PorscheDoc

If you look at the first picture he posted, yes, the cam gear is off 180 degrees. The red dot as he put it, should be at the 1 o clock position, not the 7 o clock position.

painkiller

Kenny, if you need a hand pm me your number. I should be free tues afternoon to help.

John

Zero10

I thought it should be exactly lined up. That's how I've always done it. When you have the OT line perfect, the cam mark will be exactly on as well.

gmsracing

FYI- if you want to type the symbol for degree just hold down the alt key and type 248. So:
180°. Pretty cool!
Rob

Mongo

so did you fix the 180 degree timing yet so your valves and pistons don't hook up and mate?

Geo

The number one cylinder will be at TDC twice for each rotation of the cam. Remember, once to compress a filling/full cylinder, and once to expell the contents.

I always use the cam gear to set the number one cylinder to TDC rather than the flywheel just because of this reason. Once you get it close you can then get it exact using the flywheel.

It works exactly like US muscle cars and all other conventional four-cycle engines.

Geo

1. Think about this again.

2. Slap forehead.

3. Say "DOH!"

Geo

Come on guys, don't you know how a four-cycle engine works? The crankshaft just needs to be rotated one more time.

Or is that what you guys are saying? It's not a problem with the engine, just that the engine must be rotated once more.

It sure sounds like at least some of you are sying there is a problem. There is not.

michaelathome

Geo,

I think that what others are saying is not that it is wrong BUT the marks are there to make it easy. If Kenny wanted to take a ruler and put a new mark on the EXACT opposite side of the gear it might be easier. However that could be tough to.

It would be easiest if he removed the belt lined up TDC on the flywheel, turned the cam to the timing mark and put the belt back on. Just a thought.

I am not sure what the story is with the rest of the posts but where I was coming from was his photo # 1 with no belt on. Just spin the cam..

Michael

PorscheDoc

Haha, DOH!

Geo

No, no no!

All ALL he has to do is to rotate the crankshaft 360°. That will rotate the camshaft 180°. All will be good and right with the world. OK, I lied about that last part, but one can hope, right?

The point is nothing is out of alignment, it's just the crankshaft must rotate one more time. It would be a disaster to rotate the crank independently of the cam. It appears to be all lined up correctly already, or close enough to rotate the crankshaft. I guarantee you if you disconnect the timing belt and rotate the crank independently of the cam, you WILL bend valves. You only do this when the cam housing is off the car, but there is NO reason to do it in this case.

michaelathome

Geo,

I get what you are saying. IF it is on correctly DO NOT take it off. TURN BOTH the CRANK and the cam TOGETHER! If NOTHING changed when he pulled the belt we are OK. LEAVE IT AS IS. now I get it.

I guess where I was coming from was that where I am at w/my engine (bent valves, damn PO) it didn't really make a difference. I could turn cam without impact (there was of course resistance from compression and springs).

Here is a question, is there some point in the crank rotation that you can spin the cam without impact? I am pretty sure that there has got to be someplace. I know that it will work the other way around, as I was doing it. The pistons had pushed the valves to a location where there was no longer interference between the pistons and valves and crank spun w/out further impact. Please just don't ask how many times I tried to turn it over w/out a working belt

Michael

Tony K

To illustrate what Geo is saying, note that the cam sprocket has twice as many teeth as the crankhaft sprocket...

Geo

I rather doubt it's possible to turn the cam by hand while the cam tower is installed. There will always or almost always be a point there there is much tension on the cam from the valve springs.

Actually, it's pretty amazing how hard it can be to turn the cam (or crankshaft). It gives you appreciation for how much power is lost to friction and stiff valve springs.

FSAEracer03

LOL! George... I'd just give up at this point.

Some of you guys are so funny, tehehehe.