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Help my doggy 383

Posted By: 440challenger

Help my doggy 383 - 04/26/10 12:30 AM

Dont have all the specs but i bought this motor used about 6 years ago. It was rebuilt and runs great,but just feels underpowered.

I have had it in my roadrunner for about 3 years.
Its a 383, SRP pistons?, mopar hydraulic purple shaft unknown lift/duration, 906 heads,eddy perf intake,Bigs 780 vac carb, headers. msd ignition,timing at 38 total.

Its an auto,2800 converter,4.11 gear.
Car runs great, besides it feeling underpowered.
it doesnt have the pull that puts you back in the seat. I just got done building a smog 440 with the a summit cam it it will destory this mild 383. Is this just the nature of a mild 383 with (im guessing) low compression?

Anything you guys reccomend doing/checking?
thanks!
Posted By: SomeCarGuy

Re: Help my doggy 383 - 04/26/10 01:02 AM

If the engien really is runnign OK, then there is little you can do short of putting in a bigger cam and/or aftermarket heads. CR might be a bit low though for aluminum heads.

I would say look at things to lighten up the car, it will make it easier to get moving and might even help you out a bunch if you have manual steering. I know it sure made my 69 RR MUCH easier to live with when I was albe to cut some wieght with aluminum WP and housing, alng with a mini starter and ditching my iron intake. Aluminum master is next when the time comes.

Short of that, not much you can do. My RR had more grunt with the 440, but the 383 is fine for my use. Just will never have the pop the big engine did. Of course I get better MPG now...
Posted By: RapidRobert

Re: Help my doggy 383 - 04/26/10 01:08 AM

Quote:

Anything you guys reccomend doing/checking?
thanks!

Get a baseline on what you have now: compression test/leakdown test/idle vacuum/initial timing/slot curve/mixture. I'd advance the cam 4 deg for a start to effect some gain that you can feel keeping in mind that it'll decrease the PV clearance on either the intake or the ex valves (not sure which).
Posted By: 440challenger

Re: Help my doggy 383 - 04/26/10 01:09 AM

I have alum master w/ maunual brakes. maunual steering. Alum rad.

It cruizes good, Just it not fun to drive without that grunt. I dont know if im used to driving my challenger (low 11 sec street car) or if i can get more out of this 383 combo. Im going to check my inital timing tommrow and see where im at.

I found a video on you tube that kind of shows how my motor acts. its not as slow as the one on youtube but it resembles the same traits as how it takes for ever to wind out and doesnt go anywhere

http://www.youtube.com/watch?v=5g6M9daFPh4
Posted By: 440challenger

Re: Help my doggy 383 - 04/26/10 01:16 AM

I was thinking about advancing the cam. I see mopar preformance makes a bushing kit. How does that work on a big block?I have used the woodruff keys before but not a bushing.
Posted By: Dodgem

Re: Help my doggy 383 - 04/26/10 01:21 AM

Quote:

Quote:

Anything you guys reccomend doing/checking?
thanks!

Get a baseline on what you have now: compression test/leakdown test/idle vacuum/initial timing/slot curve/mixture. I'd advance the cam 4 deg for a start to effect some gain that you can feel keeping in mind that it'll decrease the PV clearance on either the intake or the ex valves (not sure which).





at least 4 deg on a purple shaft maybe 6 will really wake it up.
Posted By: Dougsmopars

Re: Help my doggy 383 - 04/26/10 01:37 AM

Them cars would put you back in the seat bone stock. If yours is doggie i'd look into the combo and find whats not matching up. Check cam timing. I've seen people install them 4 degree retarded car was a stone dog. 4 degree advance will give a boot to bottom end. I don't use offset keys i use timing sets with advance notches. If your gonna pull it apart to degree the cam thats the time to throw a new chain in.
Posted By: RapidRobert

Re: Help my doggy 383 - 04/26/10 01:39 AM

Quote:

I see mopar preformance makes a bushing kit. How does that work on a big block?I have used the woodruff keys before but not a bushing.

you wouldn't happen to have some SB offset keys on hand would you . Heres my BB ones. You drill out the locating pin hole so the round BB bushings will fit and pick the one you want/install it and turn it to offset it to make it turn the cam sprocket CW then stake it/epoxy it in place

Attached picture 5947230-offsetSBkeys.jpg
Posted By: moparmattkos

Re: Help my doggy 383 - 04/26/10 01:47 AM

Quote:

Car runs great, besides it feeling underpowered.
it doesnt have the pull that puts you back in the seat. Anything you guys reccomend doing?



