Diesel Crank replacement

[smithy010]

Ok.
I've been thinking about this for a while, but i can't excatly work out what the best way is.

I've got this diesel engine from the loon, and it needs a new crank. I've been thinking of the best way to take it out and replace it without pulling down the top end.

The procedure thus far, that i have nutted out.
In parentheses i have put the possibly problems with this method.

With engine removed.

1 Remove flywheel
2 Remove Driven plate 6 bolts. Mark Flywheel position. (Problem: If i use a different crank in reinstallation, the new crank will not be marked)
3 Lock Camshaft and injector pump
4 Remove front sprocket, timing belt, seal plates, etc.
5 Remove sump, oil pump.
6 Mark Conrods and big end bearing caps 1, 2, 3, 4 (With crankshaft remaining in one position, it will be hard to access each conrod- can i turn the pistons over with the valves locked in position?
7 Remove big end bearing caps.
8 Push pistons slightly up cylinder. Fit pieces of plastic tube to bolts.
9 Remove main bearing caps, remove crankshaft.

The problems i have are with marking the conrod caps, and possibly having to turn the engine over to remove each conrod.

Should i be worried, or am i being a moron?

Also, when i am retiming the crankshaft to TDC, a dial gauge would normally be used on the top of the piston right?
If i've still got the head on, how can i do this? It will be too inaccturate to do it on the crank somewhere..

[Golf Loon]

You are mostly right. Turn engine upside down. Remove sump, flywheel and other bits.

Remove the bearing caps. Put the crank in and once the new one is in, you can set tdc.

On a petrol you stick a screwdriver down no. 1 sparkplug hole. When its at the top of the stroke its at tdc. On a diesel you must have to remove glowplugs?

Is the diesel a non interference motor? I know the petrol is.

When you have set TDC, refit the flywheel and you are set.

[gtimk5]

"Definately not a moron Smithy. We are to give out advise. No need to mark the flywheel as the bolt hole are offset so the flywheel will only go in 1 position Position the crank with the pistons half way up/down the bores That way you should be able to undo the caps without rotating it. You will haver to reset the cam/pump timing afterwards. You got a manual? We can explain how to reset if you need to know. There are enough of us here to explain!:)

[gtimk5]

You are mostly right. Turn engine upside down. Remove sump, flywheel and other bits.

Remove the bearing caps. Put the crank in and once the new one is in, you can set tdc.

On a petrol you stick a screwdriver down no. 1 sparkplug hole. When its at the top of the stroke its at tdc. On a diesel you must have to remove glowplugs?

Is the diesel a non interference motor? I know the petrol is.

When you have set TDC, refit the flywheel and you are set.

Hey Loon, I wax 3 minutes behind you mate! The deisels are an interference motor

[brackie]

Smithy.... You'll need to check piston protuberance before you order a new head gasket. A dial gauge would be the go, but if you don't have one then a good straight edge and feelers will give you the amount that the pistons stick out of the block. It's very important to get it right. There's a range of notched head gaskets and one will suit. Also importantly you must torque the conrod nuts properly. Check for bearing crush by torquing one nut and then slipping a 2 thou feeler under the opposite end of the cap. If it gives clearance all is well. Cleanliness is next to Godliness in all of these operations ;)

If you're re-ringing make sure that the ring gaps are offset and that none are on the thrust side of the piston. Rings will take a long time to bed in (assuming the bores aren't oval in which case they won't bed in at all!) so lug the motor hard over the first 500km or so. As Andrew says it be as well to check injection pump timing too. I assume a new belt is the go.

[smithy010]

Thanks, you people are very helpful.

Brackie, i'm not doing the top end, so won't need to worry about the head gasket, however the engine supposedly has had a ring job, so i will definitely take your advice for running in.

If i lock the pump and maybe even camshaft before i take the cam belt off, all i should need to do is time the crank to TDC cyl 1, then put the belt back on.... is it that easy?

I have a tractor manual, and while it has good pictures, it's pretty crap explanation wise... all it says is use VW tool no.1234xxx.. which of course i don't have...

