Stock compression on a '84 350???

[Carlsoti]

Does anyone know what the stock compression on a 350 from 1984 is? Also, what is the stock CC of the combustion chamber?

[spinem]

160psi....google says 64cc.... and ne wherere from 14-20in of vacc depending on build of motor.

[Carlsoti]

Thanks for the reply. Do you know what 160psi turns out as a ratio? 7.5:1, 8.5:1, etc?
64cc combustion chambers for a stock 350 truck head? Really? That seems kinda small for a stock truck motor, considering most aftermarket head's CC start larger that that, and get bigger from there. I was hoping to get a bump UP in compression with the 67cc chambers on the Dart heads I'm putting on this weekend. Oh well. I guess it'll be good to have my own vehicle again, regardless of compression ratio.

[spinem]

Originally Posted by Carlsoti

Thanks for the reply. Do you know what 160psi turns out as a ratio? 7.5:1, 8.5:1, etc?
64cc combustion chambers for a stock 350 truck head? Really? That seems kinda small for a stock truck motor, considering most aftermarket head's CC start larger that that, and get bigger from there. I was hoping to get a bump UP in compression with the 67cc chambers on the Dart heads I'm putting on this weekend. Oh well. I guess it'll be good to have my own vehicle again, regardless of compression ratio.

well stock on that truck, from factory should be 8:5.... yes, the stock heads are small /w/ dime sized valves.

Get some cheap rebuildable 327 heads at your local junk yard....
250bucks gets you foreged pistons, 45 gets you standard ringss....that gave me 190psi lowest, 210psi highest, with a max of 9:5.
this was 5years after rebuild... its now been 20 years, and still blows 190psi.

just rememer, better compression isnt always good. I have to run premium as an example.

added:::its currently being rebuilt to these specs, ill let ya know what i get off the dyno, compress test, vacc test.. exc...

[Carlsoti]

Thanks, again. FWIW, I'm not building for power, just to get my DD back on the road so I can stop bumming rides. I picked up a set of Dart iron eagle s/s heads with 67cc chambers for $100 each off of craigslist a while ago. the intake ports are a bit large for an otherwise stock engine @ 165cc, but if the truck will get me to work and back, I'll be ok.

[spinem]

no problem my friend, i wouldnt respond if u were irritating me...

and there ya go, 100 bucks aint bad. just make sure you get them rebuilt from a professional shop that does good work.
Also, ask how much to polish, port, polish and port while ther r at it.

another thing to remember, keep all the parts together, this push rod, this lifter, this rocker, this valve, this cylnder, and so on. you get the point.

if u mix up valvetrain parts it will not work. it will fail in 100mi or less.

anso, make sure the builder shims the springs as needed. if they dont do it, have it done some where else, it requires a micrometer. pronounced (my-chrom-it-tore)

[Pyrotechnic]

I have a feeling the stock heads are 76CC but the only way to really know for sure is find the casting numbers on the heads. I know later on (TBI swirl port / Vortec era) they went to smaller chambers and a bigger dish, but I believe 1984 was still 76CC.

[HOGDADDY]

Originally Posted by Pyrotechnic

I have a feeling the stock heads are 76CC but the only way to really know for sure is find the casting numbers on the heads. I know later on (TBI swirl port / Vortec era) they went to smaller chambers and a bigger dish, but I believe 1984 was still 76CC.

Yep they are 76cc GM quit putting the 64cc in vehicles a long time ago maybe late 60's and I forget.

[Carlsoti]

Cool. Thanks.

[Carlsoti]

eyeballing the chambers, the stockers are in the mid 70cc range, so i'll get what i want. I think that ,sometimes, colder plugs and a timing change can help a slightly higher compression engine run on "non-premium" gas. if done properly, you can find a decent "middle ground" between HP and cheap gas.