I'm putting a timing belt on a B18C, I'm doing it by the book - align cam gears with crank mark on oil pump and then install the belt in the correct sequence.
But when I go to put tension on the belt the crank turns on its own slightly (the cam gears don't) so then its all slightly out of alignment.

Why does he crank turns on its own?
To try and fix overcome this, I set the crank mark a few degrees to the right so it's just before TDC and then put the belt on so when tensioned and the crank turns on its own it will eventually line up with the cam gears marks but is still seem to find its own position to as before.

As it sits in this condition the cam gears are 1/2 tooth out each from being lined up when the crank is at TDC. Would piston to valve contact be possible here with this?
It has Brian Crower stage 2 cams and stock B18C pistons.



Thanks,

 

Milling the head and block will cause timing marks to not line up exactly right. The best solution is to use adjustable cam gears and degree the cams to put them at the correct position.

 

Yeah it has being resurfaced. It that also related to why the crank wants to turn slightly before the cam gears when you 1st put tension of the belt?

How it sits:


Thanks,

 

Yes. By milling you are reducing the distance between the crankshaft and cams. The belt's spacing between teeth is constant, so for the belt's teeth to mesh with the teeth on the crank gear and cam gears, one of those gears is going to have to move out of position. The best way to overcome this is to use adjustable cam gears and a degree wheel to get the cams back in time.

 

Ok.
So if I adjust them so both timing marks line up that means both cams are actually back at 0 deg now, even though when you look at them they will be reading at +/- 'x', correct?

 

You won't be able to say for sure unless you degree the cams.

 

Geeezzz... one more multi-post. MODS, please merge OP's threads on this topic.

My response in your other thread supports what DaX has stated above. DEGREE your camshafts and the markings at TDC can be a bit off as you have experienced.

 

exhaust cam gear isn't even at TDC. That doesn't help...

 

Yes so if I advance the exhaust slightly that should line it back up. They both are at 0 deg in the photo

Is there any reason why you cant degree cams less than 1 deg? In this case it doesn't even need to be adjusted up to 1 degree to get lined up - its not far off as it stands. About 1/2 degree on each cam would line both up again.

Thanks,

 

This should be answered in the engine building & Machining thread that you already setup