more sbc questions

[Silent viewer]

i have a couple questions.
1. i am getting ready to assemble my buddies 327 and are debating pistons. the motor is a large journal 327 that we are planning to use 441 heads on, the 441 heads are 76cc heads which means with a flat top piston we are not going to get high compression. we are thinging abot using some domed pistons instead to boost the compression a bit, it seems like the domed pistons for a 327 are not as easy to find as i thought for a good price. we just want something like a speed pro .125 dome i think. anybody have any advice for us??

2.similar question, i am thinking about domed pistons for my motor, 350 with vortec 906 heads, i am planning to run a holley stealth ram efi setup with factory tpi computer and harness. what am i going to get using this setup with a .125 domed piston?? is this a bad idea??

3.last question, do i want to replace cam bearings?? i really doubt that my 350 is going to need bearings but the 327 may need them, the motor is 60 over so it had been rebuilt before we got it so i am assuming that they are not the stock bearings. i have seen cam bearing tools on ebay for around 30 bucks but i have been told they are a pain in the butt to do them correctly.....

thanks for any advice!

 

[RITTER]

My buddy ran .125 domed pistons in his 327 with camel hump 2.02 and a 150 shot of nitrous in a malibu, his best track time was 12.4 @ 109 and it ran just fine on pump gas.

 

[megaladon6]

to figure out compression and clearance issues go to:
http://kb-silvolite.com/calc.php

it only cost me $40 to have the cam bearings installed. i'd do them just as cheap insurance. the last thing you want to say is "well i guess i should have..." right after some loud noises and alot of cursing.

 

[455OLDSMAN]

My buddy ran .125 domed pistons in his 327 with camel hump 2.02 and a 150 shot of nitrous in a malibu, his best track time was 12.4 @ 109 and it ran just fine on pump gas.

Them malibu engine was a 350 with flat tops dude. Your thinking of the monte engine.

 

[wolfs1959]

there are other choices on the comp. ratio. flat tops arent all the same some have different compression hights. you can get a flat top with 10 to 1 if you want wich is more than enough for a street machine. I personaly prefer flat tops. In my opinion ridges in the cylinder can cause spark nock (pre detonation) and Iv always shied away from domed pistons for that reason just me though everyone has a different way of looking at things. you can also have the heads milled to smaller chamber volume it only costs like 60bucks alot cheaper than new pistons.

just off the top of my head speed pro also has a 100 dome piston wich i think makes like 9.6 to 1 comp ratio with 76 chambers dont take that word for word its just off the top of my head.

it really all depends on what you are wanting to do with the engine.

YES!! have new cam bearings installed why rebuild an engine without replacing bearings?

Joe

 

[v8power]

if you do the cam bearings yourself, they go in order listed on the box, and it never hurts to double check the clearances of the cam bearings. the boxes always lie, and you might need to run some fine sand paper in there to get all the clearances right. After every bearing installed blow the block out nice and good because you always will get some metal shavings that you do not want.
another thing to do with your heads is to measure the combustion chamber using a transmission fluid and some plexy glass sealed over the top with your gasket, measure your cc's to know for sure, because thee cc's off can mean allot in compression differences, you can do the same for the pistons in the block. then from there you can calculate the exact compression.

 

[Silent viewer]

ok first, i know that the combustion chamber is 76cc for sure

i am really wondering how to get 10 to 1 with flat tops and the 441 head with out using domed pistons

we ARE replacing every bearing except maybe the cam bearings, people dont swap the bearings on motors that they do a simple cam swap on wether it had 100 miles or 100,000 miles or more. i have built 4 or 5 engines at this point and never replaced the cam bearings and never had any issues, 2 of these motors i have torn back down for upgrades and checked the cam bearings and still have not seen any issues.


this motor is being built for daily driving in the summer, a little hot rodding around town and possibly a run or two down the track on occassion but not very likely. i am not trying to build something crazy with either motor build up i am doing right now, just something a bit above factory, ok maybe more then that but we are not going crazy with them. i am not trying to get 400+hp and run nitrous or anything....

 

[82355supreme]

To get 10:1 with flat tops, you'd have to have the heads milled to 72cc & use a .016 shim head gasket. This would give a 9.98:1 CR.

 

[bigdan]

did you invest lot of $$$ in those 441 ...
if not sell them & get a set of vortec 062 heads
those have 64cc and much better flow then those 441's

you wont believe the difference an easy 35hp swap
only downside to this : you need a vortec bolt pattern intake

dan

 

[Silent viewer]

This motor is actually my buddys and i have told him several times to go for the vortec heads and he seems to really want the 441 heads on there and he also does not want to buy another manifold. iagree vortecs are the way to go, thats what i am using and i have passed up several pairs of 906s that i was going to get for him. i think i am going to replace the crap 882s off of the motor in my cutty here really soon.