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528 Mopar Crate Hemi Vacuum advance or not???

Posted By: kz5rt2

528 Mopar Crate Hemi Vacuum advance or not??? - 06/28/13 01:36 AM

Hello all,
Been a while since my last post but I've been working feverishly and finally getting my ride on the road.

I have to throw this out there... The engine was built by Gary Stanton and I specified the Chrysler electronic ignition kit with vacuum advance. He wrote a note when I received the engine and stated this engine does not run on vacuum advance and will damage the engine if used. Do you guys agree with this.

He set total timing at 32deg @ 4000rpm.

THanks,
Wes
Posted By: RapidRobert

Re: 528 Mopar Crate Hemi Vacuum advance or not??? - 06/28/13 01:52 AM

I dont agree. Bottom line you want no pinging at any point in time. In order adjust: initial with vac gauge method/total going by the std amt for the eng type is a very good baseline/springs, staying just under pinging at WOT up thru the gears on your hottest/driest day & lighter spring or trim the weights to slow it/vac adv (2 adjustments, the 3/32" allen wrench to adj the slope & want to be just under the pinging point in everday driving and total, want to be just under the pinging point at a steady high vacuum cruise at an RPM at or above where the springs are maxed out (all systems maxed). File the notch in the arm to add total & solder strips of feeler gauge on the back side on both sides of the arm to limit the arms' travel into the can. Alot of work to get it spot on but there's alot gain to be had
Posted By: RodStRace

Re: 528 Mopar Crate Hemi Vacuum advance or not??? - 06/28/13 01:56 AM

To me, the only reason to remove vacuum advance is if it's a race car (idle or full throttle) or if it has another way to modify the timing curve for load, like a computer.
However, if the builder of an expensive engine has provided a specific dist, answered your question and is going to be at all responsible for the performance/longevity of the engine, I would follow his advice to the letter.
Posted By: kz5rt2

Re: 528 Mopar Crate Hemi Vacuum advance or not??? - 06/28/13 02:21 AM

I agree, but everything I've understood says the advance will hurt nothing at a high MAP, higher rpm's there won't be anything.

I also have a leak between the engine and bellhousing. I believe I freeze plug. He suggested dropping in a couple GM stop leak pellets into the radiator, do you agree?
Posted By: DodgeCharger

Re: 528 Mopar Crate Hemi Vacuum advance or not??? - 06/28/13 02:51 AM

I would call him and ask him why? I run my 528 with a locked out distributor. 33 degrees .
Posted By: torkrules

Re: 528 Mopar Crate Hemi Vacuum advance or not??? - 06/28/13 05:09 AM

Quote:

Hello all,
Been a while since my last post but I've been working feverishly and finally getting my ride on the road.

I have to throw this out there... The engine was built by Gary Stanton and I specified the Chrysler electronic ignition kit with vacuum advance. He wrote a note when I received the engine and stated this engine does not run on vacuum advance and will damage the engine if used. Do you guys agree with this.

He set total timing at 32deg @ 4000rpm.

THanks,
Wes



its tricky business setting up a vacuum advance on a non stock engine. I set mine up on a distributor machine, and it still needs adjusting.

I found that a total timing of 28 degrees total works best on my 472 Hemi.This, of course, depends on a lot of factors (cam overlap/duration, comp ratio, fuel, gearing, car weight, hills, etc).

I have a cam with less overlap so my compression pressure is high. With 28 degrees total and running 14 initial, its difficult to get full advance any later than 2500 degrees unless you find some really stiff springs.

The vacuum can is geared toward better efficiency under high vacuum,low load conditions. the trick is not to have the full advance come in too soon. What i'm finding is that i'm getting some light intermittent pinging holding a steady rpm of 3000 in 3rd gear up hill. Shift into 4th, and the ping is gone. It would appear its pulling enough vacuum at that rpm to over advance slightly at. you would think the vacuum would drop going up hill.

This means the screw in the can has to be adjusted, but at some point it will come in so late that its pretty much useless to run it. All you can do is experiment with it, but be careful. Heavy pinging can cause damage.
Posted By: 540challenger

Re: 528 Mopar Crate Hemi Vacuum advance or not??? - 06/28/13 01:21 PM

Quote:

I agree, but everything I've understood says the advance will hurt nothing at a high MAP, higher rpm's there won't be anything.

I also have a leak between the engine and bellhousing. I believe I freeze plug. He suggested dropping in a couple GM stop leak pellets into the radiator, do you agree?



Sounds like alot of BS total timing in at 4000rpm

I can understand the no vac. advance ONLY b/c alot of people don't know how to set it up correctily

But you have a leak on a brand new engine and he tells u to put stop leak in it I would have went off on him for that one

If this is a mopar performance engine it should be covered under warranty

If he built u a custom engine he should cover at the very least the parts need to fix the leak assuming u did/do the labor
Posted By: kz5rt2

Re: 528 Mopar Crate Hemi Vacuum advance or not??? - 06/28/13 01:51 PM

Yes I know... I'm not happy about it. It was a Mopar crate engine out of the catalog, they do have warranty but not long after the purchase date. It took me about two years after I bought the engine putting everything together until last week of starting it for the first time.

I'm going to scan in the typed letter they included with the paperwork of the long block when I get home.
Posted By: torkrules

Re: 528 Mopar Crate Hemi Vacuum advance or not??? - 06/28/13 05:52 PM

Quote:

Quote:

I agree, but everything I've understood says the advance will hurt nothing at a high MAP, higher rpm's there won't be anything.

I also have a leak between the engine and bellhousing. I believe I freeze plug. He suggested dropping in a couple GM stop leak pellets into the radiator, do you agree?



