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Reply to "Questions regarding George's 275/285 Custom Street Cam Profile"

quote:

Originally posted by Danford1:

... Do the same EVO at 80 BBDC and IVC at 70 ABDC events pertain to other engines such as the Ford 302 ...



Yes and no. How's that for a concise answer? Smiler

Theoretically the answer "should be" no. The 302 has smaller valves, in-line valve heads, different combustion chambers, different stroke, different rod length. But practically speaking, I've seen a lot of factory performance engine cams from several manufacturers with about the same timing. For instance, the Ford 351 Cobra Jet cam (1971 specs) opens the exhaust valve (EVO) at 82° BBDC and closes the intake valve (IVC) at 72° ABDC. Those same specs were used for the 390 GT, the 1968 hydraulic cammed 427 and the 428 Cobra Jet. The 429 Police Interceptor camshaft specs were very similar, EVO = 86°, IVC = 73°.

Perhaps more pertinent, Ford camshaft #C9OZ-6250-C, was a hydraulic tappet performance camshaft for the 289/302/351W, its specs were EVO = 84°, IVC = 74°. The earlier 289 performance camshaft, C4OZ-6A257-A, specs were EVO = 78°, IVC = 72°. If you advance that cam by 2° you'd have 80/70. That cam was described as having a "reasonable idle", a "strong" power curve that extended into the 6000+ rpm range.

So yes, you can use that spec for the 302, or something close to it.

quote:

Originally posted by Danford1:

I want it all, torque and power just off idle on up to 6000 rpm or more, works with 2000 stall converter C4, 2.80:1 highway gears, has a lope at idle and gets great highway fuel economy.



While you can expect a wide flat torque curve, don't expect the same wide power band as the 351C with 4V heads ... the 302 will run out of steam sooner than 7000 rpm.

Its going to be hard to "have it all" because of the gears you plan to use and the torque converter stall speed. The Cobra Jet cam normally goes along with 3.50:1, 3.70:1, 3.91:1, or 4.11:1 gears, and/or a 3000 stall converter.

The highway gears and 2000 stall converter point at using a mild cam, the mild cam will definitely help low rpm power too, but it may impact the high rpm pull. I guess we'll find out how good those Windsor Jr. heads are. Fuel economy is directly related to overlap, but so is a lopey idle. To have both there will need to be some compromises there too.

Crane offers two different series of hydraulic roller cams for the 302, depending upon if its an older engine that wasn't equipped with a roller cam, or if its a newer engine that was equipped with a roller cam (firing orders are different). Tell me which type of engine you've got, and I'll take a look at the Crane catalog and make a recommendation.
Last edited by George P
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