Degreeing a Cam vs. Lining Up the Dots

-
With a (looks like a used/stock?) timing chainset like you have, you can only CHECK where the cam is degreed at now. You WON'T be able to change that number.

In order to actually be able to degree the cam, you will need a timing chainset with a crank gear-sprocket that has multiple keyways in it, and preferably more than just three 2 or 4 degrees keyways.
 
I put the original sprockets and chain back on to see where the dots lined up. I first tried a new Cloyes double roller. Dots lined up the same with both sets. Picture is with the old set. William: I came up with the same numbers as you.
 
moper said:
I think you might have the events a little off and I think my math is sound...
It's a small cam so I don't think it's opening during the exhaust stroke. If that's the case & using these numbers: intake opens 22.5 ATDC, int close 62.5 ABDC
exhaust opens at 62.5 BBDC and close 22.5 ATDC

Doing the math on the intake stroke: 180 - 22.5 = 157.5
157.5 + 62.5 = 220 / 2 = 110°
On the exh stroke: 62.5 + 180 + 22.5 = 265 / 2 = 132.5°

overlap is 0.
Click to expand...

I have been told that if a cam had 0 overlap, it couldn't do much more then idle:dontknow:
Maybe its 0 degree @ .050........

a stock 318 cam has over lap in the 30 to 40 degrees, right?
 
clifftt said:
I wanted to run a cam close to the stock 4bbl cam. The numbers are (supposed to be) a little bigger than that. This a weekend driver, Rusty, no race horse that you might build. Love your avatar, always makes me look!
Click to expand...

When comparing solids to hydraulics, the hydraulic will always have about 10* more duration, do your solid is a good bit smaller than the stock Road Runner cam.
 
William has the correct specs. nailed down with 45 overlap, that would make the cam a 265 adv. duration running .465 int / .465 exh lift with 1.5 rockers.
(C-265-0-b) grind code

stock 273 4bl grind (.415 int / .425 exh lift , 248 adv. dur.)

pretty good jump in size, the ISKI E-4 specs at (260 adv. dur, .425 int /.425 exh)

your cam should be notable change

Enjoy; Lon
 
The .050 numbers i got for a 224 duration cut on 110 LSA are

IVO 2
IVC 42
EVO 42
EVC 2

And an overlap of 4 degrees.

It should be a very trouble free cam and will idle super smooth.
 
Definately no MBA... Math is one of my worst subjects and as I noted - I assumed the events so I'll hapilly defer to the others here...lol.
 
frosty_the_punk said:
The .050 numbers i got for a 224 duration cut on 110 LSA are

IVO 2
IVC 42
EVO 42
EVC 2

And an overlap of 4 degrees.

It should be a very trouble free cam and will idle super smooth.
Click to expand...

Correct!!!

The IVO is BTDC and the EVC is ATDC

Usually on cam cards the number being positive for IVO is BTDC. If it had been a negative number, that's ATDC. For the EVC it's the opposite.
 
Should be a nice mild cam with just a little more duration than the E-4 by 8°
@ .050. The lift is about the same. What would a cam with .050 more lift do?
 
Yesterday I spoke with Nick at Clay Smith. I asked him at what lift am I supposed to measure the intake opening number on the card. He says they don't specify that. He says to use the Lobe Center Method: Run the intake lobe to full lift and zero the dial indicator. Then turn the crank counterclockwise a little past .050, then go clockwise (to put tension on the chain) and measure at .050" Note the number on the degree wheel (mine was 151). Then continue to turn the crank clockwise, past the top of the lobe until the indicator reads .050" again (mine read 56). Add 'em together (151 + 56 = 207), then divide by 2 (207 / 2 = 103.5) That's your Intake Center Line.

I'm in agreement with Moper and Frosty, that the math from the card shows the centerline should be 110, but I measured 103.5. (Just for grins, I verified I am getting the full 224 degrees measured at .050" opened and closed.) So, do I need to advance the cam about six degrees to get close to 110?
 
to get from 103.5 to 110....you are going to have RETARD the cam...
 
Got me a Summit double roller set (made in USA), set the crank gear at 6* retard. Now I'm at 110*!
 
You have a retarded engine.
 
Well, as much trouble as you're having, the only thing I can suggest now is to round up some local help, a mechanic friend. Hell, it doesn't matter if he only works on Lancia 'er somethin'. Just get a "second set of eyes" over there that can check your work, some obvious "doh" that you might be overlooking.

I'm not cam expert, but I've stuffed a few into engines, here and there. When I find cam grinders who don't want to put out specs in a standardized or at least popularized form, I get irritated.
 
You must log in or register to reply here.
-

Back
Top