What cc are 346 BB heads?

[my73charger]

I am going to get some aluminum heads as soon as I can afford it.  I currently have 10.3-1 compression and I want to keep the compression close to that.

[firefighter3931]

346's will be around 90cc give or take a few. How do you know what compression ratio you've got ? Have you done the calculations ? You need to measure piston to deck clearance, gasket thickness, valve relief/dome volume (depending on what pistons you've got) and measure combustion chamber volume to come up with a "true" staic compression ratio.

Going by the manufacturers rating for the pistons can be inaccurate due to variations in any of the aformentioned specs. Just because the slugs are advertised as 10.3:1 doesn't mean that that it is necessarily so.  

Ron

[my73charger]

It is a fresh rebuild and was checked after assembly.  The pistons i went with are a Speed Pro forged aluminum domed piston with a rating of 10.5-1.  I am probably going with Edelbrock RPM heads due to budget constraints.  How would the 88cc head effect my compression?

[Chryco Psycho]

with alum heads you need mor ecompression to compensate for heat loss , you should be able to run 10.8:1 with alum heads
the problem you will run into is the domed piston is not designed to fit the Eddy heads & the valve reliefs will not line up with the valves 

[my73charger]

Do you have a reasonably priced alternative Chryco?

[Chryco Psycho]

using  a dome piston ... no
if you used a flat top piston you would have better flame travel & could use a smaller CC head like the bulldogs to get awesome quench & exactly the compression you need to max the combo

[firefighter3931]

How far are the 2295's in the hole ? Those pistons will work with a closed chamber 84cc e-head as long as the cam isn't too big. If the deck is stock spec those pistons will be .050 below deck. A comp 294-s solid cam will fit with plenty of clearance. Something similarly sized would also work. What cam were you thinking about running ?

Personally, i'd pull the heads and measure before making any decisions on a head purchase. Allthough a flattop piston would be better, the domed 2295's can work with the right combo. AS long as the cam isn't too big.

Ron

[my73charger]

Here is my Cam:
Competition Cam
Basic Operating RPM Range:    3,000-6,200 RPM
Intake Duration 050 inch Lift:    244
Exhaust Duration 050 inch Lift:    244
Duration at 050 inch Lift:    244 int./244 exh.
Advertised Intake Duration:    292
Advertised Exhaust Duration:    292
Advertised Duration:    292 int./292 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:    0.501
Exhaust Valve Lift with Factory Rocker Arm Ratio:    0.501
Valve Lift with Factory Rocker Arm Ratio:    0.501 int./0.501 exh. lift
Lobe Separation (degrees):    110
Intake Valve Lash (in):    0.000
Exhaust Valve Lash (in):    0.000


Here is my piston:
Product Line:   Speed-Pro Power Forged Pistons
Bore (in):    4.350
Piston Material:    Forged aluminum
Piston Style:    Dome
Compression Distance (in):    2.029
Dome Height (in):    0.140
Dome Volume (cc):    12.10
Valve Reliefs:    Trough
Wrist Pin Style:    Floating
Pin Diameter (in):    1.0939
Top Ring Thickness:    1/16 in.
Second Ring Thickness:    1/16 in.
Oil Ring Thickness:    3/16 in.
Quantity:    Sold individually.
Notes:    Approximate compression ratios: 11.34:1 with 78.5cc and 10.34:1 with 88cc head.

[firefighter3931]

You won't have any problem with that cam...it's small enough to give you adequate piston to valve clearance with the closed chamber e-heads. The dome on the 2295's is actually pretty small as far as domed pistons go...being only 12cc. Still it would be worthwhile to get a deck measurement and see how far those pistons are down in the hole. Then your actual compression ratio can be calculated.

Ron

[my73charger]

Ok Thanks Ron.