Line boring crankcase

[roialex]

Hi so after multiple mesure i finnaly found that my mag case is wraped.I am from quebec and I don't have any porschr expert machine shop near me.
Can I send it to a normal engine machine shop ?
Is there any probability that they broke my crankcase?
What if I heat the crankcase to high temp and torque it down with crankshaft in so it unwrapped?

Thanks for advice.

[Tippy]

I have no problem having run of the mill machine shops doing most machining, but in the case of a mag 911 case, I'd take it to a machine shop that knows these engines.

You cannot heat the case and realign. Doesn't worky that way.

It's needs a proper align bore.

[roialex]

ok thanks I made some research for porsche machine shop near me and only found Anchor Atlantic in NJ any other recommandation?

[JFairman]

I've read good things about them here, and also heard good things about Verden Tool in Dover NJ. 973-366-7510
good luck.

[Walt Fricke]

+1 on Verden

One thing you really want to discuss with the machine shop is having the bore in the case standard after they are done. This usually requires that they mill off a small amount of the mating surfaces of each case half. That way when the line bore tool cuts new bearing holes to the standard/original diameter, they are all fresh and aligned with each other, but you can still use the standard sized bearings. Oversized bearings are expensive, and if you ever have to grind your crank you will find that bearings with an oversized OD and undersized ID probably don't exist - or are even more expensive.

If the shop knows all about this, that is a sign you can trust them to know how to do this on a 911.

But Quebec is full of racing addicts, and plenty of them have Porsches - I meet them at the PCA races I go to. Most speak French, too. Alain Goulet comes to mind. Don't you have any local fellow Porsche owners you can turn to to see about shops in Quebec, or at least Ontario?

[roialex]

Yeah i know alain too I spoke with him few weeks ago in his garage. The things is alain don't do any of the machining by himself. I will call him tomorow to see if he got any recommandation. Thanks For the advice

[faapgar]

There are two guys in that area I used for 40 years.One is Verdon Tool & the other is Rich Jascic in Blairstown NJ.908-362-8163.He did two for me last month and he has done around 80 now.Cost is $1200-1500 for an average.QUICK TURNAROUND.Fred Apgar

[roialex]

Is that an average estimate of all machine shop 1200$/1500$ for a proper line boring job ? Plus return shipping or return shipping included ?

[faapgar]

Shipping would be extra for sure.Call him up.He is very thorough and up front.Line bore includes intermediate shaft as well as cylinder spigots.Fred

[roialex]

Ok thanks you will do on monday for sure, i think he's not open this weekend. Also called anchor atlantic to found out they are not doing case work only head so will give a try to Rich Jascic

[Steve@Rennsport]

FYI,...

Simply line-boring these mag cases will not fix the problems. The case MUST have its parting lines machined flat again before line-boring back to standard.

AFAIK, only Ollie's and Competition Engineering have both the requisite tools and experience to perform these critical operations.

[crg53]

To take any doubt out of getting the line boring job done perfectly, why not ship the cases to Steve Weiner at Rennsport Systems | Porsche Performance Systems and Support, he is on here all the time with top notch advise. I know it's all the way to Portland Oregon, but shipping wouldn't be that much more, and you would have peace of mind, worth more than the extra cost of freight.



Sorry Steve, I was typing as you were posting. :-}

[SexOnTheBeach]

Ions ago I sent a mag case to Ollies in Cali, it came back perfect, so my point is they been doing this since the beginning of my Porsche time!!

[Jeff Alton]

We have had a few done recently at Ollies. All perfect, it is the only place I will send them.

Cheers

[Wayne 962]

Originally Posted by Steve@Rennsport

AFAIK, only Ollie's and Competition Engineering have both the requisite tools and experience to perform these critical operations.

Agree with Steve. The mag cases are a weird bird. Send it to Walt and it will be done right. About a decade a go, the full machining process was about $3500 per case. The list of everything that needs to be done is detailed out in my book.

-Wayne

[kwikt 911]

If the case is only disassembled to reseal is an align bore required?

[faapgar]

Originally Posted by Steve@Rennsport

FYI,...

Simply line-boring these mag cases will not fix the problems. The case MUST have its parting lines machined flat again before line-boring back to standard.

AFAIK, only Ollie's and Competition Engineering have both the requisite tools and experience to perform these critical operations.

Hi,Rich has the proper tools and 45 years experience to do this work.Studs are removed and the parting lined machined flat then bored back to accept standard bearings as well as the intermediate shaft.Cylinder spigots are trued as well.The fun part is starting the car and the oil pressure is as new.He does 356 as well.He has done 1000,s of jobs for me & every one was perfect.Sharp guy & on time.$3500 sounds like hero pay for saving a life.Rich Jascic 908-362-8163

[Tippy]

$3500 is ludicrous...

There's nothing magical about the operation. If there is, I'd love to hear....

[Steve@Rennsport]

Originally Posted by kwikt 911

If the case is only disassembled to reseal is an align bore required?

Yessir, absolutely.

Many years ago, I proved this to a client on his 2.7 by by relaxing all the case through-bolts, then re-torquing them to spec.

The crank would barely turn without an extraordinary effort.

No cutting corners on mag-cased engines,.......

[tharbert]

Originally Posted by kwikt 911

If the case is only disassembled to reseal is an align bore required?

Yes. The case warps as it's unbolted. There is a recent thread where someone tried to reassemble a mag case without it being machined. The crank seized as soon as he tightened the thru-bolts.

In addition to the align bore and cases halves machined back to standard, several other things need to be done too. Because of the warpage, the spigots won't line up either so they need to be machined back level to each other. Imagine trying to bolt the cam towers on only to find the heads don't line up.

The head studs and a particular bolt in the case web need to be time serted.

As Wayne points out, all this is explained in his engine rebuild book.

I had mine done by Ollies too...