Hey folks, I am in the process of building another motor for my 87 GN, and I am wondering about the billet main caps that will supposedly strengthen the bottom end of these motors. My question concerns the reliability threshold of the stock caps. Are the billet pieces needed for an 11.50 car for instance? I am building a conservative motor, and will be happy with mid elevens or so. I already have the caps, so I will probably use them, but I am having a hard time finding a machine shop to do the work locally. I just wanted input from those of you that have made this choice before. What were the pros and cons of the stock caps vs the billets? Thanks, Rudy E.
How far should you go with stock main caps?
- Thread starter Rudy E
- Start date
FreddieWilliams
New Member
- Joined
- May 26, 2001
Been there... done that!!!
Rudy,
Do yourself a favor and install a set of steel caps or a girdle.
I cracked a stock cap (#3) running 11.67 @118MPH in a 3700# car. My car only ran 11.67 at ths HP level because I never got the car to hook properly (1.8 60' ft). WIth a decent 60' time (~1.61) The car should have run 11.47 or better.
Take a look at the damage below:
Broken Cap Pic
Rudy,
Do yourself a favor and install a set of steel caps or a girdle.
I cracked a stock cap (#3) running 11.67 @118MPH in a 3700# car. My car only ran 11.67 at ths HP level because I never got the car to hook properly (1.8 60' ft). WIth a decent 60' time (~1.61) The car should have run 11.47 or better.
Take a look at the damage below:
Broken Cap Pic
You can either do the caps or the girdle. You dont have to do both as that is complete overkill IMHO, not to mention a waste of $500+ in parts plus labor.
Jason Kramer has been well into the 9's with his TSM car with just a girdle and stock caps. Jason has posted on this board many times and said to date, no one has broken a block with one of his girdles. But quite a few guys have broken them with just the caps as the billet caps can still walk. The girdle seems to clamp the caps in place nicely eliminating most of the walk.
Jason did mention that someone did break a crank on a girdled block, but you are back to the age old problem of the weakest link failing. You fix the block and then the crank becomes the weak link. Many guys (including myself) have been into the mid to low 11 second range with stock caps. Question is how many times will you do that before something lets go?
Jason Kramer has been well into the 9's with his TSM car with just a girdle and stock caps. Jason has posted on this board many times and said to date, no one has broken a block with one of his girdles. But quite a few guys have broken them with just the caps as the billet caps can still walk. The girdle seems to clamp the caps in place nicely eliminating most of the walk.
Jason did mention that someone did break a crank on a girdled block, but you are back to the age old problem of the weakest link failing. You fix the block and then the crank becomes the weak link. Many guys (including myself) have been into the mid to low 11 second range with stock caps. Question is how many times will you do that before something lets go?
turbodave231
Moderator
- Joined
- May 24, 2001
As long as you don't detonate the engine, stock caps will go low 11's and high 10's. If you detonate, all bets are off.
DR
DR
malibuick231
Member
- Joined
- Apr 23, 2002
I have been running low 11s for three years now on a stock caps and crank with a good balance job.But if I had it to do over I would use the girdle.
- Joined
- Aug 20, 2001
No, you just know how to tune your car.
Orlando is going 10 teens @ 133 with the stock caps. Not that I recommend this, but it is possible, assuming the car has a healthy diet of good gas, and never detonates. I personal have two center caps, which should surfice well into the 10's, assuming the tune is good.MIKE10SECV6
New Member
- Joined
- Jan 24, 2003
Just curious,but can a strap be put on 2 and 3 with longer bolts without doing an alignhone?
I am asking to see if you could do this "in car",by dropping the pan and adding straps and put it back together.
I am asking to see if you could do this "in car",by dropping the pan and adding straps and put it back together.
good question. I seen a stage 1 that had the center caps milled flat and a 1" peice of 4340 with longer main bolts. Looked like they were supporting the center of the cap the block was place on top of the cap and held in place buy the main studs. I think that is a great idea just not sure if it could be done without a alighn hone.
