TLC for my GTD (rebuild), IT RUNS!

[Toby]

All this doom ad gloom .  The bearing won't spin if the bearing is acting as it should and not binding. Bearing will only spin if it is binding/seizing onto the crank.
It will only do this if it is 1) starved of oil, or
2) not starved of oil supply but too tight to allow enough oil to flow, or
 3) In an extreme case, starvation has led to shell wear to the point that it can fold under the other half, or
4) anything else forgotten.

 If the 'shim' reaches part way into bearing edge, then any crushing by the cap onto the bearing will continue.

Why would it need line boring?
I can't imagine how much that would cost here in the UK, then the bore will be oval, or special components required.

This is not a new engine, so what had the engine been doing previously, other than running? This is surely a recently  introduced problem.
If it was a preexisting issue that was overcome somehow, by some P.O. then again there has been something introduced, possibly by mixing components, or someones overzealous use of an air hammer ratchet thingy.


I would try a paper shim under the one side you believe to be overtightened. Just to see if it works. A dial gauge to check for a bent crank might help reassure you, but I don't think it's the issue

You are truly a fount of mis-information.

The bearing being loose in the bore will certainly cause it to spin. It does not have to be seized to the crank, although that will do it.

As for shimming the bearing insert as well, that might work, but then again you won't know unless you mic everything and check main bore alignment, like I have been advocating.

I think you also need to read up on what line boring is. You clearly have no idea what it is if you think it will result in oval shaped bores. BTW don't you guys ever rebuild AC VWs? Almost all rebuilds get a case line bore. Look at a AC VW bearing catalog sometime. The list undersizes for the inside and ovesizes for the outside of the bearing since shaving the case mating halves is not practical.

It is not too uncommon to find this kind of bind in old motors. If the block has twisted, it may well have only done so when the head and main bearing caps were removed. Or is may have happened so slowly that the mains "wore in" as it happened. I have seen both.

The reason for the doom and gloom is that I have built enough motors to know what you can and can not get away with. Guessing as to the problem and devising a "fix" based on that guess, can be an interesting intellectual exercise, but wasting all that time and money based on a guess is foolish when figuring out the problem guaranties success. But its your nickel. Just don't whine later if you "teenager" fix does not work.

[Mark(The Miser)UK]

All this doom ad gloom .  The bearing won't spin if the bearing is acting as it should and not binding. Bearing will only spin if it is binding/seizing onto the crank.
It will only do this if it is 1) starved of oil, or
2) not starved of oil supply but too tight to allow enough oil to flow, or
 3) In an extreme case, starvation has led to shell wear to the point that it can fold under the other half, or
4) anything else forgotten.

 If the 'shim' reaches part way into bearing edge, then any crushing by the cap onto the bearing will continue.

Why would it need line boring?
I can't imagine how much that would cost here in the UK, then the bore will be oval, or special components required.

This is not a new engine, so what had the engine been doing previously, other than running? This is surely a recently  introduced problem.
If it was a preexisting issue that was overcome somehow, by some P.O. then again there has been something introduced, possibly by mixing components, or someones overzealous use of an air hammer ratchet thingy.


I would try a paper shim under the one side you believe to be overtightened. Just to see if it works. A dial gauge to check for a bent crank might help reassure you, but I don't think it's the issue

You are truly a fount of mis-information.
[
color=blue]I think you mean font...[/color]

The bearing being loose in the bore will certainly cause it to spin. It does not have to be seized to the crank, although that will do it.

As for shimming the bearing insert as well, that might work, but then again you won't know unless you mic everything and check main bore alignment, like I have been advocating.
 I've said running limits from VAG allow upto 6 thou bearing to crank clearance. I never said bearing to clamp should be slack.Whatever the clamping force is currently would be maintained by adding a 'shim' across bearing and holder. Paper shim is just to check  for improvement. To go to unneccessary expense of line boring and finding bearing inserts here in the UK  is a joke. Bearing cap will surely be weakened, or is that an allowable compromise?

