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Valve Adj After Rebuild ??

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George Zeck

George Zeck

Jedi Warrior
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Hi All --

Just curious -- should the valves be adjusted at all after a rebuild? I have ~ 6,000 miles since the rebuild and a buddy asked me - wasn't sure.

BTW - think I fixed the carb issue (at least identified it). Choke issue was a bad jet sticking (replace) and the bowls are full of junk (new fuel filter & super clean out) and minor rebuild of sorts.

Tx-

George Zeck
 
the "book" recommends adjustment EVERY 6000 miles...

i use a click-adjust. 10 minutes from valve cover off to valve cover on.. and most of that time is turning the crank to get the valves in the correct positions
 
Roger that, very easy job and no mess.
 
turn the crank, third gear hehe.

I usually leave em a little loose for the first run then tighten them, and re-check again on a rebuild.

Click adjust?
 
Procedure is called Rule of Nine

#1 valve is fully slack when number #8 is all the way down, spring fully compressed, valve fully open.

1+8=9

#3 valve is fully slack when number #6 is all the way down, spring fully compressed, valve fully open.

3+6=9

flat crank motors all have cam lobes in which there is an opposite.

now, when we get to scatter pattern cams,,, uh,,, I dunno!

Jay
 
Of course my new motor has 20 valves and they are all shim under bucket so the cams have to come out after measuring the lash to change each shim under each bucket. Seemed like a good idea at the time.!
 
you can use the "RULE of NINE"..

that is when #1 is fully open, #8 is fully closed
when #2 is fully open, #7 is fully closed
3,6
4,5
5,4...... you get the idea..

the BOOK says.. "more easily carried out in the following order, and this also avoids turning the crankshaft more than necessary...

1,3,5,2,8,6,4,7.
 
Jayrz said:
Of course my new motor has 20 valves and they are all shim under bucket so the cams have to come out after measuring the lash to change each shim under each bucket. Seemed like a good idea at the time.!
Click to expand...
That sounds like mtorcycle technology. That way nothing backs off when you are constantly running 10,000 RPMs. What kind of head is that? Got a picture?
 
I'm going to adjust my valves for the first time on an A series engine.
Having read this thread, the manual and watched John Twist's video that's what I'll do.
John never checks for TDC or anything, a valve open (rocker side/driver's side up, valve is pushed down {passenger side}, thus opened) means you can adjust the "opposite valve" which is then closed (rocker down, clearance between rocker arm and tappet thingy) soooo.
valvetable.jpg


Because valves work in pairs and a partially open valve means its opposite is fully closed so you can adjust it and not worry about TDC.?
John just bumps over with the starter, I assume engines have a tendency to stop turning when a cylinder (or pair of them) reach close to TDC? That seems to be the case

What to set them to?
I think book says set cold, John says hot.
or is .013 hot, .015 cold? I don't have my book sitting here.
 
.012 Cold

I use a wrench on the crankcase nut, and move one at time, in order as given in the book...

1,3,5,2,8,6,4,7.

which <span style="text-decoration: underline">"avoids turning the crankshaft more than is necessary" </span>
 
If the engine tends to stop near TDC (not that it has to be exact TDC, as John's video explains) then bumping with the starter sure seems easier.
 
OK guys, I'll try to make this short.

I learned this trick about 45 years ago and it works on every engine.
Make the firing order into a fraction-
1 3
4 2

When number 1 cyl is on overlap, number 4 is on compression.
Set both valves.
Next, turn to number 3 on overlap, set number 2 valves.
Then, number 4, overlap, set number 1
Finally number 2, overlap, set number 3

This requires one full revolution of the engine and no more.

Try it if you see fit.

Dave :savewave:
 
By overlap, do you mean both valves of, say #1 cylinder are open? And that you can then set both intake and exhaust of #4?
 
I need to do this as the engine has just passed 600 miles since the rebuild and the valves sound a little "tickie".
My set up calls for different settings on the exhaust vs the intake.
Which are exhaust and which are intakes?
Thanks for the above tips!
Years ago we used the rule of 9. I had forgotten all about
that little gem.
 
Bill;

Yes, at the end of the exhaust stroke, both the intake and exhaust are partially open at the same time.
One (ex) is just closing and one (in) is just opening.
With a small amount of practice you can see them both moving as you turn the engine. Then set the valves on the other cyl. and there you go

Hope this helps.

Dave :savewave:
 
Pythias said:
By overlap, do you mean both valves of, say #1 cylinder are open? And that you can then set both intake and exhaust of #4?
Click to expand...

Yes, that's what he means. I did that for years on my non-British cars but I didn't memorize the fractions. I just remembered that 1 & 4 work up and down at the same time as do 2 & 3.

Most people I know just use the rule of 9 and turn the engine over twice.

As for telling which valves are intakes and which are exhausts, that's pretty easy to determine as soon as you look down on the head. Remember that the intakes are "siamesed". Valves 1=E, 2&3=I, 4&5=E, and so on.
 
Doug;

You don't have to memorize the fractions.
It's just the firing order split in half.
So 1342

13
42

and 18436572

1843
6572

It has to be easy for me to understand

Dave :savewave:
 
dklawson said:
Pythias said:
By overlap, do you mean both valves of, say #1 cylinder are open? And that you can then set both intake and exhaust of #4?
Click to expand...

Yes, that's what he means. I did that for years on my non-British cars but I didn't memorize the fractions. I just remembered that 1 & 4 work up and down at the same time as do 2 & 3.

Most people I know just use the rule of 9 and turn the engine over twice.

As for telling which valves are intakes and which are exhausts, that's pretty easy to determine as soon as you look down on the head. Remember that the intakes are "siamesed". Valves 1=E, 2&3=I, 4&5=E, and so on.
Click to expand...

Thanks. I see what you mean. I think I'm doing this this weekend.
 
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