[FantomPoncho]

Thanks to all for the suggestions. I'm certainly going to consider a solid lifter cam.

The car this motor is going into is my '66 Lemans. It has no serious body or frame modifications. It has Global West upper and lower A-arms in the front and Global West control arms in the back. Everything else is pretty much stock street trim.

The heads have the Comp Cam 995 springs. I don't know how they were installed, but I'm pretty sure they can handle lift close to 0.600". Please correct me if I'm wrong.

I would love to go with a roller, but it's just not in the budget. So its a hydraulic or solid cam to choose from.

[T A 70]

Originally Posted by torqjunki

Have to throw in a vote for a SFT, especially if you are used to a little valve train noise. It will be quieter than the rhoads HFT stuff. Not sure where the faulty logic started about solid flat tappets only needed for high rpm, but for a Pontiac, it is not true. Not true for SBC either, I've tried it. SFT properly chosen for the application will make more power everywhere and likely idle better as well. If you want hyd roller power for cheap, go SFT, but let someone like Harold Brookshire or very knowledgeable Pontiac person chose it for you. So much more to it than lift and duration.

Good advise....Along with Greg Merrick and Harold that's how we chose one of our cams. It was nice because the entire head/valve assembly and porting were all considered into the mix and done pretty much the same time.
Like a lot of folks here Cliff got the spec's and built one up for us. Car pulled so hard it ran out of fuel almost immediately...a pusher at the tank fixed that.

[Singleton]

You could do what I did a couple weeks ago when I needed a solid flat tappet cam for my 428 6X combo. Go to Crowers web page and fill out the cam recommendation form. I got a call from Dave Crower the next day with his recommendation, which turned out to be a reverse split pattern cam. http://forums.maxperformanceinc.com/...d.php?t=709354 Got a nice price from dealing with him direct also.

Lunati, Comp, and Bullet also have similar cam forms on their sites. Try them all.

[66bonne]

I certainly understand budget limitations but you may want to still talk to Ken Keefer about the right cam for your application.

Jim

[Scarebird]

I was not happy with my cam either. My current basic specs were 224/234 (288/308° advertised) with 0.450" lift. This with a KRE 85cc headed 440 with RA3 manifolds, Q-Jet and Performer intake with 2-1/4" exhaust.

I believe it is too much cam so I am having a spare roller reground to this:

Adv.dur. = 272°/282° (I/E split = 6°)
Dur. @ .050" = 214°/224° (I/E split = 10°)
Lobe lift = .2947"/.3100"
Lift @ 1.5 rr. = .442"/.465"
LSA = 112° ICL = 107° ECL = 117°

This grind is Summit's 2801, which has been copied by a few other makes, and is a rough copy itself of Pontiac's own 068. This is the same cam that most Tri-Powers came with, as did the 71-72 455 HO's. As Paul S. stated, it should match the rest of the drivetrain, not the other way around. I like to drive my car and realize that only 0.01% of the time am I flat-hatting it...

Mark

[pastry_chef]

Originally Posted by Scarebird

I like to drive my car and realize that only 0.01% of the time am I flat-hatting it...

I guess everyone is different.

I have a primary daily driver modern fuel-injected HO V6 that I like to drive.
Actually never had the V6 wide open cause I've never NEEDED it to "drive".
3/4 throttle lets the car pass with surprising authority as the OD trans puts the four inlet valve somewhere between 5,000 and 6,000 RPM and scoot. And then it gets 30 MPG highway normal cruising, about 20 MPG mixed.

Most of my buddies and I have a second car in the Muscle/Sport category that gets occasionally driven and guzzles the fuel more.
When driving the Muscle the cars "get hit" frequently when the mood hits and its SAFE and RESPONSIBLE to do so. That is why they have "pricey" custom engines $7000 or more.
High CFM Aluminum heads and intake need an aggressive Cam to show their real shine.

Two cars - Jeckyl and Hyde.

[Scarebird]

Originally Posted by pastry_chef

...High CFM Aluminum heads and intake need an aggressive Cam to show their real shine...

A KRE head (240 CFM) is more about modern port velocity and combustion chamber shape. A stock LS6 moter is cammed 204/211°, using ports and CC's KRE emulated. My gamble is that I can get 95+% of the power of a far bigger cam (+20°) with the rest of the motor remaining the same - and much better daily drivability.

I will see if I can lash it to a dyno this week before the bigger cam comes out for a baseline measurement.

