Early 1.9 to 2.1 conversion - stop me if I'm being stupid!

[itchyfeet]

I was chewing up fanbelts prior to the failure - i'm wondering whether something was seizing slowly, & this should have been a warning ?

Unlikely, usually alignment issues between pulleys
prossibly a bent crank pulley if single type they are quite delicate, other things are duff waterpump or alternator, if the fan and pulley are not spaced right it's out of alignment.

[hightop ratty]

I was wondering whether it may have been the water pump (been clutching at straws a bit trying to find answers - hopefully the strip down will reveal some answers).

[CJH]

Still waiting for my M10 x 1.25 nuts to arrive before I can assemble the case halves. In the meantime I've swapped the valves over in my new heads.

Old cheesy valves:


Bentley says that "When new valves are installed in properly reworked seats, it may not be necessary to lap in valves", but it's an easy step, and it provides a perfect way to check that the valve/seat geometry is correct.

New TRW valve, with shiny machined face:


With a smear of grinding paste. Take care throughout to keep grinding paste well away from the valve stem and guide.


Lapping by hand - it only takes a minute or so of turning. Lift regularly and reorientate the twizzle stick.


After lapping. Nice, even, well defined grey line, showing that valve sits flat on the seat and the seat is (very nearly) central on the valve face.


All done:

[CJH]

I found the missing 17mm circlips too. Safely stored away in my second circlip set (hadn't even realised I've got two, and when they weren't in the first set I found I was stumped). So I've been able to pre-fill my new hydraulic tappets.

Made by Kolbenschmidt - different design from the ones Itchyfeet used. Note the grey disk which appears to be some sort of oil control device. Note too the slightly smeary camera lens - messy job!


There have been reports (and here) of problems with these tappets draining down very quickly, particularly the ones under load from the rockers, so I'm keen to make sure they're assembled correctly. But what's correct? Well I reasoned that the hole in the outer body and the hole in the inner plunger ought not to be aligned. I expect they will rotate in use, but they may as well start 180 degrees apart. And I worried about the orientation of that oil control disk, but concluded that it doesn't seem to be important, but nevertheless I chose an orientation and stuck to it, so now they're either all correct or all wrong (there didn't seem to be a consistent orientation when I dismantled them from new). It also seems to make sense to put the tappets into the engine with the borehole in the body facing upwards - again I imagine they rotate in use, but let's start them off with the best chance of not draining down.

Assembly is the same procedure that Itchyfeet described. I used the sawn off end of a gash pushrod as the pusher:


I'm also replacing the paperclip-type securing clips with 17mm circlips. Can't do any harm I hope, and they seem less likely to fall out. In the vice I was surprised how much pressure was needed to compress the plunger. It won't compress quickly, as the oil needs time to seep out of the bore hole in the body - just visible below.


All was going well, but the seventh one I dismantled has a fault. The oil disk is wedged in slightly off-centre, so not only is it bent, but it's impossible to remove (non-destructively). I wonder if this is the same problem that ajsimmo reported. New one on the way. In fact I'm going to have to go back and check the other seven, to make sure I haven't inadvertently done this to any of them during reassembly.


Needless to say, I'm concerned over the uncertainty over these tappets, so I'll be using Scat telescopic pushrod tubes in case I need to go back in and replace the tappets.

[CJH]

My new nuts arrived this morning, so at long long last the case is back together!

This Loctite SI5900 appears to be challenging for this application. The instructions say to "Assemble parts within 5 minutes". There was no way I could apply the sealant, mate the two case halves, and get enough of the nuts done up in that time. I don't believe that even an experienced engine builder could do so. But I think that instruction just means it starts to skin over in that time, so the clock really starts once the thin bead has been smeared out (it's quite 'thick', so finger works best). I had no experience of how much sealant to use, so I used what I thought was a minimal amount. As it turns out, this is on the upper bound of what's required.



The concern is not the material that oozes out of the gap on the outside of the case, where it can be cleaned off, but what oozes out on the inside of the case, where it's inaccessible. The bits I cleaned off the outside were gossamer thin, and not well attached to the case, so I guess that explains the slivers of sealant that I found in the oil pickup strainer when I stripped this case down.

I had practiced dropping the right case half onto the left case half a few times, to make sure I knew what I was up against when the sealant was on - the con rods make it a bit of a challenge. I can just about balance them vertically, but it takes a while - I think the assembly lube on the big end bearings adds to the challenge as it's so sticky I think it even behaves elastically. So I didn't even try to balance them, and resorted to holding the case in place with one hand, via the head studs, while I sorted the con rods with the other. A bit of a fiddle, and I could have done with another pair of hands.

Anyway, all done now. And everything still turns freely. On with the cylinders and pistons. I might even make it before the end of 07/17.

[itchyfeet]

Why did you choose the loctite over curil T?

[CJH]

Why did you choose the loctite over curil T?

