Theoretical Motor Build Up!
#11
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Joined: Mar 2004
Posts: 2,696
Likes: 93
From: Pa
My opinion, you're going to need a head that flows 485 cfm each runner to reach 1000 hp. I think you will need a cam with more lift,and duration, somewhere around .780.280/288. You may need to stay with the smaller cam with the carbs so it will idle. I doubt the smaller cam will flow enough to make 1000 hp. The 10.5 compression would definatly help the theoretical engine reach it's goal.
#12
Originally Posted by GPM
The one I ran was in a blown application so it was cut on a 112, with the EFI it idled at 1000 rpm. It was a little big for the 598 so I cut back to a 276/284. I would think the 4.75 crank could use the larger one. What are the other specs on your cam?
The ramps on the 280/288 cam were much more aggressive @.200 and it munched a lifter after 6hrs. (comp thought it was defective because the rest looked perfect, they took care of new cam and lifters, small token but I didn't turn it down!!) The boat gained no speed even with the extra 40HP and propped to turn 6500 vs 6100 with the smaller cam.
I ran a dart tunnel ram and 2X775 Race demons, aluminum flywheel. Response and acceleration was wicked in the mid range alll the way through 6000+
I switched to the Schubeck radius lifters after many talks with Joe and several circle track guys who'd had great luck with them. Its a totally different cam due to the 1" radius but it was ground by Bullet racing cams 276/284 .730/.730" lift on 115 C/L. The motor made right at 895HP@6400 and the same tq. I purposly took a little lift out of it just to tone things down a tad....everything else stayed exactly the same other than valve springs. Both myself and my builder were really impressed with the power the Schubeck system made...you can run a lot less valve spring because the lifters weigh less than half of a solid roller lifter.
Corey
Last edited by jdnca1; 02-04-2005 at 09:12 PM.
#15
Originally Posted by GPM
Very nice! do you recall the initial duration on the cams, curious how they match up with mine. What heads did you run?
Craig and I spoke to the guys from Sonnys at the PRI show a couple of years ago and they "guaranteed" a minimum 125HP pick-up by going to their chief style heads with 73cc chambers on my motor staying on pump gas....Sounded cool until I thought about everything that would need to be changed, concluded I'd be better off to start over with a different motor.
#16
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Joined: Mar 2004
Posts: 2,696
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From: Pa
I really can't compare apples to apples here because I was playing with a Procharged 598. I tried 5 different solid rollers, rangeing from 272 to 280 @ .050 intake duration 280 to 288 exhaust. .748 to .782 lift. 112 and 114 lobe seperation installed in the motor from 106 thru 112 center line. I also tried cnc BB2 xtra and cnc Big Duke. both combos at 9 to 1 compression, and EFI.
#17
We played the advance on mine also...went from +6 to -2 retard....Predictively the less advance the more power...it just kept wanting more cam! I ended up running them both straight up.
#18
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Joined: Mar 2004
Posts: 2,696
Likes: 93
From: Pa
Both of my combos made their best power with the 112 lobe sereration set in at 108. The BB 2 xtra lost 60 hp and 75 lb of torque at 112 lobe center.peak hp moved up from 6200 to 6500.rpm.
Last edited by GPM; 02-05-2005 at 09:08 PM.


