TO Split or not to split

[Rich76_911s]

I am wondering if you all think that I ought to split the case on the engine that I have been tearing down. I had a bad leakdown number on the number 4 cylinder so I wanted to get it apart to see what was going on. I thought that it would be cheaper if I didn't split the case, since I don't think there is anything wrong in there. But at the same time I want to do the job correctly and dont want to skimp now to have to pay later. I am not in any rush to get it all together as the rest of the car is in as many pieces as the engine. Just wanted to get some thoughts. And I can't seem to find anything that would have been giving such bad leakdown numbers. The #4 piston, cylinder and head all look pretty good to the naked eye the exhaust valve is a little darker than 5 or 6 but looks better than 1,2,3. Thanks for your advise.

Rich

[Eagledriver]

It doesn't look like you've pulled the cylinder or piston out for #4 yet so how do you know you don't have a broken or stuck ring?

We need to know alot more about the engine to recommend splitting the case or not.

-Andy

[vichang4]

How many miles on the current crank and main bearings?

[asphaltgambler]

Ditto, mileage and time??

[Rich76_911s]

I bought the engine at a swap meet where I was told that the engine had 65,000 miles on it. I got a good price and he gave me a fair price on my 2.7 that had not been run in 17 years. I have never run the 1989 3.2 engine because I am doing a rebuild on the tub too and it is far from ready to accept the engine. Which is the reason that time is not exactly of the highest priority. During the leakdown test I got absolutely no pressure held in the #4 cylinder all the rest were 12% and below. I have not gotten to the rings yet, but am hoping to get to them by the end of the weekend. Honestly I just don't want to cut corners now and have to redo the teardown and rebuild later, but at the same time I don't want to tear it apart if it is just wasteful use of time and money. u

[Jim Richards]

Originally posted by Rich76_911s
I was told that "insert seller comments here"

"I was told that" means you have no real history to go by. My advice is to find out what's what by splitting the case. Just my opinion. Whatever you decide on, I hope it turns out well.

[Rich76_911s]

That is the what I was thinking too. I wanted to check and make sure that you guys didn't think that it was foolish to break open a case that in all likelihood doesn't need it. I really appreciate everyones help, other than Waynes books I really have no knowledge about this stuff. If anyone still reads this I have another question that I am confused about too. As I said earlier I have a 1989 3.2L engine, but I tested the headstuds to see if they were magnetic but none of them were. I thought that the intake headsteads were steel and the exhaust were another material. I tested to make sure the magnet was strong enough to stick to other studs on the case. What am I missing here? Thanks again.

Rich

[asphaltgambler]

To me, it would be a mistake not to. You have it right there. The big $$$$ dollar factor is IMO starts at the P/C's and up to the valve covers. The big labor (read effort) is in the short block assembly. I don't understand why some people do the whole top end w/o at least splitting the case to make sure all is right with the world.

Think of it this way. Would you sink $200K into a home remodeling job w/o first verifying that the foundation is sound??

[Carrera3.5L]

I agree with the "split the case" guys, you have already done the majority of the work, why not spend a few more hours for the peace of mind?

Sure, chances are the bottom end is just fine. I tore my 3.2L down with 88K on the clock and the bottom end looked perfect. I COULD HAVE reused the bearings.

New mains, clean the pump and intermediate shaft assembly won't cost that much and is cheap insurance, especially since there is some question as to the motor's past history.

You don't seem to be in a hurry anyway, just take it down. You'll sleep better at night.

Ralph

[ChrisBennet]

Pros and Cons of splitting as I see it:
Pros:
- Not much more money than just doing top end.
- If the motor was leaking at a case seam you can reseal things.
- It's a chance to catch anything bad happening to the bearings, etc
- You'll possibly sleep better.
- It's more satisfying. That's a big reason.

Cons:
- At least in my experience it is not just a few more hours to do the bottom end "while you're in there". Between measuring the crank, measuring the case or having a machinist measure it, sending out the crank for checking and polishing, cleaning the case, checking the squirters, I spend many many hours. (I'm embarrased to say just how long it takes me for fear of being labeled retardarded. If you're going to label me, I prefer the term "diminished capacity".)
- Did I mention the hours of case cleaning and sealant scraping?
- You're disturbing a part of the engine that was working fine before.
- Especially if it is your first motor, you may discover that making a leak free lower end looked a lot easier in the brochures.

