100000 miles expressed in brush wear:

http://986forum.com/forums/uploads02/121562383696.jpg

I decided the put the original brush set back as it`s one unit with the rectifier and the quality of the aftermarket version seems worse than the original. There`s still a lot of meat left in these brushes.

http://986forum.com/forums/uploads02/131562383730.jpg

Done.

http://986forum.com/forums/uploads02/141562383762.jpg

Very impressive work. Are you going to "nut and bolt" restore the whole car or just the engine and periphery?

Huh, I really hope I don`t have to touch anything else, but probably that`s a very naive assumption :) The rest of the car seems ok though, apart from the 11 years rest.

Hi Greg,

first step is always to measure all parts, especially the cylinder heads. Because this is an full alloy engine you have to check for flatness, warps and if anything is straight.

You can check the head surface by using a steel ruler. Put the ruler on the head and put a torch behind the ruler so it shines in your direction. If you can see light come through between the head surface and the ruler, in general the head needs to be resurfaced.

Now it depends how much material needs to be machined from the head and if the head is warped in any way. Most time you can compensate with a thicker cylinder head seal, but if not the struggle begins, because than you have to reseat the valves, sometimes adjust the valve length and so on. Good thing on a M96 engine is that you can adjust the cam position / timing.

So before doing anything else first step is to do measurements and check if everything is straight. ;)

Hope this is helpful.

Regards, Markus

Hey Markus, thanks for the useful tips, I`ll do the measurements soon.

Best,

Greg

At last I found some time to work a bit on the engine. As a replacement of the original dual row IMS bearing I decided to go with a roller bearing designed for higher speeds and higher radial load. For thrust control I`ve thrown in a simple ball bearing that I had machined to fit behind the roller. It`s a 2T scooter crankshaft bearing with C3 clearance to bear high temperatures.

http://986forum.com/forums/uploads02...1565672264.jpg
http://986forum.com/forums/uploads02...1565672276.jpg

Together they are just as wide as the original.

http://986forum.com/forums/uploads02...1565672291.jpg

I had a groove machined on the outer ring to fit the original snap ring.

http://986forum.com/forums/uploads02...1565672309.jpg
http://986forum.com/forums/uploads02...1565672326.jpg
http://986forum.com/forums/uploads02...1565672340.jpg

The whole unit is submerged in oil normally that I think is sufficient for lubrication. However, oil has to find its way around the IMS that spins in the engine case.

http://986forum.com/forums/uploads02...1565673282.jpg

http://986forum.com/forums/uploads02...1565673259.jpg

Here`s a closer view. At high RPM and at certain viscosities much of the oil may be scattered off from the shaft due to centrifugal force. This may increase the chance that the bearing is not amply lubricated at all times.

http://986forum.com/forums/uploads02...1565673309.jpg

Probably it`s overkill, but to overcome this possibility, I thought a bypass oil channel in the engine case could set the same oil level behind the IMS in all circumstances. So, after a few second hesitation I decided to drill an oil gallery in the engine case. There`s not much room here, so I fabricated a mini drill to do the job:

http://986forum.com/forums/uploads02...1565675141.jpg

Engine case wall is pretty thick here, so there`s plenty of room for a little oil gallery.

http://986forum.com/forums/uploads02...1565675151.jpg

In situ position. Horizontal lines indicate the oil level at min and max sign at the dipstick.

http://986forum.com/forums/uploads02...1565675586.jpg

Oil should easily reach the stationary center parts of the IMSB unit via this hole.

http://986forum.com/forums/uploads02...1565677120.jpg

The oil gallery actively contributes to the better lubrication of the IMSB as well: the spinning sprocket generates a high oil pressure in its cavity that forces oil into the gallery and thus the back of the IMS.

http://986forum.com/forums/uploads02...1565677480.jpg

Oil within the IMS gets depleted via this small hole drilled on the sprocket.

http://986forum.com/forums/uploads02...1565677518.jpg

It’s always great to see people try new things. Can’t say I agree with using two different bearings (as an engineer, I see many issues with this...a larger roller bearing seems better to me as thrust forces in this application should be minimal), but I am interested to see how your oil gallery works out.

