GPM

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.

jdnca1

The first cam I ran in the motor was Erson 272/278 .770/.760" on 114 CL. Cam worked well all around but was totally done @6100. made 860HP there, ~805 Tq @5000. Motor was 10.2:1 with this cam. When I changed lifters I decided to step the cam up a little more and went to a Comp 280/288 .785/.772" on 115 CL, bumped CR to 10.5:1 Power jumped to 901 @6500 torque also went up slightly ~820 @5100. Both tq and power curves were long and flat..no peakiness at all with either cam. The idle was very rough but managable with both cams....noticably rougher with the latter cam even on the 115.

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

GPM

Very nice! do you recall the initial duration on the cams, curious how they match up with mine. What heads did you run?

Swede

It looks like Chief Engines goes 705CI with the Super Tall Deck

jdnca1

The smaller cam was 298/304 and the bigger was 311/325. Heads were fully ported and polished Dart 360's. I think they ended up around 393 and flowed ~425 .800" lift on the intake and ~315 on exhaust.....My memory is a little foggy on the flow but those #'s are close.

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.

GPM

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.

jdnca1

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.

GPM

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.

khadley

Craig

BLOWER MOTOR

that's all you need

WETTE VETTE

Blowers make it too easy!!!!