pulling cam covers

[shadrach74]

I used the search, but I found no info on my question.

Both cam coves are leaking enough to create smoke when stationary. Tried to re-torque and that made it worse. I have the cam lock left over from the IMSB retrofit that was done at an indy.

2 questions:

1) What size bolt is used to hold the cam locks in place.

2) the cam locks that came with the IMSB retrofit look very different from one another. Does the IMSB retrofit come with the tools to secure both cams on the 5 chain engine in my 2002 S?

I suspect the IMSB came with one cam lock for the 5 chain engine and one for the 3 chain engine. I am in a pickle as to how to secure both cams at the same time without spending money on buying or fabing a second part...

Ross

[JFP in PA]

You cannot use the tools for locking the cams to hold and retain the cams when removing the cam covers, that requires entirely different set of tooling.

This is what a home brewed version of Porsche's cam holding tool look like:



A nicer made unit:



And this is the factory unit:

[shadrach74]

Thanks JFP,

Can I ask why the the LN units cannot be used? In looking at you picture, I cannot see the reason why?

R

[Duffy3074]

Because it only retains one cam................

[JFP in PA]

Originally Posted by shadrach74

Thanks JFP,

Can I ask why the the LN units cannot be used? In looking at you picture, I cannot see the reason why?

R

Very simply: Because the cam holding tool screws into the end of the cam rather than slides into a slot as the locking tool does, and therefor has a much better grip on the cams. There is a lot of spring pressure on the cams and you do not want to have them move away from the cylinder head saddles when the upper saddles (part of the cam cover) are removed.

And just a by-the-by, be very careful with the cam covers, they are machine matched to the mating cylinder head, and cannot be mixed or replaced.

[shadrach74]

Originally Posted by JFP in PA

Very simply: Because the cam holding tool screws into the end of the cam rather than slides into a slot as the locking tool does, and therefor has a much better grip on the cams. There is a lot of spring pressure on the cams and you do not want to have them move away from the cylinder head saddles when the upper saddles (part of the cam cover) are removed.

And just a by-the-by, be very careful with the cam covers, they are machine matched to the mating cylinder head, and cannot be mixed or replaced.

So, if you crack a cam cover you must find a good MIG welder or your engine is toast???

[JFP in PA]

Originally Posted by shadrach74

So, if you crack a cam cover you must find a good MIG welder or your engine is toast???

Basically; the cam cover and cylinder head saddles are machined as one assembled unit, switch covers on a head and the saddle journals no longer match and are out of round making the new assembly useless, which is why Porsche sells them as a set.

And these alloys are easier to weld with a TIG than a MIG welder.............

[shadrach74]

What's interesting is that a friend that works for an Indy swears that the LN lock is a knock off of the factory tool. He also said that valve spring forces are very low at TDC. And that he has done this procedure a number of times with the slotted locks.

I'm not ringing in personally as i have no idea, just tryin to get as much info as possible, unfortunately some of it's contradictory...

[JFP in PA]

Originally Posted by shadrach74

What's interesting is that a friend that works for an Indy swears that the LN lock is a knock off of the factory tool. He also said that valve spring forces are very low at TDC. And that he has done this procedure a number of times with the slotted locks.

I'm not ringing in personally as i have no idea, just tryin to get as much info as possible, unfortunately some of it's contradictory...

The LN tool is a knock off of the OEM tool, but of the cam locking tool, not the cam holding tool; they are two different items with different part numbers.

Your indy is correct in that spring pressures are reduced at TDC, but they are still there or you would not need the locking tool to keep the cams from moving while doing an IMS witht the engine at TDC. The cam locking tool keeps the cams from turning under spring pressure, the cam holding tool keeps the cam in the journal saddles after the cam cover is removed, other wise one end of the cam would simply pop up from spring pressures, possibly breaking the cam itself.

At the end of the day, it is your car, and you can do it any way you please........

[shadrach74]

I'm buttoning it up and taking it to a different Indy that has the hold down tools. This is a DIY that will cost more interns of time, effort and specialty tools than it's worth. The tolls alone are $500 to buy or $50wk to rent. Having the tools fabeducated adds an unknown cost and time to completion. The whole ting appears to be a PIA that I'll happily pass on to a pro.

Thanks for talking me down of the edge. I'm sure I could have completed it but the returns of the DIY we're minimal (if at here are any at all) and the risks great...

[shadrach74]

JFP, are you actually in PA and of so, where?