Chevy 400 Build
- Thread starter LilSpann601
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The meiling high volume oil pump, pickup tube and oil pump rod came in today. All i need now is the oil pump bolt. May be going with a ARP one.
Update: Plans have changed. The machinist called and said that he wouldnt recommend me use the heads I brought to him. He said that the valve seat wouldnt be right unless I went with a stock rebuild and the rocker studs would not hold up with a cam lift over .480. I plan to use the big mutha thumpr cam something in the .5xx range. What cc heads should I run, or should I find another set of vortec heads I want to make around 500-600 hp?? Can someone with experience with heads enlighten me??
Update: Plans have changed. The machinist called and said that he wouldnt recommend me use the heads I brought to him. He said that the valve seat wouldnt be right unless I went with a stock rebuild and the rocker studs would not hold up with a cam lift over .480. I plan to use the big mutha thumpr cam something in the .5xx range. What cc heads should I run, or should I find another set of vortec heads I want to make around 500-600 hp?? Can someone with experience with heads enlighten me??
You won't make 600hp with vortec heads. Honestly your build needs to be way more radical to make 600hp. Think stroked. 500 is more reasonable but still going to be a radical build and not pump gas friendly. The machinist should be able to design this engine for you. If he cannot then find another one. 500HP is going to take some nice heads and a more radical and efficient cam than the mother thumper. I would go for a custom grind from your favorite cam manufacturer. I would also go hydraulic or solid roller. As far as heads I would look into something from Dart or AFR. 190cc intake runner minimum. Dart Pro 1 or AFR Eliminator heads.
I would also call and talk to Chad Speier of speier racing heads about the pro filers which is what i am running. he can also help you with your cam
http://www.speierracingheads.com/profilerecono.htm
if you want power def stay away from the mutha thumpr as they were designed simply for that radical race exhaust not and not truly over the top performance imo.
http://www.speierracingheads.com/profilerecono.htm
if you want power def stay away from the mutha thumpr as they were designed simply for that radical race exhaust not and not truly over the top performance imo.
This is from an engine machininst I had years ago. The higher the lift, the more spring pressure is needed. The farther from the seat, the more the spring. The duration doesn't matter, springwise. Any NEW cam ussually comes with a spec sheet with spring reqs. I don't know the science, but a "spring rate" is often called out, with install specs. The early sbc screamin vette motors had the studs drill "pinned" to the head boss. Either your machinist CAN'T mod the heads for screw-in studs, or he wants to sell you some others-or both. Higher spring rates will pull the press-in studs out slowly. ALSO If you, or a friend knows how to use a dial indicator, set it on the valve stem top,no spring, with seals, retainer in place, move the valve open the total valve lift to see if the retainer runs into the guide. Trim guide as needed. Iv'e heard any over .550 lift need valve to piston checked. 8)
By the way, a 3 key timing set, allows you to 0 set, 4 deg advance, or 4 deg retard. My old skool rule is 4 crank degrees advance on the cam is good for added below 5 grand ponies. AND PLEASE, PLEASE use a cam lock plate. The destructions say 20 inch lbs tork. I went 30, it was way too loose. Here's some experience- i changed one once, the chain set,(in 1979) just for confidence. @ 8 months later, pulled out of work, STOPPED WITH NOISE. Immediately popped the dist cap, cranked it, no rotor movement?!?!? The investigation revealed, the cam bolts were thru the cover, going into the water pump. (short sbc) When the cam gear jumped off, the chain and tight timing cover, stripped all the teeth off the crank gear, 4 valves were open. While those pistons beat them bent, the valves broke their skirts off 1 side 
Put a cam lock plate on it, i think thy're 5 bucks. I only preach this because I"ve seen them -not around here. That engine went to the graveyard.
Put a cam lock plate on it, i think thy're 5 bucks. I only preach this because I"ve seen them -not around here. That engine went to the graveyard.
I'm thinking the goal of 500-600 horsepower is unrealistic. I'm sure most would consider this a budget build with cast crank and hypereutectic pistons and already plans for the use of nitrous I think it will be limited these parts.
This engine has the potential to make good power but to reach this horsepower goal and using nitrous I think forged internals should have been used from the beginning and more compression.
The vortec heads will limit power and cam selection and as stated previously some good Dart's or AFR's are needed to even come close to your horsepower goal and really a nice roller cam would help make more power with the new heads but now at this point you are limiting streetability.
I think maybe around 450 horse with some work done on your heads is obtainable with a decent cam and still be streetable.
This engine has the potential to make good power but to reach this horsepower goal and using nitrous I think forged internals should have been used from the beginning and more compression.
The vortec heads will limit power and cam selection and as stated previously some good Dart's or AFR's are needed to even come close to your horsepower goal and really a nice roller cam would help make more power with the new heads but now at this point you are limiting streetability.
I think maybe around 450 horse with some work done on your heads is obtainable with a decent cam and still be streetable.
How much nitrous can I run with the setup im running right now?
My rings are gapped about .025 if i choose not to run nitrous because of my lack of forged internals should I worry about oil-blow by??
My rings are gapped about .025 if i choose not to run nitrous because of my lack of forged internals should I worry about oil-blow by??
LilSpann601 said:
You can still run nitrous with your set up but I think a safe limit would be 100-125 depending on the kit.
If your ring package was set up and clocked properly you will have minimal loss for compression. The first and second rings are the only ones where the gap is opened for nitrous so this would have no effect on oil blow by since the oil rings remain untouched in the nitous set up process.
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