When the cam turns inside the cam housing (where the Porsche is written on) it pushes the lifter down on the spring that causes the valve to be open then onces it moves a little more there is no force on the spring and it comes back up which closes the valve. Now if a timing belt will brake,loose tension, or jump teeth some of the lifters are going to be pushed down by the cam shaft which will let the pistons hit the valves that are open before the engine(crack) stops moving.

 

Ok, I sort of had an idea about how that all worked, but now I know exactly . Thanks for the explanation Seb.

Joe, that looks like it made a huge difference. Is the glass beading similar to sandblasting, or does it coat the metal with something? It kinda looks like it's been primed.

 

Glass beading uses different media that sand blasting, glass instead of sand. Based on my limited experience with both, glass beading tends to be less abrasive and thus is better for simple cleaning up of parts. Glass beading does not leave any kind of coating on the part. That color is just the bare aluminum casting as clean as it will ever be. Oh, I also did my a-arms too while I had them apart. Even bigger difference there but no pictures to show them off. I got grease all over them anyway while reassembling.

 

if you've taken out the lifters you should be aware that they need to go back in exactly where they came out from...

 

umm, oops

What do you mean? I kept them in order until I could have a god look at them, and they all looked identical. I've mixed them up now and I don't think I can figure out which came from where. What's different about them?

 

lol thats a classic Kevin!

 

I am in the boat with you Kevin. Mine all fell out onto the floor when I removed the cam housing.

 

Hehe, this sucks. I'm sure glad this was an extra. So, can anyone tell me what the difference is between them? They all look exactly the same to me. Looks like replacing these lifters will cost more than ten times what the whole assembly cost me, I guess I'll chaulk this casualty up as a learning experience.

Also, anyone know what size wrench I need to get the cam sprocket off, it looks like maybe a 25mm or 27mm?

 

You have to use a puller to get it off.

 

Umm, puller? What's that? Or more importantly, where can I get one?

(anyone else get the sense I'm in over my head?)

 

You can get a puller at Autozone or some other store like that. I dont think you are in over your head necessarily. You gotta learn it sometime. Also, I know Autozone specifically carries Haynes manuals for the 944. Pick one of those up too. Its a huge benefit.

Happy Wrenching.

 

Thanks for the encouragement

I live across the street from a Pep Boys, and I've seen the Haynes manual there before, but I heard it wasn't too great. Nonetheless, if it's still there I'll pick it up anyway. Up until now I've been able to find great instrustions for everything I've done on Clark's garage, but I can't seem to find instrustions for the removal of the cam sprocket on there, maybe I'm just looking in the wrong place.

So is this puller something specific for this application, or can I walk in to Pep Boys and just as for a "puller" without getting the deer-in-the-headlights stare they are so famous for?

 

Clarkes Garage is great, but sometimes things are hard to explain, and Haynes has Pictures. The pics save the day for me alot. If the Boys of Pep don't know what a puller is, they need to find a new job. They will definintely know what it is.

 

I'm gonna stop in tomorrow and pick one up.

So, I still don't understand why the lifters have to go back in the same spots they came out of.

 

I would like to know this as well