Quick question while it's on my mind.... like the loon said about sticking a screwdriver in the spark plug hole to find TDC- can i do the same with the glowplug hole?

[brackie]

Thanks, you people are very helpful.

Brackie, i'm not doing the top end, so won't need to worry about the head gasket, however the engine supposedly has had a ring job, so i will definitely take your advice for running in.

Should be Ok. JUst make sure everything's @ TDC before you start.


If i lock the pump and maybe even camshaft before i take the cam belt off, all i should need to do is time the crank to TDC cyl 1, then put the belt back on.... is it that easy?

You MUST lock both. There's a locating hole in the engine front plate behind the injection pump sprocket. Yesterday I looked for the locking pin that I made so that I could give you the dimensions but it's gone AWOL. Can't remember who I lent it to :???: The cam can be locked easily by grinding a piece of flat bar a couple of thou over thickness and carefully hammering it into the slot at the rear of the camshaft.

http://home.iprimus.com.au/mundy/vw/vwtimingtools.jpg


I have a tractor manual, and while it has good pictures, it's pretty crap explanation wise... all it says is use VW tool no.1234xxx.. which of course i don't have...

Join the "Special Toolless Club" ;)


Quick question while it's on my mind.... like the loon said about sticking a screwdriver in the spark plug hole to find TDC- can i do the same with the glowplug hole?

No. The precombustion chamber is just that... It's above the block and inset into the cylinder head. I guess that a piece of wire bent and poked into the glowplug hole could find the piston crown as it comes up, but if you have it at TDC at the flywheel you needent bother. Both #1 cam lobes should be pointing up.

http://home.iprimus.com.au/mundy/vw/crossec.jpg

[Golf Loon]

Hey Loon, I was 3 minutes behind you mate! The deisels are an interference motor

Nice that we all want to help.
Dont take the head of smithy. The guy who had that engine definately rebuilt the top end and did the rings.
Good that the diesel guys can talk you through the tdc steps.
Sounds like if you lock the top end, the bottom end will take care of itself.
Di you get bearings and a petrol crank? That will answer a few questions in itself :)

[gtimk5]

Not sure if brackie still has that spare maual. Be a good idea to strike a deal on that if he has. The Bentley manual shows the timing very well and has lots of other things in it that you might need to know. :)

[smithy010]

There's a locating hole in the engine front plate behind the injection pump sprocket. Yesterday I looked for the locking pin that I made so that I could give you the dimensions but it's gone AWOL.



Haha, don't worry, i made up one of those locking pins on my old man's lathe when i was at home picking up the crank outa my old 1600 petrol engine.
Still undecided as to whether i will use the petrol crank. I'll check to see the similarities to the diesel one first. I suspect it will be quite similar. The fact that the engine has 5 main bearings, makes it pretty unlikely that the crank will bend.

I also made up a cam locker.. it's not ideal, but i think it'll do the job. It's a little saddle that clamps down on the middle of the camshaft using the tappet cover bolts either side. If i give it firm pressure, but not too much, it shouldn't cause too many troubles.

[smithy010]

What about that manual brackie?

[smithy010]

http://www.vwwatercooled.com.au/forums/images/imported/2006/08/P1010041-1.jpg

http://www.vwwatercooled.com.au/forums/images/imported/2006/08/P1010037-1.jpg

She's up on my home made frame ready for a bit of a pre-surgery scrub-up.
Once my housemate takes his washing off the line, i'll get into it- wouldn't want to get grease all over his gear.

[brackie]

I've got one...pm sent

[Golf Loon]

Nice frame Smithy. Got a bit of Diesel black on there. Show us an "after pic"

[smithy010]

Actually that's half cleaned- scraped, but just not washed... darn- it would've been more effective if i'd taken proper before pics...

[Golf Loon]

darn- it would've been more effective if i'd taken proper before pics...

Ha Ha, I always get to excited to take before pics too.