Hope this helps ,I have enclosed a pic of my last motor that felt underpowered! I just put a small nos kit on it and it woke up quite a bit!

Attached picture 5947247-lotsanazz.jpg
Posted By: Dougsmopars

Re: Help my doggy 383 - 04/26/10 01:51 AM

WOW!!!! thats a lot of fittings. lol
Posted By: 440challenger

Re: Help my doggy 383 - 04/26/10 02:04 AM

LOL! Ok if i get a new timing set which one do you guys reccomend? With an adjustable timing set would i just be able to put the motor on tdc and then set the sprocket to the 4deg advance dot or do i need to get pretty involved and get a degree wheel ?
Posted By: SomeCarGuy

Re: Help my doggy 383 - 04/26/10 02:07 AM

I used to run only Comp Cams chains, now I don;t know if I would use them based on the problems I see posted here with all of their current offerings

I had a Roll Master set a couple of years ago that was really tight. Really tight. I would think it would hold up well. Sold the engien, so???
Posted By: RapidRobert

Re: Help my doggy 383 - 04/26/10 02:08 AM

Quote:

LOL! Ok if i get a new timing set which one do you guys reccomend? With an adjustable timing set would i just be able to put the motor on tdc and then set the sprocket to the 4deg advance dot or do i need to get pretty involved and get a degree wheel ?

both, cant assume ANY part is correct
Posted By: Dougsmopars

Re: Help my doggy 383 - 04/26/10 02:23 AM

I use the Summit true roller chain and gear set. Yup TDC drop it in on the 4 degree advance notch. Car runs super. Now if this were a big dollar Hemi roller motor or a motor for an all out race car i'd go the degree wheel root. For a street car dot to dot is fine. Repair shops have been replacing timing chains for 50 years just doing dot to dot. Yes it may in reality be 1 degree either way but runs fine.
Posted By: Mr.Yuck

Re: Help my doggy 383 - 04/26/10 02:53 AM

I'll guess it's you convert/cam combo. Purple shafts cams need some stall. swap the cam on the converter
Posted By: 440challenger

Re: Help my doggy 383 - 04/26/10 12:40 PM

Heres what i found.

http://www.summitracing.com/parts/SUM-G6604-B/

Are most the hydraulic purple shafts 1 bolt or 3 bolt or could they be either? I'd like to order the parts before i rip everything apart.

Posted By: Dodgem

Re: Help my doggy 383 - 04/26/10 12:55 PM

most of them are one bolt!

you should look at one of these
http://www.summitracing.com/parts/SUM-G1056/

You would need one solid lifter too and a solid pushrod is nice to run up to the dial indicator
one of these is real nice
http://chucker54.stores.yahoo.net/crtusowidewh.html
summit
http://www.summitracing.com/parts/CCA-4799/
in use nice the degree whee goes right in it I did put a couple extra set screws in as you use the small keyway and the set screw is hard to get at

