Thread: 400 sb info!!

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good buy?

$550 for a good running 400/350? What are you waiting for?

Originally posted by 91camaro
good buy?

I just got a 400 sb but it does not have a flywheel. on a chevy 400 does it have to have a 400 flywheel or will any sb flywheel work?

400's are externally balanced with eccentric weights on the harmonic damper and flexplate.

Originally posted by kolbione
I just got a 400 sb but it does not have a flywheel. on a chevy 400 does it have to have a 400 flywheel or will any sb flywheel work?

If you're going with a standard tranny you'll need a flywheel from a 454, flexplate from either a 454 or a 400. Both of these engines are externally balanced and to my knowledge all other Chevy engines are internally balanced. Also to my knowledge GM did not put a standard transmission behind a 400.

Originally posted by NTFDAY
If you're going with a standard tranny you'll need a flywheel from a 454, flexplate from either a 454 or a 400. Both of these engines are externally balanced and to my knowledge all other Chevy engines are internally balanced. Also to my knowledge GM did not put a standard transmission behind a 400.

didnt know that about the 400 and no standard transmission NTFDAY, i used a standard transmission, but i had a 4" racing clutch and it used a flex-plate which had to be bal. learn something new every day.

"i had a 4" racing clutch and it used a flex-plate"

Mike, how did this work? I can't picture it in my mind. What did the system use for friction surfaces for the disc/discs? Can you give me a link so I can read up on it?

Originally posted by lt1s10
didnt know that about the 400 and no standard transmission NTFDAY, i used a standard transmission, but i had a 4" racing clutch and it used a flex-plate which had to be bal. learn something new every day.

Mike,
When I put the 400 in the old '62 pickup I put the flywheel off the 283 on it that came out of the truck. First time i tried to drive the damn thing it shook and vibrated so bad I took it around the block and back into the driveway. I called the service manager at the local Chevy dealership and he said that if I drove it very far with that set up it would probably break the crank and definitely wipe out the rear main seal. He said to put a 454 flywheel in it since GM didn't put standards behind 400's.

ill get you some info. tech.

Originally posted by techinspector1
"i had a 4" racing clutch and it used a flex-plate"

Mike, how did this work? I can't picture it in my mind. What did the system use for friction surfaces for the disc/discs? Can you give me a link so I can read up on it?

this is not the brand i used but its the same thing. you use a flex plate to start the car, this bolts to the flex-plate.

http://www.stockcarproducts.com/clutch1.htm

I would love to find a deal like that. Think they were only made for 10 yrs. and the better ones were made in their later years so I don't think Chevy had to much confidence in the motor either. But did you ever wonder why? I'm mean if they had been made to last they would make many of the other sbc's obsolete!!!!!!!!!!!!!!!! But I love that high winding sound of those 377's and I would build one -IF- it was only driven a 1/4 mile at a time.

Originally posted by lt1s10
this is not the brand i used but its the same thing. you use a flex plate to start the car, this bolts to the flex-plate.

http://www.stockcarproducts.com/clutch1.htm

thanks Mike.

Good deal... You BETTER get it or I will hunt you down and BEAT YOU UP! heh just kidding. I know a local racer guy that races 400's in his Nova. He doesn't have much money and does them on budgets and uses stock parts but does his own head work and tranny work and can run with the big blocks.

is a 400 smb a good engine yes. was it a great gm engine like a 283 327 350 no. like a396 402 427 454 no all them were great the 400 was the red head step child gm try to make a small block do the work of a big block they can run and you can make them go fast but they have small heads and small short rods some of the cast cranks have a big hole in the front crank pin. and a block that will not go past a 0.40 over bore . so hi hp and long hi rpm they need work. but gm did get this rigth it is called a big block .396-402 better head in stock form than some of the best smblock heads out there longer rod 6.135 stock for the big block .the big block is the best bottom end in stock form . if the 400 small block was so good why they did not put them in boats? they may have but do not think so?? a boat engine takes one hell of a beating and if they where so good mec marine would be used them and got all the tooling from gm like the 4 banger chevy so if it low rpm than go for it but a stock 396 are cheap sometimes and very mild 396 will take the beating and come back for more . if your brake the big block odds are good it can be fixed it takes lot to kill one than a 400 smb with good heads and rods a good crank all the money spent you could have a stock type big block with better heads longer rods cid and all this is free with the big block it is stock