[PONTIAC DUDE]

Anyone mess with this stuff and results?

To make the most power from your engine, you need to optimize
the air ingested and captured by avoiding valves closing too
soon or too late. Any conventional center layout single throttle
body or carbureted V8 intake manifold features longer outboard
runners and shorter inboard runners, meaning that each valve
event should occur at a different moment. COMP Cams® 4-Pattern
Camshafts are the very first series of cams designed to
accommodate this difference in runner length and avoid valves
closing at the wrong times. NASCAR teams have been using
camshafts designed this way for years, and by utilizing lessons
learned along with them, COMP Cams® has designed a series
of cams that optimizes valve events and features a large increase
in both area under the curve and stability at high RPM.
The camshafts feature four different lobe patterns with an intake
and exhaust design for outboard runners and another intake
and exhaust design for the inboard runners. While the four
central cylinders are all the same grinds, the outboard exhaust
openings are two degrees earlier with outboard intake closings
coming two degrees later. This is the first ever use of technology
in street vehicles to balance air/fuel ratio per cylinder. It can
net you a possible 1000+ RPM over other hydraulic rollers and
anywhere from 5-20+ horsepower peak-to-peak, depending
on cylinder head flow. The 4-pattern hydraulic roller cams are
CNC-ground from steel billet cores, feature cast iron distributor
gears and utilize a series of lobes with over .600" valve lift and
stability up to 7500 RPM, all while providing more consistent
cylinder to cylinder torque. The cams also feature a tight lobe
separation for both excellent power and a throaty sound.

[tom s]

Ken,Joe Sherman had a post on speedtalk about a build he just did on a SBC.He has not done a swap to compare gains.FWIW,Tom

[Skip Fix]

Saw the ad in Circle Track a month or so about them. Kind of like guys using different ratio rockers on the outer cylinders vs inner cylinders(that is even in an old Chevy Power book from GM!). The ad said they are just for HR cams now-wonder if they are geared towards the HR circle track crate motors some tracks spec for certain classes.

Heck Ken most Pontiac guys don't even swap different ratios on their existing cams to know what works best in what location- 1.65s both intake and exhaust, only intake ,only exhaust!

[marks73ta]

Very interesting and on the surface makes some sense. But you are making an assumtion that all other aspects of the port runers, manifold runner length, no crazy dynamics going on in the plenum, etc etc. But if it really equalizes one variable then why not. You just have to have all your ducks in a row to make the right calls for how much the differencesiare between your individual motor (head/manifodl combination). MArk L

[cfmcnc]

Ten years ago we did some cams with different lobe seperations on certain cylinders,twenty years ago we tried different rocker ratios on certain cylinders,Back in the late 60s -early 70s Sig Erson offered cams for Big Block Chevys to help balance out the weak flowing port to the good port,Without data from flow bench and dyno with wideband o2 and cylinder pressure transducers its all guess work,Single plane manifold can be designed to provide very good cylinder to cylinder distribution,note our Tiger design with the plenum extended front and back and with some of the interior port maninpulation ,still would not rule out the possibility of different lobes or seperations on certain cylindersbut not untill we collect more data.Bill C.

[Half-Inch Stud]

Hmmm, so a solid cam should have tighter lash on the outer or inners,
& So, a HYD am should have Rhoads style lifters on the inners.

Or the other way?

[pastry_chef]

relevant image.

[gearbanger]

Sounds like the cam deal is more of a crutch for a bad intake design, or rather poor characteristics of typical intake configurations. Seems like a single plane, two 4 bbl intake would be the better fix. But I realize class racing like NASCAR and other do not allow for that. Maybe that's why 2x4 setups seem to run better compared to a single 4 when both are properly setup.

[Kevspontiacs@aol.com]

Originally Posted by gearbanger

Sounds like the cam deal is more of a crutch for a bad intake design

this is my thinking too

[paul s.]

It's all about maximizing the output of each individual cylinder. Nascar has been doing it for years. I'm not much of a historian, but I think Clay Smith started that.

I don't see it making much of a difference on a 10 second ride, but I CAN some of the guys on this forum using it to put their combos (that have been tweaked to the nth degree) over the top.

[PONTIAC DUDE]

Not really. It's getting the most out of a combo you can. Like the pic pastry chef posted. There is no such thing as a perfect 4bbl intake.

[Skip Fix]

Even playing with runner divider lengths for fuel distribution you are not going to get them equal lengths on a single 4bbl.

Just giggling lash tighter and looser on intake exhaust we picked up almost 10 HP on my 500 IA and also on the milder 470/409, and we didn't even get into different lash on the end cylinders on the 500(470 is a dual quad dual plane so runner lengths are all over the place.

[cfmcnc]

Originally Posted by PONTIAC DUDE

Not really. It's getting the most out of a combo you can. Like the pic pastry chef posted. There is no such thing as a perfect 4bbl intake.

Latest attempt is the streched manifold and billet carb body that is streched to match,Still cant beat 1 throttle bore over each cylinder.Bill C.

[redsmokin76]

Sounds more like a sales pitch from CompCams, I don't think it's marketed to race engines. Hydraulic roller pontiac or even sbc making power at 7500rpm, don't think so. The last line of that spiel sums it up " the cams also feature a tight lobe separation for both excellent power and a THROATY SOUND"
Cheers Steve

[Skip Fix]

Steve first ad I saw was in Circle Track. a LOT of tracks use a spec GM crate motor that uses a HR cam for many classes. So I think it is geared towards those guys "race" engines. It is actually a race crate engine with special oil pan etc from GM. Whether it increases their HP that is up for testing.

[Half-Inch Stud]

InLine 6s & 8s had it really bad huh.

[Tom Vaught]

Originally Posted by cfmcnc

Latest attempt is the streched manifold and billet carb body that is streched to match,Still cant beat 1 throttle bore over each cylinder.Bill C.

Think Marcella has already worked on the making the outside runners more equal to the inside runners for length.

http://www.google.com/imgres?q=marce...,r:6,s:0,i:108

Tom Vaught

[cfmcnc]

WE did our first Streched cast single four manifold in 1997,did three that year ,all made good power SBCs.Bill C

[Tom Vaught]

Does not surprise me one bit about that info, Bill C.

Tom Vaught

[PunchT37]

I can see 4 pattern cams make more of a difference on engines like Fords where there is a major difference in runner lengths than Pontiacs and Chevys [small blocks at least] where the shorter runners "go around' the 2 center exhaust ports.