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The 930 bottom end has to be one of the most robust bottom ends ever designed. Seriously.

It lasts a long time.

I have Glycos in mine running 1.4 bar with likely detonation.

Tore it down and the bearings are perfect. Drover it hard for 4-5 years that way.
Old 03-15-2017, 12:22 PM
  Pelican Parts Technical Article Directory    Reply With Quote #61 (permalink)
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Getting ready to drop $20,000 on engine overhaul

Quote:
Originally Posted by boosted79 View Post
"I'm going back and forth on this neither mechanics want to leave the bottom end alone. Both are instant that if we do the top end we have to do the bottom end."

Sounds like my dentist. I've got a slightly loose molar, every time I go there he tells me "it's going to blow up, fall out, etc, etc. I need to pull it and start doing bone grafts for an implant" at the cost of a few grand. He started telling me this 5 years ago, the tooth is still there and still working..

Your guy sounds like he's a pro at separating people from their money. Tell him what the oil pressure is and ask him why he says the bottom end needs to be rebuilt. Is it knocking, did you run it without oil, is it leaking from the case seam or what?


No this car has only been cared for and well maintained.

Please don't get mad with me but understand how this is for me. On one hand I probably do need the valve guides replaced.

Then I have you guys telling not to do the bottom because the you can't buy good bearings.

End the end this has become a albatross.

Has anyone on here recently done the bottom in of the 930? Did you run into the problems discussed above?

Last edited by 93097004xx; 03-15-2017 at 01:45 PM..
Old 03-15-2017, 01:18 PM
  Pelican Parts Technical Article Directory    Reply With Quote #62 (permalink)
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Mine didn't blow, I'm replacing the aluminum rods with some billet rods. Can't reuse rod bearings because aluminum rods have hole drilled in bearing for retaining pin so if rod stretches to the extreme it won't spin the bearing. I'm going with the clevite bearings.
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Old 03-15-2017, 01:22 PM
  Pelican Parts Technical Article Directory    Reply With Quote #63 (permalink)
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Quote:
Originally Posted by boosted79 View Post
"I'm going back and forth on this neither mechanics want to leave the bottom end alone. Both are instant that if we do the top end we have to do the bottom end."

Sounds like my dentist. I've got a slightly loose molar, every time I go there he tells me "it's going to blow up, fall out, etc, etc. I need to pull it and start doing bone grafts for an implant" at the cost of a few grand. He started telling me this 5 years ago, the tooth is still there and still working..

Your guy sounds like he's a pro at separating people from their money. Tell him what the oil pressure is and ask him why he says the bottom end needs to be rebuilt. Is it knocking, did you run it without oil, is it leaking from the case seam or what?
lol, my dentist did the same thing. Little worn spot on my lower gum and insists that I should get a graph, or the tooth, may die, explode, whatever. Its been 4 years and all is still good. Back to the OP. Do the rebuild if you wish, but at the end of the day you will be paying $20,000 for peace of mind. The car will run exactly the same as it currently does. Instead, send it to TurboKraft for some mods with a $20,000 check and you'll actually get something for your money.
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Old 03-15-2017, 02:10 PM
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"I'm going back and forth on this neither mechanics want to leave the bottom end alone. Both are instant that if we do the top end we have to do the bottom end."

No one is getting mad at you, we're just trying to save you some money and get you some peace of mind. If the car really only has 54k on it and it isn't showing any symptoms (low OP, knock, leaking etc. ) there is no reason to tear into the case, period. If it's been well cared for there is no reason the bottom end won't go at least 100k miles. Even if the rear main seal is leaking it can easily be replaced w/o splitting the case. I would be very hesitant of using a mechanic who tells you that he will only do a total rebuild when there is nothing indicating that the bottom needs it. That is NOT what a good mechanic will tell you. He may be good from a technical standpoint but if he can't give you a good reason why the case needs splitting then he isn't good from an honesty standpoint. A top end isn't a bad idea, guides, valve job, rings. As for being an albatross, look at what you paid for the car and what it's worth now. Sure you put some money into it but I'd bet you are way ahead of being even.
Old 03-15-2017, 02:43 PM
  Pelican Parts Technical Article Directory    Reply With Quote #65 (permalink)
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Quote:
Originally Posted by 93097004xx View Post
No this car has only been cared for and well maintained.

Please don't get mad with me but understand how this is for me. On one hand I probably do need the valve guides replaced.

Then I have you guys telling not to do the bottom because the you can't buy good bearings.

End the end this has become a albatross.

