SFI 25.2 Mustang/LSx build "The Renegade"
09-18-2010, 02:44 PM
#3462
Dart billet next time around? Sucks that ya didn't get to really pour the coals to it and see what it could do. Still went pretty good though.
You're not the first, and certainly won't be the last to crack a block trying to go at the speeds you're aiming for that's for sure.
Good luck with the rebuild
You're not the first, and certainly won't be the last to crack a block trying to go at the speeds you're aiming for that's for sure.
Good luck with the rebuild
09-18-2010, 04:27 PM
#3465
This weekend was a real learning experience. I cant say enough about Shawn, he is a hardcore racer and a very good friend to boot, almost the best of both worlds.
As far as the block goes, its got a 1/4" hairline crack at the 5 o'clock position off #6 cylinder. Before the engine was finished Shawn called and said look man, you really need to get a new block, this one is its last legs and I am not confident it will last a full season. Knowning that we would only make the last half of the season we made a gamble and try the block with the old hardware and see if we could get it too last 5-6 races. Shawn knew my financial situtation and said he was going to do the best he could but there were no guarantees how long it would last and I was ok with it.
So we show up at MIR early, shawn is ready to rock. We put the car on the scale to verify the numbers and it was off by a good amount so we got it cleaned up and started getting ready for the first shot.
I backed the boost down to what I thought was going to be about 30# and backed the leave RPM down to what should have been 5.5# of boost and lowered the 2 step 100 rpms. Drive the car up and everything is running clean, do my burnout and we start the staging process. Car comes right up on boost, I inch it in grab the transbrake but the car isn't making the boost it should. Let go the car feels good and for some reason the boost came in really late.
First shot off the trailer it went a 4.98 @ 160 on a 1.37 60'. Boost in the beams was down to 4# and the boost curve was really lazy, it was down almost 10# at the 60' mark and full boost was in 1.5 seconds later than it should have been. I just chalked it up new car strange ****.
Second shot, we add 50 to the stage limiter, 1/2# of boost on the brake and leave everything the same. Boost in the beams is still the same 4# and the boost curve was very lazy and again it was down 9.7# of boost at the 60'. The car goes a 4.98 @ 158 and the average boost curve was down 1.2# from the previous run so that makes sense.
thrid shot, we add another 1/2# of boost on the brake, bring the boost in quicker and let her eat. We cooled car down and drove it to the lanes, right as I started the burnout, shawn backed me out of the beams because it was spitting water out of the exhaust. We chalked it up to a cold car. The Boost was still the same in the beams, car ran a 4.8x @ 157 with the same boost curve as the previous run. As I slowed the car down I could tell there was something on the windows, possibly oil from the turbo or water.
We get back to the pits to see what happened and verified #6 was leaking water.
What we learned.... I took the head off this morning to find a crack in #6 at the 5 o'clock position. Concientally, that cylinder had been cut off center by the first engine builder making it thin in that spot which shawn complained about last year.
I think we also found the boost problem. The new wastegate I added from Precision has a bad flange on it. The wastegate has a sleeve that sits out .030 which should be compressed. The flange on the car has a recess that is .110 deep so the inner sleeve floats .080 or has a space between the sleeve and the valve that is .080.
We found a couple things we're trying seem to work, just didn't have time to test them at higher boost levels. As far as next year, Shawn and I need to get together and get some parts moving. A couple options...
Tall Deck RHS 4.125" Bore + 4.250 Crank
Tall Deck RHS 4.125" Bore + 4.125 Crank
Std Deck RHS 4.125" Bore + 4.125 Crank
As far as the block goes, its got a 1/4" hairline crack at the 5 o'clock position off #6 cylinder. Before the engine was finished Shawn called and said look man, you really need to get a new block, this one is its last legs and I am not confident it will last a full season. Knowning that we would only make the last half of the season we made a gamble and try the block with the old hardware and see if we could get it too last 5-6 races. Shawn knew my financial situtation and said he was going to do the best he could but there were no guarantees how long it would last and I was ok with it.
So we show up at MIR early, shawn is ready to rock. We put the car on the scale to verify the numbers and it was off by a good amount so we got it cleaned up and started getting ready for the first shot.
I backed the boost down to what I thought was going to be about 30# and backed the leave RPM down to what should have been 5.5# of boost and lowered the 2 step 100 rpms. Drive the car up and everything is running clean, do my burnout and we start the staging process. Car comes right up on boost, I inch it in grab the transbrake but the car isn't making the boost it should. Let go the car feels good and for some reason the boost came in really late.
