Need Help With More Hp From 434 SBC

[killacamaro]

Hello everyone!I just found this site and see it is a very informative place.I could really use your expert help!I have a sbc 434 with Pro 1 dart 230's flowing 330 In/250 Exh at .750 lift,4"stroke 6"rod,eagle rotating assembly with JE dome pistons,about 12.8 compression,cam lift is 284/286 at 112 and 734/704,1050 dom with Dart Ported 4150 intake,1 7/8 hedder,vacuum pump,and belt drive.The motor made 670hp and 588tq at 6800 rpm.I'm in the process of refreshening it and was wondering what could i do to make more hp and torque!I've seen smaller motors make more power than mine!I will also spray a 300 shot.Thanks for your advice in advance!

[rookie]

Originally Posted by killacamaro

Pro 1 dart 230's flowing 230 In/250 Exh at 7500 284/286 at 112 and 734/704,1050 dom with Dart Ported 4150 intake.
The motor made 670hp and 588tq at 6800 rpm.

?'s on #'s, I'm guessing 230 is 330 on intake and 7500 is 750 lift???
What size intake valve?
330 and 250 are damn good flow #'s for a 23* head.
284/286 @ .050 lift? 112 LSA? is this a nitrous motor?
If not I would add 2 points of compression and close up the LSA. from 112 to 104 or 106 range.
If it is a nitrous motor, add about 300horse shot and hang on!

[killacamaro]

My mistake on miswording was kind of sleep when i posted! Yes I have nitrous cam,but I,ve seen similiar motors make 700 to 750 hp.I was thinking of a bigger cam and maybe a lighter rotating assembly.Just wanted to know what u guys knowed for a fact would help,thanks! killacamaro@bellsouth.net

[want-a-be]

You need to be making good torque up nearer 7500 rpm. If you took your whole torque curve and moved it up 700 rpm you'd be over your 700 hp goal. From your 670hp @ 6800rpm you'd be making 740hp @ 7500. What pistons are you running? What size ring land do they have? Are they gas ported? How much dome do they have? Have you knocked all the sharp edges off the domes (contoured them)? Is the block a stock block or an after market block? How much deck height are you running? What size chamber are you running in the head? What is your piston-to-valve clearance on your intake and exhaust? How much valve spring pressure are you running?

There are probably more questions I need to know but this ought to get us started.

Don

WCRE/Ace Rod Shop

[Dusty]

I agree with rookie to tighten the lca. I wonder if you could angle mill the heads to pick up some compression and cut the pistons a bit to avoid buying new pistons with more dome. With the sucess we've had with a 1250 dominator on a 350 i wonder if something larger would help especially how rapidly those heads are demanding air with the big inches.

[killacamaro]

Originally Posted by want-a-be

You need to be making good torque up nearer 7500 rpm. If you took your whole torque curve and moved it up 700 rpm you'd be over your 700 hp goal. From your 670hp @ 6800rpm you'd be making 740hp @ 7500. What pistons are you running? What size ring land do they have? Are they gas ported? How much dome do they have? Have you knocked all the sharp edges off the domes (contoured them)? Is the block a stock block or an after market block? How much deck height are you running? What size chamber are you running in the head? What is your piston-to-valve clearance on your intake and exhaust? How much valve spring pressure are you running?

There are probably more questions I need to know but this ought to get us started.

Don

WCRE/Ace Rod Shop

Sorry for the wait I've been out town!Thanks for the reply Don!I'm running JE contured pistons(non gas ported) with a ring land of 1/16 1/16 and 3/16 bottom. Bowtie block eith a 9.8 deck height.64cc chamber on head with 2.10 Int and 1.625 exh 238cc head.Piston to valve clearance 80 Int and 130 Exh.230/240 at 2" on spring!Thanks!

[killacamaro]

What's up Dusty!I thought about upping the compression but was told by several engine builders(Joe Sherman/L.Meaux) it wouldn't make that big of a difference in a 600-700hp motor.This is a nitrous motor so I couldn't tighten up LCA! I was thinking of going with a bigger cam and lighter(better) pistons.Tried a 1250 already with know luck!Thanks Dusty!

[Lasse]

How about headers? Are 1 7/8" primaries little small side in 700hp engine, especially when nitrous is pushed in?

[Dusty]

I would disagree with your engine being a nitrous motor at present with a 300 shot. You are giving up a whole lot on the motor with that lobe separation of 112. We run 10.5:1 383's at 106 if you held the cylinder heads constant between you and a 383 you would be looking at a cam in the 102-104 range. You have great head flow so lets call it 105 now you have two ratios more compression so that'll widen it further to the 106 to 108 range. Now if you were spraying alot of nitrous the 112 would be right seeing how you want 2-4 degrees wider LCA for that. I don't think giving up on the motor in favor of the nitrous at this point is the best way to go.

[killacamaro]

Originally Posted by Dusty

I would disagree with your engine being a nitrous motor at present with a 300 shot. You are giving up a whole lot on the motor with that lobe separation of 112. We run 10.5:1 383's at 106 if you held the cylinder heads constant between you and a 383 you would be looking at a cam in the 102-104 range. You have great head flow so lets call it 105 now you have two ratios more compression so that'll widen it further to the 106 to 108 range. Now if you were spraying alot of nitrous the 112 would be right seeing how you want 2-4 degrees wider LCA for that. I don't think giving up on the motor in favor of the nitrous at this point is the best way to go.

I'm kind of lost at your first response Dusty?What do u call a nitrous motor(500plus nos)?The cam is supposed to be cut for nos and the heads are to that is why the exhaust is way better than the intake!I have been a 8.68 in a stock suspesion 78 (2880pds)camaro so far on a 250 shot.I'm not giving up on motor!I always ran both ways but I didn't want to talk much about the nos cause that would lead to a whole other subject! My goal is to get it the best I can on motor while I got it down!I know it will fly on the spray already.I would like to get close or beyond the 700hp range without changing heads or intake since I recently purchased a new Wilson 2 Stage Pro-flow 4150 to 4500 Nos plate !How much hp and tq do u make with the 383.R u spraying it?How fast has it been and what type of vehicle?Thanks Vince!