Adjusting cam timing? HELP!

[blueflag]

Right then. I've put my (now adjustable) exhaust cam in, set TDC on number 1 cylinder on the timing disc, set the pointer. I've put a clock with a nice long stylus on the exhaust valve on number 4 cylinder and established the lobe centre by getting values at 1mm after opening and before closing but it doesn't make any sense to me(I'm a bit thick) I've got a figure of 160.5 degrees BTDC. I thought it was supposed to be about 105 (ish).
Am I missing something or should I be checking on another cylinder?
Triarm by the way. Be gentle, I've been on nights and am sleep deprived
Cheers
Mike
The cam is in the correct position (ish) using the manufacturers marks and the engine turns over fine by hand.

[racesupplies]

Hi Mike,how much did you get skimmed off in the end? Cheers Carl.

[blueflag]

Hi Carl!
I went the lazy way, I offset the idler gear 5mm and it gave me ten thou (.25mm, but I'm old!) not much but better than nowt. I've still got ideas about the smaller cam gears you told me about but it'll have to be on my spare engine. No time I'm afraid!
I'm losing what little hair I have left with these cams though mate....
Mike

[racesupplies]

Havent got a clue on your cams/motor,sorry mate.

[Variablevalves suck]

Hi mate,
out of interest do you have figures for opening/closing, i assume you are going with 1mm from seated and is the backlash correct as this will affect readings.

[Variablevalves suck]

Anyway- you need the exact position that the valve reaches 1mm openning measered from tdc, say 65deg (this needs to be noted) then continue to turn the motot till you hit max lift, 160.5 as you say. You now need to add the two together and divide by 2 and this is the angle.

[Variablevalves suck]

Or another way-
http://www.factorypro.com/tech/tuning_c ... ow_to.html" onclick="window.open(this.href);return false;

[sa.racing]

Easiest way to measure lobe centre is to take the valve open figure @1mm lift for arguments sake lets say 40deg add the valve close @1mm lift 7deg 40 + 7 = 47 + 180 = 227 now divide that by two 113.5 then you need to subtract your valve close 113.5 - 7 = 106.5LC
dose that make sense?

[blueflag]

You guys here are great!
After a nights sleep and going through what you said, I got it straight in my head in 2 minutes!
Thanks for the link valves it's bookmarked now.
Now I'm off to do the inlet cam....
Cheers all,
Mike

[Variablevalves suck]

Good to hear you figured it out- i put the link up cuz i'd had a few cans last night and when i going throgh the process i confused myself so had to look it up, better safe than sorry!
Chris.