Attached picture 5947683-Cranksproket5.JPG
Posted By: Dodgem

Re: Help my doggy 383 - 04/26/10 12:57 PM

another

Attached picture 5947685-Cranksproket1.JPG
Posted By: Dodgem

Re: Help my doggy 383 - 04/26/10 12:59 PM

back

Attached picture 5947688-Cranksproket2.JPG
Posted By: Dodgem

Re: Help my doggy 383 - 04/26/10 12:59 PM

alone on crank

Attached picture 5947689-Cranksproket3.JPG
Posted By: Dodgem

Re: Help my doggy 383 - 04/26/10 01:01 PM

and yes I was degreeing the exhaust lobe

Attached picture 5947690-new2.JPG
Posted By: Paul_Fancsali

Re: Help my doggy 383 - 04/26/10 07:25 PM

Before I would go crazy working on the engine I would get a good dist and get the total timing up to at least 42-44 degree's esp if the car comp is below 9.1 On the carb I would check jet sizes most carbs are over jetted not sure in your case but timing and geting it all in by stall speed sure will help.I'm sure the timing will get a pooch to go better try it it cheap and easy to do or change
Posted By: Dougsmopars

Re: Help my doggy 383 - 04/26/10 09:05 PM

42 to 44 is to much total for a big block mopar. 36 to 38 tops.
Posted By: JAKE68

Re: Help my doggy 383 - 04/26/10 11:31 PM

Quote:

42 to 44 is to much total for a big block mopar. 36 to 38 tops.


I agree. Without knowing what cam he has it is hard to try and cover up the problem without throwing a bunch of tricks,do dads and such at it and get good resaults. he could have a 509 cam low compresion low staul coverter and you could never make it right. Put a dial indicater on the thing and find out what cam it is. Then maybe put a deree wheel on it and find out where it is instauled at. That would tell you what direction to go. If it is anything like the video that guy was shifting and he wasn't on the pipe yet.We have found on the dyno that most pump gas big blocks like 32-34 total.
Posted By: 71383beep

Re: Help my doggy 383 - 04/27/10 02:18 AM

FWIW...my 383 was doggy with the big open chamber 906 heads. With a set of 516s on her now she is a totally different animal and she is running the .474 cam. It DEFINITELY puts you in your seat and will annihilate the tires from a stop.

So my says that you may be very low on compression and that is really all you need to work on.
Posted By: Dougsmopars

Re: Help my doggy 383 - 04/27/10 02:27 AM

if it's a 509 throw it in the dumpster. Anyone who has done any real drag raceing will tell you those old out dated cams are junk. Plenty of new designs that make a lot more power.
Posted By: JAKE68

Re: Help my doggy 383 - 04/27/10 11:59 AM

i agree that there are alot of newer cams that will have better manners and make more power with less but that 509 is by no means junk. It just likes compresion,converter and gear to work good. If any of the combo is off it could be a turd.
Posted By: Paul_Fancsali

Re: Help my doggy 383 - 04/27/10 05:15 PM

My reply for 42-44 is for a car with low comp and too much cam like the 509 Too many people go by the Mopar perf bible that are often way out of date.I had a Mopar perf tech guy tell me a 509 would be ok in a small block with exhaust manifolds NOT. Now I do my own thing and if it works for me so be it.
Posted By: NachoRT74

Re: Help my doggy 383 - 04/27/10 06:47 PM

Quote:

FWIW...my 383 was doggy with the big open chamber 906 heads. With a set of 516s on her now she is a totally different animal and she is running the .474 cam. It DEFINITELY puts you in your seat and will annihilate the tires from a stop.

So my says that you may be very low on compression and that is really all you need to work on.



stock pistons ?
Posted By: RemCharger

Re: Help my doggy 383 - 04/27/10 07:16 PM

Quote:

My reply for 42-44 is for a car with low comp and too much cam like the 509 Too many people go by the Mopar perf bible that are often way out of date.I had a Mopar perf tech guy tell me a 509 would be ok in a small block with exhaust manifolds NOT. Now I do my own thing and if it works for me so be it.

Paul, you're right. Them little guys need timing. It is NOT a 440.
Posted By: 71383beep

Re: Help my doggy 383 - 04/27/10 10:42 PM

Quote:

Quote:

FWIW...my 383 was doggy with the big open chamber 906 heads. With a set of 516s on her now she is a totally different animal and she is running the .474 cam. It DEFINITELY puts you in your seat and will annihilate the tires from a stop.

