My VA Speed Engine Build
03-25-2010, 10:19 AM
#21
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Looking good Joe. But if I were you, what's an extra $400(ish) for a good ATI damper really worth if it extends your new engines life considering the amount you already have in the build? Seems to me like it's cheap insurance especially when you look at the fact that after you put that underdrive pulley on you have broken 2 timing chains.
Just looking out for you man.....
Just looking out for you man.....
03-25-2010, 12:03 PM
#23
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Looking good Joe. But if I were you, what's an extra $400(ish) for a good ATI damper really worth if it extends your new engines life considering the amount you already have in the build? Seems to me like it's cheap insurance especially when you look at the fact that after you put that underdrive pulley on you have broken 2 timing chains.
Just looking out for you man.....
Just looking out for you man.....
The ASP pulley I have has been on the car for over 2 years and has been pulled off several times with the screws stripped in the threads and fluids spilled all over it....Not sure if that would hurt it though.Shawn let me know what you think.
Last edited by 6.0monsta; 03-25-2010 at 06:43 PM.
03-25-2010, 12:51 PM
#24
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I would agree. This is obviously being built right with a quality shop/parts. Might as well delay installation into the car and go on and finish the build off with a high quality damper like the ATI unit and leave no stone unturned. Either way, the car sounds like it will be one hell of a runner.
03-25-2010, 01:26 PM
#25
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Kurt,
Were you running only single rollers on those engines?
Were you running only single rollers on those engines?
The timing chain failures are not connected to HP, they are a product of a bad harmonic in the engine if you run full load under 4500rpm. Did not matter what chain I used although the better ones lasted longer before failure. Locking your converter at wot may drop you into the zone.
The car I was working with was the Motorola Cup Corvettes in a road race application, they were just under 500hp NA engines with a 7200rpm rev limit. They would run without failure for many races with all parts looking happy on inspection. The problem showed up when they would lose a gear in the trans during the race (normally 3rd) and they would start skip shifting in order to finish the race. The engine would fall back to 3500rpm or so then drive into the bad harmonic zone (3800-4500rpm) causing the links in the chain to bind with failure happening within one hour of race time no matter what chain I tried. We found the problem by putting two trigger wheels on the engine, one under the front cover. This testing along with help from ATI helped us cure the problem. The repair is to run the right engine damper from ATI, it will have a 3 ring weight with a "44" stamped in the steel inertia ring. This damper is not to be used on the LS series of engine if your engine rpm regularly exceeds 8000rpm, for those engines the regular 2 ring or 3 ring damper is best. We did test all the popular dampers then (2001) and the ATI was best followed by the stock one if your rpm was under 7000. I use the "44" damper on my truck which now has 105,000 boosted miles with a 5200rpm shift point and locked converter in 3rd gear. I used the 40 dollar LS2 chain in that engine.
Kurt
The car I was working with was the Motorola Cup Corvettes in a road race application, they were just under 500hp NA engines with a 7200rpm rev limit. They would run without failure for many races with all parts looking happy on inspection. The problem showed up when they would lose a gear in the trans during the race (normally 3rd) and they would start skip shifting in order to finish the race. The engine would fall back to 3500rpm or so then drive into the bad harmonic zone (3800-4500rpm) causing the links in the chain to bind with failure happening within one hour of race time no matter what chain I tried. We found the problem by putting two trigger wheels on the engine, one under the front cover. This testing along with help from ATI helped us cure the problem. The repair is to run the right engine damper from ATI, it will have a 3 ring weight with a "44" stamped in the steel inertia ring. This damper is not to be used on the LS series of engine if your engine rpm regularly exceeds 8000rpm, for those engines the regular 2 ring or 3 ring damper is best. We did test all the popular dampers then (2001) and the ATI was best followed by the stock one if your rpm was under 7000. I use the "44" damper on my truck which now has 105,000 boosted miles with a 5200rpm shift point and locked converter in 3rd gear. I used the 40 dollar LS2 chain in that engine.
Kurt
03-25-2010, 01:49 PM
#26
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I still have my stock pulley. Wonder how much power the ASP pulley is worth if any? May be something interesting to try on the engine dyno is Shawn is willing. If the ASP isn't worth any power I'd much rather get rid of it and go back to stock.
Last edited by 6.0monsta; 03-25-2010 at 06:43 PM.
03-25-2010, 03:20 PM
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^ After my TC break, I put the car back together with the stock under drive pulley. I then re-dyno'ed the vehicle to ensure the power was where it should be. The following were my numbers with identical setups with the only variables being the ASP pulley versus my stock pulley and 5 thousandths shaved off my stock heads to ensure a level deck.
ASP pulley - 483whp/431wtq
Stock pulley - 480whp/442wtq
Identical tune with less than 1% error in the a/f between both dyno's.
