help on my 400 small block?!?!?!?

[chevy kid]

I have a 400 small block, does anyone know if it is the most powerful small block chevy? or any good tips on making it powerful?? also if I could just buy new heads to fix the over heating problem that the 400 has?? thanks...

[mustangmann9]

hey man, try summit they have tons and tons of performance parts for v8's

[OverBoardProject]

Not all 400 sbc have overheating problems.

A friend of mine is running 2.

His first has his water jackets 1/2 filled with concrete, runns 400++hp drives fast and this car actually runs cool with a thermostat.
This is in his 69 Chevelle street rod

The thing that he noticed on his motor is that the bottom of the cylinder walls is thick.

In his 1/4 race car he has a 400sbc with a little more Hp (probably about 500hp, but he runs NOS on his street rod to easily surpass that mark without any problems)
He has no concrete in the water jackets, and he has heating problems.
This engine is in his much lighter 76 Vega.
This motor has thin cylinder walls on the bottom.

Both these motors are punched out to a 406

[jveik]

the most powerful stock smallblock from chevy is most likely the 302. it has good compression and stuff and i heard that they only advertised it at somewhere around 280 or 260 something horses for insurance reasons and that in reality it made over 400 horsepower

[OverBoardProject]

Originally Posted by jveik

the most powerful stock smallblock from chevy is most likely the 302. it has good compression and stuff and i heard that they only advertised it at somewhere around 280 or 260 something horses for insurance reasons and that in reality it made over 400 horsepower

I'd like to see the dyno figures to prove that one!

[curtis73]

Actually some of the "factory race" 302s pushed over 420 hp. You could easily make one that made well over 900 if you wanted to push it, but the amount of power they can make is irrelevant. He's asking how much they made. The highest factory rated 400 made about 300 gross HP, so about 230-250 SAE net. The 400 small block came in to being a little past the prime of the muscle car so it fell into smog hell pretty quickly and some only made about 180 hp in the late 70s. Many factory SB2 engines like the LT1/4 make well over 300 net, and some SB3 engines like the LS1 and LS2 make close to 500 from the factory.

Your 400 can easily be made to perform on street duty at about a 400 hp level with really good tuning, and maybe 500 with expert tuning. The secret will be matching great heads with a hot but streetable cam.

[TRACYCULBERSON]

Originally Posted by OverBoardProject

I'd like to see the dyno figures to prove that one!

Yeh !! I personally would like to see the dyno sheet on the 302 . Now
one thing for a fact is if you are lucky enough to have a 69 z-28 with a original 302 you have got something.Even if you have a 302 engine alone you still have something .The 400 is a good engine especially the 406.
I ran a 406 for sometime on street tires its ET was 7.70 to 7.80 .
If you still need some pointers let me know i have a great set up for
small block chevy especially the 400.
Good luck with 400

['97ventureowner]

I have a sb400 that I have modified in my '64 Bel Air. It was bored .030 over (making it a 406 cu.in.) and I have no problems with overheating. I did not do anything special to the waterjacket, but I did install a 4 core radiator. If you can afford to, I would reccomend a 3 or 4 core radiator to handle your engine's cooling needs. I also purchased (from Summit Racing,) a cooling fan which is pitched a little different from stock fans to bring in more air through the radiator fins. It is a five blade fan replacing the stock 4 blade fan.

[OverBoardProject]

The best fan that I've ever tried is the electric fan from a Ford Taurus. Apparently a Mustang has an even bigger E-fan too.

They're a 2 speed fan, that pumps out a lot of air even on low speed.

I used the 2 stage switch from a BMW, and easily had the job done and tested in way less than a 1/2 day

[TRACYCULBERSON]

Originally Posted by OverBoardProject

The best fan that I've ever tried is the electric fan from a Ford Taurus. Apparently a Mustang has an even bigger E-fan too.

They're a 2 speed fan, that pumps out a lot of air even on low speed.

I used the 2 stage switch from a BMW, and easily had the job done and tested in way less than a 1/2 day

Well I also had know trouble with my 406 over heating .The engine was
very peppy and had tremedous amout of torque.It was the best small block I have had
and in the car that the 406 was in i also had 400 35 over and some how we came up with 415 cubic inches i dont remeber how .But it was all roller and it sucked for street purposes. it also had 350 30 over that was ok , but doesnt hold a candle to 406

[OverBoardProject]

I don't know why Chevy dropped the 400, instead of the 350. They have more potential

[TRACYCULBERSON]

Originally Posted by OverBoardProject

I don't know why Chevy dropped the 400, instead of the 350. They have more potential

The 400 small block was great . I had a crowd pleaser once the 406 went in.But i had a decent 350 small block 4 bolt main but at the time i was young and listen to everybody except the right person and had a very bad combination that was weak.The damn thing was slow . Then a friend of mine that races for mazda moter sports which by the way those rotary engines are quick.He helped me with a combo he had used and built for other people and bam there was it was fast . Its all about
fast cars and freedom man. There is nothing like having the fastes car around in you local area . Someone will finally come along with more knowlege ,or money and de throne you.


Later dude

[OverBoardProject]

I've got a friend that builds up 400 blocks into 406's
He does consistant 9 second passes on 94 octane pump gas, without any NOS

He'll hopefully build up a Ford 302 for my street rod. Or at least advise me on it.

He wants to build up the 71 350 that's in my for 1 of my street rods, and I might let him if I can find a high compression 500 Cadalac motor to dump in.

[TRACYCULBERSON]

Originally Posted by OverBoardProject

I've got a friend that builds up 400 blocks into 406's
He does consistant 9 second passes on 94 octane pump gas, without any NOS

He'll hopefully build up a Ford 302 for my street rod. Or at least advise me on it.

He wants to build up the 71 350 that's in my for 1 of my street rods, and I might let him if I can find a high compression 500 Cadalac motor to dump in.

I have heard about those 500 caddy engines over the years.But do not have any hands on knowledge or anything like that with that engine.
In the near future i have a 71 gmc sprint . I have already built the engine but i am going to make a few changes before putting it in.I have a cowl hood ,the car is factory air and windows.It has been in my basement since 1984 so it is a solid car.I have the body ready to lift off frame I am going to do a frame off restoration.

[OverBoardProject]

Sounds like fun Tracy.

Here's what I'm working on as I have the time.

When I got it

After Sandblasting, and POR-15

It's the car that I'm dumping the Ford motor into