YET ANOTHER cam timing question.....

[degreeoff1]

OK Waynes book is sorta vague on the whole issue IMHO OR (most likely the case with my warped way of thinking) I am reading it incorrectly.

after placing the pin in the sprocket hole @ TDC (compression stroke) (tightening the cam nut) and turning the engine 360 deg...I get nothing on the dial indicator (right?)

now after turning another 360 deg about 30 +(-) deg before the Z1 mark lines up with the case I get movement on my dial indicator to end up @ .17" (4.3mm AKA dead on the GE40 cam timing spec's) is that all there is to timing a cam? Am I doing something wrong? Did I get lucky? or ....................??

Waynes book states (and I quote)rotate the crankshaft EXACTLY 360 deg so that the Z1 mark lines up with the case parting line. (end of sentence) After turning the crankshaft for a while, (what? during the 360 or after???) you will notice the dial indicator will begin to move. take note of how far the dial gage moves when you finish the rotation. At this point this point in the procedure the camshaft should be rotated 180 deg.....

[john walker's workshop]

be sure that you start at #1 cylinder at TDC, adjust the intake valve to spec, install the dial gauge with enough pre-load so that the pin follows the etainer as it goes down, zero the gauge, rotate 360° clockwise. by this time the gauge should have started turning, unless the cam is way retarded. after you turn 360°, line up the pulley mark to the split in the case, remove the cam nut, remove the timing pin, turn the cam counter-clockwise until you reach the spec you're after, and then the crank BACK 360° to where you started and try again. this time you should be a lot closer or right on. then you do the same on the other side.

[cmonref]

degreeoff1,

John Walker is the great imparter of knowledge, and his description is terrific. Too bad you deleted the problem that started it all, because the rest of us would have learned even more if we knew what the question was.

[degreeoff1]

First off sorry I deleted the original question.... I had forgotten the 2 crank turns to 1 cam turn....

But ALAS there is more......time for the other side and Wayne's book says I should have the little dots pointed up @ TDC on both cams....well I had zero problem with the left side but I can not get the right side rockers in without valve interference....in other words the GE 40 cams rub the cam lobe @ that orientation unless I am @ the tail end of the adjustment screw....The only way it seems to work is if I am 180 deg out (dot pointing down)

Keep in mind that I do not have the dowel pin in on the right side cam.

Oh wealth of knowledge please help?

[Eagledriver]

You should only have one intake rocker in when doing the procedure (on each side of the engine). By all means turn the engine to allow installation of the one rocker. Yes you cannot put it in when the cam is trying to open the intake valve (doesn't that make sense?).

As you turn the engine over the intake valve will open for number 1 at TDC (4.3mm) and the number 4 intake valve will stay closed in that area of crank rotation. If you turn the engine 360 degrees from there the number 4 intake valve will open at TDC (4.3mm) and the number 1 intake valve will be closed.

The dots on the cams will move in unisyn as you do this. Dots both up, 360 degrees later (at the crank) dot's both down.

If you think about what the pistons are doing and what the valves are doing this will all make sense. The pistons for number 1 and 4 move in and out so they are both at TDC at the same time. They take turns firing 360 degrees apart.

-Andy

[degreeoff1]

Ok so I understand that part where TDC for #4 should be 720 deg away (crank) from the #1 TDC.

The issue I am having is that the ONLY way I can install the #4 cam is with the dot facing down (where I can install both intake and exhaust rockers) other wise I have to back the adjuster ALL the way out and have zero room to adjust. Is this a GE 40 cam difference? I have no dowel pin in place so crank position should be irrelavent right?

Thanks again, after work tonight ECT I will get a picture.

[degreeoff1]

OK this is where my reading and comprehension skills suffer a bit. I re read waynes book and installed the rockers with both dots facin down. All is good firing sequence seems good and I even measured piston to valve clearence and all is good. Its amazing at how the way a thing is written VS how it is read can alter my perception....I feel kinda dense but I see the light and its on to teardown and reassembly with sealant etc.

Thanks for putting up with my novice views

Josh

[Eagledriver]

I think you've got it but just to correct one of your statements the TDC for number 4 should be 360 degrees away from the TDC for number 1 (not 720 degrees). 720 degrees takes you back to TDC for number 1 again.

-Andy