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400

 
ridinhin85
I love my Chevy Chevette!
Posts: 1
Joined: 12/09
Posted: 12/24/09 03:56 PM

will a chevy 400 get hot on the street 40 over with 10.9 compression  

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canted
I have an SS396 tatoo
Posts: 499
Joined: 02/08
Posted: 12/24/09 04:23 PM

Welcome to the forum. The 400 is a good foundation, have never built one myself but I'm sure someone will chime in that has.  
Jim
70 El Camino
461 solid, m20,
pics in readers rides
thanks for over 3000 views

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tuffnuff
Moderator
Posts: 7841
Joined: 12/09
Posted: 12/24/09 05:09 PM

ridin,,,
The 400 is a much misunderstood engine for a number of reasons.
It has siamesed cylinders that are joined, so there is no water that flows between bores.
This is OK, because there are holes on each end of the block, to vent steam.
The problem arises when any small block head, other than 400 heads are used.
Because these heads do not have the steam holes,,,, you have to drill these 1/4" holes to match up with a 400 gasket.
the other drawback is the the poor rod/stroke ratio,,,, 400's use a 5.565" rod
But you can use a 350 rod that is 5.7" and get corresponding pistons.
I've built quite a number of these engines and the 3-3/4" stroke turns your SB into a small BB, which it now is.
In my opinion, 400 heads are junk and a good set of heads really wake these sleepers up.
Good luck

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

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gettnlarge01
I mow my lawn and find Chevys
Posts: 3330
Joined: 09/09
Posted: 12/24/09 05:09 PM

whats the bore size? std or oversized  
luck is when skill and opportunity meet

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Pontiacman2
Moderator
Posts: 8956
Joined: 09/08
Posted: 12/25/09 05:43 AM

If it was me I would get a 350 and sell the 400 they do have overheating problems and thin bores and weaker blocks.  
Pontiacman2
Pontiacman2

Professional Hi-performance engine builder

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gettnlarge01
I mow my lawn and find Chevys
Posts: 3330
Joined: 09/09
Posted: 12/25/09 07:06 AM

I'm running a .030 400 in my Caprice with no overheating troubles. With a good cooling system and the engine built correct he shouldnt either  
luck is when skill and opportunity meet

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69nova355.
I mow my lawn and find Chevys
Posts: 2560
Joined: 08/09
Posted: 12/25/09 07:31 AM

i have seen no troubles with overheating if holes are drilled right.  

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tuffnuff
Moderator
Posts: 7841
Joined: 12/09
Posted: 12/25/09 07:46 AM

+1
gettn,,,
I am extremely brutal on ALL my builds,,, bar none.
I stretch everything to it's plastic limit,,,
then I tear it apart, whether it needs taking apart or not.
I scrutinize everything,,, worn components get replaced with better parts.
This continues and it's my method of determining what works, and what doesn't.
I forgot to mention that I clean up (port) water passage holes in heads and block, to match gaskets.
The steam holes are the biggest culprit for the undeserved heating problems a 400 gets.
A 400 is no longer a small block,,, it's a big block,,, period.
It needs a big block rad,,, not a puny SB rad.
I'm not going to debate the structural integrity of the core block,,, there are good and bad.
Just as there are good and bad 350's lots of "Hecho en Mehico" <--- right
so lets call a spade a spade,,,, and not a shovel.
I have had good luck with 400's and I'm looking for one now.
I will offset grind the crank .100" and use early 2" journal rods
for a .385" stroke with +.060" pistons
(4.187" bore with clearance and 3.850" stroke) for a displacement of 425 Cubic Inches.
Now if this isn't a Big Block,,, then I rest my case.
OHHH,,, the 400 crank is not debateable since every 383 SB has one, right.
Bottom end is ok too if preventive precautions are taken,,, beef it up.
I have built a couple of these and they are no slouch with Vortec heads.
I'm not trying to ruffle anybodys feathers, just saying it works for me
no heating problems with a Big Block 3 core rad.

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

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Pontiacman2
Moderator
Posts: 8956
Joined: 09/08
Posted: 12/25/09 07:51 AM

Yes  but most people in my area don't spend the money on a good cooling system that is usually why.  
Pontiacman2
Pontiacman2

Professional Hi-performance engine builder

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69nova355.
I mow my lawn and find Chevys
Posts: 2560
Joined: 08/09
Posted: 12/25/09 08:05 AM

the 400 with the vortec heads would put down some great torque numbers too.  

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tuffnuff
Moderator
Posts: 7841
Joined: 12/09
Posted: 12/25/09 08:27 AM

69
It is a brute in SB disguise
Vortecs are the poor man's answer to a prayer
young lads getting into racing
In reader rides,
I have a SB on a test stand
with Vortecs and it's as snarly as a junkjard dog.
Pman,,,
Yes, most folks fail to upgrade a rad after a build or going more inches.
Nobody considers the added BTU's of a larger engine,
and since the 400 looks like a SB,, it gets treated like one.
This is clearly not fair, it is a small Big Block.

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

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69nova355.
I mow my lawn and find Chevys
Posts: 2560
Joined: 08/09
Posted: 12/25/09 08:47 AM

i agree tuff, i like the vortecs. p2s 383 runs very strong with them and is a low rpm tire shredder. with the bigger cubes you get a nice setup with them. have not checked out your readers rids yet but am going to now.  

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tuffnuff
Moderator
Posts: 7841
Joined: 12/09
Posted: 12/25/09 09:44 AM

Votecs give the biggest bang for the buck,,,
A lifesaver for entrance level go fast guys
2 heads and 1 aftermarket manifold and I would put my money on the steel Vortec before Ed.....ck's any day,,, unless Ed's put more effort into manufacturing his product (better quality control) since I got stung on his junk.
Sorry,,, I fully expect to get kissed when I get F'd
Holley makes better manifolds too and so do many other, less advertised brands.

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

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gettnlarge01
I mow my lawn and find Chevys
Posts: 3330
Joined: 09/09
Posted: 12/25/09 09:44 AM

I know what you mean Pman. Same story here most of the time but if they dont listen to reason I'll buy it at a deal. LOL    Your 400 plan is almost identical to the one in the shop 55chevy.Its been built for about 15yrs now tuff  
luck is when skill and opportunity meet

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tuffnuff
Moderator
Posts: 7841
Joined: 12/09
Posted: 12/25/09 10:06 AM

I built my stuff over 20 years ago, as per Speed-O-Motive input.
We shouldn't try to reinvent the wheel
that thing is about as good as it will ever get,,,
"IF" we are talking old school carbureted engines
Personally I don't care for the new and improved,,, that stuff is all going to get crushed into metal suitcases.
NOBODY will be able to repair that hi-tech crap once the warranty runs out and the dealership mechanics get on to bigger, better, newer ideas.
Mark my words
Can you even imagine a G5 fetching $100,000.00 bucks at Barret Jackson in 20 years now.
ha ha ha LOL
It will be a R2D2,,, your mother was a snow blower, huh

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

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