Interesting notes post rebuild. The car would usually have ~1, sometimes 2 counts of knock at peak tq(4600~4800rpm) with the ASP pulley. Not always, but it wasn't suprising to see it in my logs. Matter of fact, the car was always more prone to knock around the 3800~4800rpm area, again using the ASP pulley.
After the rebuild with the stock pulley, the car never knocked once. I probably ran 30 logs of WOT and I could not get the damn thing to even get 1 count of knock. The heads were shaved 5 thousandths to ensure the deck was even. So technically, there was a slight bump in compression that "should" have made the car more prone to knock. However, that was not the case and the car ran like a damn top post rebuild.
My theory? The car was experiencing a harmonic in this zone, which was making excessive noise and tripping the overly sensitive knock sensors. This would explain why the knock cleared up when the stock pulley was used and the harmonic was eliminated. This could also explain the increase in tq although I am sure the slight compression enhancement had a larger role in that.
ASP pulley - 483whp/431wtq
Stock pulley - 480whp/442wtq
Identical tune with less than 1% error in the a/f between both dyno's.
Interesting notes post rebuild. The car would usually have ~1, sometimes 2 counts of knock at peak tq(4600~4800rpm) with the ASP pulley. Not always, but it wasn't suprising to see it in my logs. Matter of fact, the car was always more prone to knock around the 3800~4800rpm area, again using the ASP pulley.
After the rebuild with the stock pulley, the car never knocked once. I probably ran 30 logs of WOT and I could not get the damn thing to even get 1 count of knock. The heads were shaved 5 thousandths to ensure the deck was even. So technically, there was a slight bump in compression that "should" have made the car more prone to knock. However, that was not the case and the car ran like a damn top post rebuild.
My theory? The car was experiencing a harmonic in this zone, which was making excessive noise and tripping the overly sensitive knock sensors. This would explain why the knock cleared up when the stock pulley was used and the harmonic was eliminated. This could also explain the increase in tq although I am sure the slight compression enhancement had a larger role in that.
Last edited by 1.8t; 03-25-2010 at 03:29 PM.
03-25-2010, 06:03 PM
#28
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^ After my TC break, I put the car back together with the stock under drive pulley. I then re-dyno'ed the vehicle to ensure the power was where it should be. The following were my numbers with identical setups with the only variables being the ASP pulley versus my stock pulley and 5 thousandths shaved off my stock heads to ensure a level deck.
ASP pulley - 483whp/431wtq
Stock pulley - 480whp/442wtq
Identical tune with less than 1% error in the a/f between both dyno's.
Interesting notes post rebuild. The car would usually have ~1, sometimes 2 counts of knock at peak tq(4600~4800rpm) with the ASP pulley. Not always, but it wasn't suprising to see it in my logs. Matter of fact, the car was always more prone to knock around the 3800~4800rpm area, again using the ASP pulley.
After the rebuild with the stock pulley, the car never knocked once. I probably ran 30 logs of WOT and I could not get the damn thing to even get 1 count of knock. The heads were shaved 5 thousandths to ensure the deck was even. So technically, there was a slight bump in compression that "should" have made the car more prone to knock. However, that was not the case and the car ran like a damn top post rebuild.
My theory? The car was experiencing a harmonic in this zone, which was making excessive noise and tripping the overly sensitive knock sensors. This would explain why the knock cleared up when the stock pulley was used and the harmonic was eliminated. This could also explain the increase in tq although I am sure the slight compression enhancement had a larger role in that.
ASP pulley - 483whp/431wtq
Stock pulley - 480whp/442wtq
Identical tune with less than 1% error in the a/f between both dyno's.
Interesting notes post rebuild. The car would usually have ~1, sometimes 2 counts of knock at peak tq(4600~4800rpm) with the ASP pulley. Not always, but it wasn't suprising to see it in my logs. Matter of fact, the car was always more prone to knock around the 3800~4800rpm area, again using the ASP pulley.
After the rebuild with the stock pulley, the car never knocked once. I probably ran 30 logs of WOT and I could not get the damn thing to even get 1 count of knock. The heads were shaved 5 thousandths to ensure the deck was even. So technically, there was a slight bump in compression that "should" have made the car more prone to knock. However, that was not the case and the car ran like a damn top post rebuild.
My theory? The car was experiencing a harmonic in this zone, which was making excessive noise and tripping the overly sensitive knock sensors. This would explain why the knock cleared up when the stock pulley was used and the harmonic was eliminated. This could also explain the increase in tq although I am sure the slight compression enhancement had a larger role in that.
Hopefully Shawn will chime in soon. I would like to see a pull on the dyno of the asp pulley vs the stock pulley to see if there is any power loss.
Last edited by 6.0monsta; 03-25-2010 at 06:43 PM.
