Press fit question, Aluminum to Aluminum

O

outsider347

Active User
Registered
Joined
Sep 3, 2012
Messages
311
Hello Gents.
Happy New Year to all.-

Just about to start a Porshe 911 aluminum engine rebuild.
I drilled & tapped the oil galley plugs & pulled them out to get a proper cleaning of the galleys. The original plugs were solid aluminum, and I plan to turn new aluminum for the job.
The original plugs were also epoxied into insure sealing. Looked to be JB weld type of product & I will use it as well.
When I was pulling the plugs, Had to apply a bit of heat to get the plugs moving.

Question:
What would be the suggested interference fit (??) aluminum plug to Aluminum bore. For the job to press in smoothly?

Note: the oil galleys are the mains...can't have a screw up here
Tks for your help.
ed
 
Why don’t you ask this question on the Porsche forum? There has to have been some members that have done exactly what you are getting ready to do.
 
Actually I did post there and got "0" response.

This being more of a machinist question...that's why I am looking for help here
 
Buy 1 real Porsche part and measure. OD tolerance is probably controlled to +.01 mm -0 or tighter.
 
What is the diameter of the hole you are trying to plug? I usually use a .0008-.0025" interference for sizes under an inch depending on how tight I want it. Somewhere around a thou or two is my go-to.
 
Fitting aluminum with interference can be problematic. Aluminum likes to gall when rubbed with aluminum. Even the hardest aluminum will gall if things aren't aligned perfectly. My old-time toolmaker friend likes to characterize it as 'toothpaste' during assembly. -- I think that's extreme, but it is a good indicator to proceed cautiously.

Because the factory used epoxy will tell you that they factory left significant clearance in order to have any epoxy remain during assembly. An interference fit will just squeeze out all the epoxy. People here with far more experience in using epoxy with aluminum can give you and idea of the appropriate clearances. I like the idea of buying one to get your dimensions.
 
Rennlist.com was of no help? Site receives high traffic volume at least in the 991 forum.
 
Gents
Apologies , not getting back here sooner. I live S. of Buffalo and have been involved in snow removal since last Thursday.

I have a few more things to report back here & will do as soon as I get back to my shop.
At the moment ......Eat, Sleep, snow
 
You must log in or register to reply here.
Back
Top