can the stock crank handle 450rwhp N/A?
#1
can the stock crank handle 450rwhp N/A?
So I've noticed the car burning some oil lately....nothing major, but enough to convince the wife to put the money away while we can so I can redo the engine. The nice thing is I have a couple of blocks, a complete rotating assembly and a set of heads laying around. So I'm thinking of doing a "fun" 355 to replace it.
Srp Forged slugs .030 over with a 1" compression height
Scat H-beams in 6.125" length
A set of AI or LE heads and cam.
The goal is to not spin north of 7K rpm and have it be dead reliable (car is a DD and will be for the foreseeable future)
The main question is, if I do this and later on decide to spray it for some fun, am I going to regret not going with bigger cubes and a forged crank?
Currently the idea is to keep it N/A, but if I really don't like the power output, I'm going to do what I need to. The rods should handle anything I throw at it since they are the 7/16ths ARP2000 cap screws. The pistons are 4032 alloy, so thy can handle some spray, but not the world that some want to throw t some engines. I figure with swapping to a 95 or LSx pcm should cover the electronics. The only real issue would be the stock trans (definitly needs a converter and at least a shift kit) and stock rear.
What do you guys think? Am I off base completely or does this sound reasonable...
Srp Forged slugs .030 over with a 1" compression height
Scat H-beams in 6.125" length
A set of AI or LE heads and cam.
The goal is to not spin north of 7K rpm and have it be dead reliable (car is a DD and will be for the foreseeable future)
The main question is, if I do this and later on decide to spray it for some fun, am I going to regret not going with bigger cubes and a forged crank?
Currently the idea is to keep it N/A, but if I really don't like the power output, I'm going to do what I need to. The rods should handle anything I throw at it since they are the 7/16ths ARP2000 cap screws. The pistons are 4032 alloy, so thy can handle some spray, but not the world that some want to throw t some engines. I figure with swapping to a 95 or LSx pcm should cover the electronics. The only real issue would be the stock trans (definitly needs a converter and at least a shift kit) and stock rear.
What do you guys think? Am I off base completely or does this sound reasonable...
#4
So if 450rwhp seems like a low hope, what do you guys think I can safely push...
The nice thing is the car is a DD, but it literally drives a mile every other day. I'm going to keep it HR since I don't feel like spending the coin to go SR.
So the question is what should my rwhp goal be?
The nice thing is the car is a DD, but it literally drives a mile every other day. I'm going to keep it HR since I don't feel like spending the coin to go SR.
So the question is what should my rwhp goal be?
#7
TECH Fanatic
iTrader: (1)
Limiting revs to 7000, and with an A4, I think 450 rwhp with a HR is a touch on the optimistic side for a 355. Yes, you can do it, but your power peak is going to be so close to 7000 that you'll be shifting just as it peaks, instead of past peak which is what the car needs for best performance.
Targeting your peak at 6400-6500 rpm is more realistic, and the car will be quicker. Give that plan to AI or LE, and if you do everything right on your end, you'll be happy. That's what I did and ended up with 425 SAE rw.
The stock crank will hold that plus a 150 shot, no problem.
Targeting your peak at 6400-6500 rpm is more realistic, and the car will be quicker. Give that plan to AI or LE, and if you do everything right on your end, you'll be happy. That's what I did and ended up with 425 SAE rw.
The stock crank will hold that plus a 150 shot, no problem.
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#8
TECH Apprentice
Something worth mentioning is your 1" compression height and 6.125 rods is going to put the pistons .160 in the hole with a 9.025 block and 3.48 stroke. You would have to put a 3.75 stroke in it for that combination to work.
#10
I plan on having the block 0 decked. It's also going to need the mains worked on a bit, so it leaves me enough room to play. According to SRP it's intended for a 8.99" deck height I figure with the little bit of main work, and then decking the block I'll have a 0" deck clearance, with a .040" MLS head gasket and 52cc heads puts it at 12.5:1 compression, with good squish. As far as I can tell it should make for a fairly efficient engine.
Edit: I was wrong it's a 1.125" compression height piston. and compression is right about 12.125
Edit: I was wrong it's a 1.125" compression height piston. and compression is right about 12.125
Last edited by duh; 02-19-2012 at 03:15 PM.
#11
TECH Apprentice
Ok that makes since now. Alighn honing the mains will do very little to affect deck height if unless you really go overboard with it. If you were to cut the caps .003 and open the housing bore back to spec youve only moved the crank towards the top by .0015. The piston probably wouldnt see anymore than half of that, which rounded up leaves you with a mere 8 tenths of a thousandts difference. In a nutshell dont expect to get .010 from alighn honing the mains.
#12
Personally I'd spend the extra $550-$600 and get a forged crank and stroke it while I'm at it and know that the bottom end can handle whatever I decide to throw at it later. I'd also put billet 4 bolt main caps on while I was at it, but that's just me.
#13
That's what I was debating about. Would it be worth it to save some money on rods and pistons since they will be more common parts and throw a stroker crank and possibly make more power. The only real issue then would be spending twice as much in the heads since I wont be using stock castings. Urgh! Too many decisions to make!!!