Mag case machining

[gereed75]

Who besides Ollie’s is doing mag case machining, especially align boring/main bearing clean up??

[faapgar]

Where are you located?I have a guy who fixes them after they have been machined by Ollies and others.Done all my stuff for 50 years.When he passes I will not do another 911 engine.Fred

[gereed75]

East coast/ PA.

[Jeff Alton]

Interesting comment Fred. What is that you have found Ollie's is not doing correctly and needs fixing?

[Bigtoe32067]

Yea, inquiring minds want to know.
Plus Id like the name of the guy you use if possible. I have a mag 2.7 I’m about to send somewhere.
You can pm me if you prefer
Thanks
Tony

[faapgar]

I will tread water this morning on this and answer carefully later.Fred

[Inkblot]

Ted @ German Precision did my mag case. It wasn’t perfect first go around, but he took care of me and corrected it. He’s now in Yuba City, CA, and a little hard to get ahold of.
I think EBS also does machine work, and they have a good rep. I’ve never had anything machined there, but they’ve always been friendly and helpful for other parts, etc.

Jake


Sent from my iPhone using Tapatalk

[Jeff Alton]

Not sure if EBS does their own machine work of sends it out. Perhaps they can comment...

[Jeff Alton]

Originally Posted by faapgar

I will tread water this morning on this and answer carefully later.Fred

Please do! Your original post certainly suggested one of the go to shops for this work doesn't know what they are doing....

Cheers

[faapgar]

Ollies has always been a great shop.These are more recent events.Maybe personel changes.A shop is assembling bottom end and crank will not turn or not turn freely.This requires a remeasure then remachine,Bearings are an issue as well.I only use OEM Porsche mains anymore unless I find someone selling Glycos from pre-2000 year.I have bought 2 older sets of Glycos this year pre-1990 that had factory part #.911 101 902 00 that had 2 lines on each shell half from a dial indicator check.Lucky I guess.I have assembled work for customers years ago from them that was fine.The art of resurface of the case halves is just that and case needs to be bolted together with your new bearings to check line bore afterwards to be sure.I DO NOT LIKE paying the VW DIESEL TAX hit on OEM mains from the mothership though.$1200 plus at my cost when I paid less than $100 not so long ago.Fred

[gereed75]

I have also heard of a recent incident where two original matching number cases were screwed up at Ollie’s, and thus the reason for the original post This was attributed to the departure of key personnel. It actually sounds like the same instance referenced here

I hate to throw out the baby with the bath water based on one instance, especially when they have been so good for so long. Anyone use them lately with good results?

Anyone using someone else with good results recently?

[jpnovak]

Craig Garrett (Cgarr at G2 Racing) has resized a number of mag cases with excellent results.

[faapgar]

Mag cases go a little oval with age and can be line honed to standard.Aluminum usually needs the halves resurfaced and I.S.hole line honed.Two different jobs & cost.Fred

[Rosco_NZ]

I understood best approach to machine crank to fit bearings .. rather than machine crank std size & hope bearing tolerances work ... or is this a compromise?

[MST0118]

I used Walt at competition engineering for s 2.8 line bore back to standard, shuffle pin, etc. He did s great job but he’s more expensive than Ollie’s.

[faapgar]

When you want it done right once consider cost for shipping.Neil Harvey is offering this service.I do not know what the cost is so he should offer a cost to resurface the halves and time allotted.Contact him.Ciao Fred

[Walt Fricke]

Cgarr is a master mechanic through and through, and I think his prices, like his work, are as good as anyone's. He knows the drill.

Rosco - that doesn't sound like a good idea. If you line bore without shaving the case halves, you end up with wider bores, which call for oversize (outer measurement) bearings. Those are quite expensive, or were anyway when I had this done. If you turn the crank, now you need over/under bearings, and those really get expensive.


If you have to turn the crank, you have to turn it. But for sure don't if it is in spec. A shop good enough to do the machining will get the bearing saddles to spec, so standard bearings will have the proper clearances with a standard crank.

[Rosco_NZ]

I think I have to turn the crank to 0.25 under ... yes the case will be line bored to standard and part lines machined flat. But the way I understood it, since the bearing tolerances were unreliable, case halves could be assembled with bearings and crank ground to provide exact required tolerance (to accommodate poor bearing finished tolerances). Maybe there is a downside to this .. but I can’t get a straight answer yet.

[Bigtoe32067]

Ok next can of worms
Main bearings Glyco yes or no
Rod bearings glyco yes or no

I’ve read their rods are jinky but their mains are ok. Any thoughts less than 500 words?
Thanks
Tony

[Walt Fricke]

Rosco - well, main bearing tolerances aren't unreliable. Where did you get that idea? It seems Glyco rod bearings for some years were unreliable - mine had quite excessive wear for very little engine hours, like under 10. But there are ways to get bearings which meet specs - like Clevites, or expensive actual Porsche sourced bearings. Perhaps Glyco has remedied this, perhaps not.

But nobody has been complaining about the Glyco mains. And you can measure whatever bearings you get to be sure they are right. Same with the rod bearings, of course. You can use your measurement instruments to confirm things before assembly, and the squishy stuff to check clearances after a trial assembly.

But I'd sure advise against grinding your crank (an irreversible process, basically) to deal with bearing QC problems. What do you do with the next rebuild? Grind journal by journal?