# cam specs



## 68gtohawk8369 (Oct 26, 2009)

What are the cam specs for a ram air 3 and ram air 4 . My engine was rebuilt with a hydraulic roller with a 446 in. lift cam I am seriously considering a set of d port edelbrocks over the summer I think in the past I have read a famous 068 pontiac cam was similar to 446 inch lift .


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## 05GTO (Oct 6, 2004)

68gtohawk8369 said:


> What are the cam specs for a ram air 3 and ram air 4 . My engine was rebuilt with a hydraulic roller with a 446 in. lift cam I am seriously considering a set of d port edelbrocks over the summer I think in the past I have read a famous 068 pontiac cam was similar to 446 inch lift .


RAIII specs are 301/313 .410/.410 119 LSA
RAIV specs are 308/320 .470/.470 114 LSA
068 specs are 288/302 .410/.410 116 LSA

You can get a .447 lift on the 068 and RAIII by using 1.65:1 rockers.


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## 66tempestGT (Nov 28, 2009)

if i was going to spend that kind of money on some modern cylinder head technology would wave goodbye to the antique camshaft grinds also.


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## BearGFR (Aug 25, 2008)

66tempestGT said:


> if i was going to spend that kind of money on some modern cylinder head technology would wave goodbye to the antique camshaft grinds also.


:agree - And that's what I did on my 69, even with round port iron heads.

68gtohawk8369, keep in mind that all the "old" cam profiles were designed when octane was freely available, the fuel had lead, and cylinder pressure wasn't a concern beyond the idea that "more is better". I'm not saying those factory cams were "bad" - they were very good - for the time and the situation. In fact if you compare the specs on the Ram Air IV cam and the SD455 cam, you might find some striking similarities  (can you say, same?)

Today we've got to worry big time about cylinder pressure (at least on gas) because of fuel quality. The game has changed. Lead is also history and with it the protection/lubrication for exhaust valve seats as well as the effect on octane rating. Modern cam designs take all that into consideration while still trying to deliver profiles that make good power, and many of them do a very good job of that. Plus in the 40+ years since those original cams were designed, we've learned a few things  and are able now to simulate and model (due to computers and software) and directly observe what's actually going on inside an engine with much more detail and accuracy than was possible back in the 60's.

Bear


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