[Holeshot71]

Anyone ever run the Edelbrock 7157 041 cam? I was pleasantly surprised to find one of these with some parts that I bought a few years ago.

[djustice]

Originally Posted by Holeshot71

Anyone ever run the Edelbrock 7157 041 cam? I was pleasantly surprised to find one of these with some parts that I bought a few years ago.

That cam was in my engine when i got the car over 10 years ago. It vent flat abot 2 years ago, and i pulled the engine an added a topend kit and converted to rollerc am with same specs. I have no other flat tappet to compare it against, but for me it ran ok, and hard a bit of a lope to it, ok vakuum.

[straycat]

Darn I forgot the cam that originally came in the 400 engine that was in my 65 was a Edelbrock 7157. Been sitting in that motor for 20 years now on a stand. Former owner ran best 13.07 /10? as I recall before spun bearing number 2 rod with 6X8 heads. I'm going to try a Comp HR that came available with lifters that came available locally at a drastically reduced price. NIB. Card says GrindP8 3016B/3038B HR112.0. Too good to refuse. Still love an 041 with Rhoads combo in my 68 that been there for at least 20 years. Thanks for the discussion on 041s.

[turbo69bird]

I’m probably gonna. Need to knock on some wood here but I’ve had tons of solid flat tappers and hydraulics in a lot of different engines. Even turbo engines with high spring pressures. Many of these engines sat for long durations over winters with Nothing special on start up no pre prime anything. I’ve never wiped out a lobe on a cam and I started in 1987. Idk if I’m doing something right or everyone else is doing something wrong

I don’t even run special oils. I do throw some zddp in on occasion but I buy cheaper Napa brand oils. Nothing super special of it’s not that I use rottella that I have here from my diesel or occasionally some aeroshell from
My airplane.
I Used to put well over 100 track passes a year on my engjnes usually in the 140 passes a year range
s. Running multiple classes a weekend. For a long time I launched that car at 6400 rpms. I’ve burned pistons , I’ve broken driveline parts , banana’d rears even split a cylinder once , never wiped a lobe.

Of course my brand new RAIV rebuild will be the one now that I said that. But it’s always boggled my mind why so many had this issue .because I don’t do anything special. None of my buddies I race with have wiped a love either w other makes.
Maybe the winter here cryos our cams. iDK.
I have pretty much every cam
I ever raced still here in a box somewhere all are usable still. I usually go new because I want to try something but not because they are failing

[Formulajones]

Originally Posted by Holeshot71

Anyone ever run the Edelbrock 7157 041 cam? I was pleasantly surprised to find one of these with some parts that I bought a few years ago.

That used to be the cam supplied in their RPM "top end" kit when you bought the whole package (cylinder heads, intake, camshaft) and they would advertise something like 450hp and 500 ft lbs. on a 455 combo.

I remember people in the late 90's buying that package and using it with decent running cars for the time. Not even sure Edelbrock still sells that as a package deal or not.

[Holeshot71]

The 7157 seems to have close to the same specs as the other 041’s but you never see much mentioned about them. Maybe it’s because of the higher price tag than the other offerings? ��

Edit: Looks like the cam is still available. And now on sale since I checked the other day.. https://www.summitracing.com/parts/edl-7157

[Jay S]

That Edelbrock cam is going to be pretty much the same cam with identical performance as an Melling, Summit, Comp, Lunati and probably a couple others. I don’t know if CMC grinds it, it could be ground in house at Comp on a standard EPC core. You can look and see what you have if you want, find where the cam has CWC cast into the core, roll it over to the other side and see if it says “EP”. If it says EP it was either ground at comp or at EPC instead of CMC. If it says nothing there, it is likely a RA4 cam from CMC, and is ground on the same machine as the Melling and Summit cams.


Often all flat tappets are grouped together for failures, they really shouldn’t be. Mechanical flat tappets don’t have the problems that HFT cams have. They are ground on better cores, with better material. At least they have been, I don’t know what the future looks like. I think when the lash is taken up it promotes lifter spinning also. They are just plain more rugged(unless you go nuts with an aggressive profile).

Here is a photo of a Bullet SFT and a current melling SPC-8 I checked in my friend shop (2018 SPC-8) which is the same as the current CMC cams, .477” was the nose width of the lobe on the SPC-8. Which isn’t bad, I have seen some Pontiac HFT cams that had .455” width lobes. The Bullet UD grind has .564” width over the nose, and the base circle is over .625”. Mild SFT’s are pretty rugged, especially with face oiling.

[67Lemons]

Originally Posted by Jay S

That Edelbrock cam is going to be pretty much the same cam with identical performance as an Melling, Summit, Comp, Lunati and probably a couple others. I don’t know if CMC grinds it, it could be ground in house at Comp on a standard EPC core. You can look and see what you have if you want, find where the cam has CWC cast into the core, roll it over to the other side and see if it says “EP”. If it says EP it was either ground at comp or at EPC instead of CMC. If it says nothing there, it is likely a RA4 cam from CMC, and is ground on the same machine as the Melling and Summit cams.


