Cam question..

July 26, 2019, 09:58 PM

Iforgot

Cam question..

Dumb cam question..

Got a solid roller that’s 308/319 @ .020, 275/283@.050, .799/.799 ground on 112, intake center is on 106 (was 108 but is quicker at 106).
This was a custom grind ground for my 496; -2+ Brodix heads, 13:1, typical bracket engine with a 1050 dominator on top, 8” converter goes 5300, glide, 4.56 gears, 29.5/10.5 PBRs, and car weighs a nice light 3600 pounds. Runs out great, but it’s a turd.
This cam is a regrind from the first recommendation- this grind is slightly smaller.
Personally, I think something much smaller would be a lot quicker. Right now it’ll go 6.70s@104, which is .09 slower than my old pump gas 496.
Question#1- somebody got a proven cam grind that’ll work in this heap? I’m NOT liking .799 lift on stud rockers, even with a girdle.
Question#2- I believe this cam would work in a 555-565, yes or no? If so i’ll Put it on the shelf because there’ll be a 555 or so in the future.

July 26, 2019, 11:35 PM

Duane1791

Loosen the converter up 1000 rpm, camshaft is okay for that size engine.

July 27, 2019, 06:23 AM

B.C.Malibu

I've had good performance from this in a 3600 gbody 496
Comp # 11-851-9
260/270 .734/.737. 108lobe sep

July 27, 2019, 06:41 AM

Lenny5160

My understanding of cams is limited, but what jumped out at me is that heavy cars usually want less lobe separation, such as 108, and your converter is too tight.

July 27, 2019, 09:15 AM

Iforgot

B.C.- that grind is actually on the “short list” of shelf cams I already picked out.

Loosening the converter- if I can get it loosened up to 6000 or a little over, I’m afraid shift point will be higher than what I want it. 7000 is fine, but with nearly .800” lift higher RPMs worries me with stud rockers. Shaft rockers are outta the budget for now.
Old combo went to 5300 on the converter and it shifted at 6300 and it worked perfect. Sucker would xerox time slips on pump gas, plus was perfectly fine to run to the store for ice cream between rounds! Should not have sold it, one of those “ya wanna sell your engine” and my reply was “well, everything’s for sale..” That was a mistake..
Converter is an antique JW 8” that has been reworked 8,427 times (more or less haha), PTC went through it last and made it spragless around a year go. Guess I need to call some converter people Monday.
Am I overthinking the whole deal with stud rockers and basically.800 (.773 actual net lift) at 7000-7400ish rpm?
It’s got scorpion rockers, good PAC springs/titanium retainers, and a comp stud girdle. So far, no signs of valve control problems and I dang sure don’t want any!

July 27, 2019, 10:05 AM

B.C.Malibu

Car ran 6.20/ 9.82@134.5 thru the pipes.
On pump swill and a bit lean till he broke the rear studs and kissed the wall.
Crower rockers & a girdle.

July 28, 2019, 08:40 AM

Bad News

quote:
Originally posted by Iforgot:
B.C.- that grind is actually on the “short list” of shelf cams I already picked out.

Loosening the converter- if I can get it loosened up to 6000 or a little over, I’m afraid shift point will be higher than what I want it. 7000 is fine, but with nearly .800” lift higher RPMs worries me with stud rockers. Shaft rockers are outta the budget for now.
Old combo went to 5300 on the converter and it shifted at 6300 and it worked perfect. Sucker would xerox time slips on pump gas, plus was perfectly fine to run to the store for ice cream between rounds! Should not have sold it, one of those “ya wanna sell your engine” and my reply was “well, everything’s for sale..” That was a mistake..
Converter is an antique JW 8” that has been reworked 8,427 times (more or less haha), PTC went through it last and made it spragless around a year go. Guess I need to call some converter people Monday.
Am I overthinking the whole deal with stud rockers and basically.800 (.773 actual net lift) at 7000-7400ish rpm?
It’s got scorpion rockers, good PAC springs/titanium retainers, and a comp stud girdle. So far, no signs of valve control problems and I dang sure don’t want any!

Yes, you are over thinking it. Studs and a girdle will be just peachy. I ran 288/304 .810 net for many years with old crane wide body and an Edelbrock girdle. 7400 1120 HP.
I would always run a stud/girdle set up over shaft, if the shaft do not have a single bar intake and the exhaust tie in to it. As least with a girdle nice and tight there is that extra measure of clamping holding it all together.

July 28, 2019, 09:08 AM

green1

I have a .782-.774 cam in my motor shifting at 7500 with stud mounts and girdle. Holds up just fine.

July 28, 2019, 09:25 AM

wideopen231

Personally the cam you have should be fine. Agree about stud/girdle setup.The old 454 we ran in My Nova had Moroso stud girdle set up I turned the crap out of it,heck only time it saw 7500 was passing by on its way north towards 8500.Then I never figured on getting 300 runs out of it back then.

August 01, 2019, 10:23 AM

Dead On

I run a 496 with the BB2+ heads in a GM block I run low 5.8x all day in a 3000lb car.here is my cam card hope it helps. https://pix.sfly.com/mdQKb4

August 01, 2019, 10:47 PM

1800gb

Those combo's are very simular to the 496 I run in one of my novas,with the BB2 heads..13.1 comp..Lunati cam 638-40110925....At about 3150 lbs..5.80's average..been 5.70's..convertor flash 6200..shift 7000..trap 7200...

August 02, 2019, 07:28 AM

Iforgot

Thanks for the info guys!
I got to run it Wednesday night at Gulfport- they have a tnt/bracket race 1/4 mile. Nothing big but a great chance to test and get seat time.
Got there late but made 2 passes.
1/8th mile, there was .0015 between 60’ times and .0074 between both ETs.
1.56 60’
4.44 330’
6.86 660’
101.6 660’ mph
8.96 1000’
10.73 1320’
126.8 1320’ mph
It wakes up right before the 660 traps, pulls great from there out.
Launch @ 4400, shift at 6500, cross 660’ at 6400, cross 1320’ @ 7100.
It wants a smaller wiggle stick!!