383 vs 400

[MaineShark]

What are the advantages/disadvantages of installing a 383 vs. installing a 400? I'm planning on removing my original engine and keeping it in a crate, so the cost savings of re-using the block aren't really an issue.

My thinking is, if I'm going to use the 400-sized crank throw to get more torque, why not go with the 400 displacement? And I figure it should be easier to get the same power out of the 400, on the general principle of less power per cube = less difficulty.

This one won't be a race engine or anything: I want something inexpensive that will be good on the street. I also want to build my own engine, for fun and experience.

The 383 stroker article that started this engine-building kick puts a price tag of $2000 on that engine. Should a similar 400 be in the same price range?

Joe

 

[patsnitrovette]

Well ive built both motors and granted the 383 had some torque,the 406 hands down was my favorite motor.The low end it had was unreal over the 383.Ill be building another one this winter.

 

[Jack]

Joe:
You're thinking correct ... if you can get a good 400 block that'll clean up with no more than 0.040" oversize for small money ... then build the 400.
JACK:gap

 

[MaineShark]

Any ideas about approximate price, if I do most of the work myself?

Will anything external (other than the balancer and flexplate) need to be different?

Joe

 

[Jack]

Any ideas about approximate price, if I do most of the work myself?

Will anything external (other than the balancer and flexplate) need to be different?

Joe

Aside from cost of block, the pricing in the article is a good guide ... regardless 383 or 400.

Other than damper & flexplate, No external differences ... both the 383 & 400 share same externally balanced damper & flexplate ... both are different than what is on your 350.

Stock Chevy 5.7 rods will usually hit the cam lobes of even a mild standard base circle cam when using a 3.75" or larger stroke crank. This MUST be addressed early in planning. Options are: grind (cam-clearance) rod bolts, use a small base circle cam, use stroker-profiled aftermarket rods, use stock 400 rods (they're short, not recommended). If you're considering purchasing a rotating assembly kit, check if the included rods have already been cam-clearanced for a standard base circle cam.
JACK:gap

 

[offshore]

the 400 hundred had more than it's share of prob. ie:cracked blocks/cracked heads. it is a tq.monster just don't spend alot on it. whats strange is this block should have been a tough sob. there was just some thing wrong with the cooling sys9.ie:steam holes) just could'nt keep block full of water.I wish i still had one though.

 

[AKRAY4PLAY]

Joe,
Jack and offshore have some pretty good points. everything from your 350 will bolt directly onto a 400. the crank journals are different. the 350 has 2.450" mains and the 400 has 2.650" mains. most companies build the 3.75" stroke crank for either main size. an internal balanced 400 crank takes the same flywheel and balancer as the 350. a small base circle cam is a must and 6.0" rods are the way to go. with longer rods, comes more expensive pistons, so some people settle for the 5.7" rods and give up some performance. the cooling problems are on the first two years of the 400, they had no steam holes. you need them to perge the bubles that form under the head in the block webbing of the siamesed cylinders. the 400 block is stronger than a 350 block if you are looking for major power in the future. GM is making the 400 block again, it is offered in iron and aluminum. you can even get it in rocket block configuration for making a much larger displacement, ie. 454. bottom line, you do get more for your money with the 400, Brian

 

[MaineShark]

Major power will be the next time around. This is just going to be buying a used engine and rebuilding it, so I can retire my 100k+ mile original engine, get a bit more power, and get some experience building an engine.

Inexpensive is the name of the game, here. I'd like to shoot for $1500-2500, doing as much of the work myself as I possibly can.

If anyone has any good sources for rotating assembly kits (particularly pre-balanced), that would be the first step, since that will probably be the biggest portion of the cost.

Also, any advice on selecting the correct cam, etc. would be helpful.

Joe

 

[Glensgages]

MaineShark, a few things to consider. The 400 block has 'siamese-bores', where-as all 4 cylinders on each side 'touch' each other, possibly limiting the cooling ability of a hi-HP 400. The 4" bore-blocks (327/350) have 360-degree water jackets (i.e.- the bores DON'T touch). I've heard that 400 blacks are weaker in the main-cap/web area, too, but I'm not sure. The larger bores have, on ocassion, caused problems with head gaskets sealing, too. A buddy, who's built several 350s, 383s, and 400s, suggests the 383 for these reasons; better cooling, stronger 'web' area, and better head gasket sealing. If your C3 has cooling problems as it is now,... Just a few things to think about..... just my $.02 worth.....

 

[cruisin-davey-g]

What are the advantages/disadvantages of installing a 383 vs. installing a 400? I'm planning on removing my original engine and keeping it in a crate, so the cost savings of re-using the block aren't really an issue.

My thinking is, if I'm going to use the 400-sized crank throw to get more torque, why not go with the 400 displacement? And I figure it should be easier to get the same power out of the 400, on the general principle of less power per cube = less difficulty.

This one won't be a race engine or anything: I want something inexpensive that will be good on the street. I also want to build my own engine, for fun and experience.

The 383 stroker article that started this engine-building kick puts a price tag of $2000 on that engine. Should a similar 400 be in the same price range?

Joe

Hi: "Glensgages" is giving you the strait "poop" on these engine build ups. If you're going to use a 400 block, make sure you don't use a 4 bolt main. These blocks are prone to the webbing in the mains to stress crack under heavy loads. My racing buddies (go-fast boys) found this out. It's better to pick up a seasoned 2 bolt & use that unless you're going to do a real biuld up, where I would suggest that you make it a 4 bolt & "spade" the mains. Hope this helps.

 

[Glensgages]

Upon further review... cruisin-davey-q stated a point I'd neglected. If you DO choose a 400-block, get a two-bolt block; I'm told they have stronger 'webbibg' area. Then, you can convert it TO a 4-bolt/cap block, by 'splaying' ('spade'?) the outer bolt-holes on either side (i.e.- 'angle' them for better clamping, and keeping the bolts 'further' apart). This may run your costs up a bit, but the strength is outstanding! IMHO, trick set-up would be 350 2-bolt block converted to 'splayed-caps' 4-bolt, a steel-billet 400 crank, etc. This type set-up would produce an EASY 400 (425? 450?) HP on pump-gas, run 13s (12s?) in a Corvette, yet run FOREVER without breaking, or over-heating! Just my $.02 worth.....

 

[cruisin-davey-g]

Upon further review... cruisin-davey-q stated a point I'd neglected. If you DO choose a 400-block, get a two-bolt block; I'm told they have stronger 'webbibg' area. Then, you can convert it TO a 4-bolt/cap block, by 'splaying' ('spade'?) the outer bolt-holes on either side (i.e.- 'angle' them for better clamping, and keeping the bolts 'further' apart). This may run your costs up a bit, but the strength is outstanding! IMHO, trick set-up would be 350 2-bolt block converted to 'splayed-caps' 4-bolt, a steel-billet 400 crank, etc. This type set-up would produce an EASY 400 (425? 450?) HP on pump-gas, run 13s (12s?) in a Corvette, yet run FOREVER without breaking, or over-heating! Just my $.02 worth.....

"Glengages": Hey, right on with the explaination. Yeah, I meant that (splaying), not spading (sounds like I'm gardening). I do so much of both (mechanics & gardening), I tend to get the terms mixed up sometimes. That, & tthe fack I'm not real keen on the typing-thing. Tend to do the "plick-plick" thing with one finger. Thanx, "Glengages" for adding your 2 cnts worth & clearing that up! Davey G! (Putting a Plant on top of my blower instead of a hood scoop?)

 

[MaineShark]

I'm just going with a 2-bolt, without splayed bolts. This is going to be a fairly low-power motor, so I'm not worried.

Joe