Hayduke
New Reader
6/12/22 4:06 p.m.
Howdy all, working on a 1990-ish 2.3 Ford Lima with Esslinger head (milled an unknown amount), cam, cam pulley, etc. I got the car in December and have been working on other areas before giving the drivetrain a proper shakedown. I'm looking to replace the timing belt as it may be 20 years old with a nice sheen of oil. But I wanted a better understanding of where things are now in case something moves while I'm replacing the belt.
The cam rotates clockwise in the pic below, #1 piston is at TDC, I assume the dimples on the pulley and the cylinder head would have lined up if the head had not been milled. When I rotate the crank to align the dimples the pointer was ~8* from TDC.
Question is... does the adjustment done on the cam pulley (~8*) basically zero the change caused by the milled head? Or does it add to it? I'm thinking it zeros it but wanted to be sure.
OHC? If so, the cam timing marks are unaffected. The marks should still line up, but the distance from crank to the cam is a wee bit shorter, so if you can hold the cam at stock position and rotate the outer driven portion counterclockwise to take up the slack, you should be good to go.
Find yourself a good article on Degreeing a camshaft. You will need a degree wheel, a coat hanger, an old spark plug to modify into a piston stop, or a brass thread-in piston stop. Then you need a dial indicator and a cheapo magnetic base. Step one, calibrate the degree wheel by threading in the piston stop. With the stop in place, you rotate the crank clockwise until it stops. Then you rotate it counter clockwise until it stops. Those two points are equidistant from TDC. Adjust your degree wheel and coat hanger so they point to the same number of degrees before and after TDC at those two stop positions. Now you know your crankshaft timing to a high degree of resolution and you are ready to degree the camshaft. And for the life of me, I can't find the article by ...Nick Ienatsch.. I think... in Cycle World or MotorCyclist or Sport Rider sometime in the mid 1980s
The reason for adjustable cam pulleys on these engines when used for racing is that on a dyno you can change cam timing to move the power/torque curves.
Very common on the old 2 L pintos used for years in SCCA FC class. Before adjustable cam sprockets we used to have to use offset keys between the cam and pulley.
In your case I would do as Brian suggested, get it to TDC, mark where the cam sprocket is, and change the belt.
Milling the head will retard the cam timing. It looks like the cam is advanced 8 degrees, but you'd have machine quite a bit off the head to require 8 degrees advance to square it up. My guess is it's been advanced to shift the power band lower. But you won't know for sure where you are unless you degree it.
