oil modification on 1974 2.7 911

[porsche builder]

Just wanted to share how I did oil modification on my 2.7...I used a cordless drill n started with a 3/8 drill bit with a copper pipe around the bit to protect the case, held drill at approx 28 degrees n aimed at the cross passage, about 1/2" down the hole ..next I put pressure on drill against copper pipe n it started bitting into the side wall, once it cut in far enough then I put down pressure on the drill to drill a straight hole, then I increased drill sizes till I got to 12 mm..then I went to the local hardware store and bought a 1/4 pipe tap n cut it short n welded a cut off socket onto it..on the case I took out the oil plug for the oil passage n drilled straight threw the first webbing of the case u will see in my picture, only way I could get a tap in there n drive it n then get the pipe plug in it..worked awesome..the trick was the copper pipe to protect the case..

[theiceman]

What is the purpose of the oil Modification Posche Builder ?

[jpnovak]

Nice work.

This is the standard oil bypass modification. Needed on most early cases.

[RedCoupe]

Every shop needs a mahogany work bench and a stainless steel fridge for beer! Classy shop!

[db_cooper]

Originally Posted by theiceman

What is the purpose of the oil Modification Posche Builder ?

I recall (my memory could be faulty) it has to do with the excess oil, when the oil is in by-pass from the oil pump, the excess oil is diverted upstream of the oil pickup and available to the oil pump..rather than being dumped back into the sump.

The idea was to prevent oil frothing and keeping the engine case oil level down.

Later engines have this feature built in from Porsche.

There is a tech write up somewhere.