Of course, it will take at least a few years and tens of thousands of miles, plus pulling the bearings for inspection for a definitive answer, but I hope to be around for that. ;)

Very innovative. I will be watching with interest.
I hope your theory pans out :cool:

Thanks! I think I will have to replace the DMF in about 5-10k miles, so I`ll have a chance to inspect the bearings as well. Hopefully it won`t fall apart before that :)

Everlasting boxster project: I haven`t touched the thing for a while, and now instead of progressing forward, I took a step back and split the crankshaft bearing housing to take a peek into the main bearings. Luckily they all are in fantastic condition. Maybe I`ll check the clearances with plastigauge just in case, but there`s no apparent sign of wear.
Here are a some pictures:

http://986forum.com/forums/uploads02...1578552871.jpg
http://986forum.com/forums/uploads02...1578552899.jpg
http://986forum.com/forums/uploads02...1578552919.jpg
http://986forum.com/forums/uploads02...1578552956.jpg
http://986forum.com/forums/uploads02...1578552969.jpg
http://986forum.com/forums/uploads02...1578552983.jpg
http://986forum.com/forums/uploads02...1578553000.jpg
http://986forum.com/forums/uploads02...1578553016.jpg
http://986forum.com/forums/uploads02...1578553029.jpg
http://986forum.com/forums/uploads02...1578553040.jpg

Back to work!
 

Glad to see an update. I was wondering what was going on.

Yeah, every project is getting delayed since the little one arrived. Hopefully the Boxster will run at least when he gets the license :) Thanks for keeping track of the progress!

Crank issues
 

Update: I was a bit too optimistic last time when I said everything inside the crank bearing housing was in perfect condition. I lifted off the crankshaft and took a second look. I discovered a few things:

1) The most shocking is this by far:

http://986forum.com/forums/uploads02...1579059868.jpg
http://986forum.com/forums/uploads02...1579059963.jpg

I assume this piece was already missing in the factory, otherwise I can`t really see how it could have escaped from here without getting jammed in between the journal and the bearing. Must have been a late Friday session on the assembly line when this got through quality control. Actually, if it was just fine for 100k miles, I might as well put it back, right?

2) I still could find pieces from the plastic chain tensioner pad that fell apart. This little thingy is a real pain in the butt. Make sure you replace yours in time! Makes a lot more sense to replace these regularly than any IMS update.

http://986forum.com/forums/uploads02...1579060048.jpg

3) One of the thrust washers seems a bit more worn than it should be. Looks like it got mixed with some plastic from somewhere, or just burnt, I don`t know.

http://986forum.com/forums/uploads02...1579060080.jpg
http://986forum.com/forums/uploads02...1579060096.jpg

The other one, that`s not pushed by the crank when the clutch is being operated, seems brand new.

http://986forum.com/forums/uploads02...1579060110.jpg

4) When the casing was machined, these ugly burrs should`ve been removed I guess. They come off easily and can cause damage anywhere they get to. German precision, where did you go?

http://986forum.com/forums/uploads02...1579060203.jpg
http://986forum.com/forums/uploads02...1579060226.jpg

More to come once I received the parts.

I interviewed for a position at Mercedes Benz Vans last year (its a local production facility). One of the interviewers said "Perfection is an unobtainable goal; we just do the best we can." LOL

So I assume you didn`t take the job :)

Crankshaft assembling
 

I received all the parts for the crankshaft assembly, so I put it all together last night. A pair of new bearings, oil spray jets, one thrust washer and new bolts.

