What do i need to do to get these crankshaft to work on my 350 motor, Can some one give me idea :?:
Chevy 350 with a stock 400 crankshaft
- Thread starter Chevyonbillets
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Get the block machined to accept the crank and find a piston & rods combo that'll fit the crank and the block.
The stock size mains in a 400 are 2.65 and in all other small blocks they are 2.45.
So the crank should bee turned down to 2.45.
And the 400 are also externally balanced, so you should probably use 400 flexplate and balancer.
If you use 400 (5.65 long) rods i belive you can use stock 350 pistons and check skirt clearance to crank.
But whit 350 (5.7 long) rods you need special raised pin height in the pistons. But you probably gets all sorts of 383 pistons for all kind of rods now i think straight of the shelf from most piston manufacturers.
And you need to check rod to block and rod to camshaft clearance. Probably grind some in the block to clear the rods.
So the crank should bee turned down to 2.45.
And the 400 are also externally balanced, so you should probably use 400 flexplate and balancer.
If you use 400 (5.65 long) rods i belive you can use stock 350 pistons and check skirt clearance to crank.
But whit 350 (5.7 long) rods you need special raised pin height in the pistons. But you probably gets all sorts of 383 pistons for all kind of rods now i think straight of the shelf from most piston manufacturers.
And you need to check rod to block and rod to camshaft clearance. Probably grind some in the block to clear the rods.
TwoBlackMarks... pretty well nailed the answer. Machine the crank to the 350 2.45" mains. Have your machinist make sure the crank is in good shape. If not, a good cast steel Eagle or Scat carnk is reasonably priced. Use the 5.7" rods. 383's are so common any more that they aren't any more expensive than 350 pistons. If you assemble this yourself, put the crank in the block with the beaarings and snug the mains. Mark the areas on the block where interferance occurs. Remove the crank, and grind a little and recheck. Then after the crank throws clear, put all 8 pistons and rods in the block without the rings. Check clearances again and grind some more. Any good machinist can do this but I did mine at home with a Dremel and a lot of patience.
Before you put the rings on the pistons, put your cam in with the timing chain. Sometimes, with some cams, theere may be interferance problems. Contrary to belief, a normal sized street cam doesn't need to have a small base circle. I use a regular base circle cam and have no problems. Your machinist should also clearance some of the rod bolt heads for cam clearance.
Have your engine balanced. It's money well spent. The 400's are externally balanced and will need the 400 balancer and flywheel or flexplate. You can have it internally balanced and use the 350 balancer and flexplate but there is no advantage on a street engine. It's also more expensive to have them internally balanced.
As with any engine build, make sure the block has no metal filings left over & is clean enough to eat off of ... literally !!!
Before you put the rings on the pistons, put your cam in with the timing chain. Sometimes, with some cams, theere may be interferance problems. Contrary to belief, a normal sized street cam doesn't need to have a small base circle. I use a regular base circle cam and have no problems. Your machinist should also clearance some of the rod bolt heads for cam clearance.
Have your engine balanced. It's money well spent. The 400's are externally balanced and will need the 400 balancer and flywheel or flexplate. You can have it internally balanced and use the 350 balancer and flexplate but there is no advantage on a street engine. It's also more expensive to have them internally balanced.
As with any engine build, make sure the block has no metal filings left over & is clean enough to eat off of ... literally !!!
jrm81bu said:
I was talking to one of my friends he was telling me the same thing to machine the crank , I am going to check how much is going to cost me on monday
Chevyonbillets said:
I realize you already have the 400 crank, but ...
Didn't know if you knew that you can buy a brand new 383 crank ready to drop in for less than $200 ...
http://www.summitracing.com/parts/ESP-103503750/
http://www.summitracing.com/parts/SCA-910375/
By the time you have a 30+ year old crank 'fluxed for cracks and the journals turned, or you can have a brand new crank ready to bolt in ...
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