A Shadetree's 930 Rebuild
 

So I'm about to embark on my first engine rebuild. The 930 gave up the ghost out of no where last season and its time to get her running again.

Figuring that I have a pretty steep learning curve ahead of me, and that others may be in the same boat, I am going to try and document: the rebuild; tools, parts and costs; and the challenges of getting a previously de-smogged 400+ hp 930 to pass California emissions (although I'm not holding my breath).

Not only is it my first rebuild but its also my first blog so bear with me.

Blood, Sweat & Broken Gears

I'll be using Wayne's book as well as the collective knowledge here on Pelican extensively.

Good luck with the re-build point to note replace as much as your budget will allow head studs being one of the main items....

I'm with you on that. Thanks Davy.

Good Luck Rob!

I'm much in the same boat as you. Just now starting reassembly. I'll definitely follow your thread.

Thanks Targa... good luck with the reassembly and check back into the blog and let me know if you've got any good lessons learned that I may be missing as I progress.

Blood, Sweat & Broken Gears

Having a camera handy during the tear down will help, and save a lot of time - but dont start without Waynes book - has heaps of good pics.
Cam tensioner blocks, piston orientation etc etc.
With waynes book, it is definitely do-able. Allow yourself plenty of time (months not weeks) unless this is a fulltime task.
Dont rush anything. It is a mission to have to go back in there for some stupid annoying glitch.
If you get it right first time, it will start on first turn of the key and you will be one very happy guy.
Alan

+1on Alan's suggestion. The older I get the worse my memory. I took a picture of every part before and after removal. (digital cameras are great!) I must have taken around 150 photos.

Waynes book has lots of excellent pics. But you will be surprised how often you get stumped trying to work out the orientation/sequence of a bunch of washers, tensioners etc.
I got stumped trying to figure piston orientation once and it cost me many hours. And the cost of getting it wrong doesnt bear thinking about.
Alan

I am completely on board with you when it comes to the camera. I have a ton of pictures just from my first day with the motor. A couple odd ball things I found are below: Deterioration on the injector blocks and wear on the fan housing from the pulley.

http://2.bp.blogspot.com/-PP9vXUkUjD...+Blocks+v2.JPG

http://3.bp.blogspot.com/-2EVOE7G8xf...Housing+v2.JPG

Something else that I ran into on a couple of the hard oil lines was that the fittings that attached to the engine seemed to have been locked up. I was always under the impression that the intended design allowed you to spin the fastener while keeping the hard line stationary. two different fittings were locked up to the point where I had to detach the opposing end of the line and then spin the entire piece to remove it from the engine. Is there something I can soak these in before re-installing so that they work as intended?

http://4.bp.blogspot.com/-RAgp0rTmeK...nes+Ind+v2.JPG

It looks to me like the fitting you have circled is the one that attaches to the cam tower. What you should have done is attach 2 open end wrenches to that fitting and while holding the larger fitting still in the cam tower break compression fitting, (the smaller nut) free. This leaves the larger fitting in the cam tower and eliminates the need to rotate the oil lines.

For the uninitiated, what book are you guys referring to?

Thanks.

Pelican Parts - Product Information: BK-135124

Thats what I thought and I gave that a go but it felt as though I was on the brink of forcing it too much. At the end of the day its off now but thinking ahead to re-assembly I'm thinking of maybe soaking the entire fitting in liquid wrench to see if I can't free it up a bit. Any concerns over that approach?

Thank!

Throw out the Liquid Wrench. Buy a product called SeaFoam Deep Creep. It is amazing. Soaked my exhaust nuts with it and removed them without heating or breaking a single stud. Had a couple of piston squirters that were plugged. Gave them a shot of Deep Creep and in 2 min. they were flowing free.

Sounds good. Thanks.

What are people using as a flywheel lock for the 930 motors. I've got the lock mentioned in Wayne's book but it doesn't work with the 930.

thanks

Unless the starter gear ring is attached to your flywheel the porsche flywheel lock wont work. (made the same mistake myself) Look at page 30 of Waynes book. There's an example of a fabricated flywheel lock from flat stock.

