Cloud9...68

As I mentioned in another post, I'm very new to this site (didn't know a 968-specific forum on Rennlist existed!). I'm in the middle of a very ambitious (for me, anyway) project - after agonizing quite a bit as to whether to keep or sell the 968, which was getting driven less and less, I've decided to keep it, and convert it to a mostly-track car, because it's on the track that I've gotten the most enjoyment out of it, and Austin is blessed with not one, but three(!) outstanding tracks within about 20 miles of my house, including a fantastic driving academy, Driveway Austin. I'll provide more details as to my overall approach to the project, but right now, I've finally gotten most of the engine parts, including the fully-assembled short block, back from the machine shop, so I'm finally ready to start re-assembling the engine, and this is what I need to focus on.

Things took MUCH longer at the machine shop than I had anticipated (the shop has a great reputation, and thus a long queue), plus I kept thinking of additional things I wanted to get done, so what I thought was going to be a week or two gap between disassembly and re-assembly has turned into about six months and, stupid me, while I did take a fair number of pictures, I didn't take nearly as many as I should have. So, I'm staring at about a half dozen labeled boxes full of engine parts, and in some cases, only the vaguest of recollections as to where they all go. I think it will all start coming back to be as I start the project, but I'm sure there will be times I get stuck.

So, to the point of this post. There's a guy in Georgia who's on his third rebuild who has kindly offered to help me through the rough patches, but I don't want to bug him incessantly, so I was wondering if I could have a show of hands of people here who have rebuilt their engines, and preferably took lots of pictures along the way, who wouldn't mind if I contacted them on occasion for advice. The main things I'm looking for are:

1. The optimal sequence. I'd like to avoid too many occurrences of having to take a bunch of stuff off to re-do something because I did it in the wrong order

2. The proper greases and lubes and such to use on specific parts

3. Help with remembering how all the various fasteners and tie-downs connect, and where

4. General tips, along the lines of "if I had it to do over again, I would have done this, rather than that"

I've done a ton of work on this, and other cars (disassembling the entire rear suspension to install spherical and solid bushings everywhere has been probably the most ambitious thing so far), so I'm far from a mechanical newbie, but I've never taken on something with so many opportunities to mess up, so I'm a bit apprehensive about this project, and would greatly appreciate any support from those who have blazed the trail ahead of me. Thanks.

RajDatta

One way to go about identifying the bits and pieces is by posting pictures. People should be able to help you identify most of those pieces.
Raj

Cloud9...68

Yes, I plan to take pictures of every step of the re-assembly process, however seemingly trivial (although I promise, I won't post them all!). If nothing else, this will give me a good excuse to really clean everything up! I'll definitely post pictures of steps where I'm unsure of something. No doubt, I will learn a ton through this process, and hopefully help others as well.

RajDatta

You can never post enough pictures. I would not hesitate to post as many pictures as you like.
Raj

kwikt

If I lived closer, I'd like to assist you. I've rebuilt 911 engines but no 4 banger Porsches yet. Can't wait for the pics.

Kevin

Eric_k

Between the this site, the manual, clarks-garage.com and the rest of the internet you shouldn't have a problem finding information. Also search the rennlist 944 Turbo section, you find a lot of rebuild questions answered there and most of it will be applicable to the 968 engine.

I could never break my stock 968 engine, but with the 951 engine I'm getting more opportunities to play with internal enigne parts.

Cloud9...68

OK, I have my first rebuild question. Them manual states very explicitly that the crankshaft cradle needs to mate very flush with the front surface of the block, with no "lip", otherwise it could cause a leak where the oil pump attaches to this area, because the oil pump's seal goes across this interface. When I put my cradle on, I couldn't get it to move far enough back to avoid a slight protrusion of the cradle relative to the block. I've attempted to capture this in the pic below:

Attachment 603928

I'm spent a fair amount of time trying to press the cradle back enough to prevent this lip, but I'm convinced it was this way from the factory. The manual says that if a lip remains after all efforts to align the cradle to the block, to use an oil stone to polish away any remaining lip. Our blocks are made of a very hard alloy, so I think it would take a week of nonstop filing to polish away the lip with a stone.

So, should I try the method the manual describes, or leave it alone, and rely on the loctite 574 to seal over the lip? Or should I try something more aggressive, and finish up with a stone? The front part of the engine is just about the only part of this car that's never leaked. Thanks.

dp951

Attachment 603942

Eric_k

Its hard to tell from the pic, but it looks pretty close. You can also try putting the girdle in the freezer first. I tried that but it was hard to work with cold and didn't seem to make a difference. Whacking it with a mallet while partially tightened helped a little. I ordered an oil stone from McMaster.com and it worked like a charm. Smoothed it up very nicely with not much work. Wait til you strip a bolt hole somewhere, you'll swear the block is made of butter.

Cloud9...68

Thanks for the replies. I loosened all the cradle nuts, and shoved it as far back as it could go, and it didn't move back one micron. I'm glad to hear the stone worked, but I cringe at the thought of having to order one, as I want to get going on the re-assembly in the worst way, since what I thought would be a couple of weeks between disassembly and re-assembly has already turned into about 7 months. Anybody have any idea where I could find one of these stones locally? Thanks.

Edit: By the way, what exactly is the thrust bearing? The short blokc was assembled by the machine shop, since I aasked them to check the deck height (I read too many internet recommendations...)

Cloud9...68

I'm striking out on finding an oilstone locally, so it looks like I'll have to order one. Aarrgh!! The very first step of the assembly process, and I already hit a roadblock. I have a feeling this is going to be a very long thread - hopefully I can add some value. Do I need a fine, or a coarse stone?

Eric_k

I have a dual sided one (4506A4) but only used fine.

dp951

Attachment 604235

Cloud9...68

A guy who rides with me in my vanpool has a full knife sharpening kit, with a variety of stones, which he lent me, so I won't have to order one, which is a relief.

dp951, where are those pictures of the engine rebuild located? Are they in a thread here? Or are they from a manual? I can't quite make out what the photo is pointing to and calling the thrust bearing. The machine shop (a highly reputable shop here in Austin) put the short block together. I don't remember seeing anything other than the main bearings when I took it apart, so I'm not understanding what this thrust bearing is. Could you please give me a little more info? I'd look in my manual, but it's on my home computer, and I'm at work now, but I've spent a lot of time reading through it, and I don't remember any mention of thrust bearings. But I definitely want to make sure I'm not missing something in such a critical area. Thanks.

fortysixandtwo

Is your engine project sitting in the sun? Heat on the lower block section can cause it to expand slightly and cause the front edge to not line up. It's ideal that the upper and lower block sections are at the same temperature for a day or so, before assembling.
I've never like the idea of removing material to make the parts match, I see it as treating a symptom.