Single pattern Camshaft

[patmckinneyracing]

Anyone running a single pattern with iron heads? Is there any issues with running a single pattern cam?

I'm looking at this howard camshaft for my setup:
http://www.summitracing.com/parts/HRS-1 ... refilter=1

 

[bjohn07]

ive used single and duals, and it really depends on what kinda setup ur running. ive always been able to make more power off single styles though. although the dual style is good for vacuum. but i either get a custom grind or get ahold of comp cams and see what there tech line suggest based on the specs of your setup.

 

[patmckinneyracing]

Here's the setup currently:

*350 standard bore 2 bolt mains
*Flat top hyper pistons (9.5:1 CR estimate)
*882 heads with slight port work, 2.02/1.60 valves
*SUM-1103, .442/.465 lift, 214/224 at .050, 2000-4500 power range
*Stamped steel factory 1.5 rockers
*Edelbrock performer intake, 600cfm edelbrock
*Flowtech headers, 2.5 inch flowmaster exhaust
*700r4 full built 2000 stall, Monte SS rear 3.73 posi

I bought a set of summit 1.6 stamped steel rockers to give it a .501/.501 lift and a set of Crane lifters. What do you guys think of this cam? Decent performer?

I do have power brakes but that is the only accessory running on vacuum. With the 108 lsa, should be pretty lopey right?

 

[88olds421]

Those came specs sound similar to the Edelbrock Performer Plus camshaft, the only difference I think is that the LSA is 108 instead of 112. It should sound pretty good. If you are looking for more power I would go with a comp grind, like an xtreme energy 262 or a 268 grind. I had the 268 in my old 350 with 1.6 roller rockers and it sounded great, the vacuum was ok for the power breaks, any less and I would have needed a vacuum canister.

 

[82cutty]

I am no cam guru by anymeans..... When I got my cam for my Olds 425 they recommended a cam with an 108 centerline to help bleed off my compression so it would idle fair. I have a mild cam @ .505/.505 lift with 10.25 to 1 compression 226/234 @.50 with 1.6 rockers. My dual pattern helps with the Olds small exhaust valves. I dont know if you will have enough compression to use it well, it will work but may not as well as it is designed. Call Comp and give them your specs....
Steve

 

[patmckinneyracing]

The other cam I'm probably more apt to get is Lunati's 262 or 60102 and with the 1.6 rockers will give me .499/.521 lift.

I was over on teamchevelle.com and those guys just constantly bust my chops for running 882 iron heads. They have the 2.02/1.60 valves, had port work done, milled a bit, and had aftermarket valve springs and screw in 3/8 studs for only 400$ 5 years ago when I first built the engine. It's like "Omg your not running aftermarket heads...you're going to hell." lol

 

[86Cutlass383SR]

i've always heard that the cam needs to match the head flow. Since most heads flow more intake than exhaust, the cam needs to have more exhaust lift and duration than intake.

Also,since you'll no doubt be running mufflers, the exhaust will be more choked than the intake will be. To help get that exhaust out, a long exhaust pattern cam helps here, too.

 

[88olds421]

I have heard that as well and I have also heard that it needs to match up with the torque converter as well if you are running an automatic.

 

[megaladon6]

with your setup, longer exhaust duration isn't needed. vortec heads need it due to the small valves and outlets.(relative to the intake flow) remember, the exhaust is under pressure from the piston stroke. that's why the valve is smaller than the intake.
but i don't believe that it will cause any problems if you do use a dual pattern.