I think thats what I'm going to do... just wasn't sure if there was a commercially available unit.

Thanks again Targa for the continued feedback.

Piston / Head Damage
 

Heads and cylinders came off this weekend and I found broken rings on three of the pistons. On the corresponding heads and pisotns I found some damage. Curious to see thoughts on what may have been the cause and what the potential solutions may be.

A couple of the heads have pock marks on the inside surface. Is it possible that these are the result of small fragments of rings being blasted around inside the combustion chamber? On the pistons that had broken rings it also looks as though certain portions of the smooth finish and edges have been worn away leaving a porous surface.

Thoughts and opinions are appreciated.

http://forums.pelicanparts.com/uploa...1298264229.jpg
http://forums.pelicanparts.com/uploa...1298264245.jpg
http://forums.pelicanparts.com/uploa...1298264274.jpghttp://forums.pelicanparts.com/uploa...1298264325.jpg

Broken rings usually from o/boost. There are some real experts here on this board who can practically tell you what the engine had for breakfast , just by looking at it. The pock marks in the head suggest some hard bits have been bouncing around a bit - like a piece of spark plug electrode or similar, or a bit of broken valve guide. (I think detonation affects the piston more than the head - hopefully the experts will chime in).
Dont know what your budget is like, but it would pay to get the heads checked over before reassembly - make sure they are true, and the guides are OK (you can check this latter yourself - I'm sure Waynes book has a bit on this). If the guides need doing, probably best to farm the job out, unless you have some machine shop experience.
You have done well so far. Hopefully the ring lands on the pistons are not damaged.
Alan

PS, those inlet manifold blocks need replacing.
Alan

Not looking to cut any corners on the rebuild (don't really want to do it again anytime soon!) so any suggestions are welcome. At the risk of showing my newness to the inside of one of these... can you offer any more info on the inlet manifold blocks?

Your injector blocks.
Alan

On the topic of the injector blocks. For CIS motors, are people just replacing the blocks with the stock piece or going with some sort of uprated aftermarket billet unit?

Crap!!!
 

So when I removed the cylinders, I wasn't able to remove 4 of the 6 pistons because the crank is locked up and I couldn't rotate it to gain access to the wrist pins. I split the case tonight hoping that maybe it would allow the crank to free up, but that didn't work. Now I'm stuck. Can't get the pistons out because I can't access the wrist pins.... can't split the cast to get to the wrist pins because the pistons are in the way.

There has to be a solution... but I'm completely stumped. How do you split a case when the crank won't rotate and you can't first remove at least one side's pistons?!

Was the engine locked up before?

If it wasn't it shouldn't be locked up now.

Are the timing chains jammed up inside the engine?

Take your time and be very delicate while you take everything apart. I can't stand when I look at an engine and I see dings and pry marks.

Also, can you make sort of a wrist pin puller with some all thread, a nut a couple of washers and maybe a wooden dowel drilled out (I like to use something soft so the piston doesn't get marred up.

The engine being locked up was the cause for the original tear down. Not sure how I'm going to gain enough accees to those wrist pins. Below is a picture of the clearances that I'm trying to work with.

https://lh3.googleusercontent.com/-h...00/Pistons.JPG

Can you explain this a bit better.
1) there has to be a reason why the crank is locked. You say the engine was locked before the teardown - what happened there? If the reason is within the case halves, then you need to split it anyway.
2) I am unsure why you cant split it now - with the pistons in place.
Are you sure the timing chains arent bound up down in the bottom - they can usually be freed.
3) you say you have split the case and crank still stuck. But your pic shows it still intact.
If it is split, you should be able to lift the crank out.
Alan

Sometime last summer the motor stalled on my in the paddack and wouldn't turn back over. Tried push starting the car because I had had starter issues in the past but had no luck. Rear wheels were locked solid and the car just skidded to a stop.

