Slant Six Forum
https://slantsix.org/forum/

Dutra RV15-RDP cam -- where to buy these days?
https://slantsix.org/forum/viewtopic.php?t=56026		 Page 1 of 2
Author:  SlantSixDan [ Thu Aug 21, 2014 12:36 pm ]
Post subject:  Dutra RV15-RDP cam -- where to buy these days?
Overseas friend wants an RV15-RDP cam. Needs to be bought outright (no send-in-for-regrind). I guess Erson's been through at least one management/ownership change; what's the current go-to for the Dutra grinds?

(wants this specific cam, so thanks-but-no-thanks on the "CamMaster made me a nice grind that works good" or "Camp Cams has a 260 grind that's pretty close" type replies)
Author:  Reed [ Thu Aug 21, 2014 12:45 pm ]
Post subject: 
Dan- I would be willing to send a core cam in to Oregon Cam cam grinders and ship the regrind off to your friend, if he is willing to pay.
Author:  dartsport76 [ Thu Aug 21, 2014 12:55 pm ]
Post subject: 
Oregon cam also has blanks for $150, but I'm not sure thats what you want...

I have read/heard that Erson is up and back at it again, but I'm not sure that they have any of their old cam grinds. One would think you could send the specs to either company and have one made...
Author:  SlantSteve [ Thu Aug 21, 2014 1:58 pm ]
Post subject: 
Erson don't regrind used cams anyways, apparently they only use new blanks from what I was told.... By the way, I think you mean "COMP cams" ..
Quite a while back I considered buying an Erson but there was just too much margin for error on a cutom grind. From what I could gather they were a special order item through any Erson stockist/dealer,then there was the company change of ownership. By the time my order gets passed through all those hands and then shipped to me it was just too expensive and wasn't worth the risk of receiving an incorrect grind,or poor workmanship...too many unknowns and too much mucking around for little benefit. I got a grind locally and am very happy,dealt face to face and got what I asked for...like I said that was a while back,Erson may have had another change of ownership or different ordering options now....you could always stamp "ERSON" on another cam!
Author:  Doctor Dodge [ Thu Aug 21, 2014 4:16 pm ]
Post subject: 
Sad that the Erson situation has change so much over the years but that is life...

The key thing I did with them is get them the original exhaust lobe profile off the Mopar Performance 244 cam and then combined that with one of there intake profiles, to make a nice "street performance cam the would lash "tight" and give the user some performance "adjustability" with lash settings.

There is no reason why this can not be done with other cam grinder(s)... (Erson was the 3rd one I did it with)
It is a matter of finding one that will work with you AND will follow instructions and...listen to testing results... and keep track of the master(s) so the process does not have to be "re-invented" every time.

Some likely intake profiles at Oregon Cam Grinding are their #84, the #346 and the 1418 (1416?)
DD

http://www.oregoncamshaft.com/Mechanical-Cam-Specs.html
Author:  emsvitil [ Thu Aug 21, 2014 9:29 pm ]
Post subject: 
Does Oregon cam grinding have the mopar 244 exhaust profile?
Author:  SlantSixDan [ Thu Aug 21, 2014 10:07 pm ]
Post subject: 
H'mm. Sounds like I'm misunderstanding the nature of the RV10RDP and RV15RDP cams. I thought these were specific grinds with particular specs for the intake and exhaust lobes. No?
Author:  SlantSixDan [ Thu Aug 21, 2014 10:12 pm ]
Post subject: 
(No, I didn't mean Comp Cams. I know of them. I will not use their products.)
Author:  SlantSteve [ Thu Aug 21, 2014 11:04 pm ]
Post subject: 
Quote:
(No, I didn't mean Comp Cams. I know of them. I will not use their products.)
So what exactly did you mean?
From what I have been told the Erson custom grind was a common chev type intake master used on their own RV10 and RV15 cams and the Mopar exhaust profile.
Author:  emsvitil [ Thu Aug 21, 2014 11:17 pm ]
Post subject: 
The RV10 and RV15 cams use erson intake profiles, mopar 244 exhaust profile and non standard (i.e. not 110) lobe separations to approximate the mopar 244 cam lobe separations.

The RV10 is a close approximations of the mopar performance 244. The RV15 has a bit more intake duration.
Author:  Doctor Dodge [ Fri Aug 22, 2014 8:55 am ]
Post subject: 
Quote:
The RV10 and RV15 cams use Erson intake profiles, mopar 244 exhaust profile and non standard (i.e. not 110) lobe separations to approximate the mopar 244 cam lobe separations.

The RV10 is a close approximations of the mopar performance 244. The RV15 has a bit more intake duration.
I could not have said it better...

We need to start with the cam lobe "masters" and once you have those, the rest (lobe separation, advance, etc. is "adjustable" during the grinding process.
What I have learned is that there is a lot more to a cam lobe's geometry then the advertized lift and duration numbers we commonly rely on.

The next thing I study is the lobe's stated lash setting, that give us an idea on lash ramp shape and how forgiving the cam with be, with changes during the heat cycles.
Lash clearance specs also gives me an indication on noise quality and how much 'wiggle-room" I may have in the clearance settings.
(wider clearance, usually means more adjustability)

I usually request the "plots" for any lobe shape / master I am considering and that gives me the cam event info needed to figure-out intake track velocities and apply velocity info to the intended engine build and end-use.
This info also shows me the intake valve closing point, needed for an accurate DCR calculation.

Complex stuff here and lots of variables in the math equations but that is how "good working" cams get designed for specific applications.

Below are the lobe event "plots" for the Erson RV15 / 295 RDP design ground at 108 c/l I liked this cam better when ground with 110 separation and installed "straight-up". ( the longer intake lobe acts like "advance" with RDP cams)
DD

Image
Author:  SlantSixDan [ Fri Aug 22, 2014 11:06 am ]
Post subject: 
Quote:
Quote:
(No, I didn't mean Comp Cams. I know of them. I will not use their products.)
So what exactly did you mean?
I meant "generic cam company providing something other than an RV15M-RDP". I could just as easily have said CamCo or Kemp Kams, etc.
Author:  SlantSixDan [ Fri Aug 22, 2014 11:07 am ]
Post subject: 
Got it -- thanks for the data and explanation. Time to make some phone calls, looks like.
Author:  Doctor Dodge [ Fri Aug 22, 2014 11:12 am ]
Post subject: 
Erson may still be able to do this grind if someone on their new team picks-up the phone and is willing to look for the masters.
Have you tried calling them?
DD
Author:  SlantSixDan [ Fri Aug 22, 2014 11:22 am ]
Post subject: 
Not yet, but planning to. Once I understand correctly exactly what I need to ask for when I get 'em on the phone. D'you think it'll work to say "RV15M-RDP" or "RV10M-RDP", or am I going to need to spec in terms of lobe designators or grind numbers? Guess I'll find out once I get some phone time!
Page 1 of 2 All times are UTC-08:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/