Anyone running a Oregon 1475 cam? I was wondering what to set the initial timing at with this cam. I am thinking around 10-12°. But wanted to ask here first.

Durham Missouri

Do you have the specs handy for this cam?

Lorena, Texas (South of Waco)

This is what Tim had on the build sheet.
Lift .475 @ 1.43:1
Dur 280° (236° @ .50")
110° LSA
LC 106° Intake
114° Exhaust


Durham Missouri

This should be interesting.

Whats the rest of the parts going into this build?  Such as pistons and machine work you plan or have had  done?

Stick or automatic trans?  You mention Tim - Is that Tim Mcmasters?

Oldmics

Yes Tim McMaster built the engine. I bought it off him 3 years ago for my stalled unibody project. I decided to pull the anemic 6 cyl and put it in my wagon. Been working on it since last September. I also rebuilt the complete front suspension and all new brakes with Versailles spindles and discs. Plus cleaned up the firewall and frame and painted them semi gloss black. Here is a copy of the build list he sent me.

Durham Missouri

That is a pretty big cam.. 10 to 12 may not be enough.. Probably take more like 16 to get it to idle well.. Just have your distributor set up so you don not get too much total advance from running a lot of initial advance

That camshaft is similar to the Crower Monarch camshaft I use in the 312 dyno mule for testing.  The Crower camshaft is 238°@0.050” and is ground on 110° lobe centers.  The initial timing with that camshaft is reasonably happy at 12° BTDC but I always insure that for most testing the timing is set at 38° for the total with the vacuum advance disconnected.  Idle speed if on the high side can throw you a curve on the initial timing which is why I will use the total timing numbers to set the distributor.

Lorena, Texas (South of Waco)

I know how to set the initial timing. How do you set the total?

Durham Missouri

Here are a couple articles that explain the process.. Your distributor could have a 10 13 or 15 degree arm in it.. If you shoot for 38 total advance and you have 16 degrees initial then you want 22 degrees of mechanical.. To achieve this you would want either the 10 degree arm or the 13 degree arm..The distributor arms are in distributor degrees so you double that to get crank degrees..  IE.. 10 arm = 20 crank degrees 13 arm = 26 crank degrees.. So if you were shooting for 38 total timing and you have the 13 arm you would need 12 initial advance.  If you have the 10 arm you would need 18 initial.. I usually opt for the 10 degree arm for any engine with a cam bigger than 230@.050.. Cammed up motors idle a lot better with a lot of initial and less mechanical advance. Esp with low to modest compression.

http://www.bob2000.com/dist.htm

https://www.fordmuscle.com/archives/2000/03/timing/

Add this as an alternative to what Royce brings up.
 
First you’ll need the total timing mark (ie. 38°) on the damper.  With the engine running and the vacuum advance unplugged, you’ll rev the engine up until the timing light indicates that the mechanical advance is fully engaged and will not advance any further.  That will be the total timing.  Depending upon how the springs are set up in the distributor, this could be anywhere between 2200 rpms and 4500 rpms.  Once the mechanical advance is fully extended and with the engine holding steady at that rpm, simply move the distributor so the 38° mark is aligned with the pointer.  Once the engine is brought back to idle, then the initial timing can be checked.  If you don’t like where the initial timing is, then the ignition curve can be shortened or lengthened accordingly so that both ends of the ignition curve is happy.  The vacuum advance can be hooked back up when you’re through.
 
One note here is that once the total timing is achieved, you may see the total timing start backing up if continuing to rev the engine beyond the point where the mechanical advance is fully in.  This is the elasticity in the timing chain and at this point you are seeing camshaft retard taking place.  Nothing to be concerned about but does reinforce the need to only take the engine rpms to the point of maximum mechanical advance and not running it well beyond that.

Lorena, Texas (South of Waco)