hi im going to be building a stroker 335(dont want a 350)

would copression be too low with 10cc dished pistons and 64cc edelbrock heads....makes 9.5 on a 350 stock piston


my other thuaght was to put trickflows 56cc...but im worried about copression being to high at that point for 93 octane gas

the cam has 218/224 duration at .50

335 stroker with 10cc dished pistons and 58cc heads is 10.1 CR

 

What material are the heads, AL?

What induction system?
Weight of car?
Stickshift or auto?
Location? ie. elevation, temp, etc?

you seem to already know how to do the math, ie you know 10:1 is where you'll be right? or did you need help rechecking the math, or are you just asking if that (10:1) is a good place to be?

 

Have you used any of the on-line calculators for figuring out your static cr AND dynamic cr? Your cam plays a big part in how much static cr you can run.

 

Food for thought
Bore 3.766 (.030 over )
Stroke 3.75
Chamber vol 58cc
Piston dish 10cc
Piston deck .025" (stock avg.)
Gasket thickness .028"
Gasket diameter 3.870
Static C.R. 9.5:1
With 64 cc heads 8.9:1

Do you have the cam specs for advertised duration and LCA?

 

Hey Sonix,
A little off topic here but where do you drag race in the Calgary area? The only track I know of is in Edmonton.

 

skinnyz, off the top of my head that last calc seems low...8.9:1 on a stroker? i'd recheck, but i'm kinda busy here now... Also, that a reasonable gasket bore? never seen that size before?

I don't drag race... yet. My car hasn't run for more then a month at a time before I break something.

Racecity is in the SE quadrant. They are still open for the 2009 racing season, I *think*, then they are being shut down. I think there's a track in Red Deer as well, but don't quote me on that.
PM Stephen_87Iroc for more info, he's into racing here in Calgary.

 

Thanks
I'm pretty sure on those CR values. 64 cc, 10cc dish, .025 piston below deck. That's a Corteco gasket specific for a 305.

 

Did you ever consider using a 350 block with a 3.25" crankshaft? Much better breathing capabilities.

 

Or better yet, use a 350 block with a 3.48" stroke... even better breathing capability!

 

umm i dont know the lca...but the lsa is 112 and advertised dur is 270 and 276


how would the compression be with 56cc heads...i want to be able to run pump gas 93 oct

 

I found this cam which matches your specs. Comp cams 12-417-8. A 112 LSA with an intake LCA of 110 (as installed).
Using that info you get:



Bore 3.766 (.030 over )
Stroke 3.75
Chamber vol 56cc
Piston dish 10cc
Piston deck .025" (stock avg.)
Gasket thickness .028"
Gasket diameter 3.870
Static C.R. 10.01:1

With the cam installed as spec'd you get a dynamic compression ratio of 8.03:1 which is about middle of the road for a daily driven performance engine.
FYI. Check out this article regarding dynamic vs static compression to get a better understanding of how the two relate.
http://www.empirenet.com/pkelley2/DynamicCR.html
For the record (and this is just my opinion based on my own experience) you should have no trouble running 10:1 with iron heads and 93 octane. Remember to get a handle on your ignition timing and keep the inlet air as cool as possible.

 

oh thx for the info..you helped me big ...do aluminum heads make a big difference in the compression also

 

they lower compression due to the heat transfer

why are you stroking a 305

when I first started i was on the 305 tip but now if I get a 305 out comes the crank and if they have h.o. heads I take those and the rest is scrap

 

They have the same static compression, but they make less power for it, if everything else is equal.

 

The reason aluminum heads require more compression to make the same power as iron heads, is because of heat transfer - aluminum dissipates heat too fast. HEAT = POWER for our purposes. Iron retains heat in the chambers much better than aluminum does. Aluminum requires more compression (compression creates heat) to make up for this.