Bracket Talk
Let's talk camshafts for a minute

This topic can be found at:
https://drr.infopop.cc/eve/forums/a/tpc/f/80760912/m/7267013796

October 28, 2021, 05:18 PM
chasracer
Let's talk camshafts for a minute
I'm looking at a couple of grinds but I have a couple of questions.

We have two cam sticks and everything about them is exactly the same EXCEPT for the lobe center angle. One is 112 and the other is 114.

According to what I understand we would be moving the available torque up a bit in the RPM range with the wider cam? IS there anyway on paper to understand how much movement that would be? 200 RPM, 500 RPM?

If we take that wider cam (114) and advance it during installation, are we moving the torque curve of it to a lower RPM range? And again on paper can we determine how much that would be?
October 28, 2021, 05:25 PM
Canted Valve
Cris Wideopen231 uses computer simulation programs, maybe he will have an opinion. As I know you're aware, there are a lot of variables the could impact accuracy.


Illegitimi non carborundum
October 28, 2021, 06:30 PM
TD3550
Here is a little something from Clay Smith in Layman's terms. Me on the 598 and the 632 i run a 115.0. Spec grind from Comp. Was going to do a 117, had a change of plans. Due to some thin margins, it went in @ Zero

https://claysmithcams.com/blog/defining-lobe-center-/
October 29, 2021, 05:50 AM
wideopen231
If you can give me bore, stroke, accurate head info,induction flo and cam open and close numbers I will run thru computer and see what it says,

If you just want cam change then I can just put in set of heads close to what you have and the cam numbers and tell you what changes will do. While its not a dyno the cheap lil progarm gets real close to real world numbers when compared and given accurate info. every needs one.If nothing else it is fun as hell to just play with cam numbers, compression or head flow numbers on it.

the more info the more accurate return info will be.While program will not let me paste and copy or send info,I can take pics of curves and text them.




America home of free. Brought to you by 2nd amendment.
October 29, 2021, 09:05 AM
chasracer
PM sent.
October 29, 2021, 01:58 PM
wideopen231
basically I ran Charlies cams thru program with very little difference on two he had. I also ran a tool part of program that makes cpl hundred comparison changes. It showed one that was about 20 hp higher and had less exhaust duration. Now is that iron clad. Heck no.

The desk top dyno has shown some surprising results in comparing it to real world dyno numbers. I had one guy pick up .15 from suggestion on cam and another pickup nothing. Then again guy who picked up zero, his car would not change no matter what we did.

The program is cheap about 60 to 70 bucks summit or jegs and fun as hell when you just want to play with ideas and see how they should work. You have to give it exact numbers to get almost exact out of it. As told Charlie. I get nothing for advertisement and make nothing for sale's Disclaimer done.




America home of free. Brought to you by 2nd amendment.
October 30, 2021, 05:14 AM
Woody B
I'm going to say unless the cam is really bad, or really good (one is perfect for the application) you won't see any difference in 2 degrees of lobe separation.


I used to be a people person, but people ruined that.
November 02, 2021, 10:00 AM
chasracer
For anyone that is interested Sig Erson has a grind that almost matches the R-M 420-116 stick.

The differences are the exhaust opening and closing points are one degree different. And the exhaust lobe lift is .440 instead of .450 on the R-M cam.

The Sig Erson# is E129030 ($367)
Also available as a 4/7 - E129030-47 ($395)

I also got my hands on the Engine Dyno software, just the cam change and a bump in CFM makes a decent difference.
November 02, 2021, 01:18 PM
1320racer
RM cams ARE Erson cams