How does this cam look for a 9.6/1 SCR 496?

Isky Grind No./Type
Z-55 SOLID Bracket racing. Rough idle. 3000 Stall. 4.11-4.56 axle ratio.
Up to 850 CFM Carb. 10.5 to 1 compr. RPM-Range
3500-7500 Valve Lift - INT
.590 EXT
.590 Valve Lash Hot - INT
.028 EXT
.028 ADV Duration - INT
300° EXT
300° .050 Duration - INT
254° EXT
254° Lobe Center
108°

I've got a 3500 stall in my TH400 and 3.73 gears, maybe 4.10's in the future. Not wanting to turn more than 6200....

Or would I be better off with this one?

Isky Grind No./Type
Z-33 SOLID High performance use/bracket racing. Lopey idle. 3000 Stall. 10.5
1 compr. 3.90-4.11 axle ratio.
Up to 800 CFM Carb. RPM-Range
3000-7000 Valve Lift - INT
.560 EXT
.560 Valve Lash Hot - INT
.030 EXT
.030 ADV Duration - INT
290° EXT
290° .050 Duration - INT
250° EXT
250° Lobe Center
108°

I was very happy with it (installed 2 degrees advanced) in my 10/1 461 that I just pulled and sold.

I sure was wanting to try one of Harolds 288/296 cams for this build...

IMO, I think your CR is a little low for either of those cams.
How about Harold's 402A4 ?
http://www.holley.com/HiOctn/ProdLine/Products/IEC/IECC/Chevy7.html

Off the cuff I would have said the Z55 for oval ports and the smaller Z33 for rects, given the rpm band you're talking. What heads?

It would prefer more squeeze, as Bill indicates, or backing down to a cam akin to what he recommends, 247-250/252-255 split on a tighter 107lsa.

yeah, I forgot that my 461 was right about 10.2/1 not 9.6.... The only pistons I could find had a 5cc dome that put me at 9.6 or they jumped to an 18cc dome that put me at 10.7 I definitely want to be able to run 91 octane.

The heads are an extensively worked set of 781's that flow well enough to propel my friends 3000.lbs Camaro with a 468 into the 6.2x's in the 1/8th. He's had them on a flowbench and has the numbers, I just haven't gotten them yet.

So I need to back off the duration or bump up the compression, right?

Gotta say this.
I ran the UD 288/296 F10 (255/263 .612/.630 110LSA) solid cam in my 9:1 468 with Edel Roval heads, Dart intake, 950 DP, 2" headers in a 3550lb Nova with 4.10 gears, and ran high tens in good conditions at 122. (I am off a bit on the numbers cause I lost the cam card....like a bozo)
So I am tired of hearing that 9:1 CR is too low for a cam like this. UD (I'm sure it was Harold, recommended this cam some 6 years ago....and he was dead on) Said they made 550hp with a stock LS6 with only the cam change.
Awesome cam.

I urge you to step up and buy the right cam.
There are but a few folks who know what to design, and Harold (Now with Lunati) is one of them.

Ron

Ron

#'s look right to me...
UDH say's 9-11 CR for the cam IIRC.
With a 288/296f10
Chris_68_SS claims low 11's in a Chevelle & 620 hp @ 6200. And only 10.2 CR 454. Not that I can make the parts he lists match that CR. 10.7 was closer. I based my cam choice on his combo along with all the other 288/296 lovers around here.

IIRC a number of people like/have the 288/296 in a 496 with only 9.6 or so. I think Wolfplace dynod one but with 310 heads... Ask him if he doesn't see this.

Ron and Scott, how much stall were you running with those cams and what did you idle at? I don't have power brakes so vaccum isn't a problem.

A little more info on the heads, they have 2.25 and 1.9 valves if that makes any difference.

Also, I can't find the f10 on lunati's site...?

Purs,

I run a 10" older B&M race converter in my Nova. It flashes to about 4000, but won't brake stall much past 2800. Works great on the street too.

Idle speed was 1000, but that's just preference. In gear BTW.

When I bought that cam, it wasn't in the UD catalog. So they ground it for me.

It's sitting in my basement......I am going to a roller this time around. Maybe I should have stuck with the solid!

Ron

Originally posted by Scott_68_SS:
#'s look right to me...
UDH say's 9-11 CR for the cam IIRC.
With a 288/296f10
Chris_68_SS claims low 11's in a Chevelle & 620 hp @ 6200. And only 10.2 CR 454. Not that I can make the parts he lists match that CR. 10.7 was closer. I based my cam choice on his combo along with all the other 288/296 lovers around here.

IIRC a number of people like/have the 288/296 in a 496 with only 9.6 or so. I think Wolfplace dynod one but with 310 heads... Ask him if he doesn't see this. =

It was 489 with a custom Comp roller with Isky Red Zones & AFR 315CNC heads & it made excellent power on a very honest dyno,,, mine :D

Very close to the above general specs, 254/260, .698/.666, 111 separation & a true 9.8 compression.
I personally wouldn't get all excited about the low compression as 500" engines like cam.
This thing had over 500 lbs ft from 2900 & peak was 610 at 45-4600
670HP @ 62-6300
Don't remember the vacuum but it idled just fine at about 850.

sweet! thanks guys. I've never tried to pick a cam for an engine this big with heads that flow like this. It's a nice problem to have. Can't wait to get it on the dyno, then the track. It'll probably be the end of January though before it all comes together. Thanks again for the input everyone.

I've seen one pull a 2400 holeshot no problem.
Except that tight a converter didn't allow 1000rpm idling in gear. Needed about 1300 and a nice bang.
So as tight as will allow it to idle in gear.

Chris_69_SS used a 3500 no name shelf converter. Link (http://www.chevelles.com/cgi-bin/forum/ultimatebb.cgi/topic/4/20838.html?)

I have a manual, and the car is mostly in pieces waiting on the fresh motor...

Purs,

You might look into a custom ground Isky solid.

In the back of there catalog in the "Lobe Specification Chart" (Page 167) they have a group of Oval Track solid lobe proflies that IMO look alot nicer than the Z-33 or Z-55. More aggressive profiles with shorter advertised durations that may help boost your DCR with the low static CR that you are running.

Call Ron at Isky, or give Mike Lewis (Wolfplace) a shout here on this board, he may be able to help also.

http://www.iskycams.com/onlinecatalog.html

I like small solid oval track profiles! They rock!