I think you also need to read up on what line boring is. You clearly have no idea what it is if you think it will result in oval shaped bores. BTW don't you guys ever rebuild AC VWs? Almost all rebuilds get a case line bore. Look at a AC VW bearing catalog sometime. The list undersizes for the inside and ovesizes for the outside of the bearing since shaving the case mating halves is not practical.
Sorry, are you saying you can by oversize and undesized bearings or are you saying you can buy shell bearings that are are bored offset as well as oversizes or undersized in their bearing surface? The The latter would be interesting but then direction of offset would need to be known

t is not too uncommon to find this kind of bind in old motors. If the block has twisted, it may well have only done so when the head and main bearing caps were removed. Or is may have happened so slowly that the mains "wore in" as it happened. I have seen both.
As an ignorant 'teenager' ; please explain how a main bearing wears in tighter, and indeed this in this case so that clamping with this bearing alone results in binding.

The reason for the doom and gloom is that I have built enough motors to know what you can and can not get away with. Guessing as to the problem and devising a "fix" based on that guess, can be an interesting intellectual exercise, but wasting all that time and money based on a guess is foolish when figuring out the problem guaranties success. But its your nickel. Just don't whine later if you "teenager" fix does not work.

[Sounds like you've built more engines than I have. I've not built lots, but they do accumulate over a period of nearly 40 years of doing so, mostly not for others , but for myself, family, and a few for friends. But this is where our dissimilarities increase further. I have never had an engine fail from anything I've ever done, but compare and contrast with your preceding comment...

[wil892]

Thanks for all the responses! I had some time to consider them all, and then decided to take it to a engine machining shop, who measured all the main bearing journals. Sure enough the no4 was tight, not by much though.
So he has line honed the journals, and rechecked the diameters. I have not seen the block yet because i'm working, but when I get home i'll be cleaning it all up and reinstalling the crank, AND checking with plastigauge to check all the clearances are fine.
Clearances on the other bearings were perfect at about 0.032mm.
Fingers crossed anyway, i'm not sure how many more hicups I can take!!

On the upside I wasnt happy with the conrods that I intended to use as I thought the caps may have been mismatched even though they were subsequently made perfectly round. So I decided to use the conrods which came out of this engine, and I managed to get them all checked out on our uber cool Mitutoyo CMM machine at work. I don't have the numbers with me but they were all great, we even measured the wrist pin bushings and they were fine as well which is great.
Will hopefully be able to update this with a postive build just after christmas!

[Mark(The Miser)UK]

Well that's a relief, so a relaxed Christmas for you then.
Did the shop have any suggestions as to why it had become tight?

[wil892]

Well finally I have built the bottom end of this engine. I'm pleased to say the crank spins and plastigauge says i'm right in the middle of new bearing clearances, which is great!
I've installed the pistons and torqued everything, and have just measured the piston protrusion.

The piston protrusion is showing 0.69mm which is at the lower end of 1 hole annoyingly as the UK only seems to keep 3 notch headgaskets (we must be lazy) in stock. I will be using new stock FEBI headbolts, would using an AAZ 1 notch gasket cause problems? My deck surface does have some small pits round some of the coolant holes which makes me want to use a 1.6 fibre one.
A fibre one will have to be sourced from the dealers so looking at £30

PS. Mark the shop didn't say what could have caused it, it was such a small amount. They just said well its an old engine these things happen. But i'm happy it now spins great. It was a relaxed christmas as well! I hope everyone elses was

[Mark(The Miser)UK]

A 2 hole hydraulic for £15...http://www.ebay.co.uk/itm/Audi-VW-1-6-Diesel-Payen-Head-Gasket-BN950-80-90-GOLF-CADDY-PASSAT-JETTA-/270864980346?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3f10cf997a

[wil892]

Ok just to update the situation on the head gasket, I managed to fine a genuine 1 hole gasket after a lot of searching so that was good. I have taken photos of the build and will be writing it up.

BUT!!!

Today it started, I cannot believe it, the first engine I have ever built. It ran on all four cylinders and sounds beautiful. The only issue is that it won't rev, have a look at the video, but there are no bubbles in the fuel line.
The only thing I can think is the brand new injection pump. The pump was bought off ebay, it is a Genuine VW Brand new SB engine injection pump, not a VW exchange unit. The date stamps say 1991 and all the part numbers are exactly the same as the old pump. It obviously flows fuel but won't increase injection quantity. The pump was supplied with all bungs and screws in place and was completely sealed but I am concerned there is something sticking inside the pump. Anyway have a look at the video, its awesome!

[Mark(The Miser)UK]

Try turning in the max fuel screw by the fuel lines, by a half turn, then if it works adjust to 'taste'

[wil892]

Ok I will try that, what would that do to allow the pump to increase fueling if it isnt already from the throttle lever? I'm also going to check I didnt put the IN and OUT fuel unions on the wrong way round, as I know the OUT only has a very small hole.