Often all flat tappets are grouped together for failures, they really shouldn’t be. Mechanical flat tappets don’t have the problems that HFT cams have. They are ground on better cores, with better material. At least they have been, I don’t know what the future looks like. I think when the lash is taken up it promotes lifter spinning also. They are just plain more rugged(unless you go nuts with an aggressive profile).

Here is a photo of a Bullet SFT and a current melling SPC-8 I checked in my friend shop (2018 SPC-8) which is the same as the current CMC cams, .477” was the nose width of the lobe on the SPC-8. Which isn’t bad, I have seen some Pontiac HFT cams that had .455” width lobes. The Bullet UD grind has .564” width over the nose, and the base circle is over .625”. Mild SFT’s are pretty rugged, especially with face oiling.

A gentlemen on another forum just measured his SPC-8 from 2022 he thinks, it’s a CWC core & he came up with .460 lobe width at the peak. Maybe this helps clear up the approximate date on when they switched cam cores on the SPC-8.

[OG68]

When talking about Performance cams, what (in your opinion) constitutes "mild" or "aggressive" ? Is it a certain lift, duration or a combination of the two? Numbers please.

[P@blo]

The question I had earlier was would a narrower lobe matter if it was trimmed off the rear portion of the lobe?

I might be not thinking of this correctly but if the lobe was 0.70", it would not change the lobe/lifter face contact area one bit. More contact area would be properties of lobe taper and lifter crown machining would it not?

Might be chasing waterfalls here...

[Jay S]

Originally Posted by OG68

When talking about Performance cams, what (in your opinion) constitutes "mild" or "aggressive" ? Is it a certain lift, duration or a combination of the two? Numbers please.

With HFT cams it might be better to break it more up into spring pressures that you have to run to control the valves for the cam and rocker combination, 260lbs at max lift is mild, then 260 to about 350 would be medium, with the high end of that range starting to get aggressive, and 350 and up very aggressive. For seat pressure 90 or less is mild, 100 to 130 medium, after about 120 seat pressure is getting aggressive on a HFT, past 130 is getting very aggressive for a HFT.

There were some original 744 combinations that were actually at least moderately aggressive, even though they only had .407” lift.

[Jay S]

Originally Posted by P@blo

The question I had earlier was would a narrower lobe matter if it was trimmed off the rear portion of the lobe?

I might be not thinking of this correctly but if the lobe was 0.70", it would not change the lobe/lifter face contact area one bit. More contact area would be properties of lobe taper and lifter crown machining would it not?

Might be chasing waterfalls here...

It is like chasing waterfalls. CMC just has one core available for all the off the shelf Pontiac cams. 066 or a 041, is the same core if it is from CMC. If it is custom I think you can get a better core. Not sure how long that will be an option though.

The narrower lobe is all off the front.

The crown and taper are suppose to be matched, they often aren’t, but it is usually the lifters that are the problems.

Less tapper and crown is sometimes used for higher spring pressures. Mopar 440 six packs used special cams with less taper and less lifter crown for higher sustained RPM’s and more spring pressure. You can’t mix their lifters or cams with standard cam componets. Crower actually sells what they call flat face lifters for some applications. I think they still have a slight crown, just not as much as a standard lifter. I am not certain though, they could be flat, I have never had any.

[phil400]

Originally Posted by Jay S

With HFT cams it might be better to break it more up into spring pressures that you have to run to control the valves for the cam and rocker combination, 260lbs at max lift is mild, then 260 to about 350 would be medium, with the high end of that range starting to get aggressive, and 350 and up very aggressive. For seat pressure 90 or less is mild, 100 to 130 medium, after about 120 seat pressure is getting aggressive on a HFT, past 130 is getting very aggressive for a HFT.

There were some original 744 combinations that were actually at least moderately aggressive, even though they only had .407” lift.

Jay, I've read the 744 had/has terrible valve train dynamics, from the low lift combined with the long duration, do you think that's why Pontiac used some heavier springs even though it had low lift?

[Jay S]

Originally Posted by phil400

Jay, I've read the 744 had/has terrible valve train dynamics, from the low lift combined with the long duration, do you think that's why Pontiac used some heavier springs even though it had low lift?

It was for sure part of the reason, I think they put heavier valve springs on the 4 speed 068 cars later also. Kenth has commented in this thread, I think might have that info memorized. I think it is at least curious why Pontiac didn’t use more than .407” lift instead of an extra 30* of negative dwell over the nose on the 744. Especially on the later SD 455, would have thought they might have figured it out by then.

