A Shadetree's 930 Rebuild

[Alan L]

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

[Alan L]

PS, those inlet manifold blocks need replacing.
Alan

[930LDR]

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?

[Alan L]

Your injector blocks.
Alan

[930LDR]

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?

[930LDR]

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?!

[nocarrier]

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.

[930LDR]

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.

[Alan L]

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

[930LDR]

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.

[Targa Time]

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

[piggdekk]

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

[nocarrier]

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.

[tom1394racing]

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.

[930LDR]

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.

[Alan L]

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

[tom1394racing]

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

[Alan L]

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

[350HP930]

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.

What Do You Think My Incomplete 930 Project Is Worth

[930LDR]

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!