Engine gyrues help. Is 400 CI a good engine?
Thread Starter
Burning Brakes
Joined: Feb 2001
Posts: 769
Likes: 0
From: Granbury TX
Engine gyrues help. Is 400 CI a good engine?
I've noticed the stampeed to build 383's for the last few years and I'm wondering why I don't hear much (or anythihg) about the 400 ci small blocks. It should be much easier to build and require a lot less trick work or specality items. I now have a 400 offered to me for next too nothing and I seem to remember about 10 or 12 years ago that there was a lot of excitement about the 400's.
What happened? Why havent I heard anything about them in the past few years? Should I consider using this 400 for my next build? I'm looking for direction and guidance here. Help!
What happened? Why havent I heard anything about them in the past few years? Should I consider using this 400 for my next build? I'm looking for direction and guidance here. Help!
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Re: Engine gyrues help. Is 400 CI a good engine? (The Dude)
406ci is easier and cheaper to build than 383ci because there is no clearancing and you use stock ( size ) replacement parts. Probably just not as many 400ci
blocks around as there are 350ci blocks. :D
blocks around as there are 350ci blocks. :D
Advanced
Joined: Feb 2002
Posts: 97
Likes: 0
From: Sapupla OK
Re: Engine gyrues help. Is 400 CI a good engine? (Strike3)
I have heard that the 400 can have cooling problems and crack in area of the two exhaust ports that are close together.
No first hand knowledge, but that might be why you don't see too many
Ken (molchaser)
No first hand knowledge, but that might be why you don't see too many
Ken (molchaser)
Instructor
Joined: Oct 2003
Posts: 186
Likes: 0
Re: Engine gyrues help. Is 400 CI a good engine? (Strike3)
i love mine! you can make big power with a 400. just think of it as a bored 383. the cooling problems came from the first two years of the block, they did not have any cooling (steam) holes in the heads to relieve the air bubble that forms on the under side of the cylinders. 350's have cooling that flows around the entire cylinder, 400's are siamesed so the cooling does not flow between them. once you get steam holes, the engines are basically the same to build. 383's are just 350's with 400 cranks that have the main journals ground down to 2.45"(350 main) from the stock 2.65"(400 main). of course the newer cranks are cast specifically for the smaller main size to aid 383 builders. my 406 is making 600 hp at the crank without "assistence" and on pump gas. i will be glad to share the build info with you, as well as some other ideas i have about 400's. if your interested, just email me, Brian
Melting Slicks
Joined: May 2001
Posts: 2,131
Likes: 4
From: May help you? You can sure as hell try!
Re: Engine gyrues help. Is 400 CI a good engine? (Strike3)
If you build it with aftermarket heads (and you will almost have to in order to get it to make the power it has the potential for) you should have the heads drilled for the steam holes and use the 400 head gasket. I'd also use the 5.7 or even 6 inch rods (not the shorter 400 rods). Pistons are readily available that will work with the longer rods. I'd also have splayed 4 bolt main caps installed if the block you're building is 2 bolt main (most are). Keep in mind these motors were originally intended for big chevy, big torque, family hauler applications so the bottom end could use a little beefing up. There's plenty of power potential with the 400 block so go for it. Building a 400 would be MY preference over a 383, especially if you're getting such a good deal on the block.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Race Director
Joined: Mar 1999
Posts: 10,258
Likes: 1
From: Calif.
Re: Engine gyrues help. Is 400 CI a good engine? (molchaser)
I have heard that the 400 can have cooling problems and crack in area of the two exhaust ports that are close together.
No first hand knowledge, but that might be why you don't see too many
Ken (molchaser)
No first hand knowledge, but that might be why you don't see too many
Ken (molchaser)
Second, the reason that 400 blocks are scarce these days is somewhat related to both the old wive's tale I just explained and the early 383 builders. See, the early 383's used the crankhafts out of 400 engines. The journals were turned down so they would fit in 350 blocks. But, since the 400 blocks were "prone to overheating" :rolleyes: they were often discarded. Couple this with the short period of time that Chevrolet manufactured 400s and you have a scarcity of them now.
Virgin, unbored, magged 2-bolt 400 SBC blocks are going for $400 around here.