Has anyone on here recently done the bottom in of the 930? Did you run into the problems discussed above?
At only +/- 50,000 miles, you would not need valve guides replace unless they had been severely damaged by oil starvation, excessive heat (like running the engine with the fan belt off, and/or rats' nests under the fan shroud, etc.), or some other kind of severe mechanical failure - not even close to the service interval for those, even though the air cooled, turbo engine wears them out faster than a "normal" engine. The fastest, typical wear that I have ever read about is over 70,000 miles, and with your rate of driving, you would not even come near that mileage during your ownership, or in your lifetime, for that matter.

The bottom line is that your engine is not even remotely a candidate for an overhaul, and any mechanics saying otherwise are being remarkably dishonest and trying to take advantage of someone they can tell has very little mechanical knowledge.

Last edited by Rawknees'Turbo; 03-15-2017 at 02:46 PM..
Old 03-15-2017, 02:44 PM
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To ship it you will need a wood pallet and some straps to secure it to the pallet. The straps are probably lowest cost at Harbor Freight.
Then some Visqueen clear plastic sheeting or a cheap harbor freight blue tarp and duct tape to wrap and cover it.

Stay away from these guys that won't do the top end without splitting the case and rebuilding the bottom end too.

If you're not familiar with Turbokraft here's a link to their website.

Turbo Kraft Porche Parts and Custom Builds | Porsche Service Arizona

Turbo Kraft, Inc.
1716 W Broadway Road
Mesa, Arizona 85202 USA
Unit #123
Tel: 480.969.0911
Fax: 602.798.7699
Email: info@turbokraft.com

The owner Chris Carol posts here frequently and helps everyone with the best Porsche 911 and 930 advice you can get.
Old 03-15-2017, 02:46 PM
  Pelican Parts Technical Article Directory    Reply With Quote #67 (permalink)
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Quote:
Originally Posted by Rawknees'Turbo View Post
At only +/- 50,000 miles, you would not need valve guides replace unless they had been severely damaged by oil starvation, excessive heat (like running the engine with the fan belt off, and/or rats' nests under the fan shroud, etc.), or some other kind of severe mechanical failure - not even close to the service interval for those, even though the air cooled, turbo engine wears them out faster than a "normal" engine. The fastest, typical wear that I have ever read about is over 70,000 miles, and with your rate of driving, you would not even come near that mileage during your ownership, or in your lifetime, for that matter.

The bottom line is that your engine is not even remotely a candidate for an overhaul, and any mechanics saying otherwise are being remarkably dishonest and trying to take advantage of someone they can tell has very little mechanical knowledge.


I'll take responsibility for some of this I asked him for a complete overhaul.

The other mechanic is demanding a complete overhaul not Bob.

Bob has only ever done me right.

It really is blowing my mind doing just half the engine.

But if that's what you guys recommend that's what I'll do.

Bob has not seen this car in 5 years.


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Old 03-15-2017, 03:10 PM
  Pelican Parts Technical Article Directory    Reply With Quote #68 (permalink)
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Quote:
Originally Posted by 93097004xx View Post
It really is blowing my mind doing just half the engine.
Why do you think the top end (pistons, cylinders, heads, cams, cam chains, chain wheels and tensioners, etc) needs work? The mileage says its not even close to needing work (and the age of the metal parts is unimportant), and there are no running symptoms to indicate any problems due to unusual mechanical failures or owner neglect or abuse.
Old 03-15-2017, 03:13 PM
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Try to let go of the possible imperfections that might or might not lurk in your crank case. This area was something the engineers got right. If you do the top end it sounds like you'll have a really well sorted 930 of which we have yet to see a picture. I just get the sense that there's a lot more downside risk opening that case.

Take the remaining funds and blow it on 40-50 track days.
Old 03-15-2017, 03:19 PM
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Originally Posted by 93097004xx View Post
Ok why I want to do this? I'm 40 years old and might have the car another 8/10 years. I want to enjoy it as it was meant. To be driven like a porsche 930.
buuuuuuuuuuuuut

Quote:
Originally Posted by 93097004xx View Post
I change the oil every 100 miles.. yes I've put 1700 miles in 20 years!! Lol

Crykie. THE worst thing you could do to your car is exactly what you have done for the past 20 years - NOT DRIVE IT.

Your statements above are so beyond oxymoronic, it's physically painful. A 930 was built to be driven, hard and often. Not 1700mi / 20yrs.

