TO Split or not to split
 

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

http://forums.pelicanparts.com/uploa...1101520921.jpg http://forums.pelicanparts.com/uploa...1101520969.jpg

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

How many miles on the current crank and main bearings?

Ditto, mileage and time??

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

"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. :)

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

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??

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

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? :D
- 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

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

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.

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

http://forums.pelicanparts.com/uploa...1101612791.jpg http://forums.pelicanparts.com/uploa...1101612821.jpg

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

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

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!

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?

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

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

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

dunno about the stud question but you might want to replace them with some new ones. problem is Rich, this is where it all starts. you bought an engine. you were JUST going to do the top end. you are now going to split the case 'while you are there' I would prepare yourself for a nice long drawn out project that may well end up being a more expensive but ultimately much more rewarding and a whole lot more reliable (and probably more powerfull!) than you first thought!

good luck

Andy

Split the case. Replace the rod bolts with ARP/racewear. Replace the head studs with steel. Forget about it for a very long time.

Tom

You're probably okay without splitting the case - just replace the rod bolts with ARP or RaceWare ones. If the studs are threaded all the way down, they are the later-style 993 ones, and should also be okay (these ones don't seem to break).

-Wayne

Wayne, would you really buy an engine at a swap meet, without any documented history, and only rebuild the top end?

Again I appreciate all the input and opinions on this matter; I can't believe even the author of my favorite book got in on it. I'm not sure how this post got back up to the top of the list. After doing a little research, OK reading a couple chapters of Wayne's book and looking at the pictures, I came to the conclusion that I must have the 993 headstuds, non-magnetic, identical to the picture in the book, ect, one problem adverted! If I decided not to split the case how do you clean the mating surfaces where the cam housings, oil cooler, ect meet the case without getting debris into it? Still haven't made a 100% decision yet, but all opinions and advice has been noted.

Thanks,
Rich

I agonized over this decision also. And Wayne knows I have a tremendous respect for him in many ways. But I'm going to suggest splitting. The closer you get to the center, the simpler engines get. When you open the case halves, all you've got in there is a crank, and intermediate shaft with oil pump at one end, and a fistful of bearings. The bearings will probably be showing copper. So, minutes after splitting you'll be feeling justified in the decision. Measure everything.

Are you rebushing the wrist pin bores? If you don't split the case, and you don't rebush the wrist pin bores, you very likely could end up with an engine noise that is not dangerous, but you won't like it and you'll wonder what the noise is.

I did not have to scrape sealant. Don't have the crank "worked." Just measure it. You can be in and out of there very quickly, IMHO. If you do this, you're going to feel like you built a 250k mile engine.

I didn't see the "swap meet" thing. Hmm, I thought this was a 65K documented engine. Might be best to go through the bottom end then, as you don't know what fools owned the engine in it's early life. At least take a close look at the rod bearings (you can remove and inspect the rods and bearings without undoing the bottom end). If they look perfect, then it might be safe to assume the rest of the bottom end is generally okay. These SC and Carrera motors are *very* durable on the bottom end, if they have been semi-well cared for.

-Wayne

What, Tom Clancy's here in this forum?

:)

I try to post answers to all the questions in this forum...

-Wayne

Well guys I decided to and exicuted the case split today. I've never seen the inside of an engine before pretty awesome. That said, I don't know what is supposed to be going on in there. I have what look like gouges from a single scrape of a screw or something in several places, and a couple small cracks on the inside of the case. The cracks don't go deep but you can feel and see them. What worried me the most is that there was about a dozen metal remanents at the bottom of the case near the oil pump screen. They look like what used to be on the case before those gouges took place. Is this normal and how could it have happened. I haven't seen anything that could presently do this damage. I have never forcfully turned the engine to the point were I think I could have done this damage. Right now my mind is spinning in 5th gear expecting the worst. It would make a good paper weight even in a hurricane though. I will try to post some photos tommorrow. Any information would be greatly appreciated.

Many Thanks and Happy Holidays
Rich

P.S. Clancy's books bring a couple hours of enjoyment, your books bring a lifetime supply. No competition!

Add photos, and we'll give our opinion. I am confused though, as in a previous post, I thought you said you bought this engine at a swap meet, and you hadn't run it yet?

-Wayne

Wayne I appologize for the confusion. By turning it over I meant by hand. I found where all the metal pieces came from. The intermediate shaft drive gear has some fairly large pieces nocked off of it on the edge that is towards the flywheel. Here are the pictures that I promised sorry they are a little late. Enjoy your family's and the holidays everyone. I sure am glad I decided to split this case even if it is shot at least I didn't rebuild the top end to have a bottom end like this. There is a picture of the crack with a red arrow I am just pointing to where the crack continues into. http://forums.pelicanparts.com/uploa...1103908580.jpg http://forums.pelicanparts.com/uploa...1103908602.jpg http://forums.pelicanparts.com/uploa...1103908627.jpg http://forums.pelicanparts.com/uploa...1103908664.jpg http://forums.pelicanparts.com/uploa...1103908696.jpg http://forums.pelicanparts.com/uploa...1103908722.jpg http://forums.pelicanparts.com/uploa...1103908756.jpg http://forums.pelicanparts.com/uploa...1103908776.jpg

Are you absolutely sure that is a crack? It looks like it might just be left over from the casting process, thus nothing to worry about.

NO way am I absolutely sure it is a crack, and if you are right Santa delivered me a present a day early. I really mean that I have never seen the inside of an engine before, and do not know what is normal wear and remanents of the casting process.

Rich

That really looks like a casting remnant to me. I seriously doubt it's a crack... Looks raised, not recessed. Can you confirm?

First time I opened a 911 motor I was suprised at the amount of flashing and casting remnants that were on the case...

I split my 1980 911SC engine earlier this year. I have those "casting" marks in my case as well. My machinist said "no big deal". I did find metal in the oil pump sump screen, which was to be expected due to "spinning" the number 3 and 4 rod bearings. However, thay were flakes, not chunks.
Just as an FYI, I've spent 9 months rebuilding my engine. I've also collected a considerable number of specialty tools that were needed. With new JE Pistons and re-plated cylinders and all associated parts, I've spent around $6000.00. I could not be prouder of my work!

Competetion Engineering did my crank.... worth every penny!!!! I learned the hard way to not cut corners.... If you want to hear my sob story... just let me know!

Looks sortof normal to me, but I would have someone knowledgeable inspect it...

-Wayne

Thanks for all your replies and opinions your help is greatly appreciated. Yeah the chuncks of metal are without a doubt parts of the intermediate drive gear, at least that is what I think it is called. What the heck would have caused that? First thought is a jumped chain or something. As a side note it is a 89 with the tensioner update. I am heading back to Philadelphia tuesday morning so work on the engine has come to an ubrupt halt. It is in Colorado at my parents house. Time to go back to work. I will certainly have everything checked out by someone professional. Probably in Pheonix, but I am not sure yet. Thanks again guys and I wish you all the best in the new year.
Rich

Make sure you get a copy of the Engine Rebuild book, if you don't have it already...

-Wayne

Oh I have a very worn copy of the book. Probably should buy another copy. My reading comprehension is terrible. I've read most of the book probably 3 times. Inparticular the machinist chapter and the teardown chapter. Sorry if I am asking questions that are answered in the book.

I've seen the aluminum intermediate gears get chewed up by a jumped chain.
-Chris