P@blo I shouldn’t have blanket said all the lobe width was lost on the front, some could come off the back off the lobe too, that is likely more of a variation in the casting batches though. Also got to thinking, and I think Crower’s flat face lifter is referring to no edge chamfer to gain some velocity. I recall seeing some Clay Smith cams for those lifters for circle track. I should have thought about that one more before I wrote that.

[Formulajones]

Originally Posted by turbo69bird

I’m probably gonna. Need to knock on some wood here but I’ve had tons of solid flat tappers and hydraulics in a lot of different engines. Even turbo engines with high spring pressures. Many of these engines sat for long durations over winters with Nothing special on start up no pre prime anything. I’ve never wiped out a lobe on a cam and I started in 1987. Idk if I’m doing something right or everyone else is doing something wrong

I don’t even run special oils. I do throw some zddp in on occasion but I buy cheaper Napa brand oils. Nothing super special of it’s not that I use rottella that I have here from my diesel or occasionally some aeroshell from
My airplane.
I Used to put well over 100 track passes a year on my engjnes usually in the 140 passes a year range
s. Running multiple classes a weekend. For a long time I launched that car at 6400 rpms. I’ve burned pistons , I’ve broken driveline parts , banana’d rears even split a cylinder once , never wiped a lobe.

Of course my brand new RAIV rebuild will be the one now that I said that. But it’s always boggled my mind why so many had this issue .because I don’t do anything special. None of my buddies I race with have wiped a love either w other makes.
Maybe the winter here cryos our cams. iDK.
I have pretty much every cam
I ever raced still here in a box somewhere all are usable still. I usually go new because I want to try something but not because they are failing

I'm in the same boat. Just haven't seen the failures at all that people post about. My thought is that now 30+ years later as the internet got more popular you are now reading about it but in reality not much has changed since before that time, and everyone is always quick to point out issues on the internet but rarely ever does anyone praise success stories. And God help you if you do, you are quickly dismissed by the negative crowd. My guess is there are more success stories than failure, you just don't hear about them on the internet because we are too busy enjoying our cars.

[Holeshot71]

Originally Posted by Jay S

That Edelbrock cam is going to be pretty much the same cam with identical performance as an Melling, Summit, Comp, Lunati and probably a couple others. I don’t know if CMC grinds it, it could be ground in house at Comp on a standard EPC core. You can look and see what you have if you want, find where the cam has CWC cast into the core, roll it over to the other side and see if it says “EP”. If it says EP it was either ground at comp or at EPC instead of CMC. If it says nothing there, it is likely a RA4 cam from CMC, and is ground on the same machine as the Melling and Summit cams.


Often all flat tappets are grouped together for failures, they really shouldn’t be. Mechanical flat tappets don’t have the problems that HFT cams have. They are ground on better cores, with better material. At least they have been, I don’t know what the future looks like. I think when the lash is taken up it promotes lifter spinning also. They are just plain more rugged(unless you go nuts with an aggressive profile).

Here is a photo of a Bullet SFT and a current melling SPC-8 I checked in my friend shop (2018 SPC-8) which is the same as the current CMC cams, .477” was the nose width of the lobe on the SPC-8. Which isn’t bad, I have seen some Pontiac HFT cams that had .455” width lobes. The Bullet UD grind has .564” width over the nose, and the base circle is over .625”. Mild SFT’s are pretty rugged, especially with face oiling.

Out of curiosity I checked the cam to see what it has cast. Underneath the Cosmoline it has CWC/CMC on each side and also B4/180. On the other end by the gear it has D2 and USA. Also the lobes are .589” wide.

[67Lemons]

I just measured an old Crane HMV-260 HFT that I pulled out of a motor & the cam lobe measures .479 at the peak FWIW.

[Jay S]

Originally Posted by Holeshot71

Out of curiosity I checked the cam to see what it has cast. Underneath the Cosmoline it has CWC/CMC on each side and also B4/180. On the other end by the gear it has D2 and USA. Also the lobes are .589” wide.

That looks like an older Eddy cam ground by CMC. One of those letter and numbers cast into is probably the lobe class (D2). That should be what the RA4 cam is suppose to look like.

With the Post Covid era sketchy metallurgy and machining, the narrower lobes are not helping. About have to have the cam nitrided these day just to get past the break in.

[Jay S]

I have the info on the Compcams RA4 cam that went flat during the break in. The flat lobes are right below the caliper in the photo.

The width of the base circle was the narrowest I have ever heard of .506”.

The cam is about 3 years old. What is most suspicious is where CWC is cast into it. The lettering does not look like an old molding that has been used thousands of times that you can barely read. It looks clear, like it is new. It looks very suspicious to me, like something you might see from off shore stuff, at very least that is from a new mold. I’ll let you be the judge though, here are the photos of it.

[Formulajones]

A cheap copy perhaps? I wouldn't be surprised.