Reiver

I just got Wayne's book on rebuilding a flat 6 911. Really a nice booklet.
So I'm looking at the "When to rebuild" section at the leak down numbers and oil consumption.
He says a newly rebuilt 6 will have from 3 to 5 psi leakdown and under 10 for a 'driven/car with miles' in good to go shape.
I don't get it, so am I just lucky or do other very high mileage cars retain good comp/lk down if taken care of.
I've had 2 leak downs done by 2 diff shops in Phoenix....Jacksons and Stuttgart SW...both well respected indy's.
The tests were done 11k miles apart...at PPI and recently and both showed similar numbers with an avg of 4-8 psi.
This was at 215k miles and 226k miles.
Did I win the Porsche lottery or what?
The 30 year old SC runs like a top, I run it correctly (warm up etc) but with gusto and it just acts like it's freakin 'new'.
I'm not woofing as they say in the Army, just amazed.

theiceman

i think sometimes people get hung up on numbers.. never ever checked my leakdown and i really dont care . it doesnt use much oil .. maybe a quart between changes at 3,000 miles , car runs great .. why would i go looking for stuff that may make me worry...

I would be curious as to what other people are reporting tho ..

Reiver

Did you have a PPI done initially?

theiceman

naw ... im kind of a high roller that way .. kinda figured id just fix it if it were broke ..

Reiver

Some of the posts on the P site indicate similar LD results on even higher mileage cars.
I find that phenominal considering the use.
The mechanic that cared for my SC for 25 years had one of his own and didn't do a top end or open the motor until he had 368k miles on it.....of course it was prop taken care of and that seems to be the issue (along with some assembly luck).
Of course..."Your experience may vary"....

ivangene

200k....all around 5%, motor has never been apart

we split the lotto winnings

Reiver

isn't that cool....ok, send me your bank account info and I'll have my agent in Nigeria transfer funds.

healey

I just picked up my first air cooled porsche ( own a 928 as well), an 88 Carrera Targa with 123K miles. PPI test with 175 compression on all six cylinders and leaddown between 2-6%. Engine has never been apart and PO liked to wind out the engine and drove it regularly for 3 seasons/year and changed the oil religiously every 3K. I am hoping to get another 100K on the engine. Compare that to cars that sit and need a top end rebuilt in 60-80K. These cars are meant to be driven for sure.
Healey

race911

Which is all about the valve guides. I lived the era, though not having a "real" shop I was still mainly dealing with 2.7L engines. But enough relatively low mileage 3.2L engines came to my attention that it wasn't tough to figure out there was a problem.

Two friends of mine who avidly (as in class record pace) time trialed 3.2L cars back in the Olden Days needed to do guides at.............~60K and ~180K. I now own the 180K (well, it's got 190K on it now) engine. Was so good inside the P/C set didn't get changed out on the rebuild.

Simple truth is that if valve guides were as easy to change as brake pads, most would be replaced every 100K or so.

Reiver

You know Jack @ S SW. We just had this conversation and his opinion is it was a serious bad batch of valve guide metalurgy. He hasn't seen the prob on newer rebuilt 3.2's.

race911

All the old engines got pulled apart because they puked tensioners. The 3.2s were the first ones to make it past 50-60K without that problem (or pulled studs, from the 2.7 era).

I've done mag engines with as few as 30K before a tensioner went, or studs pulled. Would never consider reusing guides, or replacing with factory. The aftermarket guide thing was in full force when I came on the scene in '80. I was originally schooled by Anderson, Woods, Robinson, etc. at Garretson. I'm not sure if they were using Lukes & Shorman guides then, or they were making their own. (They had the shop 935 going at that time--one of the first engines I saw apart and got the "demo" on was the engine that had just come back from Le Mans.) But no one was using OE guides.

Glad everyone's top ends are going ultra-high miles. I just don't get why there's a badge of honor pushing components past their serviceable lifetimes.

theiceman

Ken I m a not sure if its a Badge of Honor or a protection of the wallet .. But i do agree.. People are proud of the fact they can go so long without opening it up and it does speak to quality, but dont let it get the better of you ..

When i bought my gar they told me the engine had been redone at 90 K ...that would be 90 thousand kilometers .. thats nothing .. you could see all the seam sealer on both the case halfs and transmission..
Really i didnt much care . have 250,000 km on it and it runs as strong as ever ...

Reiver

If it is a badge of honor it belongs to the design and builders.
I'm more amazed than anything. I've seen cars do high miles before but they are normally very tired with low compression and no get up and go.
These cars still run 'as new' ...that is amazing.
I've also had 2 dif shop owners tell me rebuilding now makes no mechanical or monetary sense.

theiceman

..it doesnt.. that why Porsche provides complete "crate" engines for the 996 and beyond range ..
if in doubt swp it out .. all speaks to Porsches awareness of the amount of engine changes and rebuilds required.
I think Porsche sends them all to a factory to be refurbed on an assembly line

race911

Of course not on the REBUILT ones, no one uses factory guides when you've gone inside for any reason.

Not sure why your engine would have had to come all the way apart. See, unless you have some catastrophic (read: oil related) failure, no reason to split a case until you're into the mileage we're discussing here. Or beyond.

Now we're at the point of the discussion--worn out valvetrain. I've beat on ultra-high mile engines on track. We didn't have data back then, absent the speedo and stopwatch. So they work fine, until they don't.

My position is that if you've got 150K+ verified original, you're keeping the car, you're going into the valvetrain at some point. So you do it at 200K, 250K.....and then the car gets driven another 15-20K before it gets parked forever.

Now, if you don't have the bucks to spend what might be an amount equal to the value of the car, different story.

I'll let anyone who's been into at least a handful of these things tell me he doesn't shake his head when he looks at the stem taper and guides from and ultra high miler when it all comes apart.

Per my friend, dealer mechanic and just off his stint at PCA tech adviser, there's no reman facility--everything shipped at this point is new. Surprised me, but he said it's cheaper to build new than deal with figuring out which components are reusable. If anyone else has definite word otherwise, feel free to correct me.