Jump to content

Franklin Side Draft Valve clearances


Guest aircoolguy

Recommended Posts

Guest aircoolguy

As was developed on the AACA Forum, Side Draft Franklin valve clearance specs varied by Series as determined by camshaft profile as follows:

Series 14 - .007" Cold

Series 15 - .003" Intake, .006" Exhaust Hot

Series 16,17, 18 - .007" Hot

Here's what's happened to my Series 15:

After the AACA discussion I took the bull by the horns and changed the clearances from .007" and .007" HOT to .004" and ,007" HOT.

(I didn't have the courage to close them all the way to .003" and .006")

There was an immediate change in the car's behavior: Instead of shifting down to climb that snake-like hill going up to Ed's, the car just calmly

climbed that hill in high gear without apparent strain.

Is it possible such an apparently small change could make such a big difference?

Link to comment
Share on other sites

I am by no means an expert, but in my experience that kind of change is possible. Depending on you cam, a change of 0.004" could cause your intake valve to open a lot longer allowing much more fuel to enter the combustion chamber.

I have noticed a big increase in performance after valve clearances are re-set on my cars.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...