So my says that you may be very low on compression and that is really all you need to work on.



stock pistons ?



No it has been rebuilt. the problem with the first build and the 906 heads was the KB162 pistons which are something like a mile in the hole with huge 5cc valve reliefs. My compression on the first build was around 7.8:1.

Now it has the same pistons, but the deck was milled 0.020 and with the 516 heads and the felpro gasket i get a CR of 9.2:1 which really woke the motor up.
Posted By: CurYellowBird

Re: Help my doggy 383 - 04/27/10 11:02 PM

Hey 71383bee,

How do you like that .474/.474 MP cam?

I'm looking at a build for the 383 in my 71'bird and I think we talked a couple times before. Comp cams camquest version of this MP cam gives my 383 the max hp and torque and should work well with my 4 speed and AC.

What gears and transmission are you running? Hi-po manifolds or headers?

Don't mean to hijack the thread, just not alot of guys who drive the 383 as much as 440's, or the MP cams since they are "old technology".
Posted By: 440challenger

Re: Help my doggy 383 - 04/28/10 01:19 AM

Well a little update. i went to check timing today with my matco dial back and it seems to not be working... It will flash but with very long pauses in between. Who makes one that works with a an msd box?

So i ended up just popping the distributor out and i looked under the plate and realized one of the advance springs was missing! The remaining spring was the lighter of the factory installed springs. I ended up putting BOTH Mopar perf. Light springs in and stabbed the dist. back in where it was. I had no way to check timing but i did notice when i fired the motor up my rpms went from a previous 700rpm at idle to now 1k at idle,and a noticeabley smoother idle/power..

On test ride it was a night and day seat of pants difference. Now i just need a timing light to see where im at. It looks like she has some potential to make some decent power.

I do notice now when i rev it out and shift from 1st to 2nd 2nd to 3rd it lags quite a bit before it goes into gear. its not a firm shift. is this an adjustment that i can make or do i need a shift kit?

Thanks for the help so far!
Posted By: ireland383

Re: Help my doggy 383 - 04/28/10 01:35 AM

How old is the tranny fluid?
Posted By: forphorty

Re: Help my doggy 383 - 04/28/10 02:40 AM

Although you thought you were running 38 degrees advance that might not be true. Your timing light may not be accurate. There is also a possibility the outer ring on your damper may have slipped, giving an incorrect reading. Or it may be that your car just likes lots of timing.
Posted By: RapidRobert

Re: Help my doggy 383 - 04/28/10 04:53 AM

Quote:

So i ended up just popping the distributor out and i looked under the plate and realized one of the advance springs was missing! The remaining spring was the lighter of the factory installed springs. I ended up putting BOTH Mopar perf. Light springs in and stabbed the dist. back in where it was. I had no way to check timing but i did notice when i fired the motor up my rpms went from a previous 700rpm at idle to now 1k at idle,and a noticeabley smoother idle/power.

Here's a chart. I hear MSD make dialbacks act up. you could do a slight bit of math and mark the dampener exactly. .0632683" is 1 degree so 35.5 degrees would be 2.246 (2&1/4") and you could use your 2-3" micrometer and measure/cut strips of paper to use as a ruler & magic mark your dampener & you can mark 5 deg on the stock marks then move the dampener 5 degrees and mark it again & so on until you've got up to 35 40 btdc and checking for exact TDC with the ten dollar tool is a good idea as you cannot assume anything then use a non dialback light. EDIT forgot the chart

Attached picture 5951280-dirstspringcurves.jpg
Posted By: NachoRT74

Re: Help my doggy 383 - 04/28/10 04:23 PM

Quote:

Quote:

Quote:

FWIW...my 383 was doggy with the big open chamber 906 heads. With a set of 516s on her now she is a totally different animal and she is running the .474 cam. It DEFINITELY puts you in your seat and will annihilate the tires from a stop.

So my says that you may be very low on compression and that is really all you need to work on.



stock pistons ?



