Cam Timing Degree
I need some help with cam timing. First let me say My valve clearance is spot on to what the book calls for. The cams I have are nonadjustable and I have all my timing marks lined up. So I????????ve been trying to degree them and no matter what I do I don????????t get 106%. On the intake cam I get 116% and on the exhaust I get 96%. This motor ran like this before and to be honest it ran great. But I thought id degree them to see what they were at. I know the manual has a page wrong, but I didn????????t think you could get them wrong with nonadjustable cams. If I move one tooth on the crank and get a "half moon" on the idler gear I get 118% on the intake,havent checked the exhaust with this setting. Any help would be great.
??See I cant remember, this motor has been ran before so its been a wile and I????????m not sure if it has 2 or 4 holes. I hope tomorrow ill be able to get to it. I????????m not sure how many cam gears there are out there but I????????m sure the ones on it now are for the adjustable ones but I wouldn????????t think that matters any huu? Funny thing is this motor had what I thought was killer top end it'd hit the 11,500 pertty easy. And if this timing is that far off I really cant wait to see how it runs. Thanks
Well I made it out there this evening. And both cams only have 2 holes in them. Right now I have my gauges set up on the exhaust cam. I tried doing it with an adjustable cam gear, and moving it one dowel pin hole or one gear tooth didn????????t help any, I even tried one tooth on the crank gear. No matter what combo I????????d get 111% or 100% give or take 1%.I even tried taking off the chain slide and seeing how much that affected it, that????????s worth about one to two degrees. Any ideas?
Well I wasted some more time on it this evening, and still getting no were. I????????v been working on the exhaust cam. If I set it to the manual on page 49 I get 99.5% if I set it to page 48 I get 110% from looking at the pictures. Like I said if I remember right it was set at 99% give or take and ran this way, and it ran very well. I????????m tempted to just put it back the way it was.
I dont have a manual in front of me but cam timing is set on page 45 or 46 with the drawings. The you have to switch the labels on the pics to get the correct stock orientation.
One thought I had was to bolt up a cam gear with holes drilled all the way through all of it alignment pin holes. Then you could use that to make new holes in the cam gear inself to make them adjustable. Of Course you would have to use a carbide bit at the least to cut through them. I think Tim ground the alignment pins down on one to get them a little closer but that is very risky. Elongating the holes might work to but there again do at your own risk. These things have some serious loads on them and vibrating .
99degrees is extremely advanced. 110degrees I think I could live with .Thats only 2 degrees out of max spec. Im sure the engine will run this way no problem but for max performance this is unacceptable. I might have some adjustable cams left back from the heat treaters. I was running low on exhausts so Ill have to check.
Just to double check could you post your raw data numbers for comparison.
One thought I had was to bolt up a cam gear with holes drilled all the way through all of it alignment pin holes. Then you could use that to make new holes in the cam gear inself to make them adjustable. Of Course you would have to use a carbide bit at the least to cut through them. I think Tim ground the alignment pins down on one to get them a little closer but that is very risky. Elongating the holes might work to but there again do at your own risk. These things have some serious loads on them and vibrating .
99degrees is extremely advanced. 110degrees I think I could live with .Thats only 2 degrees out of max spec. Im sure the engine will run this way no problem but for max performance this is unacceptable. I might have some adjustable cams left back from the heat treaters. I was running low on exhausts so Ill have to check.
Just to double check could you post your raw data numbers for comparison.
To make sure I????????m doing this right, turn counter clockwise tell I get 1mm valve lift make note of number keep turning until I get 1mm closing lift note number then add the two numbers then again add 180 divide by two then subtract the smaller of the two numbers and thats my %. The first four numbers are of me just putting the gear in random spots. The last one If i got my notes right are were I line up all the marks,with out useing the book.
65+24 = 110%
55+14 = 110%
66+72 = 93%
15+28 = 96%
31+12 = 99% page 49
45+ 4 = 110% page 48
29+13 = 98% lined up all marks wit out book.
65+24 = 110%
55+14 = 110%
66+72 = 93%
15+28 = 96%
31+12 = 99% page 49
45+ 4 = 110% page 48
29+13 = 98% lined up all marks wit out book.
The second numbers seem just a bit high but there are a lot of variables here. And quit using percentage . My brain hurts when you do that. Do you have any worn out or good used cams you could throw on just to verify your procedure? I can throw some in the mail if you dont have any . lets get this right.