Is This Engine Shot (Timing Question)

Rob Hogenmiller · 04-07-2004, 05:15 AM

We'll believe it or not I knew about absolutely nothing before replacing an engine in my buddies 944.

After I got it put back in and about ready to start, my grandpa who has experience in cars, suggested I turn the thing over by hand to make sure nothing was hitting.

I had no idea I could do this. I figured all this was internal. Any how when going to turn the crankshaft. I can only get it to do a 358 degree rotation at the most by playing with the camshaft position.

Shouldn't the engine turn 360 degrees continually (with no belts hooked up)?

I'm wondering if this engine I put in is shot or if it is really crucial to have the camshaft and crankshaft aligned just right. I have set them like they say in the book I believe, but not much luck.

I'm going to reposition them one more time then hook the belt up again and see what I can get.

Tishabet · 04-07-2004, 05:40 AM

With no belts hooked up you will always have some of the valves open....this is an interference engine, when you're turning the crank you have GOT to be turning the camshaft at the same time or your pistons will come into contact with the valves. You probably didn't do any damage if you were just turning it by hand, you dodged a bullet!

Britwrench · 04-07-2004, 05:41 AM

There is only one way the cam timing should be: the correct way. You must have and understand the manual before working on this car.

The 944 is an inteference engine so if the timing is wrong the pistons will hit the valves. I suggest you seek a professional opinion as it may have a simple to diagnose problem.

Porsche944 · 04-07-2004, 05:51 AM

You need to pull the cam tower, align the timing marks, set the engine to TDC on #1 cylinder, install the cam tower, install and tension the cam and balance shaft belts, and so on.

Surf over to Clarks Garage (http://www.clarks-garage.com) and check out the Garage Shop Manual.

SoCal Driver · SoCal Driver's Garage

You don't have to pull the cam tower to get it back to TDC!

You can turn the engine so that all of the pistons are off of TDC then turn the cam till it lines up then turn the crank till it's at TDC.

Been there done it. Several times.

s928s · 04-07-2004, 07:18 AM

It is always best to crank it over by hand once belts are installed at the propper lines ( better safe then sorry..did that once !! ) . I keep the bent valve on my bench just a reminder to check , double check and check again, and then start . Also when turning it over by hand, and watching the reference mark on the cam gear you must rotate the crank 2x to make sure the marks line back up to TDC. ( the crank spins at 2x the speed of the cam.)

TCMdocs944 · 04-07-2004, 07:30 AM

Whewhh,

I am sweating just reading this post!

Please get everything lined up as they have said and ONCE THE BELTS ARE ON slowly turn the crank.

I would hate to see you have to do the whole thing over again from the head up.

SoCal Driver · SoCal Driver's Garage

You too can join The Order Of the Bent Valve!

Just one of many.

ae1969 · 08:28 AM

Quote:

Originally posted by SoCal Driver
You don't have to pull the cam tower to get it back to TDC!

You can turn the engine so that all of the pistons are off of TDC then turn the cam till it lines up then turn the crank till it's at TDC.

Been there done it. Several times.

Me too.....

I keep forgetting to line things up when I bolt it all down....... hehehe

P.S lets assume you are in timing.........uhmm did you remove the plugs to turn her over by hand...... a lot of compression builds up and it makes it difficult to turn the engine....
If you hear ... KLINK.... when you are turning that engine............those are valves hitting the pistons.....

Rob Hogenmiller · 04-07-2004, 09:30 AM

Well I got it all line up and it turns over smooth as many times as I want. However I'm wondering about the belt tension. It's a spring tension setup, 1987. I'm wondering is this adjustable or is it self adjusting. The one I did seems pretty tight. The old engine seems pretty loose although the spring tensioner is slightly different.

Thanks for the help. I'm wondering is this spring tensioner adjustable or not?

Britwrench · 04-07-2004, 09:56 AM

The tensioner is set by firstly aligning the crank on TDC and the cam on the notch. Loosen off the two 13mm wrench size nyloc nut and bolt and let the tensioner set itself and then tighten the nut and bolt. Rotate the engine by hand twice and then re-align the marks. Loosen and tighten the fasteners again. The balance shaft belt requires a guage to adjust.

Again, this is not the engine to be working on without correct technical information and knowledge.

URIN 2ND · 04-07-2004, 12:43 PM

In general, you should be able to twist the middle of the belt about 90 degrees...any more and it's too loose. Not that much and it's probably too tight.

This is just a general belt trick, I haven't had it fail me. Yet.

SoCal Driver · SoCal Driver's Garage

These:

Notice the oblong keyed washer under the bottom bolt. This is an important part of the tensioner.

speedracing944 · speedracing944's Garage

www.clarksgarage.com
Go there. Its is dedicated to the DIY mechanic. They have lots of "how to's" with great pics and torque values for the 944. I own a haynes manual and didn't open it once when i did my cam tower gaskets and belts. I used clarksgarage.