If these don't fix the issue is it likely the injection pump is sticking internally? If so is it best to take it the pump off or would some ATF help?

[Mark(The Miser)UK]

Ok I will try that, what would that do to allow the pump to increase fueling if it isnt already from the throttle lever? I'm also going to check I didnt put the IN and OUT fuel unions on the wrong way round, as I know the OUT only has a very small hole.

If these don't fix the issue is it likely the injection pump is sticking internally? If so is it best to take it the pump off or would some ATF help?

As part of ongoing experimentation to get my engine economical round town I unscrewed the max fuel screw. Two things happened I  found that idle speed dropped [I reached a point of 250rpm ], but also somewhere on the way the accelerator lever ceases to function.
I believe it is a gradual, but fairly steep decline where it happens.  I could be wrong about the rate of decline of responsiveness though. 

I  was looking for the lowest rpm that the engine would operate without undue vibration. Whilst it clearly gets worse at lower speeds there are plenty of peaks and troughs in resonant vibration, and they carry on up to 1000rpm and beyond. I think this may deserve a new thread... Engine economy, rpm vibration and tuning for balance.

ATF can work if that is the issue, but if engine starts reasonably easy, then  its not sticking lift pump

[wil892]

Hmm ok, so you're saying due to the fact the engine is starting pretty much instantly there should not be a problem with the internal lift pump.
I was reading a thread that suggested it could be corrosion on the governer shaft.

What baffles me is the lack of any reaction to the throttle lever being moved, there is no change in engine note at all. Just to add there is also no smoke coming from the exhaust.

Could this be an issue with air in the new pump, even though there are no air bubbles coming from the return line.

[rallydiesel]

I like to take the throttle arm right off the splines, then use small pliers to turn the throttle shaft. Take way you take out the idle limiters and the throttle indexing issue and you can feel if there is resistance internally. I then put the throttle arm back on without the springs and find the best position for the arm in relation to the cable end and the idle/max position adjustment screws. Mark the position on the arm and splines, an install with the springs. That's if it revs properly with the pliers.

[Mark(The Miser)UK]

Hmm ok, so you're saying due to the fact the engine is starting pretty much instantly there should not be a problem with the internal lift pump.
I was reading a thread that suggested it could be corrosion on the governer shaft.

What baffles me is the lack of any reaction to the throttle lever being moved, there is no change in engine note at all. Just to add there is also no smoke coming from the exhaust.

Could this be an issue with air in the new pump, even though there are no air bubbles coming from the return line.

It could be something nasty and complex, but it's worth trying the max fuel screw. Move it back if no change. 5 minute job.
It's even caught a few out who are no fools, ask Reg 

[wil892]

Update!

So I swapped over to my original pump and the engine revved perfectly, so I'm using that. I need to put more photos up but so far the engine has 450 miles on it. First oil change at about 10 miles, and second at 40 miles. Am running Shell Rimula R3 X 15w40 at the moment.

The rings seemed to seat basically instantly. Over 400 miles on this oil there is no movement on the dipstick and the car has awesome compression. It will start first revolution even with one or two seconds glow plugs from cold. I'm also getting crazy good MPG, about 55mpg which is so much better than it used to be and the engine runs slightly cooler, takes a bit longer to warm up and doesnt get hot going up hills.

Ok so this sounds perfect at the moment... Well the only concern I have is a sort of lifter chatter when the engine is cold. Basically the valvetrain just sounds noisy when it is cold, when the oil is hot it seems fine although maybe slight chatter at 1800rpm if slowing down on overrun.
There is no 'ticking' as such and the noise is not there at idle, its only when I pull away and the engine is cold say I take the revs up to 2000rpm the top end just sounds noisy, not how it used to sound (have always had hydraulic lifters). I've checked the oil pressure, and when fully hot I have 1bar at 1000rpm and 2.2bar at 2000rpm, so to me that seems fine considering I have hydraulic lifters. I have also visually inspected the lifters and cam and they are not scored and seem to be getting plenty of oiling.
I've checked the cam/crank timing and fuel timing and they are fine. Its hard to describe and it could be a noise not related to lifters.

If anyone has experienced something that sounds similar I would be really grateful to hear as its all thats standing in the way of me being totally confident in this engine.
Will

[paolomarks]

did you figure out what the ticking noise was?,  I have the same problem with mine.  Paolo