Old vs new bearing shell:

http://986forum.com/forums/uploads02...1582181756.jpg

Old vs new thrust washer: the new one has three of those oil pockets, otherwise it`s identical. This was the only version available.

http://986forum.com/forums/uploads02...1582181902.jpg

The 14 bolts for the bearing carrier are the TTY (torque to yield) type, so it should be replaced at every reassembly. Out of curiosity, I quickly looked at how much the old bolts were stretched by lining them up on my work bench and placing my straight edge on top. No difference. I might as well just reuse them, it`s more reassuring to use new bolts though.

http://986forum.com/forums/uploads02...1582182308.jpg

http://986forum.com/forums/uploads02...1582182575.jpg

I flushed the oil galleries of the bearing housing and the crankshaft oil channels thoroughly by injecting gas using a large syringe.

http://986forum.com/forums/uploads02...1582182716.jpg
http://986forum.com/forums/uploads02...1582183063.jpg

New oil spray jets/splash valves.

http://986forum.com/forums/uploads02...1582182881.jpg

I don`t what`s the proper way to guide the splash valves into their bore without damaging them, I used a pencil that I sanded off to match the size of the jets. To avoid filling the little hole with graphite ( don`t ask how I know this) I wrapped it in a piece of rubber glove material.

http://986forum.com/forums/uploads02...1582183293.jpg

http://986forum.com/forums/uploads02...1582183451.jpg

Looking good.

http://986forum.com/forums/uploads02...1582183535.jpg

Feeding side of the splash valve:

http://986forum.com/forums/uploads02...1582184054.jpg

One more shot of the thrust washer:

http://986forum.com/forums/uploads02...1582184180.jpg

Crank in.

http://986forum.com/forums/uploads02...1582184224.jpg

Torqued to 20Nm followed by a 90 degrees turn.

http://986forum.com/forums/uploads02...1582184324.jpg

http://986forum.com/forums/uploads02...1582184354.jpg

I also marked the bolts so I know for sure if I`m done with the turn.

http://986forum.com/forums/uploads02...1582184384.jpg

Endfloat is within spec.

http://986forum.com/forums/uploads02...1582184503.jpg

Good to go I guess. Conrods, IMS and chains next time when I get there.

http://986forum.com/forums/uploads02...1582184618.jpg

Dood.... making me itch!
Nice work. I enjoy following. I'm not sure of there's any moment quite so satisfying as firing up a motor that you've had down to its nuthin's.

Keep posting!

Sent from my SM-G970U using Tapatalk

Great thread! Very impressed with your level of detail, as I had no idea what is required to do this job correctly. I now know enough to drive my Indy crazy next time I bring him my car. Keep us posted, please.

Unless the moment when you drive a Porsche for the first time ever :)

Very impressive work! Great thread!

Thanks!:cheers:

Little progress since last time. New timing chains ready for assembly.

http://986forum.com/forums/uploads02...1582702651.jpg

Old vs. new chain tensioner.

http://986forum.com/forums/uploads02...1582702751.jpg

Old vs new timing chain lined up. Not a super precise way to tell, but I can`t see any obvious sign of stretch.

http://986forum.com/forums/uploads02...1582702802.jpg
http://986forum.com/forums/uploads02...1582702814.jpg

I put a small amount of sealant onto the gasket lips for the plastic oil scraper (?) to hold it in place during assembly. They put sealant there in the factory as well.

http://986forum.com/forums/uploads02...1582703062.jpg

I spent about a good two hours closely looking at the pictures I made during disassembly to find out which rod goes with which piston, which cylinder and in what orientation. I marked everything, but that was 1.5 years ago and of course I couldn`t figure out what I meant by my markings back then :confused: So I remarked everything and they are good to go.

http://986forum.com/forums/uploads02...1582703360.jpg

Rod bolts, new vs old.

http://986forum.com/forums/uploads02...1582703826.jpg

Rod bolts torqued to 20 Nm followed by an additional 90 degree turn. Hopefully that`s fine, as the respective line on the torque settings chart was a bit confusing.

