Issue with updated camshaft housing oil fitting

[jonesb930]

So as described in Wayne's book, I ordered the updated oil fittings with the restrictor inside for the cam tower oil feed lines (same lines that feed the updated tensioners). The new fitting looks correct and were the OE Porsche ones off Pelican (part# 901.105.361.01) but will not thread in either side. The threads in the cam housing appear clear and perfect. Unfortunately, I cannot find the original ones to test.

Has anyone had issues with these? I may order a chase tap and die set to see what out of spec.

[rdimarco]

Hey Bill,
My cam restrictors were very finicky to thread in, but once the perfect alignment was found they went in. I have some extras if you want to try them out. Is your motor in or out?
Rick

[jonesb930]

Originally Posted by rdimarco

Hey Bill,
My cam restrictors were very finicky to thread in, but once the perfect alignment was found they went in. I have some extras if you want to try them out. Is your motor in or out?
Rick

Rick,

The motor is out on the stand. I did confirm it’s an M12-1.0 thread. I have a bottom tap but not a thread chaser so I’m a bit reluctant as the tap does thread in easier then the fittings but does start to cut the aluminum. I may try tuning a wire brunch across the fitting threads. I’m wondering if the coating is built up a bit much.

Question for you, can you measure the threads with a vernier caliper on your fittings? I’m getting 11.94mm on my new ones.

[rdimarco]

Question for you, can you measure the threads with a vernier caliper on your fittings? I’m getting 11.94mm on my new ones.

One pair OD measures 11.84mm across the threads. 2nd pair, one is 11.85, the other 11.91mm.

[john walker's workshop]

Why do you want to restrict the oil to the cam and rockers. Just because you can doesn't mean it's a good idea.

[jonesb930]

Originally Posted by john walker's workshop

Why do you want to restrict the oil to the cam and rockers. Just because you can doesn't mean it's a good idea.

Honestly John, I was questioning this update as well. I have updated to a C2 oil pump so I figure I have more flow already so diverting from here may not really matter. This was something Porsche updated and was recommended in Wayne's book. I also "misplaced" my original adapter fittings so had to order new ones.

Bill

[jonesb930]

Originally Posted by rdimarco

One pair OD measures 11.84mm across the threads. 2nd pair, one is 11.85, the other 11.91mm.

Looks like my new ones are on the high end of spec.

[gled49]

I’m with John, why restrict the oil in an air and oil cooled engine.

[E Sully]

You could run a die over the threads on the new fittings.
As far as installing them or not, I have read quite a few positive threads after install, but no issues later on. One of the threads was on a 1973 like mine and he reported very good running afterwards.

[PeteKz]

Bill, ditto John and Glen's questions. Was your oil pressure low, or chain rattling (low oil pressure to the tensioners), or some other reason to add the restrictors?

I recall reading that Porsche installed those restrictors to reduce oil flow to the cams and rockers, to prevent oil buildup in the cam housings and causing leaks at the covers, and to reduce oil foaming. That might be an issue on race cars and engines that are constantly at 1+g turns and 8000 RPM, but not a concern on street cars.

I did the reverse on my last build. I used a turbo oil pump in my 3.0/3.2 build, so I had excess oil capacity and decided to put it work cooing the heads. I increased the diameters of the holes into the oil spray pipes to allow more oil into the pipes and onto the cams, rockers, and heads.

[jonesb930]

Originally Posted by PeteKz

Bill, ditto John and Glen's questions. Was your oil pressure low, or chain rattling (low oil pressure to the tensioners), or some other reason to add the restrictors?

I recall reading that Porsche installed those restrictors to reduce oil flow to the cams and rockers, to prevent oil buildup in the cam housings and causing leaks at the covers, and to reduce oil foaming. That might be an issue on race cars and engines that are constantly at 1+g turns and 8000 RPM, but not a concern on street cars.

I did the reverse on my last build. I used a turbo oil pump in my 3.0/3.2 build, so I had excess oil capacity and decided to put it work cooing the heads. I increased the diameters of the holes into the oil spray pipes to allow more oil into the pipes and onto the cams, rockers, and heads.

Pete,

It's a fresh rebuild (still assembling). I do have larger oils squirters for the pistons now to assist in cooling them so I figured restricting the cam towers could compensate. I did add the larger 964 Oil Pump as well though. They are easy to swap out later as they are accessible so I suppose we'll see what the pressure looks like once its running.

Bill

[PeteKz]

Yup, it's easy to swap them in and out and see if that makes a difference in your oil pressure. If little or no difference, then I would run without them. With the 964 pump, you should have plenty of oil.