare between 410" XR280HR-10 cammed Dippy compared to your crate MP 360 Dippy??
I'm thinking the first one is downright Dippy-Trippy.
I haven't really wound out the 410 yet. It is real strong, I can feel that. It's going to take a few hard runs for me to really tell. But what I can say is I am even more impressed with the MP 360 than I already was. There was probably some sloppy assembly on some of them, but as far as the combination of parts and cost when they were making them, really very hard to beat!
I can tell in the 410, even with rolling starts it will smoke the tires. The 360 will smoke them too, but not in a rolling start. Both have 2.94 gears and same stock rims and 235/70/15 tires.
Sounds like more motor than the car handle on the street. How about some 275 drag radials in the rear? Those tall tires and gears...hope your last name is Goodyear or Goodrich...
Posted By: scratchnfotraction
Re: Possible to lessen choppy idle due to cam? - 08/31/14 03:01 AM
Quote:
Quote:
good info here Larry, not your average engine swap on a M-body cop car adding those huge pipes under there. they did look like like a top notch shop when I picked the 318 up.
I need to get over there on a weekend again for the 'ride'
The ride? You mean the drive. You will be driving it!
I will bring tires
Posted By: scratchnfotraction
Re: Possible to lessen choppy idle due to cam? - 08/31/14 03:02 AM
Quote:
Quote:
good info here Larry, not your average engine swap on a M-body cop car adding those huge pipes under there. they did look like like a top notch shop when I picked the 318 up.
I need to get over there on a weekend again for the 'ride'
The ride? You mean the drive. You will be driving it!