If you look at the pic above, where I've already removed one piston, you'll see that the structure of the case half makes it seemingly impossible to remove one half of the case as the bottom of the pistons come into contact with the case itself (look along side the connecting rod)

The picture above was taken prior to splitting it which is why all the nuts and bolts are still in place.

Rob
i don't see any reason why you should not be able to split the case without removing #4 & #6 pistons.
The only complication will be that when you remove the Right side of the case, ( the one with #4 & #6 pistons ) you will have to lift out the crankshaft with it leaving the intermediate shaft and oil pump in the left side of the case. Be sure that ALL the case thru bolts and perimeter nuts are removed, (check Wayne's book to be sure) and remove the flywheel and pulley. In reading your posts it not clear if you are stating that the case wont split due to the perceived problem of the case webs, or you actually attempted to separate it and could not. If the latter, I will have to +1 Allen L statement to check your timing chains and make sure they are not bound up around the sprockets.
Good Luck

Rob,
I think the problem is that 4 and & are blocking one half and no 1 is blocking the other one.
luca

Ok so I guess the engine locked up while you were driving the car not while you were taking it apart.

Sounds like something internal seized up. I would try putting the center through bolts back in the case but leave them a bit loose. Evenly loose if you catch my drift.

Try lightly tapping the case apart while trying to rotate the engine and see if that helps you spin the crank. Watch those timing chains from binging up in there.

Is there any rotational play or backlash in the crank at all? Maybe your oil pump is locked up? Just a thought.....

Good luck.

Put the engine in the horizontal position with the pistons parallel to the floor.

Take the timing chains out of the case so they droop towards the floor and lay the chain spockets in them. This will keep the chains from binding as you rotate the crank.

Make sure the remaining piston skirts and the rods are not binding on the case and are free to move.

Remove all the perimeter nuts and through bolts and start to tap the case apart at the four corners until you see a uniform gap all around the perimeter.

Check the piston skirts and rods again to make sure they move freely and are not binding.

Then take a large lever arm (I use steel pipe sections) on your wrench and try free up the crank by rotating it in the clockwise direction.

Apologies if my post(s) weren't as clear as intended.

I have been able to physically seperate the case already. The problem is that the piston skirts (if I have the lingo correct) get hung up on the case internals. The issue may be worse than originally suggested as I currently only have workable access to the wrist pins on one piston on each side.

Tom - like your suggestion. At what point should I become concerned with exerting too much force in trying to free up the crank? I had been under the impression that you really don't want to be turning it counterclockwise too far (maybe I'm mistaken).

Finally is there a particular technique in trying to rotate the crank? I was using the pulley nut which ofcourse loosenes right up when you try to go counterclockwise.

Thanks all.

Are you sure the timing chains are not bound up? They would bind if left as in your pic. If you look in Waynes book you will see them draped over the side of the case with a timing sprocket in the bottom of the loop to keep them from slipping back in the case. I have had many issues before trying to rotate an engine/crank on a stand like that while the chains are not supported as per Waynes method.
I am still puzzled about your engine seizure. It sounds more like a gear box issue.
If you put the car in neutral you should still be able to push it without the wheels skidding even if the engine has seized. UNLESS the g/box has seized.
Alan

Whoops...I meant clockwise (direction of actual rotation)

Any one got any idea what would bind the engine like this - assuming it is bound up?
I can only think of a timing chain failure - which should be evident without splitting the case.
Yes, there are gears in the case with oil pump etc, but I cant really imagine what could have failed there to cause the engine to lock.
Alan

Hey Rob,

Sorry to hear about your bad luck.

Depending on what's toast in your motor and your desire to go EFI (might as well as long as your injection blocks are toast) if I part out my car instead of selling it whole I may have a whole lot of goodies you might be interested in.

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/593975-what-do-you-think-my-incomplete-930-project-worth.html

Alan - Pulled the chains out and had them draped... no big difference. Picture just happen to be one I had from a prior stage of the tear down. When the motor gave out you could definitely roll the car with it in neutral. It was just when you pop the clutch to push start it the wheels would lock up.

Tom - Thanks for the directional correction!