Install valves in briggs flathead..

[Magice]

So I am in the process of refreshing my 5hp briggs flathead. The valves are all out, seats lapped, etc. Now when I put the valves back in is there anything I need to be aware of, anything to measure, etc?

 

[Russ2251]

Check clearance between tappets and valve stems. Check against factory specs.

 

[Magice]

tappets?

 

[Russ2251]

Tappets are what contact camshaft and then in turn, contact valve stems. Check when at top dead center on compression stroke with springs installed. Head need not be installed at this point.

 

[Kenny_McCormic]

Check guides.

 

[Magice]

How? Also, during reassembly should I use assembly lube, or just motor oil

 

[Russ2251]

When valves are lapped, they drop a little deeper into seat which decreases valve lash, or gap, between stem and tappet.
How bad were seats and valve faces? Did you have to remove much metal?

 

[Magice]

I'm not too sure. They weren't in great shape I can give you that

I lapped with some coarse then finished it with fine.

I take it you file the stem down until it's at level with the number in the book?

 

[Russ2251]

Re-assemble with plenty of standard motor oil.

 

[Russ2251]

I'm not too sure. They weren't in great shape I can give you that

I lapped with some course then finished it with fine.

I take it you file the stem down until it's at level with the number in the book?

No, no. Must be machined square and then measured for squareness. You will never achieve proper squareness by filing by hand. You may get away with it, but it won't be optimal.

 

[Russ2251]

If metal has to be removed from valve stem, don't go past maximum clearance. If you do, valve will have to be replaced or seat reground (to lower valve which decreases clearance) and checked again. Be sure that valve margin is not less than 1/64. If it is, replace valve.

 

[ed1380]

yup. thats what ive always done. by the time you get it started theres enough oil slung around

wow by the time i wrote this you got 2 posts in. and ive even visited this page 2 times before. OMG HAX R FOR NOOBS

 

[Russ2251]

OMG HAX R FOR NOOBS

Huh???

 

[Russ2251]

By the way, to go through all this trouble to refurbish engine and not know what a tappet is...well...it's just troubling.

 

[Magice]

Well these motors are a dime a dozen.. And I've learned alot.

I actually had a very good shop teacher guiding me through it.. But he left because he was retired / temporary and new teacher doesn't know squat. So I'm on my own.

 

[kibble]

OMG HAX R FOR NOOBS

Huh???

Let me translate: Oh lordy, I have failed at posting quickly.

Russ, you're awesome dude! I haven't done it yet, but I just learned that the valve lash would have to be redone, if you lap the valves. Didn't think about that before but it makes plenty of sense.

 

[Russ2251]

By the way, to go through all this trouble to refurbish engine and not know what a tappet is...well...it's just troubling.

Mr. Magice:
I meant no offense by this statement. I apologize.
Valve lash for your engine is:
Intake cold - .005 to .007 inch
Exhaust cold - .009 to .011 inch
These numbers assume stock cam.
The closer it is to the lower numbers, the better. Anything within this range is acceptable.

 

[jr dragster T]

Tappets and Lifters are the same thing.