[smithy010]

Hi all,

I pulled the crank out of my diesel today, and realised something strange. Obviously i locked the pump and camshaft with the flywheel at top dead centre. When i pulled the sump off, i realised that 1 and 4 were at the bottom of their stroke, and 2 and 3 were at the top.... SHouldn't 1 be at TDC when the flywheel is at the tdc mark?

[smithy010]

Spot the difference between the two cranks....

That's besides the stuffed journals on main no.4 and big-end no.3

The one with red tape (bottom) is out of a 1600 petrol, and the top one is from my 1500 diesel.

The only differences i can find, is the diesel crank has unmachined counterwheights, but the petrol crank is machined all the way up the counterweights, leaving a sharper edge on the counterweights.

http://www.vwwatercooled.com.au/forums/images/imported/2006/08/P1010042-1.jpg

[smithy010]

Just a thought.....

If the pistons are differently sized from the petrol to the diesel engine, would the counterweights be of a different size?....

If the crank is balanced taking into account the piston mass, this would be true, in which case if i put the 1600 crank in the diesel, it would be unbalanced..

Anyone know more?

[brackie]

Just a thought.....

If the pistons are differently sized from the petrol to the diesel engine, would the counterweights be of a different size?....

If the crank is balanced taking into account the piston mass, this would be true, in which case if i put the 1600 crank in the diesel, it would be unbalanced..

Anyone know more?
Yes the crank would be balanced in accordance with the weight of the pistons and conrods (diesel and petrol use the same conrods but the pistons have flat crowns and are heavier).

No, I don't believe that the difference in mass would be significant. If you have a diesel and a petrol piston and gudgeon pin assembly out on the bench weigh them and see. Remember that it's common practice to fit flat topped pistons to petrol motors (so increasing mass) and boring out the same and fitting oversize pistons.

[smithy010]

Anyone have a diesel and petrol piston out on the bench?

I think the old crank is grindable, i've just gotta decide whether a slight imbalance will not be a problem, so it doesn't cost me the cash for a grind.

[Golf Loon]

It all looks the same smithy. I dont reckon vw would have changed anything they didnt need to. Stuff it in and see how it turns.

[smithy010]

I thought about it a little more and realised that i have two pistons on one side of the crank and two on the other side, so the crank will be totally mass balanced. There may be some slight imbalances along the shaft... (negligible, according to my advanced mechanics course last year.)

All good.

Now to get some bearings, and get this baby running!

[Edison]

so the crank will be totally mass balanced.
Not really, your thinking on a different plane, it's wobble forces would be like one end of the engine up, the other end down. The mass of the piston sortof needs it's own weight balanced as close to the piston as possible, as you transfer it along the crank you get wobbles in other planes...don't you?

[smithy010]

That's what i meant by unbalance along the shaft. You're right in this way. I probably overstated it by saying it would be negligible, but the difference may not be much.

Hopefully the mass of the pistons will not be sufficiently different to upset the "wobble" along the crankshaft.

What do you think edison?

[Edison]

Stand back and crank it... :wink: :grin:

[Golf Loon]

Its not a high performance engine, I reckon it`ll work.
Get some bearings. :)

[smithy010]

Yep. 190 or so from tooleys for mains, big ends, and a bottom end kit.

Things are tough when you've gotta save up for something like that!

[Golf Loon]

Cheaper in the UK. ;)
I can hook you up, or do some internet research.

[smithy010]

How about sharing your source loon?

I've found a pretty good place in the states... 100AU for Big ends, mains, gaskets, seals, and engine mount rubbers (left and right). Waiting for a quote on postage.

[Golf Loon]

Its not a secret.

GSF. German Sweedish and French. www.gsfcarparts.com

I just paid 70quid delivered for rings and bearings.

[smithy010]

It's cheaper from the states... just depends on freight charges.
Just over $100 from the states, and 130 from pommyland.
Do bearings come without the thrust washer attached these days? What are the advantages?

[hiho]

Hi Smithy, how is your diesel project coming along?