A comment on the fb WBX page I though was worth sharing and recording here

I dont recommend dirko-s for the case halves , but if you have used it and closed it up right away you will be fine, i now use loctite SI 5900 for the case halves, as thats what ive been using on the watercooled Porsche's for 10 years and never had one problem or one leak whatsoever, with the Curl-T after 5 years of daily use it will start to seep oil, it doesn't matter how good the rebuild is or how perfect it runs if it leaks one drop of oil its a terrible engine rebuild according to the Porsche world
The SI 5900 smells and acts just like dirko-s but is just slightly thinner

[CJH]

Barrels and pistons in. All 5 (had to do one twice, because I forgot the lower O-ring).





Piston number 4 is tricky. With access through the water pump hole, which is nearer the crank axis than the water pipe hole used for number 2, the con rod isn't vertical, so tends to fall to one side.

Heads on tomorrow

[ajsimmo]

Made by Kolbenschmidt - different design from the ones Itchyfeet used. Note the grey disk which appears to be some sort of oil control device.


All was going well, but the seventh one I dismantled has a fault. The oil disk is wedged in slightly off-centre, so not only is it bent, but it's impossible to remove (non-destructively). I wonder if this is the same problem that ajsimmo reported. New one on the way. In fact I'm going to have to go back and check the other seven, to make sure I haven't inadvertently done this to any of them during reassembly.


Needless to say, I'm concerned over the uncertainty over these tappets, so I'll be using Scat telescopic pushrod tubes in case I need to go back in and replace the tappets.

Yes, it is exactly the issue I had - a bent oil disk. I also had a couple with chips/sharp edges as if they'd suffered​ impact damage. All were replaced by BW without issue. More recently, all have been ok.

I have altered my routine when prepping lifters for first use. I now strip them, and wash everything with brake cleaner to remove all trace of the shipping oil, and blow dry with the air line. Then fill with clean engine oil, but also a light smearing of assembly lube on the piston before reassembly. Then a coating on the base and sides before fitting. It seems to make a huge difference, both to initial startup and subsequent starts, with greatly reduced tendency to drain down.


Sent from my B1-830 using Tapatalk

[CJH]

That's good to hear, thanks Andrew. Since I'll be stripping mine down again to check I haven't bent any of the disks I'll follow your procedure as well. Have you been particular about the orientation of the bore holes, either the plunger with respect to the main body, or the body orientation in the engine? Given how tight the tappets are in the engine It's difficult to see how the oil can drain down, even if the bore hole is facing downwards. But evidently they do, so orienting them with the holes upwards seems to make sense. Then again I'm pretty sure that the cam rides off-centre on the followers, so as to rotate the followers. I suppose that the chances of the plunger and body bore holes both pointing down at the same time are fairly small.

I haven't asked Brickwerks to replace my faulty one, as it's over two years since I bought them - I've simply ordered a replacement. But if this is a known fault I may mention it to them.

[itchyfeet]

Your bits of wood are nicer than mine

[CJH]

Your bits of wood are nicer than mine

Haha, well you know, if you're going to do a job....

I've been prepping the heads as per your thread. Fine grinding paste and a spare barrel to make sure the compression surface is perfect, and wet and dry round the green o-ring face.



I now have a variety of sealants I could potentially use for the water jacket rubber gaskets: two 20ml tubes of Dirko-S, a 70ml tube of Dirko Grey, a 70ml tube of Reinzosil 300SI, and most of a 300ml tube of Loctite SI 5900. They all appear to do a similar job. I can't recall why I've got two 20ml tubes of Dirko-S - do you get two in a gasket set, one per head? Is 20ml considered a 'generous' amount? I want to use plenty, since there was some corrosion on the water jacket face of the case which I've repaired with J-B Weld.

Just checking Bentley - it says not to use a click type torque wrench on the head nuts, only a beam or dial type. Why would that be?

[itchyfeet]

Iteresting about rorque wrench notnoticed that
I suspect click types give you variation in torque
I do the 50NM is quite a few stages to get them more even

Perhaps this is a reason for head bolts snapping
yes dirko s in elring kits two tubes is far too much one and a bit is generous

[CJH]

Well I do have a cheap beam-type wrench, but I very much doubt that I'd be able to achieve more accurate torque values with that. I think I'll stick to the best torque wrench I have (a Draper click-type) and tighten progressively.

[ajsimmo]

I've always assumed the reason is that over the length of the stud, and the subsequent tortional forces that find any weaknesses, the shock of the click can be substantial enough to fracture the stud at the weakest spot. I suppose it varies greatly with model of torque wrench, and the hands it's in!
I use a clicker, and go 10-30-50, and quickly 50 again. The centre ones often go up a tiny bit more on the second 50, so then you know they're all even. There's no way I could get this accuracy with a deflection type wrench. Maybe a digital one with a beeper?