power difference between different brand cams

[Frankshaft]

We definitely got a conversation going. lol. Anyhow, sorry for the suspense, the 2 cams were nearly identical in power. Same peak tq, at same rpm, there was a slight drop in tq from the Erson cam at 5900, 6000 and 6100, about 6 ft/lbs. I think the difference was oil pressure. On dry sump engines I have done, I have seen 1 lb of oil pressure make 1 hp diff. Like, start pulling it with 95 lbs, and say, that's to much, drop it to 70, and literally it picks up 25 hp. This one was up from 65lbs to 75. It has a new, different oil pump, as lifter shrapnel took out the old pump. Also, the different style lifter could be not bleeding off as much oil pressure. Either way, its up 10 lbs, which, for this deal is actually good. Its just a bracket race deal, and he double enters the thing usually, so, it gets run a lot. After 6100, it is nearly identical. Flip flops 1 or 2.

So, it wasn't to exciting, the Erson cam made for all practical purposes, the same exact power. One other thing, when we dynode it last, we dumped the break in oil, and tried Shafer synthetic 5-50, he swears by the stuff, runs it in everything. It made more power, we didn't do that this time, and it matched peak hp. So, is it possible the Erson cam makes a few more peak hp, I think it does. So, for losing 20-50hp, ahhh, no.

[Warp Speed]

After I won the EM Contest, Comp made me a similar cam to show what I was missing- It made 20 more HP than the Isky I won with. That was when I started using Comp all the time.

Comp probably just narrowed the LSA 1 deg. I've heard that's worth 100 emc points.

Randy

LOL

[Warp Speed]

We definitely got a conversation going. lol. Anyhow, sorry for the suspense, the 2 cams were nearly identical in power. Same peak tq, at same rpm, there was a slight drop in tq from the Erson cam at 5900, 6000 and 6100, about 6 ft/lbs. I think the difference was oil pressure. On dry sump engines I have done, I have seen 1 lb of oil pressure make 1 hp diff. Like, start pulling it with 95 lbs, and say, that's to much, drop it to 70, and literally it picks up 25 hp. This one was up from 65lbs to 75. It has a new, different oil pump, as lifter shrapnel took out the old pump. Also, the different style lifter could be not bleeding off as much oil pressure. Either way, its up 10 lbs, which, for this deal is actually good. Its just a bracket race deal, and he double enters the thing usually, so, it gets run a lot. After 6100, it is nearly identical. Flip flops 1 or 2.

So, it wasn't to exciting, the Erson cam made for all practical purposes, the same exact power. One other thing, when we dynode it last, we dumped the break in oil, and tried Shafer synthetic 5-50, he swears by the stuff, runs it in everything. It made more power, we didn't do that this time, and it matched peak hp. So, is it possible the Erson cam makes a few more peak hp, I think it does. So, for losing 20-50hp, ahhh, no.

Need to work on that dry sump system!

[Frankshaft]

Any hints? Wrong pump? Again, it was a bracket deal, nothing super scienced out. I was surprised it picked up that much. There is a lot of power hiding in the oil, oil sysyem and windage, that is for sure. I have seen 2 quarts of oil either gain, or lose 20 hp, numerous times on wet sump deals.

[CGT]

We definitely got a conversation going. lol. Anyhow, sorry for the suspense, the 2 cams were nearly identical in power. Same peak tq, at same rpm, there was a slight drop in tq from the Erson cam at 5900, 6000 and 6100, about 6 ft/lbs. I think the difference was oil pressure. On dry sump engines I have done, I have seen 1 lb of oil pressure make 1 hp diff. Like, start pulling it with 95 lbs, and say, that's to much, drop it to 70, and literally it picks up 25 hp. This one was up from 65lbs to 75. It has a new, different oil pump, as lifter shrapnel took out the old pump. Also, the different style lifter could be not bleeding off as much oil pressure. Either way, its up 10 lbs, which, for this deal is actually good. Its just a bracket race deal, and he double enters the thing usually, so, it gets run a lot. After 6100, it is nearly identical. Flip flops 1 or 2.

So, it wasn't to exciting, the Erson cam made for all practical purposes, the same exact power. One other thing, when we dynode it last, we dumped the break in oil, and tried Shafer synthetic 5-50, he swears by the stuff, runs it in everything. It made more power, we didn't do that this time, and it matched peak hp. So, is it possible the Erson cam makes a few more peak hp, I think it does. So, for losing 20-50hp, ahhh, no.

Thanks for sharing your results, I appreciate that. Its nice to see some "actual" results devoid of theory, speculation, or marketing intention. How much Peak Torque does the engine make, if you don't mind me asking? Any chance of viewing some dyno sheets? Sounds like a nice bracket piece.

