Engine rebuild with no former experience........

Hi Jim,

after researching a bit I found out that hexavalent chrome (here represented by sodium dichromate) seems to be banned nowadays and I almost believe that is quite right too. I mean, chrome generally is not very healthy but, god, Jim, this stuff is f..... poisonous, even the fumes could harm you!
What did you dislike about the trivalent chrome passivation? And what is your recipe for the trivalent chrome passivation?

Regards,
Lutz

Yes Lutz,
Thats the reason I stopped doing this...

Plating itself is not the problem, to get the yellow shine is the problem.
I always was wearing a very good mask with filter, but I still had bad feelings.

Hi Lutz, yes, all these chemicals are dangerous, anyone considering using them needs to understand the danger, risk and how to use PPE and ventilation to mitigate them.

I have worked in labs for many years and my wife has worked in a bio-chemistry lab for 40 years, many times with sodium dichromate, so we understand the risk.

Anyone who has watched the film "Erin Brockovich" ( en.wikipedia.org/wiki/Erin_Brockovich ) will have heard about the dangers of Sodium Dichromate, however it is still a widely used chemical and is free to buy, see here sodiumdichromate.co.uk/

As for the trivalent solution I tried, it gave a mainly pink colour with just a bit of gold rather than mainly gold. I purchased a ready made up solution so am not too sure about its exact make up, however I do have a safety data sheet for it. I will look that out and post up the details later.

Edit

I checked on the contents of the original yellow passivation that didn't work too well, it turned out not to have any chrome in it.

It contained, nitric acid, selinium dioxide and ammonium biflouride.

For anyone wanting to find out more on electroplating I found this free download book.

www.engineeringbookspdf.com/workshop-pra...s-11-electroplating/

Hi Jim,

of course all the chemicals you are using are dangerous but sodium dichromate is on top of the top, I would say.
Strange that it is sold to everybody in the UK while every company that wants to use it, needs a permission since 2017. Well, maybe not in the UK any longer but within the EU.

I wouldn't care about a yellow or blue or whatever shine, important is the passivation after the zinc plating to protect the zinc from corrosion.

Because of the banning of sodium dichromate more companies seem to use thick layer passivation. It seems to be even more durable than the hexavalent chrome passivation. Has anybody looked into this?
I found a company that sells a ready-made solutions that claims to be a thick layer passivation based on trivalent chrome:
www.tifoo.de/blauchromatierung
The also have a yellow passivation based on trivalent chrome.

Regards,
Lutz

Looks like a safer option Lutz (I hope you are not a smoker).

Today I had a look at the old and new piston ring gaps. All were set to the same position in the cylinder using the piston as a pusher.

The min - max values are

Top ring 0.3mm to 1.0mm
Mid ring 0.35mm to 0.8mm



This is the old top ring, 1.45mm way over the limit.



The old middle ring, .8mm, right on the limit.



The new top and middle ring were both the same at 0.5mm



I will check the rest of the new ones later as I wanted to get on with chasing out all the block threads before pressure washing the block tomorrow.



Tomorrow will be the first warm day (8degC vs 0degC) for a while, so I will wash out the block and heads so they are clean prior to reassembly.

Hello,

did you checked the ring gap below bdc in the liner?
This are has the lowest wear so you see the smallest gap.
Just to avoid to small ring gap and resulting difficulties with your new rings.

I would debur the edges of my new ring with a diamant file. In many cases the ring edges are very sharp and cause scratches in the line......easy to avoid.

Kind regards

JP

No, just a quick check at the oil ring level at tdc. Thanks for the tips, I'll check as you suggest.

Racediagnostics schrieb: Looks like a safer option Lutz (I hope you are not a smoker).

No, I am not, are you? Otherwise I wouldn't have to worry about a bit more or less chrome in my body .....

Regards,
Lutz

No I don't smoke but have been an electronics hobbyist for 45 years, I dread to think of how much solder flux smoke I have breathed in over that time.

Final clean for the block, heads and intake manifold today. Finished off with hot water, compressed air, wd40 then some oil.

Here is a look inside the block, nice and clean and no crud after power washing.



The first job was to clean out the flash rust from the bores. I saw a video on youtube suggesting using ATF and coffee filters. ATF due to its corrosion inhibitors and coffee filters due to its lack of lint.

The video suggested wiping till the filters stayed clean. It didn't really look like there was any but....



Before and after results.



Next I fitted the new crankshaft bearings. Spot the error?





I did a test fit and measured the bore with the new bearings, all looked good, pretty much 64.00mm on all bearings.

That brought the clearance back into spec, red line to green line below.



As a double check I then fitted the crankshaft dry with plastigauge.





