Running a 400 big block? ?Then whats your combination?

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T67POWER

T67POWER

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I am getting a new 400 big block and have two options.
Run the stock pistons and cut the head for compression OR put a better piston in the engine.
The more i think about it, i will most likely put a better piston and cam in the engine.
But i am wondering if anybody here has built a 400 and how it performed for them.
If you have a 400 big block combination then please let me know how it worked for you.
Please list your combination. THANKS.:iconbigg:
 
T67POWER said:
I am getting a new 400 big block and have two options.
Run the stock pistons and cut the head for compression OR put a better piston in the engine.
The more i think about it, i will most likely put a better piston and cam in the engine.
But i am wondering if anybody here has built a 400 and how it performed for them.
If you have a 400 big block combination then please let me know how it worked for you.
Please list your combination. THANKS.:iconbigg:
Click to expand...

Save your coin, be patient, then "STROKE IT"!!!!
 
I just posted in your "400 stock bottom end" thread...

I would put a 440 crank it it.

You're gonna have a 400 crank turned, right? Might as well have a 440 crank's mains tuned down to fit the block.

Run stock re-conned rods with good bolts.

Get a hyper piston (cheap) and go, man GO!! What is that 451 inches? Yee haw....!

Seems to be that it would cost NO MORE to do this than a OEM crank 400.
 
No one really exactly answered the question at hand. He did ask about a 400, I didn't see anythoing about him wanting to stroke it. If he's thinking about cutting heas for comprsion or new pistons, inexpensive seems to be the way of thinking here
 
rumblefish360 said:
No one really exactly answered the question at hand. He did ask about a 400, I didn't see anythoing about him wanting to stroke it. If he's thinking about cutting heas for comprsion or new pistons, inexpensive seems to be the way of thinking here
Click to expand...

He asked for combinations, the 451 is the best, especially for a budget build. I think the point of the answers is that if he's going to go through the effort of getting new pistons and cam which would require some level of machining/balancing, ($) might as well try to find a 440 crank and have it made to fit. A 440 crank surely can be found cheaply enough, probably for $150 or less. Bet you could find someone to literally give you a cast one. (400 cranks are cast) The rods can be re-used so it's just the extra cost of the crank and to cut the 440 mains down. You'd have a stout short block that will likely be a much better performer than just sticking new pistons in a 400.

But if that's not an option then yeah, get new pistons. Cutting heads for compression is a band-aid fix to an inherent performance flaw. You can always get the heads cut at a later point.
 
He asked for combinations, the 451 is the best, especially for a budget build.
Click to expand...
But it's not a 400. He asked for 400 combos. What you suggest. That's a 451, a 51 cubic inch difference and the added cost of stoking it. Enter the price of a crank over the base cost of keeping the stock stroke.

No matter how you slice it, it's not a 400 combo, it's a 451 combo.
 
As far as bearings go the selection for 400's is limited. This is one of the reasons many guys have the block machined to accept 440 cranks, much better bearing selection main bearings + the longer stroke. As far as strength go's the 400 is by far the strongest mopar big block. Stock 400 cranks are all cast so if you want a forged you need aftermarket or 383 as they had forged.

I would say the 400 in stock stroke would perform much the same as a 383,likes to rev due to the short stroke but can use good breathing heads as it has large bores.

Heres what I would do to a stock 400.

4bbl alum intake
largish solid cam
heads that can support 280-300 cfm
forged crank
lightweight hyper pistons
aftermarket lightweight rods
balance to 7000 rpm and good solid machine work to square it up. The 400 block is one of the worst for core shift so have it sonic checked.
 
The 400 i am buying is completely rebuilt with 30 over pistons.
It has never been fired and sits on a new engine stand.
It was built in 1992 and has been in dry storage.
There is no rust in the engine and the oil pump was cranked over with a drill to oil everything up.
I am thinking of taking it apart and checking everything out and installing a set of 30 over keith blacks.
The crank was done,block, all bearings,heads,new everything.
They spent $1800.00 on the rebuild but it was all stock with a economy cam.
It is real easy to build a 451 BUT, if everything checks out, it only needs a good piston and cam with a little bowl work to make it a great engine.
I most likely will get arp rod bolts and shot peen the rods.
It has the same stroke as a 383, so i would think it would scream.
It reminds me of a 340 as far as the stroke being less but the bore being even bigger then a 440.
If i go to a stroker crank,i think it will cost almost the same as turning a 440 crank and hardening it after the cut.
If i go that road then it will be a 512 cube engine instead.
If someone built a 451,how much coin did it cost in the end????????
 
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