No it has been rebuilt. the problem with the first build and the 906 heads was the KB162 pistons which are something like a mile in the hole with huge 5cc valve reliefs. My compression on the first build was around 7.8:1.

Now it has the same pistons, but the deck was milled 0.020 and with the 516 heads and the felpro gasket i get a CR of 9.2:1 which really woke the motor up.



ok will check specs of those pistons... I'm trying to guess how much will mill down the 452 heads using KB240s on a 400 what suposelly sits .020 or so in the hole, to get around same compression ( 9.2-9.5 rate )... using metallick gaskets of course

( and same cam )

EDITING... they are about the same piston with just simply diff bore LOL... will have to try to reach 84cc, from the initial 90-92cc I got measured... that's around .040 mill job...
Posted By: Mr.Yuck

Re: Help my doggy 383 - 04/28/10 10:42 PM

Quote:

42 to 44 is to much total for a big block mopar. 36 to 38 tops.



plllussst... ran 383's up to 42 easy on a good day and good gas. give it as much timing as it will take.
Posted By: sharpie

Re: Help my doggy 383 - 04/28/10 10:47 PM

Wait a second, is a 780 normal for a stock-ish 383? That sounds like a way-large carb for a stock engine...
Posted By: 71383beep

Re: Help my doggy 383 - 04/28/10 10:50 PM

Quote:

Hey 71383bee,

How do you like that .474/.474 MP cam?

I'm looking at a build for the 383 in my 71'bird and I think we talked a couple times before. Comp cams camquest version of this MP cam gives my 383 the max hp and torque and should work well with my 4 speed and AC.

What gears and transmission are you running? Hi-po manifolds or headers?

Don't mean to hijack the thread, just not alot of guys who drive the 383 as much as 440's, or the MP cams since they are "old technology".



I am very happy with it. It has got excellent street manners and can bring it when it needs to. The motor dyno'd at 400/430 hp/tq which was my goal.

Its a pretty mild build really...040 over on the bores, KB162 pistons, mill the deck 020, built 516 heads with the 2.14/1.74 valves IIRC and a bit of bowl blend and porting, Comps 474 version (nostalgia purple plus) cam, street dominator intake, FBO prepped 650 mighty Demon, and the FBO ignition.

Haven't tried it at the track. Running a 727 auto with the TF2 shift improver kit and 3.73 gears. I prefer to slapstick it. From a stop first gear is virtually useless with the tires I have, but its a fun cruiser! There certainly is faster out there, but she holds her own pretty well. I can drive it anywhere and she holds an idle very well with power brakes.

I have been following your thread too. FWIW i would just try and coax 400 to 450 hp from your stock 383 and keep it mostly stock appearing. Unless you already have the 440 that is. I do have to agree that as much fun as having an absolute killer 500 hp motor is it does eat in to how much you really can use the car. Especially it being a fairly rare real 4 speed high impact bird. 400 hp is still a lot of fun and it has good street manners means IMHO that you can do more with the car. I have several friends that have invested so much into there cars that they are no longer as tame for taking on nice cruises or going to a long distance show. they kill at the strip which is cool, but they sometimes miss out on just cruising the backroads and raising a bit of he[[! A 400 to 450 hp mill will still be respectable at the strip and you won;t have to modify the car much to handle it. Anyways thats just my
Posted By: 68HemiB

Re: Help my doggy 383 - 04/28/10 11:57 PM

I have nothing to add.

I just wanted to say that I was out on an errand this afternoon, and was stopped at a traffic light behind a Jeep GC with a non-personalized plate that immediately reminded me of this thread.

4ARF383

That is all. Carry on.
Posted By: GwaiiEagle

Re: Help my doggy 383 - 04/29/10 12:10 AM

Quote:

Quote:

42 to 44 is to much total for a big block mopar. 36 to 38 tops.



plllussst... ran 383's up to 42 easy on a good day and good gas. give it as much timing as it will take.



A low compression 383 will take all the timing you care to give it.
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