03-25-2010, 06:24 PM
#29
Interesting...I always have 1-2 degrees KR around peak torque. I always attributed it to false knock because of the forged internals. I tried taking out timing in those areas and it always still pulled 1 degree or so. Looking like I may send Shawn my stock pulley.
Hopefully Shawn will chime in soon. I would like to see a pull on the dyno of the asp pulley vs the stock pulley to see if there is any power loss.
Hopefully Shawn will chime in soon. I would like to see a pull on the dyno of the asp pulley vs the stock pulley to see if there is any power loss.
03-25-2010, 08:48 PM
#31
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Actually Shawn has been busting his *** all day building the baddest ls engines on the planet
Joe,yours is ready to dyno,got it on the dyno cart and everything-we had a dyno servo failure again(about the 50th one in 4 years,but Superflow don't have any issues with them.)anyway,i think we'll have some results wednesday at the latest and ready to ship by friday at the latest.
I'll try to pop up some pics over the weekend.
Joe,yours is ready to dyno,got it on the dyno cart and everything-we had a dyno servo failure again(about the 50th one in 4 years,but Superflow don't have any issues with them.)anyway,i think we'll have some results wednesday at the latest and ready to ship by friday at the latest.
I'll try to pop up some pics over the weekend.
03-25-2010, 09:03 PM
#32
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Actually Shawn has been busting his *** all day building the baddest ls engines on the planet
Joe,yours is ready to dyno,got it on the dyno cart and everything-we had a dyno servo failure again(about the 50th one in 4 years,but Superflow don't have any issues with them.)anyway,i think we'll have some results wednesday at the latest and ready to ship by friday at the latest.
I'll try to pop up some pics over the weekend.
Joe,yours is ready to dyno,got it on the dyno cart and everything-we had a dyno servo failure again(about the 50th one in 4 years,but Superflow don't have any issues with them.)anyway,i think we'll have some results wednesday at the latest and ready to ship by friday at the latest.
I'll try to pop up some pics over the weekend.
Should I send you my stock pulley?
03-28-2010, 06:54 PM
#35
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Got a couple pics off my old hard drive
The foundation of this engine is our Darton sleeved block-this thing has been a great performer.In the last couple month be have build a couple great engines from this same block-656hp mild mannered l92 headed 427 and a 750hp 275cc catherdral port headed road race 427.The blowby has reduced dramatically using this block over a std ls7 block due to much stronger sleeves that make for alot better ring seal.
The foundation of this engine is our Darton sleeved block-this thing has been a great performer.In the last couple month be have build a couple great engines from this same block-656hp mild mannered l92 headed 427 and a 750hp 275cc catherdral port headed road race 427.The blowby has reduced dramatically using this block over a std ls7 block due to much stronger sleeves that make for alot better ring seal.
03-28-2010, 08:30 PM
#36
My car has an ASP pulley as well. I had the pulley on during the stock timing chain failure.
Good info but I don't want the thread to focus on timing chains. Shawn is installing a much better chain and he hasn't mentioned any concerns regarding my ASP pulley. I did notice it seemed to "wobble" while the engine was running before I pulled the motor out. I'll be curious if it does the same thing on the engine dyno.
Good info but I don't want the thread to focus on timing chains. Shawn is installing a much better chain and he hasn't mentioned any concerns regarding my ASP pulley. I did notice it seemed to "wobble" while the engine was running before I pulled the motor out. I'll be curious if it does the same thing on the engine dyno.
I decided to get the ATI, and it is really something else, well worth the money and peace of mind. Sometimes when you pay a pretty penny for a setup like yours, its just worth it to upgrade, and 400 bucks is pocket change compared to your motor. Aside from that, the ATI balancers make your bearings happier as well.
03-29-2010, 11:36 AM
#38
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We tried a few of the early doubles (I think it was Rollmaster) with the same results only showing up when the trans had problems and dropped the engine into the lower rpm bands. The single chains packaged better so once we solved the problem we never looked back.
Kurt
Kurt
03-29-2010, 12:05 PM
#39
FormerVendor
It's weird because I have yet to see a chain break ever even in all the rod racing and open track stuff we've done in 10 years? That's with any dampers as well. Never had one go on a drag race deal either?
Were these on deals with stock stroke cranks or with the 4.000 type aftermarket cranks Kurt?
Were these on deals with stock stroke cranks or with the 4.000 type aftermarket cranks Kurt?
03-29-2010, 12:27 PM
#40
The OP's timing chain "break" was the rollers of the chain coming off the pins. Very strange looking failure. Don't know how this type of failure relates to crankshaft harmonics, but I'm not an engineer either. All I know is the rollers looked like they cracked, and ended up falling off their respective pins.
The chain itself never broke. It was still intact, engine running, when we took it apart.
The chain itself never broke. It was still intact, engine running, when we took it apart.