Hot Rod Forum banner

stroker motor 389 cam decisions help

1K views 5 replies 3 participants last post by  cgood1976 
#1 ·
Looking for some friendly advise on my engine. Motor was already in truck and I pulled it and broke it down to know exactly what its got and do some freshening up with new bearing and seals ect. I would have left it alone but I would like to build on it and put a larger can. Its going in a 82 swb chevy, th400 trans, 2400-2800 9.5" stall, 12 bolt posi rear haven't checked gearing yet.

This is a weekend street beater, may see track in future.
Motor specs that I have found out so far
350 4bolt .060 over
400. Crank
Speed pro h860cp .060 pistons
GM 340292 292 Turbo heads they look untouched to me.
Can't find good markings on current cam but its going by by, hydrolic tappet

My thoughts currently are going air gap intake, comp xe274 cam, and maybe some runner clean up on the heads. I haven't gotten the springs off yet to check them but they are a double spring.

In my mind I'd like to shoot for 450+ HP and tq with a nasty idle yet keep some vac for breaks. If I can't, I don't mind a pump. Speed pro says 10.5 comp with 64cc heads, but I'm not sure if mine are 58cc, thats what I measured with a siringe and fluid.
 
See less See more
#2 ·
A cam by itself won get you to 450 hp
your heads will work,but porting them is a very very good idea,or spend the money on better heads
street solid roller cam,750/850 carb,long tube headers,you need to match the cam to the rpm required and head flow supplied after porting
 
#3 ·
yes i have planned on headers, its a real pita finding long tubes for my truck that clear angle plugs. i would like to replace the heads with some afr 195's but i don't think the wife would be happy about that. my best option is working on the heads i have now with hopes of a swap down the road.

are the compression ratios listed for the pistons reliable info so long as nothing has been ground down? whats the best way to determin this? i have a digital caliper do i just confirm the deck height, it says

Compression (@ .025 deck clearance)
58cc 11.26

64cc 10.53

68cc 10.09

72cc 9.69

76cc 9.33

also would this value go down with head gasket or is it including head gasket. by looks of the carbon at the top of the cylinders i'm sure i've got factory deck height but i can measure to be sure.
 
#4 ·
ok, my problems go deeper. main bearings are worn and the crank looks bad. i figure its going to be better just to replace the crank because the groves are deep and i don't want to waste time running to a machine shop just to find out it can't be turned down.

any suggestions on what to watch out for or avoid on crank suggest? my block is 80-85 4bolt truck engine according to numbers.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top