I was told that a smaller combustion chamber combined with flat top pistons will increase the Compression ratio. Is this true? I've got stock rebuild going with flat top pistons and I'mthinking of usinga set of C6AE heads that have a cc of 53. I'm not going for uber performance. What I want is a daily driver type of engine. Will this combo give me too much compression? If so, whatdo I need to change to match this compression. Are differnet heads the answer? Thanks

misc.
carb- 4100 autolite (as of right now)
exhaust- HiPo manifolds (as of right now)
intake- stock 4V (again, as of right now)
distributor- stock with petronix

 

It's possible - if the compression height of the piston is tall enough. Otherwise you wind up with a lot of expensive partsin a two barrel engine. There are also domed pistons and notched pistons to consider. They can raise your compression ratio to the point that you will need 100 octane gas.
Jim

 

hey shikoz man flat tops with 53 cc heads wow cool!!! now add a cam and dual plane intake 4 barrel and headers and you got a great street machine!!! anyway to answer your question yes flat tops and smaller chambers up the comp ratio but be careful pump gas and high compression don't mix well with todays gas unless you use aluminum heads I used a .200 dome piston and 58 cc afr heads on my 85 gt mustang and I rum 93 octane and have never had an issue with detonation on my 66 I went with flat top forged light weight pistons and used 69 302 heads with a triangle shape combustion chamber don't know the cc's think it's somewhere between 59 and 62?? anyway it works great with 93 octane and no detonation![8D]

 

short answer, flat tops and those small chambers - you'll be fine.

worst case you'll be running 93, which isnt that big of a deal.

 

I kind of expected to run 93/92 (depending on where you're located) octane in the car after the engine is complete. I started thinking about this compression thing when I was trying to figure out if I wanted to go with a dual plane intake, headers, etc. It seems pointless to have high compression without running the goods that help the engine breathe better. Hmmmm. . . more thinking to do.

Please let me know if there are any more thoughts on this. Thanks!

 

higher compression (within reason) is always a good thing.

obviously, if your going to be rebuilding you might as well slap a better intake/carb/cam/exhaust on there and let the motor breathe.

you'll be VERY happy you did

 

A lot of it depends on build too. I'm running 61cc chamber AFR heads on my 302 with flat tops and 9.44:1 static compression with an agressive ignition curve and jetting on the lean side, and I run it on 89oct without any issues. Of course, it also has a higher than stock rod ratio too