http://986forum.com/forums/uploads02...1582703940.jpg

IMS and chains joined again with the crankshaft. More tomorrow.

http://986forum.com/forums/uploads02...1582703986.jpg

Bearing carrier should be sitting in the engine case on two dowel pins. I managed to find the missing one in one of the boxes.

http://986forum.com/forums/uploads02...1583091512.jpg
http://986forum.com/forums/uploads02...1583091541.jpg

This thing here is quite heavy, so I assembled the engine hoist that`s been sitting in the corner for a while.

http://986forum.com/forums/uploads02...1583091566.jpg
http://986forum.com/forums/uploads02...1583091718.jpg

Lowered into the engine half.

http://986forum.com/forums/uploads02...1583091745.jpg

Upside down.

http://986forum.com/forums/uploads02...1583091835.jpg

I can`t locate the washer and circlip that locks the chain tensioner, I just put it out here so I remember not to put the cases together before I fix this, that would suck...

http://986forum.com/forums/uploads02...1583091870.jpg

The crank assembly is bolted into the case using four of the head bolts.

http://986forum.com/forums/uploads02...1583091929.jpg
http://986forum.com/forums/uploads02...1583092028.jpg

These guys are coming next.

http://986forum.com/forums/uploads02...1583092107.jpg

I really love this thread. I really love when guys do this in their garage.... and all the people who say that Porsche motors are assembled with unicorn dust just go silent.

Good work! Keep the pic's coming. It's the best porn.

Oh, and while im thinking about it, when you get to that point: will you please settle once and for all the question about oil level in the sump in relation to the IMSB? (I am of the opinion that when the oil level is full, with the motor off, that the oil level is still below the bearing. I get this idea from looking at photos and diagrams. And from laying on my back staring up into the dark cavities of the motor when the sump is open.... trying to imagine 8 qts of oil volume.... but i'd like to see something empirical.)

Again: good work. Well done.

Thanks, I`m glad you enjoy the build, so do I, it`s just taking a bit too long now so I`m trying not to get stuck at every single detail for weeks.

Yeah, in general, this engine is not really different than any European or Japanese engine, and I don`t think it requires more knowledge or experience than a Subaru boxer or a motorcycle engine with similar complexity. If you overlook something or you are not careful, it will blow up, but that`s true for all the others, you need to use common sense. That`s part of the game, that`s what makes it exciting. It`s very annoying though that there`s no shop manual for the engine and I have to find out everything myself. Thankfully, there`s tons of information on this forum and rennlist, just you need to filter out what`s useful.

As for the oil level, if you go a few pages back in this thread, I`m showing that when the oil level is at MIN on the dipstick the IMS is submerged into oil about halfway. At MAX, IMS is nearly completely submerged in oil.

Thanks for the update. I had to reread the whole story again. Awesome details and pictures. The head in the sink is my favorite so far, my wife doesn't like new car parts in the house.��

Fantastic thread! Thanks for sharing this project with us:cheers:

Thanks for the interest and encouragement!

For pistons 1-2-3 I could have used some conventional tool as they go into the cylinders like on any average engine. But, since I already have the Porsche-specific toolset for pistons 4-5-6, I just used that.

Here`s what it looks like:

http://986forum.com/forums/uploads02...1583388989.jpg

http://986forum.com/forums/uploads02...1583389019.jpg

It was something like $80 on Amazon and probably it`s made in China :)

Everything prepared for the procedure:

http://986forum.com/forums/uploads02...1583389394.jpg

Circlip inserted into the tool. Some builders use an extra tool to compress the ring so they can insert it into the tool, I just forced it in with my fingers.

http://986forum.com/forums/uploads02...1583389494.jpg

It`s in. I didn`t make pictures of the failed attempts, there were many though. Then I realized I have to hit the slider in the tube quite strongly to smash the circlip into the groove.

http://986forum.com/forums/uploads02...1583389735.jpg

http://986forum.com/forums/uploads02...1583389934.jpg

Ring compressor. If you don`t want to buy it, you can rent one for free at Autozone.

