Looking for a more consistent cam for my 496 with 781 oval ports. 1050 APD alcohol dominator on Edelbrock 4500 oval port intake. The heads have had a lot of work to them. They have 2.25 intake valves and flow very well for an oval port. I have flow numbers if needed. Current cam is a Lunati solid flat tappet. Cam has .669/.675 lift 275/282 duration and power range is 5000-8000. Looking for something more in the 7200-7400 max range.
Car is 67 nova, 3,120 lbs, 14.5 x 32 tire, 4.56 gear. Converter flashes 6000 with current setup. Has ran 6.04 and 9.59 with current setup, so I'm real happy with the performance. Just thinking the right camshaft might be more consistent. Next cam will be a roller, don't want to mess around with breaking in a flat tappet again.

Rob I normally run several software simulations when making a camshaft recommendation but that won’t be possible for a week as I am at the US Nationals. What I can tell you is your current cam is big at.050 and you don’t have enough gear. what is the compression ratio and what rpm are you currently shifting at at what is your trap rpm?

Ed doesn't design cams. He pays for someone to build his motor and then swears that only the best parts were used. I heard that someone peed in his master cylinder and told him it was dot5 and now pee is the best brake fluid on the planet.

Lunati 50204

269 276

685 692

402 407

110 sep
108 in/c/l

4000 7400

quote:

Originally posted by Roger McGinnis:
Ed doesn't design cams. He pays for someone to build his motor and then swears that only the best parts were used.

Says the nobody that is clueless to everything about a Cup car, Indy Car and F1 car yet posts lies here as if he knows.

Rob it is true I don’t assemble my engines same as the vast majority of class and bracket racers. The lanes at the US Nationals will be full from Thursday on with sportsman/class engines built by professional engine builders, including engines built by The Who’s who of drag race engine builders, powering The Who’s who of drag racing. You know what won’t be in the lanes? One Roger McGinnis, Internet nobody.

That all said. I do infact “design” cams, more like spec cams for my engines and those of friends and some competitors.

quote:

Originally posted by 1320racer:
Rob I normally run several software simulations when making a camshaft recommendation but that won’t be possible for a week as I am at the US Nationals. What I can tell you is your current cam is big at.050 and you don’t have enough gear. what is the compression ratio and what rpm are you currently shifting at at what is your trap rpm?

No hurry Ed, it will be a winter project. 12.8 to 1 compression. Converter flashes to 6000, shift at 6900, falls back to 6200, cross 1/4 mile at 7250 at 137.

Ok the roller cam I will spec will definitely have less duration @ .050, more lift and it’s events will yield a tighter LSA. To utilize your current converter your engine needs to make peak torque at 55-5600 rpm.

quote:

Originally posted by Mike Rietow:
Lunati 50204

269 276

685 692

402 407

110 sep
108 in/c/l

4000 7400

Thanks Mike. That looks like a great cam for my combo.

quote:

Car is 67 nova, 3,120 lbs, 14.5 x 32 tire, 4.56 gear. Converter flashes 6000 with current setup. Has ran 6.04 and 9.59 with current setup, so I'm real happy with the performance.

That's pretty damn fast for oval ports at that weight What MPH ???

I'm curious on what they flowed .......

Our Firebird has run exactly 9.59 "deepstaged" @ 142 mph in good air with a real good cnc head @ 3300lbs Best 1/8 was 6.13 @ 114 on gas.

I'd keep that cam

quote:

Originally posted by HS professor:
[QUOTE]Car is 67 nova, 3,120 lbs, 14.5 x 32 tire, 4.56 gear. Converter flashes 6000 with current setup. Has ran 6.04 and 9.59 with current setup, so I'm real happy with the performance.

That's pretty damn fast for oval ports at that weight What MPH ???

I'm curious on what they flowed .......

Our Firebird has run exactly 9.59 "deepstaged" @ 142 mph in good air with a real good cnc head @ 3300lbs Best 1/8 was 6.13 @ 114 on gas.

I'd keep that cam
My best mph is 113 1/8 and 138 1/4. I’m really happy with the performance, I’m just looking for more consistency. That’s why I thought a cam better mated to the heads might help.

I run box and nobox with this car. I’m comfortable holding numbers against cars I can judge, but I need it to be better running against the fast stuff.

They flowed 332 at 600 lift and 337 at 700 lift.

First I will say that the cam is not causing your consistency issues which you really haven't described/detailed. Your issues are likely in the combination and tuning.

That said, what else do you want from a cam change?

Next, a lot of work doesn't describe what has been done to the heads. You stated a larger intake valve, exhaust?? What is the intake an exhaust flow at your desired lift? Also based on your current valves, what's the max install height, needed to determine valve lift. Next, what's the compression ratio, the real one for your deal, not the piston catalog value.

Like I said, its the combination! and not just one part.

quote:

They flowed 332 at 600 lift and 337 at 700 lift.

I'm no head guy but that's pretty good for an old iron oval. My cnc 305 Brodix flow a bit over 370 @.700.

quote:

Originally posted by HS professor:

quote:

They flowed 332 at 600 lift and 337 at 700 lift.

I'm no head guy but that's pretty good for an old iron oval. My cnc 305 Brodix flow a bit over 370 @.700.

No exhaust flow numbers!

quote:

Originally posted by TOP38:
First I will say that the cam is not causing your consistency issues which you really haven't described/detailed. Your issues are likely in the combination and tuning.

That said, what else do you want from a cam change?

Next, a lot of work doesn't describe what has been done to the heads. You stated a larger intake valve, exhaust?? What is the intake an exhaust flow at your desired lift? Also based on your current valves, what's the max install height, needed to determine valve lift. Next, what's the compression ratio, the real one for your deal, not the piston catalog value.

Like I said, its the combination! and not just one part.

2.25 intake, 1.88 exhaust. Other work done to heads: switched valve guides from 3/8” to 5/16”, and a lot of porting and blending the short side radius for the larger valves. The Victor 454 O intake was also port matched and the sharp edges in top of plenum were radiused.
I don’t have my flow sheet with me now, but if memory serves me, the exhaust flow was 238 at 600 lift. I can check when I get home.
12.8 is the calculated compression.

Not sure on the max installed height. I know I have in the past ran a 780 lift roller with 1.55 springs on these heads and valves.

So it appears that the larger valves were installed and the pockets were ported to match the new valves with some port matching, which is typical. Usually 1.55" springs can accept .750" lift without issues, just need to make sure of the available installed height on the heads.

What trans, PG or 3 speed?

Glide

Lunati 50204

Isky Tool Room Gold Stripe springs part # 9945

quote:

Originally posted by novaX522:
They flowed 332 at 600 lift and 337 at 700 lift.

It's been a while, but IIRC, my semi closed chamber 215 cast iron oval port heads flowed the same after Brandsywine Cylinder Head Service aka Larry Woodward and Bruce McDowel(RIP) laid they hands on them and I didn't run a lick quicker or faster. Previously my heads had been worked over by SCDIV1 aka Rich Biebel. Over the years he built my 468 engine, the heads got bigger valves, first 2.15/1.88 valves then 2.25 intake valves, 11/32 guides, gasket matched, bowl blended and the 11/32 guides contoured.

This 11:1 468 engine topped with a Victor Jr. intake, 4150 carb and with a roller cam I had LSM grind... 248/254 @ .050, .740 lift, made north of 700HP and accelerated my 3880 lb. Chevelle to a best of 10.07 @ 131 with a 1.28 60 foot off the footbrake and through a full exhaust.