Cylinder Head Volume 50 cc


Piston Head Volume (cc) Piston Head Vol
(cubic in.) 00.000 they are flattops made by je said to be 12.1 on a 58cc head


Gasket Thickness (in.) i have 039's on it now
(cubic in.) 49.673
Gasket Bore (in.) 4.100 gasket
(cubic in.) 03.565
Cylinder Bore Diameter (in.) 4.040
(cubic in.) 00.515
Deck Clearance (in.) decken to zero
Note: Neg. nubmer above deck, Pos. number below deck Deck Volume
(cubic in.) 00.000
Stroke (in.) STATIC COMPRESSION RATIO 14.934

OPTIONAL DATA
Rod Length (in.) Adjusted Stroke (in.) 02.939 i have 6" h beams and a 3.875 crank
Intake Closing Point (degrees)
this one they said in the post to put 68

 

I'm with these guys... you need more RPM for that compression ratio. Problem is you better have some strong parts in the bottom end. I don't really like solid rollers unless you fix the lifter bore placements in the block... that's just one more way to make the things live.

How about you just fill in:

Chamber Volume
Piston Volume (-5cc for example on flat tops)
Head Gasket
Zero Deck or Deck Height

Bret

 

That changes things a bunch!

The JE pistons you refer to (shelf set) are -5cc. With that data & the variables you have given (using the KB calculator) I get 13.8:1 static and 10.26:1 DCR.

That's why we have to be careful with posts like this...

Either way... you have what you have & I got your PM. Actually need to get back to some other PM's (sorry guys) so I'll get with you ASAP.

-Mindgame

 

cool then i am about right we originally thought it was around 13.6:1

 

Love the Duckworth quote Bret.

I wonder what Kenny Duttweiler would say about that one.

-Mindgame

 

Yeah, I'm sure your one of the few people who know who he is too!

13.6:1 sounds much more in line with what I was thinking.

I'd put the actual IVC around mid 80's to get you just under 9:1 DCR

Bret

 

Using the IVC of 73*@.006 as quoted on Comp's site for the 306 I get 13.83 static and 9.86 DCR.

 

yeah thats around where it is now, way to early

 

No,it's about 8:15Pm.
A bigger cam will help the situation a bunch and the 396 will eat a big cam up and keep the revs down. Keep in mind I am not talking in the 280/290 range but in the 250/260range on a 108+4 or possibly a 112+4 will get it done.
His heads probably will want a bunch of lift and some pretty long duration IMO.

 

Then you have a miscalc nested in there somewhere. What is your calculated dynamic stroke length?

AFAIC, I'd cam it to spin 7200 and put the right fuel in it to keep it from going over the edge. Enough octane can cure just about anything.... for a while.

-Mindgame

 

You are right. I didn't put the +4 on the cam.

 

whats this 108+4 and 112+4 never heard of that is it advance ground in?

 

Yes, but it isn't ground in it's the placement of the drive dowel pin.

 

Then you HAVE heard of it!



And that SCR sounds ALOT more realistic! I was thinking, "damn, how'd he get 15:1??"!!

 

cool so say 112 lsa you want a +4 i always thought the more radical cams were low like 106's