E7TE vs. GT40 Heads comparison....

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Feb 12, 2007 | 11:46 PM

#16

Jrock909

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Anything you do to the engine to make it breathe easier is definitely going to free up some power no doubt... If roller rockers weren't so good how come everybody is using them in big horsepower motors, they are definitely a good benefit along with some good heads and any other mod that helps out the motor. It seems that you are always trying to shoot down any positive vibes about roller rockers Racin, why is that?

Feb 13, 2007 | 04:09 AM

#17

RacinNdrummin

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From: Maple Valley, WA

What??? I just got done saying roller rockers are a benefit to performance. I have never tried to shoot down "positive vibes" about RR. My issue is with the ratio. Too many people are insistant on using a 1.7 ratio RR because they think its an easy way to gain a bunch of power, and thats just not true, its like the equivlent of using JB weld on something that should be welded, its just a patch. 1.6:1 ratio roller rockers are plenty fine for any application, if you wanna use 1.7's, fine go for it, but dont expect gains from the ratio. If you want decent gains, change your cam.

Feb 13, 2007 | 05:14 AM

#18

baddad457

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From: south louisiana

Quote:

Originally Posted by RacinNdrummin

Yes, but the F4TE is also a roller cam which frees up more power than your .030-.040 lift did. The 94-95 5.0's were rated at 205 (195 for the auto) which are revised estimates from ford. I think the change in power numbers came directly from the change in the way the power was measured. The 351 in 94 didnt change 1 bit from 93, and it was rated at 10 HP/25 ft.lbs more than in 93. same with the 460 as far as an increase in power, yet with no change in the engine. I would find it hard to believe that the F4TE cam change was worth 25hp/5ft.lbs more than the flat tappet truck cam. I bet if you took identical truck engines, side by side, one with an F4 and one with the flat tappet, you might see a 10hp difference tops on the dyno, and most of that would be duration and the fact that it has a roller cam. .030-.040 more lift on stock ford E7's will not make a difference.

You've missed a step here. Between the flat tappet truck cam and the F4TE was the 92-93 trucks with the much smaller "base" roller. I've run a 5.0 with both and the F4TE shines above the base cam. There's no comparison. And you saying the 1.7 ratio roller cost more may be the case with a very few, but most companies sell them for the same price. THATS why I suggest using them.

Feb 13, 2007 | 05:16 AM