http://986forum.com/forums/uploads02...1583390041.jpg

http://986forum.com/forums/uploads02...1583390058.jpg

For arranging the ring gaps, I took my SAAB shop manual off the shelf. Annoyingly, there`s no such manual for the Porsche available for a hobby mechanic like me. It`s not rocket science though, you just have to rotate the rings so that you minimize the blow by between the piston and cylinder wall.

http://986forum.com/forums/uploads02...1583390081.jpg

I inserted pistons 1-2-3 into the cylinders. It`s quite straightforward, just like on a conventional in-line engine.

http://986forum.com/forums/uploads02...1585200193.jpg
http://986forum.com/forums/uploads02...1585200226.jpg
http://986forum.com/forums/uploads02...1585200256.jpg
http://986forum.com/forums/uploads02...1585200275.jpg
http://986forum.com/forums/uploads02...1585200301.jpg
http://986forum.com/forums/uploads02...1585200323.jpg

Conrod bolts are now tightened down to 20Nm followed by a 90 degree turn as per direction from the 986 manual. Interestingly, the 987 manual`s direction differs, in spite of the very same bolts. It suggests that they should be torqued down to 20Nm plus 110 degrees, which then should be completely undone and retorqued to 20Nm and 110. Weird.. Since I still could do this easily, I`m thinking of retorquing the bolts based on the 987 directions. Not that it makes a big difference, but probably the engineers made this upgrade for a reason.



http://986forum.com/forums/uploads02...1585200551.jpg
http://986forum.com/forums/uploads02...1585200517.jpg

Call me stupid, but how does one get the wrist pin in piston #5?

Ha!
I haven't done it, but one of my friends has described the process to me. I can't help, except to assure you it isn't something obviously simple.... you're in good company....
And im sorry. Haha.

I LOVE the thread!

Sent from my SM-G970U using Tapatalk

I've seen Subaru's done with the little hole, but there are 6 problems on this motor not just 4.


Air cooled jugs are easy. :D

I`ve done some practicing on inserting the wristpin and the circlip just so I won`t have to split the engine halves after they are assembled. It`s quite straightforward, but you need some tools to do the trick.

This engine has only one hole to insert the wristpin and the circlips for all three pistons. It`s covered by this plug:

http://986forum.com/forums/uploads02...1585282170.jpg
http://986forum.com/forums/uploads02...1585282194.jpg

The manual suggests that this special tool that bolts on the side of the engine block should be used to fit the mandrel, but I could assemble everything without it.

http://986forum.com/forums/uploads02...1585282587.jpg
http://986forum.com/forums/uploads02...1585282225.jpg

The steel rod with the sleeve is to be used to slide the wristpins in, one by one. I`m showing the plastic mandrel here, but that`s not the correct tool for that. My bad. The sequence is obviously piston6/wristpin/circlip - piston5/wristpin/circlip - piston4/wristpin/circlip.

http://986forum.com/forums/uploads02...1585282319.jpg

After inserting the wristpin with the rod, you use the same tool to hold the circlip in its end which then can be pushed into the piston`s groove using the sliding hammer inside the tube.

http://986forum.com/forums/uploads02...1585282296.jpg
http://986forum.com/forums/uploads02...1585282492.jpg

http://986forum.com/forums/uploads02...1585282345.jpg

Easy, isn`t it?

http://986forum.com/forums/uploads02...1585282372.jpg

Thanks for sharing. 46 years ago I was a supervised participant in the rebuild of my 948 cc Austin Healey Sprite engine and a few years later rebuilt my 3 liter Austin Healey 3000 engine with a lot of help. My own Boxster S engine was rebuilt by my shop last year, I couldn't imagine doing this. And you are doing it all at home with a new baby in the house, if I read that correctly a few pages ago. Congratulations on that and please keep posting!