[pastry_chef]

Originally Posted by Scarebird

A KRE head (240 CFM) is more about modern port velocity and combustion chamber shape. A stock LS6 moter is cammed 204/211°, using ports and CC's KRE emulated. My gamble is that I can get 95+% of the power of a far bigger cam (+20°) with the rest of the motor remaining the same - and much better daily drivability.

I STRONGLY disagree.
RESULTS have not shown this to be remotely true!

I really like the KRE guys! They have done a TON for Pontiac! more than any other single party IMO.

BUT a "modern" KRE head could not out perform or even match Jim Hands Iron Dports ported per instructions on the Pete Mccarthy video. That is reality.
Mentioning LS anything in the same comment is laughable.

IF Air Flow Research made the decision to develop a street Pontiac head and applied the same R&D as their recent offerings you would see how good things can get. But to be honest they might actually NEED to do a head and intake tandem to do it right.

Has anyone actually obtained one of these small port 235cc CV1's?
I think a test with the tiny port canted CV1 and a matched high velocity intake on Jim Hand's car would be VERY interesting! No doubt the CV combo would also need a more suitable Cam to their new flow parameters.

[Scarebird]

Originally Posted by pastry_chef

...a "modern" KRE head could not out perform or even match Jim Hands Iron Dports ported per instructions on the Pete Mccarthy video. That is reality.
Mentioning LS anything in the same comment is laughable...

LS6


LS1


KRE D-Ports


Pontiac Combustion chamber

Tell us again why an LS chamber shape is irrelevant when discussing KRE heads? With all due respect to Mr. Hand I do not think Pontiac iron heads will ever be as efficient as KRE heads and certainly not LS heads. I am sure there are Pontiac heads that have been ported to flow 280+ CFM, what sort of manners do they exhibit on the street?

[torqjunki]

"I was not happy with my cam either. My current basic specs were 224/234 (288/308° advertised) with 0.450" lift. This with a KRE 85cc headed 440 with RA3 manifolds, Q-Jet and Performer intake with 2-1/4" exhaust.

I believe it is too much cam so I am having a spare roller reground to this:"

Adv.dur. = 272°/282° (I/E split = 6°)
Dur. @ .050" = 214°/224° (I/E split = 10°)
Lobe lift = .2947"/.3100"
Lift @ 1.5 rr. = .442"/.465"
LSA = 112° ICL = 107° ECL = 117°

I am very cautious to over cam as well. I like more torque in a usable range as thats where I drive 95% of the time. Over time, I have gotten to strongly favor that 1/2 to 3/4 throttle grunt at lower rpms over wide open rips close to red line. I can do this many times while driving around with quiet exhaust without attracting much attention or grossly breaking any laws. Its why I like the Pontiac motor after all....but I understand totaly that to each his own. Scarebird...keep in mind that a hyd roller with similar specs to HFT will idle much better and have more vac etc.

[torqjunki]

As far as the LS vs traditional Pontiac thing......You really can't compare a single component like heads and think that you can start to do what the LS does. If that was possible, we all would be running around with 400ci engines with heads that have 260cc intake runners and tiny cams making big numbers. Try it...you will be disappointed! Chevy took years and years of experience and re-designed the SBC. It is a lot of small stuff that adds up like better ring packages, smaller lighter but stronger valve stems, etc etc. By far, I think the intake/fuel injection system is what allows large runner heads and small cams to shine for them.

[Tim Corcoran]

Solid lifter cams do not require constant adjustment. I have ran solid cams on the street and they do not require adjustment. I ran thousands of miles and never adjusted them. If you don't mind a little lifter noise a solid cam is the best way to go for a street rod. By the way a lot of cars over the years came from the factory with solid lifters and many today still do. My wife has a 2004 Toyota RAV4 and it has solids in it. The car has 140,000 miles on it and the valves have never been adjusted and they are still very quiet. In fact you would never know the car has solids lifters. Mind you this is an overhead cam motor but the same is true for pushrod motors. I know Ford had some six cylinder motors in the 60's that came with solids and others did too.

[pastry_chef]

Originally Posted by Scarebird

A KRE head (240 CFM) is more about modern port velocity and combustion chamber shape. A stock LS6 moter is cammed 204/211°, using ports and CC's KRE emulated.

The combustion chambers look like MOST modern heads produced over the last ten years from MANY manufacturers.

A PORT from LS6 (its called cathedral)

And why its irrelevant to KRE heads!

[rohrt]

Just for fun my Notes on the subject. I did not write this.




Most folks don't know the real reason why the LSx engines are so damn good. So I will provide an anecdotal comparison in laymen's terms so that everyone gets it.