Oil every 100mi? FACEPALM

To pile onto the overwhelmingly universal responses here - sure, do a top end and general re-seal. STOP. Nothing further.

otherwise, THE dumbest use of $20large I can possibly think of

sorry to be brutally honest, but this is literally painful - and - it sure does REEK alot like spending $20k on an unnecessary motor rebuild to be able to stand around it @ the local show 'n shine proudly exclamating 'such'. Sigh. If that's what it takes to make ya feel better, I guess?

now - DRIVE YOUR CAR... it deserves better than to sit and languish and ROT
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Last edited by krasuskyp; 03-15-2017 at 03:27 PM..
Old 03-15-2017, 03:20 PM
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Originally Posted by boosted79 View Post
"I'm going back and forth on this neither mechanics want to leave the bottom end alone. Both are instant that if we do the top end we have to do the bottom end."
If they're insistent then perhaps it's time to find another mechanic. I split the case on mine at nearly 110K miles and it was essentially perfect. If you have a well-maintained 54K mile, reasonably driven car that you've put only (shamefully, if you ask me) 1,700 miles on in beau-coup years I can see no good reason to even consider rebuilding the bottom end.

If you're really looking for a way to unnecessarily part company with ten grand there are better ways to waste it.

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Old 03-15-2017, 03:29 PM
  Pelican Parts Technical Article Directory    Reply With Quote #72 (permalink)
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Originally Posted by Rawknees'Turbo View Post
Why do you think the top end (pistons, cylinders, heads, cams, cam chains, chain wheels and tensioners, etc) needs work? The mileage says its not even close to needing work (and the age of the metal parts is unimportant), and there are no running symptoms to indicate any problems due to unusual mechanical failures or owner neglect or abuse.


I want a quite valve train. I know with a air cooled engine this will not be totally quiet.

I mean I know after 37 years this engine needs some work.

So none of you have done anything to your engines??




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Old 03-15-2017, 03:42 PM
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There's a lash in the valve train of 0.10mm/0.004". When properly adjusted on the looser end, the rockers will make noise.

37 years and 54k miles mechanically, should be near new. Only thing you *might* need is seals on the crank and other easy-to-replace gaskets since they probably went dry and shrank from none-use.
Old 03-15-2017, 03:49 PM
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" I mean I know after 37 years this engine needs some work."

WHY? Do you know? By what objective measurement can you tell this car needs some work?

The WORST thing you can do for that car is what you have been doing, which is driving tiny mileage.

You are better not driving it at all than doing tiny mileage trips.

Drive it hard for a couple thousand miles, replace the few seals and gaskets that you have damaged by not driving it, and call it a day.
Old 03-15-2017, 04:00 PM
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There's a lash in the valve train of 0.10mm/0.004". When properly adjusted on the looser end, the rockers will make noise.



37 years and 54k miles mechanically, should be near new. Only thing you *might* need is seals on the crank and other easy-to-replace gaskets since they probably went dry and shrank from none-use.


Ok I'll just have him do the top end. Thats your guys consensus.

My head is spinning because I had convinced myself of a complete overhaul years ago.




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Old 03-15-2017, 04:00 PM
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I want a quite valve train. I know with a air cooled engine this will not be totally quiet.
Nothing that gets done during a top end overhaul will make the engine any less noisy; unless the current valve lash is set way too loose (can be checked and adjusted without an overhaul), you have compression blow by, past the cylinder(s) and head(s) sealing surface due to broken head studs, or a collapsed timing chain tensioner. And based on your video, you have none of the above.

The engine will not sound even one decibel more quiet following overhaul - no joke.
Old 03-15-2017, 04:08 PM
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If they're insistent then perhaps it's time to find another mechanic. I split the case on mine at nearly 110K miles and it was essentially perfect. If you have a well-maintained 54K mile, reasonably driven car that you've put only (shamefully, if you ask me) 1,700 miles on in beau-coup years I can see no good reason to even consider rebuilding the bottom end.

If you're really looking for a way to unnecessarily part company with ten grand there are better ways to waste it.

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Old 03-15-2017, 04:09 PM
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So none of you have done anything to your engines??



I overhauled my engine back in 2008 or so, due to a knocking noise that I couldn't identify or fix (made many attempts over the course of several months) - turned out to be compression loss due to inconsistent clamping of the garbage dilivar head studs (found lots of fretting on the heads sealing surfaces). I did the bottom end as I was't sure at the time about the fretting - no problems at all with the bottom end but I changed to Raceware rod bolts just for the heck of it. The engine had about 70K miles on it at the time.

I had the cylinder heads rebuilt at the time because it didn't make since to put them back on without a going through, though nothing was out of spec (except for the compression loss damage).
Old 03-15-2017, 04:17 PM
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I miss you, Norm (nohomo, buttofcourse!).

Ditto, my friend (and not that there's anything wrong with that!).

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Old 03-15-2017, 04:41 PM
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