Sounds like alot of BS total timing in at 4000rpm

I can understand the no vac. advance ONLY b/c alot of people don't know how to set it up correctily

But you have a leak on a brand new engine and he tells u to put stop leak in it I would have went off on him for that one

If this is a mopar performance engine it should be covered under warranty

If he built u a custom engine he should cover at the very least the parts need to fix the leak assuming u did/do the labor



I agree. Stop leak is not the answer and since he built it he should cover at least some of the cost to fix it. You mentioned it's at the rear of the engine? Frost plug in the head? Pretty tough to get at unless you pull the head or engine. The block does not have a freeze plug at the back like a small block. If you have a rad tester, you could pressurize the rad and see where the leak is coming from.
Posted By: HEMIDOG 70

Re: 528 Mopar Crate Hemi Vacuum advance or not??? - 06/28/13 10:11 PM

I have a Barton built 528 hemi not a crate but it is built very close in specs. I also had a Mopar performance distributor with vacume advance since my car is a street car. He did not want me to use it he steered me to a msd pro billet locked at 32 degrees. That was the sweet spot on the dyno when testing.
Posted By: Lefty

Re: 528 Mopar Crate Hemi Vacuum advance or not??? - 06/29/13 12:54 AM

Quote:

That was the sweet spot on the dyno when testing.



That makes sense for ditching the vac advance. I didn't know the big inch motors were like that. I also would listen to Ray Barton and crew...
Posted By: 62maxwgn

Re: 528 Mopar Crate Hemi Vacuum advance or not??? - 06/29/13 01:14 AM

Quote:

I agree, but everything I've understood says the advance will hurt nothing at a high MAP, higher rpm's there won't be anything.

I also have a leak between the engine and bellhousing. I believe I freeze plug. He suggested dropping in a couple GM stop leak pellets into the radiator, do you agree?



Out of curiosity,if it is a crate motor what part did he build ? The leak may not be his doing.
Posted By: torkrules

Re: 528 Mopar Crate Hemi Vacuum advance or not??? - 06/29/13 02:53 PM

Quote:

I have a Barton built 528 hemi not a crate but it is built very close in specs. I also had a Mopar performance distributor with vacume advance since my car is a street car. He did not want me to use it he steered me to a msd pro billet locked at 32 degrees. That was the sweet spot on the dyno when testing.



Since we are talking vacuum advance I assume we are talking street?

Take the dyno data with a grain of salt. My engine showed peak horsepower at 33 degrees. The dyno tests are usually done by bring the engine up to 3000rpm, applying a load and then bringing up the rpm. What the dyno can't account for is the varying conditions on the street With a drag car it's easy. Tune it to wide open throttle until it turns the best ET/MPH, rinse, repeat. As long as you can get it to the staging lanes, idle isn't that important either.

Street is different. It has to idle, accelerate, go up and down hills. Throw in changing weather, and tuning becomes that much more tougher. The curve has to be scienced out for your particular set up (gearing, car weight, available fuel)

After all was said and done, I had to use a slower curve, and 28 degrees total timing to be able to run pump 91 octane fuel.

For years I didn't run a vacuum advance because I couldn't get it to work right. The combination of curve, total timing, and can adjustment made the engine surge too much.

After much reading and acquiring the use of a distributor machine, I got it down to where I have some slight pinging up a long 6% grade with the can connected which I can eliminate by shifting into fourth to reduce the vacuum to the can. All I have to do now is dial it back a bit more. One thing that I can say is that the general consensus of 50-55 degrees at a steady cruise, does not work. It's too much in most cases. The most my engine will tolerate in these conditions is about 44. Since my total timing is 28 I have it set to get another 16 degrees at 18" of vacuum which is where it is at 3000 rpm in 4th gear (remember the total vacuum of the can is pre set. Mine is a 9L which is 18 degrees crank. The adjustment only controls the rate. I have mine at a slow rate. It's at full advance at 20")

What I am finding is on roads with no stop light (highways, etc). My mileage is way better. In the city with stop and go traffic, it is much worse since the distributor spends very little time adding the extra vacuum advance due to throttle opening and closing.

Pinging is not a good thing to have happen. The engine will tolerate a little (I've had mine apart several times and the slight pinging it has seen hasn't caused any issues). Heavy sustained pinging will destroy and engine is short order (holed pistons, broken ring lands, damaged rings, crank pins/journals, main bearing saddles/caps, etc.)

I think the reason a lot of engine builders shun the vacuum advance is that they are taking the side of caution. With the drag guys, they don't need it. Idle and full throttle. Vacuum advance not needed. Street engines can use it, but adjusted it correctly with a fast curve and not enough octane and it could spell disaster.

As I side note, I found the older Mopar distributors had a more stable advance than the newer ones. I have several at my disposal and I tested them on the distributor machine. My feeling is the MSD would perform in the same way as the older Mopar units or better.
Posted By: kz5rt2

Re: 528 Mopar Crate Hemi Vacuum advance or not??? - 01/23/15 06:53 PM

Yes, the leak was not his doing's. It's from the back of the head. I'm sure the heads were a shelf purchase.
Posted By: DaveRS23

Re: 528 Mopar Crate Hemi Vacuum advance or not??? - 01/24/15 02:11 AM

I agree with torkrules.

Most people do not mess with the vac advance because either they don't get it or they don't want to take the time to dial it in to their combo.

But it usually is worth the effort to get it right. On a street car.
Posted By: Dr Dave

Re: 528 Mopar Crate Hemi Vacuum advance or not??? - 01/24/15 02:54 AM

I have a 528", 727 in a Cuda with Stage V intake and dual quads,3.23 rear. I am running vacuum, non-ported (constant) with a distributor set up by Don at FBO. Had it dyno tuned to set the fuel curve and it runs awesome, instant start, very responsive at all throttle positions, great power, no pings
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