dude.... that sounds awful. LOL

You are essentially hitting the spot with a 16" stick. Your wife must love you. :D LOL

Lol :):):):D

Rebuilding an Austin may have been a challenge back in the day, in the pre-internet days :)
Yes, you got that right, unfortunately the Boxster has only two seats, not ideal for a family, my wife is not concerned about it though, she says by the time it will be back on the road the baby will be able to drive it anyways :)

The everlasting Boxster project continues. I uncovered the car just to make sure it`s still there. It is. Been resting here for about 1.5 year. It doesn`t look bad from a bird`s point of view:

http://986forum.com/forums/uploads02...1588917200.jpg

Back to the engine. New crankcase seals.

http://986forum.com/forums/uploads02...1588917225.jpg
http://986forum.com/forums/uploads02...1588917296.jpg

Upper half is coming to mate with lower half.

http://986forum.com/forums/uploads02...1588917341.jpg

Mating surfaces are thoroughly cleaned and a small bead of Loctite 5900 is applied in a pattern described in the shop manual.

http://986forum.com/forums/uploads02...1588917367.jpg

Speaking of which, he shop manual makes a big deal about alignig the cases using this aligning mandrel.

http://986forum.com/forums/uploads02...1588917408.jpg

This is how it looks in real life, i borrowed this picture from ebay. It`s listed only for $4000. Used. I think I`ll pass on this for now.

http://986forum.com/forums/uploads02...1588917428.jpg

Instead, I just used the oil pump housing to align the cases and it worked. I inserted it in the engine case, tightened the bolts around the IMS bearing bore, removed it, then tightened down all the bolts in the correct sequence. The screwdriver is to lift the IMS for positioning. It also helps a lot if you place the rear IMS bearing flange in, otherwise the whole assembly gets jammed, so you really need to take your time with this step. But you also have to be quick, because the Loctite is curing...

http://986forum.com/forums/uploads02...1588917447.jpg

This is the bore where the oil pump housing with the front IMS bearing fits in. The IMS is right in the hole. It`s a super snug fit, and the slightest misalignment will make it impossible to slide the oil pump housing on. Don`t ask how I know...

http://986forum.com/forums/uploads02...1588917488.jpg

Finally the case halves are joined, sealed and the bolts are tightened, ready for pistons 4-5-6.

http://986forum.com/forums/uploads02...1588917627.jpg

It`s nice of Porsche that they marked the best crankshaft position to insert pistons. This is for #6.

http://986forum.com/forums/uploads02...1589339481.jpg

Piston going down. Manual says if the wristpin or circlip insertion fails, the piston can be removed by pulling it out using something glued on the top of the piston as leverage. I don`t want to go down that road.

http://986forum.com/forums/uploads02...1589339526.jpg

Wristpin on the insertion tool.

http://986forum.com/forums/uploads02...1589339567.jpg

I might have missed it, but the manual doesn`t say a word about how to set the connecting rod in the center so that the wristpin can slide in. I spent a good 20 minutes on trying to align the conrod in the middle by grabbiing it through the oil pan side, no luck. Then I just flipped the whole engine upside down and used gravity to hold the conrod in center. I still have no idea how this could be done otherwise
:confused:.



http://986forum.com/forums/uploads02...1589339637.jpg

Wristpin in piston #6, circlip is ready to go.

http://986forum.com/forums/uploads02...1589341781.jpg

Passing by the toilet paper roll used to hold conrod #5 aside.

http://986forum.com/forums/uploads02...1589339818.jpg

This step requires some practice. The circlip has to be inserted using quite a bit of force. If you try it out a couple of times prior to the actual assembly I think it`s hard to screw it up.

http://986forum.com/forums/uploads02...1589339918.jpg

To make sure the circlip is properly seated I used my DSLR camera and made close-ups from the other side of the engine through the insertion hole and then I zoomed in. I`m convinced it won`t fly out.

http://986forum.com/forums/uploads02/VI_21589339864.jpg