The LSx technology is really not anything new. In 1988, you could get what were called Dart "Buick" conversion heads for your small block Chevy. What? Buick, huh? Forget the name. It's irrelevant. What these heads offered were the following:
-Shallow valve angle: 14 degree as opposed to the stock 23 degree
-Raised Intake ports
-Spread, symmetrical intake and exhaust ports (as opposed to the standard siamesed port locations)
-Small fast burn chambers (No. GM did not invent that term.

Wonder how GM got their LS7 to run so good with big ports, 370cfm, and smallish cam?

GM used just about every crutch they could to bolster low speed drivability on those LS engines. Take the LS7 an example: Long tube "tuned" intake runners, highly efficient chambers that allow a 11:1 compression ratio. Short duration - high lift "BIG" LSA cams( 211/230 @ .050" .591" lift - 120 LSA! Fuel injection with superior fuel atomization, short rod ratios (1.51) and an optimized "tuned" exhaust system. The heads were designed to have the best AVERAGE flow up to .650" lift and a roller cam to exploit it. As good as this engine is it is very much like a Nascar engine with a restrictor plate. Place the LS7 motor in an old chassis (no emissions) add a MAST single plenum manifold, a Dominator, Big Roller cam, 14:1 CR ( The "3 C's" Tom S. mentioned ) and headers and say hello to 750-780HP!....... BTW that 120 LSA is no misprint. It does wonders for keeping the Dynamic compression ratio up!

LS7 specs
4.125 bore
4.0 Strock
Crankshaft: forged steel
Connecting rods: forged titanium
Pistons: cast aluminum
Compression ratio: 11.0:1
Cylinder heads: CNC-ported aluminum; 70cc chamber volume
Exhaust: Hydro-formed tubular header
Valve size, intake (mm / in): 56 / 2.20 (titanium)
Valve size, exhaust (mm / in): 41 / 1.61 (sodium-filled)
Camshaft: hydraulic roller; 15mm (.591 in) lift (intake and exhaust)
Rocker arms: 1.8:1 offset (intake only)
Air intake: composite manifold with 90mm single-bore throttle body
Fuel: premium required. 91 octane minimum
Horsepower: 500 (373 kW) @ 6,200 rpm
Torque (lb-ft): 475 (644 Nm) @ 4,800 rpm
Engine redline(rpm): 7,000


CAM LIFT INT/EXH DUR @ 0.050 LOBE SEP
LS1 0.497"/0.498" 199/208 119
LS6 2001 0.550"/0.550" 204/218 117.5
LS6* LS2 0.525"/0.525" 207/217 116
LS7 0.593"/0.588" 211/230 TK
* 2nd design LS6

[Scarebird]

The cathedral part of the port is there to better integrate the fuel spray from the injector - usually a non-issue with carbed motors.

If you have a more efficient chamber design, you can get more power for a given amount of fuel and air mix - or conversely burn less fuel for the same amount power that a less efficient chamber design generates. This is proven by the Kaufmann head's need for less ignition timing - and in the aftermarket by Edelbrock's offering their version in addition to their earlier round port RAIV clone.

*tips hat to rohrt*

[screamingchief]

Originally Posted by rohrt

BTW that 120 LSA is no misprint. It does wonders for keeping the Dynamic compression ratio up!

Sorry,,,but that comment is completely wrong...

The wider LSA does'nt keep the dynamic compression up,actually it's quite the opposite,truth is the significantly wider LSA lowers the DCR so the higher static compression ratio can be run w/o building excessive cylinder pressure as that relates to those LS cams and their relatively short durations.

Just do the math and see what happens to the IC event when you go from a tight LSA to a much wider LSA and it'll all become very clear to you.

And try to remember that the bulk of current DCR theory only looks at the specific IC event (@ the seat) as far as the cam is concerned.

Further everyone needs to remember that there is an emissions related component to running a very wide LSA cam like that as well,as that significantly wider LSA also greatly reduces the engine's overlap as well.

Not to mention that a significantly wider LSA's also helps with piston to valve clearance in very high lift cams in engine with high static compression ratios.

HTH

Bret P.

[FantomPoncho]

Interesting how a thread can easily get hijacked discussing an LS7 chebby motor. Anyway, I'm seriously looking at the Crower 60311. One more question: I just purchased (before I knew I needed a new cam) a set of stock pushrods, will I need to replace them? Also, does anyone have a part # for a good set of lifters to use with this cam?

[paul s.]

Perhaps I missed it, but, what are your goals for this engine?

[FantomPoncho]

Goals: Maximize power with existing parts and keep it streetable without having to purchase any more parts than I have to, translation - maximize power yet streetable on a budget.

[Scarebird]

Steetable is a vague definition.