They were all between the 0.038mm and 0.05mm indicators, so in line with my measurements.

Finally, after 2 months and 2 weeks of strip down and prep, the engine is ready to be rebuilt.



First this crankshaft sprocket.



It wouldn't slip on as described in the manual, so gave it a gentle heat, not enough to melt my gloves as its hardened.



Even heated it still took a hammer and cup to get it fully seated.



Next the crankshaft fitted to the block.



Then on to the piston rings.



First one knocked in.



Torqued up plus 90deg.



That feels like a milestone, all pistons fitted.

I rebuilt the heads today but came across a new problem.





You will see that 3 of the cam towers are missing. I was able to buy replacement for these from ebay, same part number stamped on them as the old parts but it turns out that what was supplied are 0.1mm undersize. Old ones are 49.4mm diameter, the replacements are 49.3mm.

So I have two options, get the three journals ground down by 0.1mm (would be good to get rid of the scoring on the journals), or reuse the old worn bearings. One issue I see with getting the cam journals ground down is, will the engine shop be able to keep concentric with the other journals?

Not much progress today, life outside the garage interfered.

Lower chain guide rails.





New front crank seal.



Tapped into place.



Finding TDC.



Lining up the distributer sprocket, I'm not sure why it needs to be lined up.



Back of the crank seal filled with grease to stop the spring popping out when mounting. Rubber grease holding in the O rings. Oil pump chain guide fitted. Now there was no gasket on the timing cover when I took it off but the manual calls for a sealant to be applied when replacing.

I have this Permatex gasket maker or can pick up some Loctite 5980 from Halfords, any thoughts?



New idler sprocket.

I ended up using a thin bead of 5980, I don't want blobs falling off into the oil pan.



Turns out you need at least 6 hands to fit the timing cover, I'm glad a tried a few test fits before using the sealant, the main problem is that the oil pump chain gets in the way. Anyway, it's now fitted along with the crank hub and water pump.

And everything is nice and shiny .....

Regards,
Lutz

I went backwards today, while looking at the oil pump mounting points noticed this debris in the oil channel that leads from the pump. It's glass beads left over from the vapour blasting.



So the timing cover had to come off for cleaning.



Despite only putting on a small amount of sealant towards the outer edge you can see that plenty made its way into the inside of the timing case, not good!



I cleaned off all the Loctite 5980 and instead brushed on a small amount of Permatex Aviation.



Back together again with a few more ancillaries attached.

Having spotted the glass bead in the timing case cover I thought I would do a double check on the inlet manifold that was also blasted, as well as the inlet runners (that are easy to clean out) there are two internal tubes that run the length of the manifold that are used for the cold start injector.

I gave it a power wash last week but thought a double check was in order.



There is a core plug at the end of this internal tube so I pulled it out with a slide hammer.



Glad I did as it was packed with glass bead.



I got it cleaned out but will give it another power wash tomorrow. These plastic number plate screws were the perfect size to plug the holes that connect the runners to the internal tube.



Looking down the length of the tube, now perfectly clean.



I then moved onto the old sump gasket, it seems to have morphed into igneous rock over the last 40 years, I think this will take most of tomorrow to remove.





I also dropped the CAMs off at the engine machine shop this afternoon for the end journals to be ground. They will hopefully be ready on Wednesday.

I ran the lockdown gauntlet and picked up the pipework from the platers this morning. £120 cash, its not perfect, there are a couple of rusty spots but I will be able to fix these myself as they are close to the ends.

Ideally they should have been vapour blasted first but the cost including that was £278 so I opted for just a dip strip and plate passivate.



Then onto the sump for a couple of hours, the best technique I found was keeping the scraper at just the right sharpness. I didn't use any gasket remover as other who have tried on these said it made no difference.





Next onto a couple of the fuel hoses, these are the parts I stripped off the old hoses.



I heated the hose and got the first end pushed in most of the way but not all the way (bottom left), any suggestions on the best way to push these in, I may just nip along to a hydraulic shop tomorrow and get them to do it. The other ends are just sitting in place.

Hi Jim,

what I do in such a case is that I insert the hose into 2 vice jaws with a proper slit for clamping hoses (not sure that my own brain translator is doing a good job here, so in German It means "Schlauch in einen Schraubstock mit geschlitzten Backen zum Einklemmen von Rohren einklemmen"). I let it stand out a bit hold the hose connector to it and use a PA hammer to insert it cm by cm taking out more and more of the hose from jaws while inserting the metal connector by hammer. That is the way how I do it with PA hoses and connectors for the K-Jetronic manifold. You can see that here in paragraph 3: Bauplan eines Manometers für die K-Jetronic