regalracer1987
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007gn what are the specs on you pistons or part number
3.8 or 4.1 ?
- Thread starter 007gn
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Here is a cut and paste of what I post a while back!
We have gone 10.009@132mph on drag radials with a production 4.1. The car would have gone into the 9's with ease but the motor was breaking up around 5200 rpm. It could have been a coil/module or even spark plug gap issues but we never got to make a clean pass after that because we broke the #2 stock main cap even though it had a Girdle on. This motor had over 100 quarter mile passes. 95% of them were in the 10's and the fastest being 10.009@ 132mph with 110 race gas along with an old school Fast system. It also made 604 RWHP at around 30 psi boost with a GT42/76 Turbo. The same motor in another car went 10.20's @132 on E85 with the MafPro setup. The car never hooked right though. I also believe the motor made 585 to rear wheels on E85.
The combo on this motor was; 291 cast production 4.1 block, RJC girdle, J&E pistons, BMS rods,( I think stock rods should have been ok) stock crank, Ported Iron heads with 1.77's and 1.50 valves, Flat tappet cam I want to say it's an odd grind like 222/216 or something but not sure. 120lbs injectors, 70mm TB and plenum, Ported intake Poston headers with HKS 46mm waste gate on the cross over pipe, 4" down pipe, TH400 trans with a brake and some crappy convertor, Weldon pump and so on.
I think the #2 main cap broke while trying to spool up the 42/76 turbo off the foot brake when the trans brake switch failed. My buddy stood on the foot brake for a while. When I took the motor to the machine shop they said #2 two main broke, the crank was no good and the Girdle had warped. Since then I got a stock stroke (3.40) Steel crank another stock main cap ( I know I should have gone with billet cap) I also sent the Girdle back to Jason and RJC and had it resurfaced. This motor is going back in my TTA along with a 215-220 Full Throttle speed roller cam, Fully ported TTA heads and a GTQ 71 turbo and so on. I am hoping to make the same amount of power.
All and all, if I didn't think it was reliable, I would have taken all of the guts and stuffed it in one of stage blocks I have sitting around. Who knows, I may crack the block on my first pass lol.
HTH
Prasad
We have gone 10.009@132mph on drag radials with a production 4.1. The car would have gone into the 9's with ease but the motor was breaking up around 5200 rpm. It could have been a coil/module or even spark plug gap issues but we never got to make a clean pass after that because we broke the #2 stock main cap even though it had a Girdle on. This motor had over 100 quarter mile passes. 95% of them were in the 10's and the fastest being 10.009@ 132mph with 110 race gas along with an old school Fast system. It also made 604 RWHP at around 30 psi boost with a GT42/76 Turbo. The same motor in another car went 10.20's @132 on E85 with the MafPro setup. The car never hooked right though. I also believe the motor made 585 to rear wheels on E85.
The combo on this motor was; 291 cast production 4.1 block, RJC girdle, J&E pistons, BMS rods,( I think stock rods should have been ok) stock crank, Ported Iron heads with 1.77's and 1.50 valves, Flat tappet cam I want to say it's an odd grind like 222/216 or something but not sure. 120lbs injectors, 70mm TB and plenum, Ported intake Poston headers with HKS 46mm waste gate on the cross over pipe, 4" down pipe, TH400 trans with a brake and some crappy convertor, Weldon pump and so on.
I think the #2 main cap broke while trying to spool up the 42/76 turbo off the foot brake when the trans brake switch failed. My buddy stood on the foot brake for a while. When I took the motor to the machine shop they said #2 two main broke, the crank was no good and the Girdle had warped. Since then I got a stock stroke (3.40) Steel crank another stock main cap ( I know I should have gone with billet cap) I also sent the Girdle back to Jason and RJC and had it resurfaced. This motor is going back in my TTA along with a 215-220 Full Throttle speed roller cam, Fully ported TTA heads and a GTQ 71 turbo and so on. I am hoping to make the same amount of power.
All and all, if I didn't think it was reliable, I would have taken all of the guts and stuffed it in one of stage blocks I have sitting around. Who knows, I may crack the block on my first pass lol.
HTH
Prasad
Speed_Dreamin'
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- Sep 30, 2005
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- 173
Any updated feedback on your new combo? Have you got things dialed in? Any track time? Street action?
Turbo6Camaro
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- Apr 17, 2013
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What is the horsepower limits on one of these 4.1 blocks. I was thinking of taking a 4.1 block and putting billet main caps in it. Stock turbo crank. Stock rods with arp bolts. And some good pistons and balance the rotating assembly. Would it hold 550rwhp reliably?
The combo I posted made 604 at 30 psi to rear wheels on a mustang dyno. I would put a steel crank in it since that's the root cause of all the problems. Same motor I had it freshened up with steel crank waiting to go into a TTA.
HTH
Prasad
HTH
Prasad
Turbo6Camaro
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- Apr 17, 2013
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- 71
Idk I guess by the time you buy a steel crank you might as well do the rods. It kinda sounds like by the time you buy all this stuff you could buy a stroker 3.8 shortblock from weber for about the same money.
- Joined
- May 26, 2001
- Messages
- 9,208
There is lots of good info in this thread, but "reliable 550rwhp" with stock crank and rods is a crap shoot?
When I built my first 4.1 years ago, the stock crank was a virgin and was fine in the 10's, but would I do it again, NO.
With the availability of reasonably priced forged parts, and the unknown capacity of a used cast crank, I would never take that chance as building any performance engine is not cheap. For example, a quality piston/ring package for a 4.1 stroker engine is at least $1000.
As far a ARP rod bolts, save your $$$ as we have never seen or experienced a stock rod bolt fail, the $$$ spent is better applied to a set of forged rods.
I know lots of guys get away with "budget builds", but we have seen many with expensive failures.
A BIG factor in reliability is how the car will be used? With lots of track use it is much more demanding and puts lots of stress on the engine which is not present on street driving, at least for a normal person!
Of course, there is a final determining factor, and that is your personal budget. The advise I give to my customers is build your car so it is operated below the limit of the weakest link.
a reg ol 109 would laugh at 550 hp all day. Thats with the stock crank and rods
no knock no crap shoot
We are not just lucky our junk lives. 
Turbo6Camaro
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- Apr 17, 2013
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With my car only weighing 3200 lbs that's helping me a lot. My car makes 512rwhp it went a 10.46 on a 26 inch tire and an easy launch. I have a 28 inch tire on it now. I think the car will do 10.20s with a good launch. I'm runnin on a bone stock short block right now. I want to build something that I don't have to worry about running 9.90s all day long. I'm talking with weber about building me one of his 249ci shortblocks. I think that will really help me get the most out of my top end.
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