Re: Fast68 & other cam guru's. Which one of these is best?
[Re: BradH]
#2345308
07/29/17 02:43 PM
07/29/17 02:43 PM
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Joined: Jan 2003
Posts: 14,545 So. Burlington, Vt.
fast68plymouth
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I Live Here
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So. Burlington, Vt.
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This is only an observation from my own experience........
1. My RB cam had sh!tty hi-rpm dynamics. It would rev to about 6300-6400 OK, then start to float its a$$ off by 6500.
2. On the same engine dyno where I saw the Racer Brown cam's RPM limitations, I also saw two different UltraDyne NF904 cams pull much better to 6800 RPM with 1.5 rockers.
Brad...... Was the RB test done with 1.5's or 1.6's? Which UD cams did you try?(I seem to recall you had mentioned a 255/263-110 test)
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: Fast68 & other cam guru's. Which one of these is best?
[Re: rt66jim]
#2345343
07/29/17 04:22 PM
07/29/17 04:22 PM
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Joined: Jan 2003
Posts: 14,545 So. Burlington, Vt.
fast68plymouth
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I Live Here
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So. Burlington, Vt.
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As I recall...... With that particular engine combo..... The RB cam made more power than the UD cams ?
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: Fast68 & other cam guru's. Which one of these is best?
[Re: rt66jim]
#2345362
07/29/17 04:54 PM
07/29/17 04:54 PM
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Joined: Jan 2003
Posts: 14,545 So. Burlington, Vt.
fast68plymouth
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I Live Here
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As I said previously....... For a basic bracket build...... It would be something fairly unglamorous. Low 270's@.050, barely over .600 lift with the 1.6's....... And IMO it would still need to be broken in with the inners removed, and the spring pressures and heights would need to be verified.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: Fast68 & other cam guru's. Which one of these is best?
[Re: fast68plymouth]
#2345417
07/29/17 07:34 PM
07/29/17 07:34 PM
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Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
Taking time off to work on my car
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Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
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As I recall...... With that particular engine combo..... The RB cam made more power than the UD cams ? The RB as tested made about 5 HP more than the smaller UD, and both made more power than the bigger UD. I always wondered how the smaller UD with the 1.6 intake rockers would have done, or a single-pattern UD 255 on 108, but just ended up running the RB 1.6/1.5 combo.
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Re: Fast68 & other cam guru's. Which one of these is best?
[Re: rt66jim]
#2345432
07/29/17 08:19 PM
07/29/17 08:19 PM
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Joined: Jan 2003
Posts: 14,545 So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
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So. Burlington, Vt.
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It's just another example of what I've seen numerous times...... Opening the valve as fast as possible doesn't always result in the best power. Some combos don't respond well to really fast opening rates........especially really fast right off the seat.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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