WHAT CAUSED THIS ROCKER ARM TO BE BEAT UP

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12-26-2008, 11:11 PM
David Love AI27

Quote:

Originally Posted by ShadowBolt

Quote:

Originally Posted by Adam Ginsberg

Jerry - using the stock steel rockers is SO simple and cheap, it's ridiculous. You can find excellent used rockers w/fulcrums for ~$20-$30. Bolt them into place, torque the bolts correctly, and go race. Hell, I think I have 3 sets laying around.

FWIW, I've gone back and forth about RR's, and decided awhile ago not to use them. Since we aren't permitted to do them properly (screw in studs, guide plates and hardened pushrods), I won't install a set at all, and stick with the stock steel units. Check them once a year for wear, retorque, go out and race. Does it get any easier?

Remember - KISS. ;)

Adam,

I would still have to shim the rockers and buy shorter pushrods.....right?

JJ

Why would you have to do both??? I would think you only need to do one or the other... if you shim the rocker the same amount as the shave, then they are back to the same distance from the cam and you should be able to use the stock rods, or am I missing something???? hell, what do I know.... need to get back in the shop and finish my end of the year cleaning... too many projects...
12-27-2008, 01:52 AM
Adam Ginsberg

Quote:

Originally Posted by ShadowBolt

Removed .050" from the heads. Eric had removed .010" at the last rebuild.

Sorry - I missed this. You have a total of .060 off those heads?????

Holy shit, Jerry. For starters, good luck getting the lower to bolt into place without modifying it, too.

For a number of reasons, I'm not going to go any further with this thread, as it'll only bring out previous history.
12-27-2008, 10:43 AM
AI#97

Quote:

Originally Posted by Adam Ginsberg

Quote:

Originally Posted by ShadowBolt

Removed .050" from the heads. Eric had removed .010" at the last rebuild.

Sorry - I missed this. You have a total of .060 off those heads?????

Holy shit, Jerry. For starters, good luck getting the lower to bolt into place without modifying it, too.

For a number of reasons, I'm not going to go any further with this thread, as it'll only bring out previous history.

I am going to guess that was supposed to be .005"...don't think there is a machinist out there that would remove .050" without a disclaimer of some sort and it certainly wouldn't be 9.5:1 any more! ;)
12-27-2008, 12:29 PM
GlennCMC70

my bet is Matt is right. .005" is a nice clean up cut. Mitch was having to pitch heads for a .023" cut.
12-27-2008, 02:07 PM
ShadowBolt

combustion chambers are now 60.5 cc's.

JJ
12-27-2008, 03:56 PM
Adam Ginsberg

Quote:

Originally Posted by ShadowBolt

combustion chambers are now 60.5 cc's.

Interesting....down from the factory's 64cc's.
12-27-2008, 04:33 PM
ShadowBolt

Quote:

Originally Posted by Adam Ginsberg

Quote:

Originally Posted by ShadowBolt

combustion chambers are now 60.5 cc's.

Interesting....down from the factory's 64cc's.

Yes, unless I totally did not understand what Tony said, iron heads can go to 10:1 and alum head engines 11:1. The GT40 heads make you lose compression from the E7's.

JJ
12-27-2008, 08:45 PM
ShadowBolt

Quote:

Originally Posted by Adam Ginsberg

Quote:

Originally Posted by ShadowBolt

combustion chambers are now 60.5 cc's.

Interesting....down from the factory's 64cc's.

Adam,
Cobra GT40's are 60 cc's, regular gt40 (non Cobra's) are 64 cc's.

JJ
12-27-2008, 10:34 PM
Adam Ginsberg

Yep - sorry, my mistake. The Lightning GT40 heads are 64cc.

So...if the heads have been milled .015 total, how is the CC 60.5cc's when the factory measurement is 60cc?
12-27-2008, 10:55 PM
ShadowBolt

Quote:

Originally Posted by Adam Ginsberg

Yep - sorry, my mistake. The Lightning GT40 heads are 64cc.

So...if the heads have been milled .015 total, how is the CC 60.5cc's when the factory measurement is 60cc?

The heads on CMC17 had 64 cc chambers. I have no idea where they came from but my machine shop milled the heads to 60.5 cc's. According to the shortblock mfg. this makes about 9:5 to 1. All I know is what I can find to read. I never hot rodded anything but a small block chebby (and that was 30 yeqrs ago).

On another note I was asked if there is such thing as a Cobra lower intake because the one I have could not flow squat! The holes at the top of the lower intake are way smaller than the ports are....way smaller.

JJ
12-28-2008, 09:50 AM
AI#97

Quote:

Originally Posted by ShadowBolt

On another note I was asked if there is such thing as a Cobra lower intake because the one I have could not flow squat! The holes at the top of the lower intake are way smaller than the ports are....way smaller.

JJ

Yes...they come as a pair usually (upper and lower)...and are usually good to 400hp...?
12-28-2008, 10:04 AM
ShadowBolt

Quote:

Originally Posted by AI#97

Quote:

Originally Posted by ShadowBolt

On another note I was asked if there is such thing as a Cobra lower intake because the one I have could not flow squat! The holes at the top of the lower intake are way smaller than the ports are....way smaller.

JJ

Yes...they come as a pair usually (upper and lower)...and are usually good to 400hp...?

They come as a pair......damn Matt, I did not know that. Thanks.
JJ
12-28-2008, 10:11 AM
AI#97

Quote:

Originally Posted by ShadowBolt

They come as a pair......damn Matt, I did not know that. Thanks.
JJ

They can be sold as upper and lower, but typically are bought at the same time to work together. Reason being is there are two lowers...one for a 302 and another for a 351.

Download the FRPP catalog as a PDF and it should have a lot of the info you are looking for. Summit racing link...

http://store.summitracing.com/partde...5&autoview=sku

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