[smithy010]

It's been a little stalled by funding and uni keeping me busy.

I'll be getting engine bearings and seals soon, then it should be all go.

One thing i'm still concerned with..... I mentioned it in an earlier post, but when i pulled the bottom end down (locked inj pump and camshaft with flywheel at TDC mark). Now, i thought at this position that pot 1 should be at TDC, but in fact 1 was down, and 2 and 3 were up....

Is this a problem?

[brackie]

It's out of phase. Can't work out why but when you reassemble it set it back to TDC in all respects. Check that both valves on #1 cylinder are closed. (If the cam and ip are locked it's most of the way there anyway.)

[smithy010]

I could probably work it out if i thought about it, but is "Out of phase" bad? wouldn't the injector pump be timed as such? I think where the camshaft is locked, Pot 1 was low, and both valves are shut. I'll double check it.

[peter_j_g]

Is it possible that the flywheel which has the TDC mark on it can be put on 180 degrees from the correct pposition?

[smithy010]

That's not possible, because there are 6 holes in the flywheel and all of them are equally spaced, except for one of them- so it can only go on one way. WHy it says TDC on the flywheeel and isn't at TDC is beyond me.. suggestions?
How can it be 180 degrees out of phase? Is it a manufacture fault?

[brackie]

Mark.. If the #1 cylinder has both valves closed (points up), and the injection pump is fixed with a pin into the engine front plate, it must be at TDC. The chances of a manufacturing fault (TDC marks in the wrong place) are zero. Even if someone had put a flywheel from a different VAG car into it TDC would still be in the same place. Go back to basics and check the IP (you can do this with a "spill" test. Take of the #1 injector pipe and you should get diesel as the pump approaches point of injection for #1 cylinder). Then check your camshaft lobes at #1 to ensure that the valves are closed (check with a feeler guage). If both of these check out then you're at TDC :???:

[Golf Loon]

Its something basic. Recheck like Brackie Says and it will come good.

[smithy010]

Thanks Lads, I'll do that just as soon as i get some time to scratch myself..

[smithy010]

Well, i've finally made some progress. I bought parts the other week, and i've been pulling the rest of it down and looking at each part and cleaning out the cooling passages and oil passages etc etc.
I was at my shed yesterday and a thought came to me- "What's stopping me from just bunging the crank in now?" So i did!

It was one of those things that you keep putting off because it's so important.

My "Engine lab" was far from clean and dust free, but i tried to be as clean as possible. Thought it would be more difficult with the pistons still in- but it wasn't too bad.
Now, the crank is in, and i haven't yet torqued up the bolts fully. Should i loctite them before i torque them?

It feels beautiful and smooth- not that it shouldn't!

So now all i've gotta do is sort all the other stuff out- engine mounts, cooling pipes, water pump etc.

One question i have is- do i have to take the injector pump bracket off to chage the engine mount? Or should i make up a little pusher and do it in- situ?

[brackie]

Sorry mate. Been very busy and not giving the forum the time it deserves.

Well, i've finally made some progress. I bought parts the other week, and i've been pulling the rest of it down and looking at each part and cleaning out the cooling passages and oil passages etc etc.
I was at my shed yesterday and a thought came to me- "What's stopping me from just bunging the crank in now?" So i did!

It was one of those things that you keep putting off because it's so important.

My "Engine lab" was far from clean and dust free, but i tried to be as clean as possible. Thought it would be more difficult with the pistons still in- but it wasn't too bad.
Now, the crank is in, and i haven't yet torqued up the bolts fully. Should i loctite them before i torque them?

No. Don't loctite them. Torquing them is all that's necessary. Do you have any Plastigauge? If so, put some into each bearing and torque it down to check that they aren't over-tight or worn (I'm assuming you're using new shells :rolleyes: ) I always check for bearing crush whenever I put a "foreign" crank into an engine or have had one machined. I've been caught out before. (Do a search on bearing crush as I've explained it previously.)


It feels beautiful and smooth- not that it shouldn't!

