Cost once I split the cases?

[kav]

I am currently doing a top end rebuild on my 1969 911T and it's been going pretty well. I have the top end stripped down, all of the heads etc back from the machine shop and parts are arriving mostly from our host.

The bottom end was not the problem so I decided not to split the cases to save time and money. The engine has 191,000 miles on it do I need to do the bottom end or as a few people have told me, "the bottom end on those engines are bullet proof, if it isn't broke don't fix it".

My question is how much extra money am I looking at if I do split the cases?

Cheers

-Kav

[Tippy]

I'll never understand that theory as the low end is minimal work. From my understanding, you'll have to line bore the mains again since the case is mag. I couldn't sleep at night not knowing the condition of the bearings and journals.

[jwasbury]

Originally Posted by kav

My question is how much extra money am I looking at if I do split the cases?

Its not really possible to answer the question precisely without splitting the case and assessing condition of the components.

I was going to only address the top-end on the 3.0L build I'm doing, but I decided to have a look at a rod bearing to assess condition. The rod bearings were baaaaad. At that point I felt it necessary to split the case and do a complete bottom up build. I can tell you that the parts alone to do the bottom end and seal up the case was pretty close to 1k for me.

That's rod, main and IMS bearings, a wrightwood racing bottom end gasket/seal kit, new timing chains, a tube of Loctite 574, tube of Curil T, and a tube of assembly lube. Used GT3 rod bearings so that was the most expensive thing.

[E Sully]

It seems if the case does not need work, and standard bearings are used it is not much extra.
My question is, once the case is line honed, is it necessary to have the case halves done to bring it back to spec for the bearings? I have read oversize bearings are extremely expensive, if available, if this is not done.
If the casework is done to bring it back to spec for standard bearings, what else needs to be done as far as cylinders and heads to meet tolerances?
Seems it can get a bit expensive.

[tharbert]

The problem is, we are talking about mag cases. I think the 3.0 is aluminum? Anyways, they tend to warp and most of the "required" machine work is to true up all the important surfaces.

Re-surface case halves and align bore mains back to STD - Since the case halves don't use a gasket, they HAVE to be true. So, when you take a little off the case half surface, it makes the main bearings out-of-true so they have to be align bored.

Deck cylinder surface - this brings all the spigots back to the same plane. If they aren't level, reassembling the top ends becomes problematic.

The head studs should be time-serted. Do a little searching here on the topic and you'll see why.

There are a couple very highly suggested improvements that aren't too expensive and represent OEM mods made to later cases:
Oil bypass mod and an accompanying 4 rib pump upgrade
Install oil squirters

[Steam Driver]

Aluminum cases aren't immune to warping either. My SC case required it as several of the MB webs were out of alignment. Relatively low mileage too, so go figure. Except that the P/O was an avid auto crosser.

[Cairo94507]

I couldn't sleep if I had the engine out and was already doing work and didn't touch the bottom end. I think it well worth it to split the cases and do it right. Once done you won't have to worry about it later.

[kav]

Originally Posted by Cairo94507

I couldn't sleep if I had the engine out and was already doing work and didn't touch the bottom end. I think it well worth it to split the cases and do it right. Once done you won't have to worry about it later.

I hear you all! I've had those sleepless nights already thinking about it. Lets say I split the cases and find no nasty surprises, just 191,000 miles of wear. Can anybody give me a ballpark figure for the parts and machine work, oversized bearings, align bore, head studs time-serted etc.

Remember I live in expensiveville, CA.

Cheers

-Kav.

[304065]

Kav here is the Ollies price sheet-- I am willing to bet that your intermediate shaft bushing needs replacement-- so price that in. You should consider sending the whole thing to Ollies to have it done right.

Home Page

[gtc]

I'll take a stab at it:
$725+ to have the case halves surfaced and brought back to standard by Ollies
About $850 for bearings, gaskets, etc, depending on brand (see Glyco rod bearing discussion) and what is replaced (#8 bearing yes/no?)
Parts:
IMS Bearings Inner - Genuine - $47.50
IMS Thrust Bearings- Glyco - $27
Crank Bearings - Glyco - $115.25
#8 Crank Bearing - Genuine - $129.25
Rod Bearings - Genuine - $102 (or Auto Associates for $400)
Rod Bolts/Nuts - OEM - $165 (or buy ARP for ~$175)
Case Perimeter Sealant - Threebond 1184 - $15
Case Bearing web Sealant - Loctite 574 - $25
Case Gasket Set - Reinz - $220.75 (you probably have this already)

Also think about oil pressure relief pistons and springs

[tharbert]

Originally Posted by 304065

Kav here is the Ollies price sheet-- I am willing to bet that your intermediate shaft bushing needs replacement-- so price that in. You should consider sending the whole thing to Ollies to have it done right.

Home Page

Graham hit the high spots. You must have the head studs time-serted. I don't think you'll see any debate otherwise. There are a couple other important studs that require time-serting as well, one of the mains cradles I think: $390.

Deck cylinder surface: $150

Minimum crank work: Evaluated, Magna-fluxed, micropolished@$100. Maybe add straightened and balanced@$110

Then, a suggested upgrade even for a simple daily driver: Piston Squirters@$440

I think your best bet is to ask for advice from one of the shops that does this type of work. Steve and Rennsport and Henry Schmidt of Supertec are expert contributors here and do this type of work. Ollies is also a left-coast go-to machine shop specializing only in air cooled Porsche engines. Give one or more a call. All these guys love to talk Porsche and I've found them very responsive and customer friendly. If you do go down this road, you're going to have to get your case and crank to them for assessment. Then the fun begins.

Keep us posted on how this turns out.

[kav]

Thanks so much for all the advise! So I'm looking at around 2k with mods, parts and labor. That gives me something to think about.

I will let you know what path I go down.

Cheers

-Kav



[xQUOTE=tharbert;8813858]Graham hit the high spots. You must have the head studs time-serted. I don't think you'll see any debate otherwise. There are a couple other important studs that require time-serting as well, one of the mains cradles I think: $390.

Deck cylinder surface: $150

Minimum crank work: Evaluated, Magna-fluxed, micropolished@$100. Maybe add straightened and balanced@$110

Then, a suggested upgrade even for a simple daily driver: Piston Squirters@$440

I think your best bet is to ask for advice from one of the shops that does this type of work. Steve and Rennsport and Henry Schmidt of Supertec are expert contributors here and do this type of work. Ollies is also a left-coast go-to machine shop specializing only in air cooled Porsche engines. Give one or more a call. All these guys love to talk Porsche and I've found them very responsive and customer friendly. If you do go down this road, you're going to have to get your case and crank to them for assessment. Then the fun begins.

Keep us posted on how this turns out.[/QUOTE]

[911tracker85]

I am just begining a full rebuilt of a '78 3.3 turbo motor.

at first I tried to justify what conditions would allow me to pass on splitting the case.

I came to realize I am spending a ton of $$ on this project. and if I scrimp on this and it shortly blows the whole dream .....

good luck