GT3 engine tools

[Cupcar]

I am going to rebuild a GT3 engine and I am working on the necessary "homework" and tool acquisition.

The factory manual shows the engine to be straightforward to work on and should be simple for anyone familiar with an air-cooled 911 engine since the crankcase is identical.

The only tricky bits I have found so far is that the cams must be at overlap to remove them without damage to them, the pistons and cylinders are a bit tricky to install in their water jackets, but that seems to be it.

A special press is required to press in the center cylinder during P/C installation and Stomski Racing sells this along with the TDC indicator and tensioner tools needed.

There is a special tool required to time the cams consisting of a plate that bolts to the camshaft housing and some other pieces that fit into this plate to engage the cams in the correct timing position. Baum Tools charges over $900 for each of the two parts of the tool = over $1800.

Does anyone know a cheaper source for the cam timing tools?

[TimT]

Don't remember where we got ours.

Anyway a pic during cam timing of our RS engine.

[Cupcar]

Now, that is how I thought it would be done! That is one very trick tool you have there, thanks for the picture. Cams and TDC in one dynamic operation, what could be better.

The tool "B" in diagram below is the Porsche tool used to time a street engine (using same principle as 993 with a keyway in the cam).

The frame (Tool #9661) with the square holes in it is bolted by the tabs on them to the camshaft housing using the upper and lower camshaft cover bolts closest to the end of camshaft opposite the chain wheels. The square pieces (Tool # 9661/2 for 2004 GT3) fit into the frame and have keys on them in the correct position to time the cams once inserted into the cam's keyway.

[TimT]

I don't have a picture of it, but we have a tool to set initial timing, before you set the fixture and dial gauges in place.

Its basically a template that has cut outs of where the cams should be at TDC... This allows you to get the cams close enough so you can turn the engine over to time with dial gauges, and not worry about bending a valve

[TimT]

Ha!!!

found a picture of the template..

[TimT]

More cam timing

[Cupcar]

From what source did you get the overlap lift specs? What cams do you have the specs for?

[TimT]

For "stock" RS cams we got the specs from PMNA, in our RS we have a custom grind, and hence custom timing specs..

Ill have to root around but I think GT3 cam timing specs are published

[Cupcar]

Tim T-

Thanks again for your reply to the forum about the GT3 tools.

Did you make your tool yourself? Do you have plans for it, it looks simple to make.

It would be nice though to have a scored plate, as you do, for the basic timing during initial camshaft installation.

Also, in the picture showing the torque angle tool, you are just torquing the cam bolt right? ,There is no adjustment possible by turning the bolt on the end of the cam is there? One would have to use a tool in the keyway on the other end of the cam to turn it relative to the chain wheel while watching the dial indicators, right?

Also, what is that silver cable snaking its way behind the torque angle dial?

[racing97]

Usually the cams are set at 110 intake and 105 exhaust centers you can advance the intake to 105 for a little better mid-range


regards

[oiler]

Thanks for the info you shared in the forum. I am working on a 2008 GT3. May I know if the cam timing tools the same as a 996 GT3?

[Cupcar]

This is what I got and should work on 2008, you need to know specs you are shooting for:

Stomski Racing - Products

[oiler]

I've got something similar but I do not have the factory manual for GT3 this year (08). So should I start with 110/105? I think the key for this car is 9661/4 not the 9661/2 I have. But the local dealer is unwilling to sell me the tool nor tell me the spec. I got stuck.

[racing97]

If you can find the spec book or manuel it may list the cam opening and closing events, I believe Porsche uses 1mm lift. Simply subtract the opening from the closing event add 180 to it for the stroke employed and divide by 2. This is how these specs are generated and I think you will find them in the manual listed somewhere although they come and go as specs listed over the years. If not and you are up against the wall and you know that emissions on street cars are mandated the less timing at TDC the better the readings so I, and this is only my opinion, would widen the L/C to 110 intake 115 exhaust.

regards

[Graham du Toit]

We are fitting new cylinder head gaskets , studes etc and also have an issue with camshaft timing on a 2004 GT3. Does anyone knwo where I can purchase a workshop manual as well as the camshaft timing tools?
Kind regards

[racing97]

Stomski Racing has the tools

regards

[Cupcar]

If one wants the factory type key tool, I believe Baum Tools sell them. Otherwise try an out of state dealer for the tool such as Sunset Porsche in Oregon.

I cannot find the actual timing specs in the GT3 factory manual- it just has one set the cams with the key tool.

The better way in my opinion seems to be a Stomski type tool which allows one to really check the timing, rather than rely on the key slot to be machined correctly relative to the lobe centers.

Recall the street cars use the Variocam device which may make a Stomski type tool a little more complicated to use - something one does not have to deal with using the non-Variocam race cams.

[racing97]

I own the Factory tools and in 2000 they where $2800.00 without dial indicators


regards

[AlfonsoR]

Originally Posted by racing97

I own the Factory tools and in 2000 they where $2800.00 without dial indicators


regards

Is the Stomski set as good as the factory in terms of quality?

[racing97]

I think they are at only a fraction of the cost

regards