So now all i've gotta do is sort all the other stuff out- engine mounts, cooling pipes, water pump etc.

One question i have is- do i have to take the injector pump bracket off to chage the engine mount? Or should i make up a little pusher and do it in- situ?
I would take the bracket off (you already have the pump off) as it makes the job easier.
Good luck! It should be a runner soon :)

[smithy010]

I HAVE MADE NO PROGRESS.- except the bearings are in, and the sump is on.

Just thought you all might like to know that.....

BUT,

I have 3 weeks of uni left. After that, i have finished uni FOREVER! (unless i am so stupid as to enrol in a masters or phd in the future).

So, after i finish this thesis and hand it in, and before i build the new suspension for the UNSW solar car, my diesel engine will be getting some time. Put her all back together, time her up, and try to get it running on a stand, then bung it in and see how i go!

[smithy010]

Owing to the recent finishing of my degree, and the fact that my petrol engine is on its way out, i have made some progress on the diesel that's been sitting on the garage floor for around 12 months now.

I put the belt on and timed it today. Gave it a turn over by hand, and it feels good. It measures well (With my new little brass adaptor for my dial gauge, that i made the other week at the old man's place).

Now, all that should be left is to go and see Mr Loon and pick up the bits and bobs that he has saved up for me (including a new wasserpumper), and i should be in business.

Has anyone had a diesel running on a stand before ? I am tossing up whether to just throw it straight in the car without test running it, or whether to mount engine and gearbox in a light metal frame that i have made up for it and run it there... Wondering how much it will rattle around if it's not in the car? Also will have to set up some sort of cooling system if i'm going to do it out of the car... Sounds troublesome.

[smithy010]

Today i put in my bigger fuel lines which i got from Matt.
It was a sweet little job. I was amazed at how easily the old lines came out and the new ones fit up.
I didn't change the tank, just drilled out the return line pipe in the existing swallowtail tank bung and inserted and silver soldered a new 3/8" copper pickup pipe in its place. Turned out to be sweet job.

I've wired up a 60Amp relay to a switch on the dash, which will be the glowplug heater. What's the average heating time with the automatic jobby?

So the diesel should be just about ready to go in.
It's about time!
I'm a moron and haven't been taking pics.

Oh, a question for the dieselers: Where does the CAV filter mount?

[smithy010]

Another question:

What temperature is the thermostat in the diesel?

[brackie]

Today i put in my bigger fuel lines which i got from Matt.
It was a sweet little job. I was amazed at how easily the old lines came out and the new ones fit up.
I didn't change the tank, just drilled out the return line pipe in the existing swallowtail tank bung and inserted and silver soldered a new 3/8" copper pickup pipe in its place. Turned out to be sweet job.
I don't know the swallowtail tank, but is the return close to the top of the tank? It should be for the diesel. Baffles in the tank also help with frothing.


I've wired up a 60Amp relay to a switch on the dash, which will be the glowplug heater. What's the average heating time with the automatic jobby?
The glow time is controlled by the glow plug relay which gets a feed from the sender on the water outlet on the rear of the head. Glow time is dependent on head temperature, but on a really cold start the time is ~20sec. I've fitted fast glow plugs and relay to my diesels which brings the time down to 8sec.


So the diesel should be just about ready to go in.
It's about time!
I'm a moron and haven't been taking pics.
Pics would have been good for learners.


Oh, a question for the dieselers: Where does the CAV filter mount?
I've never had a GLD with a factory CAV filter but it can be mounted on the right wing bulkhead.

[smithy010]

I don't know the swallowtail tank, but is the return close to the top of the tank? It should be for the diesel. Baffles in the tank also help with frothing.



That is a small concern.
What i did, was drill the original petrol return line out from the bung, so the 3/8" copper line replaces the small petrol return line, and the original pickup line becomes the return line. No baffle, but i will be trimming the pickup line so that it will be closer to the top of the tank.. Will just see how it goes. Surely there is a limit to the amount of froth a tank can contain?