400 c.i. to stroke or to de-stroke

[mudslidesrule]

i picked up a 400 smallblock last week. It is a 2 bolt block.

My question is, should i stroke this or de-stroke it. what are the pros and cons to either. I am looking for a very stout engine with a good low end torque and a relative high rpm range.

should i make it a 4 bolt block? for strength.

what combination of heads, cranks, rods, pistons, camshafts, timing sets, do you guys think is best?

I plan on doing some trail riding but i do want the power avaliable to and get!!!

[355REDNECK]

u can go as far as u wallet will let you go

[betterbeaters]

strokers make low end..  as for what to use the better the parts the more you pay

[Jthomas]

Ditch the 400 sb.     I'm really not a fan of them, they have the symese cylinders and get hot spots. Hot spots are bad.

Get a 4blt main bbc, forged crank, heavy rods, possibly a stoker crank, high comp pistons. Get a cam with a good profile for low end TQ and off idle TQ. I'd suggest roller cam and lifters, little bit more $, but they are well worth it. Idk how far you want to go into your wallet on this project. But a good 'cheap' is AFR. Just call them up, have a note pad, and just ask some general questions. They will point you in the right direction. Go from company to company getting info and prices. The. You can look for a carb and intake to match everything.

Your end result is a good torquer motor

[bigmud44]

we have both 421 & 392 they are pretty much built the same the 392 screams the 421 makes great power from 3500 up dont let anyone fool ya 400s can be made as bad as you want 

[HellYeah4x4]

Them 400s can be built to be good motors. I had one with a lil work done to it but i too had problems with it. 350 blocks are common and cheap for my money id get a 350 block and use the 400 crank to build a 383 stroker with some head work youd have a nice motor. The stock chevy rods are good for around 600hp. I like comp cams and their roller chain timing sets. For the money the weiand stealth intakes are underated i ran 1 on my 400 and liked it more than my edelbrock performer intake, For a mud/trail truck if your not worried about mileage i like my predator carbs alot jmo  

[the harvester]

get a 2 bolt block

[mudslidesrule]

Ok thanks for.the info. I have already had a 400 about ten years ago. I put 350 center bolt tbi heads on it and put in a comp cam i think it was a 460-480 an edelbrock performer intake and a quadrajet carb in an 88 k-5 with 38.5 tires. Lets just say i couldnt keep a.driveshaft in it... so i know.they are power monsters but i would plan on spending about 3 thousand on the build. I have some vortech heads and i plan on doing the build myself. But i would obviously farm out the machine work. I was just wondering what combination would be good for all around off roading. With lots of power avaliable. No mileage is not a concern. I have a jeep with a 400 trans and a twin stick dana 20 and dana 44  axles with 5.89 gears. I want to run between 35's and 40's.

[Kyle]

id stroke it! no replacement for displacement. with all the low end power ya get from the bigger stroke ya wont need the rpms very long. dart has a high rise dual plane intake that works very well for me. dont switch it to 4 bolt main, youll only weaken the bottom end. just get some main cap studs and youll be fine

[Jthomas]

Go big block if you want TQ

[the harvester]

Go big block if you want TQ

he has never once even mentioned a big block in this post . so why do you keep refering to big blocks when he asked about a 400

[Jthomas]

Go big block if you want TQ

he has never once even mentioned a big block in this post . so why do you keep refering to big blocks when he asked about a 400

He asked how to make power?

I wouldn't put a lot of money into a sb trying to make a ton of power. When you can get a bb and not put as much $ in it, still make more power.

[Thumper]

with the right combination of the right parts and of course $$$$ any motor can make tons of power and torque. I have seen 6 cyl. run circles around v8's.

[mudslidesrule]

this is what i have. i dont really have the room for a big block nor do i want one. my question is about the 400 sbc and what stroke, and what combination of cams, intakes, carb, is better. i want a strong dependable motor. i could use a 327, 350, or 400 crankshaft with any combination of rod lengths. to make anything from a 358 to a 421 stroker motor. i would like a few different opinions from some guys that have had something similar and dealt with any possible issues that could have been avoided...possibly engine builders with the experience of doing it everyday.  no bbc...just sbc...
i plan on mostly trail driving but i want the power to win some mud drags.......