First shot off the trailer it went a 4.98 @ 160 on a 1.37 60'. Boost in the beams was down to 4# and the boost curve was really lazy, it was down almost 10# at the 60' mark and full boost was in 1.5 seconds later than it should have been. I just chalked it up new car strange ****.
Second shot, we add 50 to the stage limiter, 1/2# of boost on the brake and leave everything the same. Boost in the beams is still the same 4# and the boost curve was very lazy and again it was down 9.7# of boost at the 60'. The car goes a 4.98 @ 158 and the average boost curve was down 1.2# from the previous run so that makes sense.
thrid shot, we add another 1/2# of boost on the brake, bring the boost in quicker and let her eat. We cooled car down and drove it to the lanes, right as I started the burnout, shawn backed me out of the beams because it was spitting water out of the exhaust. We chalked it up to a cold car. The Boost was still the same in the beams, car ran a 4.8x @ 157 with the same boost curve as the previous run. As I slowed the car down I could tell there was something on the windows, possibly oil from the turbo or water.
We get back to the pits to see what happened and verified #6 was leaking water.
What we learned.... I took the head off this morning to find a crack in #6 at the 5 o'clock position. Concientally, that cylinder had been cut off center by the first engine builder making it thin in that spot which shawn complained about last year.
I think we also found the boost problem. The new wastegate I added from Precision has a bad flange on it. The wastegate has a sleeve that sits out .030 which should be compressed. The flange on the car has a recess that is .110 deep so the inner sleeve floats .080 or has a space between the sleeve and the valve that is .080.
We found a couple things we're trying seem to work, just didn't have time to test them at higher boost levels. As far as next year, Shawn and I need to get together and get some parts moving. A couple options...
Tall Deck RHS 4.125" Bore + 4.250 Crank
Tall Deck RHS 4.125" Bore + 4.125 Crank
Std Deck RHS 4.125" Bore + 4.125 Crank
09-18-2010, 04:35 PM
#3466
And as far as the boost curve, it was very lazy initally but once we got into high RPMs the boost came in faster than it ever has and the car never missed a beat. It would have been interesting to have the wastegate working correctly but ya never know. a 4.8 with all the boost in a 3.2 seconds is pretty crazy.
09-18-2010, 08:33 PM
#3468
Well probably go the cheap route and get the RHS. Question is do we build a 428, 441 or a 454. I can tell you it will have a Billet CCW crank, alot of compression and aluminum rods.
If money were no object I'd build a Dart Billet, 11:1 CR, 460", Byrant 4.250" crank, GRP Rods, JE Pistons, Jesel belt/distributor/lifters/rockers, PI Canted valve heads and a big old honkin Marcella Intake.
If money were no object I'd build a Dart Billet, 11:1 CR, 460", Byrant 4.250" crank, GRP Rods, JE Pistons, Jesel belt/distributor/lifters/rockers, PI Canted valve heads and a big old honkin Marcella Intake.
09-18-2010, 11:12 PM
#3472
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That sucks Phil! I have not seen a failure like that since my N2O days and stock alum blocks; hopefully this was an isolated incident due to a pre-existing machining issue as you suggested.
09-19-2010, 06:50 AM
#3474
09-19-2010, 08:00 AM
#3477
Helllll NO. We aint no where near maxed out the 106 let alone a 114. We can go 175 with a 441 or 454 ls and a 106 or 114. On the 160 hit from yesterday we still had 10# of boost from a known efficient number and the boost was in .75 seconds late from where it should have been. Hey you wanna buy a crank and rods? I'll cut you a smokin deal?
Our 4.9 @ 160 run was down 6# of average boost and the 60' was 2 tenths slow.
Our 4.9 @ 160 run was down 6# of average boost and the 60' was 2 tenths slow.
Last edited by Phil99vette; 09-19-2010 at 08:17 AM.
09-19-2010, 08:04 AM
#3478
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Helllll NO. We aint no where near maxed out the 106 let alone a 114. We can go 175 with a 441 or 454 ls and a 106 or 114. On the 160 hit from yesterday we still had 10# of boost from a known efficient number and the boost was in .75 seconds late from where it should have been. Hey you wanna buy a crank and rods? I'll cut you a smokin deal?
