what kind of .40 pistons will i need if my vortec heads are 68cc?
chevy 400 block .040
250 vortec heads 2.02 valves
stock 400 crank 3.750
chevy 400 block .040
250 vortec heads 2.02 valves
stock 400 crank 3.750
Chevy 400 Build
- Thread starter LilSpann601
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i talked with my machinist he said i need 10 1/2 to 1
does that sound right
my heads are 68cc all the pistons i see are saying 64cc 74cc
does that sound right
my heads are 68cc all the pistons i see are saying 64cc 74cc
Got a set of sealed power sbc 400 pistons..next is the rings and balancer..then off to the machinist
update: ended up returning the pistons. they would not fit my rods...because they rods are the floating type. The pistons were 200.00 i think there called the Seal power H616CP. the other pitons i think were stock rod .040 press piston somebody. Hope fully ill have the assembly back and start building the bottom end. then its the 68cc 350 vortec next. Wonder how can i max these vortecs out???
As for as choosing a cam whats the maixmum lift cam I can choose if im running stock?
I choose a big lifting cam I hear about beehive springs?
This engine is my first builid all right I know thatim running a stock Eage 400 Crank_supports 450-500hp, 5.7 Ibeams, Chevy 400 0.040, Set of Seal Powered .040 piston thats are for 5.7 rods, .040 Moly Rings. As for the heads i researched them at they came out to be 350 68cc vortec heads. As for as I know im going with a 2.02 intake valve. How much will this comobo get me? I plan on trying to getting a Air- Gap to use with the vortec. This setup will be going to my 81 monte carlo...I think also know ill be running an electric fuel pump and need a good place to mount it.
Help me out guyzz
As for as choosing a cam whats the maixmum lift cam I can choose if im running stock?
I choose a big lifting cam I hear about beehive springs?
This engine is my first builid all right I know thatim running a stock Eage 400 Crank_supports 450-500hp, 5.7 Ibeams, Chevy 400 0.040, Set of Seal Powered .040 piston thats are for 5.7 rods, .040 Moly Rings. As for the heads i researched them at they came out to be 350 68cc vortec heads. As for as I know im going with a 2.02 intake valve. How much will this comobo get me? I plan on trying to getting a Air- Gap to use with the vortec. This setup will be going to my 81 monte carlo...I think also know ill be running an electric fuel pump and need a good place to mount it.
Help me out guyzz
Food for thought. IF you polish the combustion chambers, and smooth radius the edges at the deck surface, C/R won't matter on pump gas. Sharp edges and corners in the chamber/on the piston cause deiseling. I have a happy customer with a 327/11.5:1 no noise. You can buy a 6500 rpm mech pump. Moroso makes a liteweight pump pushrod for extra reliability. I fed a tunnel ram with 2 390 cfm holleys, no prob.
Also keep in mind that when you are running a set of Vortec heads that the valve lift has to be kept to around .450 to .470 lift, unless the guide height has been cut down, or the valve retainer will smack the top of the valve guide. I build alot of 400 based small blocks and have built a few that were basically the same set-up as yours, all of them made good horsepower with great torque. All of them ran around with cams in the low to mid 230's at .050 duration and around the .480's to .490's for lift. Chevy High Performance built one similar to this a few years back aand called it the Impersonator, it made like 425HP and 529 torque or something. Should move your Monte pretty good.
gbondo57 said:
I was thinking of running one of the red or blue holley electric pumps but I may go with a mechanical pump. Will a stock mech fuel pump work fine for my build?
crotchss said:
^This is what I needed to know. A couple of years back I built a carb turbo 3.8 and i know with the buick when you choose a high lifting cam the valve guides have to be grinded down so I see now its almost like the samething. As for as having the vortec heads built what should i tell the machinist. I know that I will want a 2.02 intake valve..what about the exhaust valve???
Also I dropped my rotating assembly off to have it balanced. The machinist told me he had to order some type of weight or metal to weld to the flexplate or somewhere to balance it out. Hopefully next week Ill have it back and I can start building my bottom-end. Right now I have my main bearings installed in the block and main caps. Should I use the stock main caps bolts?? I have some ARP main cap bolts I just wanna do everything right and not have to go back into the bottom end.
Your machinist probably had to order mallory to balance out the motor. Exhaust size I would put at 1.6" if you're gonna have a 2.02" intake valve. Figure out exactly what cam you're going to run then tell the machinist you need clearance for that cam on the guides. As far as the main bolts, if you have ARP's, I would definitely run them for extra insurance.
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