[Jthomas]

Stroke it, and use a good heavy Long rod to slow down the piston speed the shorter the rod the faster the stroke speed. And it puts a lot of pressure on the skirt. Like I said in my last post, call a cam manufactor and ask them what the best cam is for your app. And do the same for the heads. But your going to want somthing with off idle TQ with low/mid range power.  As far as the pistons go, you want to Raise the compression ratio. The hotter the burn of the flame, the more power your going to make. Run premium fuel. Or even race fuel?  Idk what bore or stroke combo to tell you, but the bigger the cubes, the more power your gunna have.   Punch the block .060 over (idk how large a bore it can take, but .060 is alright) find a crank with the largest stoke YOU WANT. they make a bunch of different sizes, the larger the crank the more $$$. So that is up to you.  And if your going to go through the money on a complete custom rebuild, get quality parts.  You do get what you pay for. The intake you choose is going to be based off of your cam specs and engine demands for air/fuel, same for the carb. That will be one of the last things you do.

My pistons are probe industries. Really nice pistons, and good on the budget.
You can find a rod/crank combo online. There as so many places I can't even list.   Scat makes nice rods and cranks, so does pink, I like eagle, but kind of pricy.   You could alway just get a GM crank. A GM performance crank and rods are great, they know what they are doing.

[marshall]

400 has a nice nodular iron crank, and decent rods. I would punch it 30 over, buy some good heads, have a nice 406.

[Swampthing]

If you plan on trail riding it a bit. I myself, would build a 383. I have run most combinations that you can make with a sbc.  And a 383 seems to be the most durable,reliable,and easily buildable.


But. now comes the fun part.  You didn't mention if you needed this motor to draw vacuum for brakes. How streetable do you want it?  Any city type driving going to be involved? Is the motor going to sit most of the winter?


Well, as everyone says, 400 sbc's have a heat problem, and in a jeep with a smaller radiator, I am sure you will have a problem.  But that is also related to compression ratio. Higher the compression. the higher the engine heat.

If you take a 350 block and put a 383 crank in it, you will have great power. I say 383 crank because you really should use a aftermarket crank. If you take a factory 400 crank, and rev it up in the rpm's for a summer. take it out and have it magnifluxed. it will scare you with the micro cracking.


While getting the motor bored. spend some money on line honing (has to be done if you use the 400 block and make it 4 bolt anyways)and get the top of the block squared off, or "decked". Remember friction is heat,and power loss.

With the vortec heads,you can get away with using flat top pistons, they compression ratio would be around 9.1to1  up to 9.5 to 1. depends upon piston manufacterer.  Which is really streetable. while still being able to run 93 octane (race gas every trail ride gets exspensive).

The reason i asked about how long the motor will sit,is because with solid lifters cams,while the motor is off, there is ALWAYS 3 valves in some stage of opening. So letting a motor sit for a period of time with out rolling it over, or backing the rocker arms off, will eventually help to weaken the springs.

If you are going to let it sit,or want a good idle,or even need to make vacuum for brakes.I would use a decent hyd camshaft.

Intake.well If you are street driving. A good dual plane intake will do you just fine. Nice lower end power,plus vacuum,and yes,rpm's..lol.

What ever motor you decide to use, The intake rpm range and camshaft rpm range need to match the head  intake port volume. The closer the match, the better the throttle response.


Well, i hope i didn't sound like a idiot,and you got something ot of this. thanks.. swampy

[mudslidesrule]

Hey swampy, thats exactly what i was looking for. Yes i do need vacuum for brakes but the jeep is offroad only and i do plan on using it in the winter to use around the farm. Yes pump gas is what i would like to.run.

[Boggen Joe]

I run a 388 stroker, eagle rotating assm. I like strokers, but seen some nice 406s. Destroyers are hi revers anything you build should be balanced to last and take the beeten lol.
So 383, 406, 377 all nice motors with different power at revs

[bigmud44]

400 has a nice nodular iron crank, and decent rods. I would punch it 30 over, buy some good heads, have a nice 406.

which with dual plane intake and torque cam will make nice off idle to about 4500-5000 engine .the vortec heads mentioned above are some of the best heads gm made for gen 1 sbc engine quest makes a very reasonble priced copy thats a little better .dart has a very good article on there website about picking heads for expected hp levels for what your wanting to do would go 406 421s need lots of extra machine work-lots of combo info on sites like yellow bullet .might want to look @ joe sherman racing engines man builds crazy hp off 400 s -there is a book you can get at most speed shops called how to get big hp out of sbc full of lots of info & several combos from mild to wild .do lots of research and good luck with your project .one more suggestion mr gasket & sevral others make a pc engine simulater that will give you good idea on how different combos you dream up will work thernot perfect but they will give pretty good understanding of how certain parts work or dont work together