Attention Camshaft Experts

[mrbilman]

I'm working on an engine for a relatively heavy 1931 Slant Windshield Town Sedan. This car will be in a lot of stop and go and less than 40 MPH driving. Because of that I feel more low end torque could be better than high end horsepower. The camshaft I have is a Snyder's Touring grind. The measurements I've taken are .286 lift at .013 lash and the intake lobe centerline is at 111 degrees ATDC. The engine will also have a Snyder's 5.5 head.
These are measurements I've taken at various valve lash:
Lash Initial intake lift BTDC
.011 14 Degrees
.012 12 Degrees
.013 10 Degrees
.014 8 Degrees
.015 6 Degrees
My question is: With what I've provided, where would you set the valve lash on this engine?
Thanks!

 

[Flathead]

Not to sound like a smartass but I would set it at whatever Snyder's suggested. The makers of the cam should know what is best for that grind. Good Luck!

 

[nkaminar]

The more or less standard is 0.012 on the intakes and 0.013 on the exhaust valves. The lash will close up a bit when the engine warms up. The camshaft from Snyder's is probably high precision but with the camshafts on Model T's, that were not precision, the lash on each valve is set by when the individual intake valve valves close and when the individual exhaust valves open. Each valve at each cylinder had different timing. Without setting the valves by their operation the Model T engine would run rough.

Valve timing is usually measured by when the valves open a certain amount, say 0.010.

 

[CWPASADENA]

Not to sound like a smartass but I would set it at whatever Snyder's suggested. The makers of the cam should know what is best for that grind. Good Luck!

I agree,
Set the lash per the manufacturer's recommendation. Valve lash has to do with the design of the quieting ramps, not the profile of the grind. If you want to advance or retard the cam itself, that is done with the position of the timing gear relative to the cam itself.

 

[cadillac512]

I agree,
Set the lash per the manufacturer's recommendation. Valve lash has to do with the design of the quieting ramps, not the profile of the grind. If you want to advance or retard the cam itself, that is done with the position of the timing gear relative to the cam itself.

This is spot-on advise and should be followed.

 

[Richard Knight]

In a low speed low performance model A engine you will have no detectable difference in how the engine performs by changing the valve stem clearance by 1 or 2 thousands. Maybe detectable on a dyno but even that I would question.