[CGT]

I gave Chet Herbert a very good Isky cam to copy, and his copy was 20 HP LEES than the real thing from Isky- So much for the exact same thing





JOE SHERMAN RACING

Im guessing it wasn't a good copy. Were either cam doctor'd? Or lift curve checked with a degree wheel? I know some "boutique" grinders copy lobes, and they tend to be off from the cam card.

[CamKing]

I gave Chet Herbert a very good Isky cam to copy, and his copy was 20 HP LEES than the real thing from Isky- So much for the exact same thing





JOE SHERMAN RACING

Well obviously the copy didnt turn out a true copy then.

Nope.
For example.
Say the Isky Lobe master had .0005" runout, then it was ground on a cam core that was only straightened to within .0005".
Now you copy it on a grinder that adds another .0005" runout, then grind it on a cam that's only straightened to within .0005".
What you end up with, is a POS.

[CamKing]

In summery.
You take a run of the mill cam from one company, and a run of the mill cam from another company, with the same specs, and low and behold, they run about the same.
No idea if one floats before the other.
No idea if one will wear-out the valvetrain sooner then the other.
No idea if the specs are correct for the application.


Great test.

[GARY C]

I gave Chet Herbert a very good Isky cam to copy, and his copy was 20 HP LEES than the real thing from Isky- So much for the exact same thing





JOE SHERMAN RACING

Im guessing it wasn't a good copy. Were either cam doctor'd? Or lift curve checked with a degree wheel? I know some "boutique" grinders copy lobes, and they tend to be off from the cam card.

In the early 90's I know of several guys running herbert cams and winning their local classes but the machine shop I deal with said in his dyno testing the herbert cams were usually down on power vs comp and inconsistent lobe to lobe, I don't know if they did their stuff in house, when I dealt with them in early 2000 they had me contact a guy named Don Johanson for custom cams...I don't know if that was good are bad. Their catalog lobes looked lazy...maybe old school?

[blwilliams]

Here is a question I have pondered more than once.
Depending on the cam grinding machine wear and tear, how close is the indexing between cylinders?
We degree the cam off of #1 cyl, how close is that IO EC figure on the other 7 cylinders?
If a machine is worn and unable to duplicate from cyl to cyl or even lobe to lobe, that can't be good.
Even if just the lobe separation varies from cyl to cyl, that is going to not be optimal.
Just wondering.

[F-BIRD'88]

Just to clarify your testing. did you test both the old cam and the new cam in this same new motor? Or did you only now test the New Erson cam and are comparing that test to old previous dyno tests of the old motor with the old (evil) cam?

One is A-B cam testing. 2 cams tested in the same motor.

The other is not A-B cam against cam testing. it is something else.

[PackardV8]

Nope.
For example.
Say the Isky Lobe master had .0005" runout, then it was ground on a cam core that was only straightened to within .0005".
Now you copy it on a grinder that adds another .0005" runout, then grind it on a cam that's only straightened to within .0005".
What you end up with, is a POS.

Surprised Mike didn't mention how copying from the small cam lobe to make a large master magnifies any inaccuracies when transferred then back to the small lobe when grinding a copy. That's why a cam master is many times larger than the lobe.

[bigjoe1]

It seems that at least some of you are shocked to find out that many cam grinders just made a copy of someone elses lobes. I know lots of them did it




JOE SHERMAN RACING

[GARY C]

Here is a question I have pondered more than once.
Depending on the cam grinding machine wear and tear, how close is the indexing between cylinders?
We degree the cam off of #1 cyl, how close is that IO EC figure on the other 7 cylinders?
If a machine is worn and unable to duplicate from cyl to cyl or even lobe to lobe, that can't be good.
Even if just the lobe separation varies from cyl to cyl, that is going to not be optimal.
Just wondering.

If you don't have access to a cam dr then you would need to degree I & E on all 7 cylinders to know for sure.

[DaveMcLain]

Here is a question I have pondered more than once.
Depending on the cam grinding machine wear and tear, how close is the indexing between cylinders?
We degree the cam off of #1 cyl, how close is that IO EC figure on the other 7 cylinders?
If a machine is worn and unable to duplicate from cyl to cyl or even lobe to lobe, that can't be good.
Even if just the lobe separation varies from cyl to cyl, that is going to not be optimal.
Just wondering.

If you don't have access to a cam dr then you would need to degree I & E on all 7 cylinders to know for sure.

The camshaft itself can vary some from lobe to lobe but those variances will most likely be less than the variances you can see in a typical block.

I had some cam lobe designs done by Mike Ingram who is on this forum, masters made and cams ground on a Berco by Demos' Cams using those masters. When I compare the design data to actual data from a plotted cam it is amazingly close. I think that by creating the master directly from the design data instead of having to make a model lobe a lot of errors are eliminated.