It looks like I'm trying to scare you off from doing the lower end but I'm not. Doing the whole motor is immensely satisfying. Just be aware that if you work on you motor on weekends between the kid's soccer games, doing the bottom end "while you're in there" may push your schedule out quite bit further than might think.

-Chris

[Rouxzy]

Chris brings up good points but there is something you need to know about Chris. He just finished rebuilding a 3.6 for me. He is more precise than the original builders of the engine. That's probably why he sleeps so good at night.
Tom

[efhughes3]

Originally posted by ChrisBennet



- You're disturbing a part of the engine that was working fine before.
- Especially if it is your first motor, you may discover that making a leak free lower end looked a lot easier in the brochures.

-Chris

Unless I'm reading some of the original post wrong, he does NOT know if it was working fine. In fact, based on what he found in the leakdown test, the motor is not in good shape for one that has such low (alleged) miles. 65,000 miles on a Carrera motor should be nothing. But his tests show otherwise.

[Rich76_911s]

I just got back from getting the pistons and cylinders off of the case. Just want to add that this is absolutely awesome, never done anything like this before and all of you and Wayne I want to thank for sharing the information and giving the confidence to do this rebuild you are all great.

Chris thanks for your opinion and included information. It seems as though you are held in pretty high regard. I hope that I am as meticolous as you have been.

Anyone have a reason why the magnet is not sticking to the intake head studs? I still can't see anything terribly wrong with the fourth cylinder either, even though it is off. I am thinking maybe I had a piece of carbon on a valve or something. Here is a rough picture of the 4,5,6 pistons before I got them off. Man those wrist pins were a pain in the neck. I really think that due to everyones opinions and my own feelings that it is best to get it done right this time. So I am heavily leaning towards splitting the case.

Rich

[Eagledriver]

It looks like you have Dilavar studs top and bottom. This could be from a previous rebuild. I don't see anywhere in here what kind of engine this is. Is it a 3 liter?

-Andy

[Rich76_911s]

Andy it is a 1989 3.2 with the motronic engine managment system.

[Jay Auskin]

You mention that you're not in a hurry. Then go ahead and split it. My personal feeling was that this added a significant amount of time to the rebuild. If nothing is wrong, it didn't cost you too much more. I think it's more of a time thing...or thinking you might need some work down there. Then definitely do it!

[Rich76_911s]

I don't mean to be a pest or anything, but I am really curious about these head studs. They are black except the ends where the Barrell nut is screwed on. They are threaded the entire length, and none of them are magnetic. Is there any way to tell if they are one of the alloys like ARP (wishful thinking) or if they are all Divalar that need to be replaced?

[Jandrews]

Seems to me like any engine bought from a swap meet ought to be split, period. You just don't know what's in there, and it is a false economy to put it all back together and install it only to find no oil pressure due to a spun bearing or worse.

Split it, and forget it!


JA

[Eagledriver]

I would guess that they are Dilavar all around. All the other studs will attract a magnet. Seems likely that they were replaced at some point as the 89 3.2 should only have the bottom row Dilavar. Some of the later Dilavar studs were threaded all the way. In fact I don't know of any other studs that were threaded all the way. Maybe some non-factory studs were threaded all the way but they should be attracted by a magnet.

I use Dilavar on my engine but I have a magnesium 2.7. I'd recommend changing the studs to factory steel.

-Andy

[Rich76_911s]

Thanks Andy for the information on the head studs why anyone would ever replace steel studs with divalar is beyond my comprehension. On pelican they even cost a couple bucks more, and I agree that it is in my best interest to go ahead and split the case. So that is what I am going to do. It seems like the reason to not do it is simply the amount of work that is involved the cost seems marginal, exspecially when we are talking about a Porsche. I am not affraid of doing work and doing it right, I am more worried about doing the wrong thing now. Thanks again all for your input I am really very appreciative of everyones help. I hope that as I gain more knowledge I will be able to help some of you out.

Rich