Been sitting like this for the last 4 years. finally have time to get back to it.

Chopped and Channeled T with a gnarly Y?  I gotta see pics man.. i'm drooling just thinking about it..

Dustin

Southern Oregon Y's Guy

http://www.facebook.com/?ref=home#/profile.php?ref=profile&id=1441322018

Yes. Its a 312 that will be offset ground to 3.62 and bored .030 over.

Stock 312 rods are 6.254" long...Are you building a stroker?

FIGHT CONFORMITY! 

After some research this is the cam I'm thinking about. What do you guys think?



Comp cam



PART NO. 37-601-5



DUR @.050 i 239 e 253



LOBE LIFT .3260 .3200



NET VALVE LIFT .490 .480



DUR @ .020 TAPPET LIFT 268 285



LOBE SEPARATI 107.0



ADVANCE 5



VALVE TIMING OPEN CLOSE



@ .020

INT 31 57



EXH 71 34



THESE SPECS ARE FOR CAM(S) INSTALLED



@ 102.0 INTAKE CENTERLINE



Also after talking with John Mummert it looks like i will be going with a 3.62 stroke. This should bring static compression to 9.3:1

Sounds like those running 9.5:1 static compression, when traveling to areas where 93 octane cannot be assured, should consider (aside from retarding the ignition & carrying along a case of octane booster) tightening up the valve lash a bit?

6 VOLTS/POS. GRD. NW INDIANA

I’ll agree with Charlie in that the E4 Isky is on the mild side for your particular combination and especially with your rpm expectations.

 

Your 9.4:1 static compression ratio comes in pretty close to what I get in checking your numbers.  I get 9.36:1 using 9.9cc’s for the head gasket volume.  With the 6.125” rod, the dynamic compression ratio values for your particular combination are as follows when using the following intake closing event numbers.

53.0° ABDC = 8.1:1 dynamic cr

55.1° ABDC = 8.0:1 dynamic cr

57.1° ABDC = 7.9:1 dynamic cr

59.0° ABDC = 7.8:1 dynamic cr

61.0° ABDC = 7.7:1 dynamic cr

62.8° ABDC = 7.6:1 dynamic cr

64.5° ABDC = 7.5:1 dynamic cr

66.2° ABDC = 7.4:1 dynamic cr

Also remember that by advancing or retarding the camshaft, the dynamic compression ratio can be moved around.  Altering the valve lash will also help to manipulate the dynamic compression ratio so there are several options.

Lorena, Texas (South of Waco)

I think you'll need a more aggressive cam than that. You'll be running out of power long before you shift. For your light car, I think something like the 505 T will be alright.


Lawrenceville, GA

6.125 rod. honestly haven't gotten to deep into cam selection but maybe Isky with 260 advertised, 216 @ .050. 108 lobe sep. Says .425 lift with stock rockers, however I have a set of 1.6 alum roller rockers. I was looking to be shifting @ 6000 - 6500rpm. Any thoughts on cam choice would be welcomed too!

If you can provide the ‘real’ intake valve closing value (ABDC) and the length of the connecting rod, the dynamic compression ratio can be quickly calculated based on what you’ve already provided.  The 'real' value is where the valve actually seats during closing.  This value varies with the lash that’s being used.  If the ‘real’ intake valve closing value isn’t known, then supply the advertised intake closing value and the intake value at 0.050”.  From those two numbers, the intake valve closing value can be estimated.

Lorena, Texas (South of Waco)