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Timing again

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JPSmit

JPSmit

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So, spent some time again trying to get the timing right. I think I am close. Still not 100% sure that I am looking at the timing mark on the small sprocket, but

1. If the #1 piston is at TDC and the timing is right,

then #2 intake valve push rod is as high as it will go correct?

and just to confirm

thick flange side of small sprocket faces engine block - correct?

BTW, I did find a timing mark on the plate behind the sprockets, (on the front of the engine.) - amazing

thanks all for your help but tonight I can truly say, "wish you were here!"

JP

PS One more question. when I pulled the head, the top 1/8th inch or so of the cylinder was slightly corroded - I assumed it was because the piston didn't travel that high. Now with the piston in, at TDC it is flush with the top - was the corrosion just because the piston rings are lower keeping the oil back?
 
I can confirm the piston rings keep the cylinders clean almost to the top, but for that 1/8 inch.
 
JPSmit said:
1. If the #1 piston is at TDC and the timing is right,

then #2 intake valve push rod is as high as it will go correct?
Click to expand...
I will confirm that this is NOT correct.

When #1 piston is at TDC (overlap) and the cam timing is right, ( #4 piston is at TDC (firing) )

Then #1 intake valve pushrod and #1 exhaust pushrod will be slightly raised, to the same height. This is called "overlap" position for #1 cyl, where the exhaust valve is just closing and the intake valve is just opening.

If you rotate the engine slightly from this position (in the proper direction of rotation), the intake valve will open more and the exhaust valve will close more.
 
racingenglishcars said:
JPSmit said:
1. If the #1 piston is at TDC and the timing is right,

then #2 intake valve push rod is as high as it will go correct?
Click to expand...
I will confirm that this is NOT correct.

When #1 piston is at TDC (overlap) and the cam timing is right, ( #4 piston is at TDC (firing) )

Then #1 intake valve pushrod and #1 exhaust pushrod will be slightly raised, to the same height. This is called "overlap" position for #1 cyl, where the exhaust valve is just closing and the intake valve is just opening.

If you rotate the engine slightly from this position (in the proper direction of rotation), the intake valve will open more and the exhaust valve will close more.
Click to expand...

/bcforum/images/%%GRAEMLIN_URL%%/iagree.gif What Donn said!!!! /bcforum/images/%%GRAEMLIN_URL%%/thumbsup.gif
 
racingenglishcars said:
Then #1 intake valve pushrod and #1 exhaust pushrod will be slightly raised, to the same height. This is called "overlap" position for #1 cyl, where the exhaust valve is just closing and the intake valve is just opening.
Click to expand...

If #1 and #4 are at TDC, #1 valves together, where will the valves on #4 be?
 
The Haynes manual gives an execellent discription of where each of the valves are when the engine is turning.
 
Baz said:
racingenglishcars said:
Then #1 intake valve pushrod and #1 exhaust pushrod will be slightly raised, to the same height. This is called "overlap" position for #1 cyl, where the exhaust valve is just closing and the intake valve is just opening.
Click to expand...

If #1 and #4 are at TDC, #1 valves together, where will the valves on #4 be?
Click to expand...

Mexico City?!?!? /bcforum/images/%%GRAEMLIN_URL%%/devilgrin.gif
 
DrEntropy Mexico City?!?!? [img said:
/bcforum/images/%%GRAEMLIN_URL%%/devilgrin.gif[/img]
Click to expand...

Or in the state of Confusion!?!? /bcforum/images/%%GRAEMLIN_URL%%/jester.gif
 
LOL
 
Well now that serve's me right!
BTW My Haynes is being used to mop up goo on my garage floor after we had a disagreement.
 
For checking the valves I always use the "9" rule-
If #1 is down check #8
if #2 is down check #7
etc
This is for checking/setting valve clearances but also applies here.
Bill
 
Good rule, works.
 
Yeah, #4 piston is at top, right? Well then it would be in firing position. The valves will be closed. they have been closed through the compression stroke, and will remain closed through the power stroke. about 30 degrees before #4 reaches bottom center the exhaust valve will start to open.

See This
 
OK, time for help again.

Front of the 1500.

The cam sprocket is for sure mounted as it was before disassembly (I didn't disassemble but I can see where the metal tarnish lines up.)

Key on Crank sprocket is pointing straight up (TDC)

A= timing mark on cam sprocket

B = Timing mark on Cam

C = Timing mark on Cam Sprocket

D = Timing Mark on front plate

E = Line that may or may not be the timing mark on the crank sprocket. The marker line corresponds to a very faint scratch on the gear tooth that points toward the other timing marks. I cannot however find any "real" timing mark.

Any thoughts to help me get it timed properly? I don't want to proceed until this is sorted out.

Thanks again all
JP
 
Hap, I've thought of it more than once but honestly can't make sense of the instructions. we had the cam conversation here not too long ago and I read them a number of times. I can go back at it though.
 
...you should have paid more attention in your Math classes.
/bcforum/images/%%GRAEMLIN_URL%%/wink.gif
(I'm a former Mathematics teacher)
 
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