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Erson Cam Group Buy
https://slantsix.org/forum/viewtopic.php?t=21400		 Page 17 of 20
Author:  jmtrops [ Sun Apr 19, 2009 3:54 pm ]
Post subject: 
I just ordered the RV15M, I will be running a 2bbl and the head is shaved .080 with some porting and larger valves. Any sugestions on setting up the cam?

Jim
Author:  ceej [ Wed Apr 22, 2009 2:49 pm ]
Post subject: 
Called today. More blanks should be in sometime this week. Delivery of the package I just ordered expected in a couple of weeks.

jmtrops:
On the RV15M, just degree it in per the sheet. Did you order the RV15M or Doc's RV15M RDP cam? The RDP I installed took a 4° pill to retard it to spec. It ran straight up, but my idle was horrid.
I found the lash specs to be a bit tight. Play with the lash ramp a bit. I am a couple thousandths looser than the spec on the cam card. (That doesn't mean yours will be.) :D

CJ
Author:  jmtrops [ Thu Apr 23, 2009 9:56 am ]
Post subject: 
I didn't know there was 2 different ones. The one I am getting is 218@ 50 - .435 lift intake and 212@ 50 - .442 lift exhaust.
Author:  DARKDUSTER [ Sat May 02, 2009 7:44 am ]
Post subject: 
Just a FYI for everybody in the cam area, I spoke to John Hartman @ Erson April 30th and they most likely won't see more cam blanks until
the end of May.

DARK :(
Author:  ceej [ Sat May 02, 2009 7:51 am ]
Post subject: 
The oxen are slow, but the earth is patient.

:roll:

CJ
Author:  Adrenalin [ Mon May 11, 2009 3:42 am ]
Post subject: 
I really can not understad why should the cam be degreed? I will be receiving my RV15 soon but shouldnt the grind be accurate? I am a little impatient I know, I will read how to degree the cam when I receive it but is it done rotating the timing gear through timing chain? If so it can not be that accurate... I chose RV15 since i thought it is a streetable cam with good idle characteristics, isnt it so?
Author:  SlantSixDan [ Mon May 11, 2009 9:19 am ]
Post subject: 
Quote:
I really can not understad why should the cam be degreed?
So that it opens and closes the valves at the best possible time relative to crankshaft (and piston) position.
Quote:
I will be receiving my RV15 soon but shouldnt the grind be accurate?
Of course the grind will be accurate.
Author:  runvs_826 [ Mon May 11, 2009 10:16 am ]
Post subject: 
Correct me guys if I'm wrong, but by changing the "degree of the cam" your essentially moving the intake center line +- X degrees. I finally had an Epiphany about cams when I was having to do some flow homework. The best way for me to explain it is a retarded cam will pull the reins untill the higher rpms allowing the cams characteristics to be amplified untill then and an advanced cam will work more in the mid-range same idea. This isn't extremely technical, but I hope it explains.
The reason to degree a cam is to change characteristics, if you don't warrant an hour of your time because it won't help the engine as a whole you can always install it "straight up". It took my dad and I quite a while to figure it out, but I think it will really help.
By the way, I just gave Erson some money a few weeks ago and installed the cam two weekends back. The cam was beautiful and hardened. It was 276/270 with .48 lift and 110 LSA, the grind was right on the money. I advanced it 4 degrees, I will report more once we get a starter to work.
Author:  ceej [ Mon May 11, 2009 10:33 am ]
Post subject: 
Moving the chain a tooth is too far. To Degree use an offset for the cam dowl. This can be done by installing an offset bushing that is appropriate in the cam sprocket, or using an offest key at the crank.
My RV15M came about 3° advanced to the specification. It ran just fine there, with a lot of torque.

CJ
Author:  terrylittlejohn [ Mon May 11, 2009 3:54 pm ]
Post subject: 
1 tooth is = 16degs, so if you are looking at the dots on the gears they can be missed matched, they have to line up straight through the center of the cam and crank, that is why using max lift at the intake lobe is more accurate.
Author:  Adrenalin [ Mon May 11, 2009 10:25 pm ]
Post subject:  ok :)
Well yes, I read a little more about degreeing and since Erson does not have any online document I found Crane cams instructions. It says you can degree a cam 6 degrees +/- to suit your taste. So I understand a bit now, we should check the cam before installation for any possible errors and degree it if we need poeser band in low RPM we advance the cam or retard the cam for high RPM power... ok .. it makes sense now.. anyhow I thought the cam would have a mark and I will fit it with anohter one in the block or somewhere and it should be ok... I guess its not the case...
Author:  Joshie225 [ Mon May 11, 2009 10:51 pm ]
Post subject: 
Usually the cam and timing set are accurate and the valve events end up where the cam grinder intended. We almost always advance the cam and with a 225 run a narrower lobe centerline than most V8 cams. Advancing the cam closes the intake valve earlier which does a couple of things. The most significant is that the piston has less time to push the mixture back into the manifold at low speeds. This is our main torque booster. Since the intake valve is closed earlier it also raises the dynamic compression ratio.

Some very good reading: http://www.elgincams.com/campaper.html
http://www.popularhotrodding.com/tech/0 ... index.html

Oh, another regarded engine builder does not retard cams unless he wants to kill power. If you want to move the power to a higher RPM range you need to increase the valve open duration.
Author:  runvs_826 [ Tue May 12, 2009 3:51 pm ]
Post subject: 
Josh we must know the same people because I was always taught that retarding the cam was going to hurt the power no matter what. That advancing was always good, and that LSA should be tight, but man alive Erson was saying you could do like 106deg :shock: . I was always taught 110 on the 302's, this was a freakin shocker to me!
Author:  turbo66valiant [ Tue May 12, 2009 6:35 pm ]
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My 230 @ 50, 470 lift turbo cam installed at 101.5 if this helps confuse anyone. Comes on strong down low but it done at 5500
Author:  Adrenalin [ Thu May 14, 2009 1:46 am ]
Post subject: 
Dear all and Doctor Dodge,

I got my RV15M with Dutra grind on it. You have been a great help for me since there is no one in Turkey that knows so much about this engine, as I said before it is only used for commercial purposes. Everyone tells me to stop working on this engine and get a V8. Ok I love V8 but I think slant 6 is worth the effort. So I have two more questions about cam assy:

1: Do you recommend any retarding or advancing my cam for my 1975 4WD dodge power wagon truck? Or should I just install it at 0 degrees? I guess it will not be possible for me to try and change cam degree since it costs a lot to install and uninstall the engine. I will have to decide on the degree... :(

2: As usual my crank seal is leaking oil and I will replace the seall during installation. In turkey most shops use the old rope type seal which is told to have a very critical setup procedure. Every shop tells me that if its not set properly my crank will jam (galling). I have read one of Doctor dodge's buildup stories and saw that there is rubber seal instead of the rope one. Can I use it in my engine or does it require some modifications? I do not trust the seals here so I want to order it from US, is the summit one ok or do you recommend another one? I guess rubber one is more forgiving and does not require setup. Can you please help me to figure out this seal thing? Is the one at Summit ok?

I will check pistons crank bearings and stuff... do you have some other recommendations while the engine is on the desk?
Thank you very very much...
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