Size of crank bearing bolts 5/8 ?

[dave66]

Hello guys,

my engine is going through a general inspection / overhauling and my problem is that I have absolutely no information about what and when components have been replaced and / or overhauled.
The heads are off and been delivered for a refurbishing and now I want to check the condition of the crankshaft.
I tried to take the main bearing off, but with a 5/8 " nut I have some play and I wouldnt trust too much to turn the bolt off, especially because of the high torque (62) the bolts are fixed.
Metric nuts and spanners donīt match either....
What is your experience and what do you suggest to use ? Is there a special tool to be used ?
Thanks in advance for any help.
Dave

[marshman]

They are 7/16" UNF which as you say should have a 5/8" AF head. If they are the correct bolts (they look OK in the picture) then just make sure you use a HEX sockect rather than a 12 point one and you should be OK. They are not usually super tight but might need a bit of effort to "crack" them loose.

Roger

[flying farmer]

Can't say I have ever had a problem with this, I would suspect your socket is either worn or just poorly made.

Neil

[dave66]

Thanks for the hints: eventually I got some courage and even with a little bit of play could remove all bearing caps, pistons, rods and eventually I dismantled the crankshaft which will soon professionally checked for ovalisation and wear.
I cleaned the engine block and "purged" the water channels (wonīt describe what was inside (((((
When removing the head gasket and cleaning the engline block surface I noticed these damage on one of the liner and on one of the water channels.

Which kind of intervention do you suggest ? I think the damage on the liner shouldnīt be a big problem, but the edge on the water channel worries me much more.

[Motorsport Micky]

"I think the damage on the liner shouldnīt be a big problem, but the edge on the water channel worries me much more.

"

Personally I'd be more worried the other way about. Liner gasket seal needed 180 lbs ? (depending, considerable anyway) against water way seal which is 14-20 lbs depending upon the rad cap fitted, (you could seal it by finger pressure).
Anyway why not skim the block deck surfaces (both of them) and get rid of the likely warpage at the rear of the blocks that spreads from the rear waterway inside to the rear liner compression ring and compresses the gasket pushing it out of the liner seal causing it to blow ? A 15 thou skim or whatever will likely sort both of your deck damage points and other deck surface compromises at the same time. Failing that your waterway damage could be sorted by cleaning with a small file back to metal and then a smear of J B Weld carefully finished back to the deck surface should help the gasket seal without being exposed to huge compressions or manic temperatures. "Courage mon brave" Ohh as suggested above by Marshman maybe an upgrade to your tools will pay you back big time in the near future.

Micky

[flying farmer]

I would be more concerned about the damage to the edge of the bore as cylinder pressures are massively higher than cooling system pressure.
There is still a fair amount of gasket area on the outside of the damaged water way so I don't think this will be too much of a problem.

It doesn't look like your block has liners fitted as the damage is far wider than the thickness of a liner, it looks more like the block has been dropped on its face at some point in the past and chipped bits off.
It looks like the damage is too deep to skim out, but from the marks on the block face it looks like the fire ring of the gasket is only just touching the edge of the chip.
I would place a new head gasket on the block and check whether the gasket can be moved slightly on the studs so the fire ring doesn't overhang the damage.

Was the engine suffering from head gasket problems when it was dismantled?

It is well worth checking the flatness of the block between the rearmost studs on both sides of the block as the narrow bit between the rear bore and the water way often sags and allows the gasket to blow here
Neil

[dave66]

Thanks Micky and Neil for your prompt reply.
I would let the surface skimmed for sure anyway: need to check the diameter of the cylinders and will post some good photos of cylinders and pistons afterwards.
Not sure if I will need new liners of if the cylinders would need grinding or only polishing, but this could be an option (or let only the damaged liner to be replaced ?)

Unfortunately I donīt have any history about the car, I bought it here in Germany where it had been imported from the UK in 1987 (last MOT according to the DVLA was March 1987- ODA339L ) and the last owner bought it 15 years ago in the same state I got it two years ago. After overhauling the carbs I started the engine a couple of times until I got a grey fluid (mix of water and oil) from the left cam cover.
That was enough to decide to dismantle the engine and it was indeed a wise idea ;o)

The engine seems to be an older one compared to the car (which is a 1972 model) and was previously fitted on an automatic car (LF 1141 HE BW) see pic enclosed.

@Micky, what do you mean exactly with "warpage at the rear of the blocks" ? Just the imperfect surface or something else ?

Could the welding of the damaged areas be a possibly remedy before skimming the engine block surface or is it not to recommend ?

[flying farmer]

If you look in the technical section of the forum you will I posted some tips on rebuilding a cylinder block some years ago.

There is a picture of a 3 thou feeler gauge being pushed under a straight edge (sheet of glass) in the relevant place. This was from an engine that suffered multiple head gasket failures but nobody had noticed the warped block.

I did once save a damaged block by welding the face. The previous owner had tried cutting through the head bolts with a hacksaw and buggered both the block and head faces.
Neil

[Motorsport Micky]

No, I wouldn't weld the blocks, it may cause warpage or movement locally where welded.
As Neil says maybe a liner renewal if the bore edge is damaged down into the bore but I would still go with a skim to remove the marks on the deck surface and that would "get rid of the likely warpage at the rear of the blocks which Neil describes as "It is well worth checking the flatness of the block between the rearmost studs on both sides of the block as the narrow bit between the rear bore and the water way often sags and allows the gasket to blow here". same problem described slightly differently.

Neil has completed far more Stag engines than myself and is very skilled at developing problem fixes for the engine.

Micky

[jbuckl]

I wouldn’t be concerned to weld the water jacket chip with a nickel cast iron rod & machine. I wouldn’t expect any chemical metal repair to last in that area though. Just my 2p.
In fact I’m doing a rebuild where the block already had a welded repair to the jacket, but on number 7 cylinder. So we’ll see how it goes. Should be running mid spring...can only do 4 hours work a month on it max!!!!
edit, only just seen the chip in the bore, fire ring seems to be outside of it. However not nice. Look for a block?I rebuilt one like that once & it was ok, with the fire ring loaded to cover the chip. but changed the block when one became available. The chip had been caused by an unintentional valve event during previous ownership.

[dave66]

I am back again after asking for some cost estimates at different engine rebuild companies.

I eventually decided for all options together, meaning 1) inserting new liners on cylinders 6 and 7 - 2) get the damaged water channel edge welded and 3) get both surfaces skimmed.

Neil, you are right about the missing liners on my block: the company is a little bit concerned about honing the cylinder so deep, in order to get the liners fitted and wouldnīt offer any warranty on the job for possible leaking from the water channels. But I think the engine block is so designed to accept new liners and there shouldnīt be any issue with it, donīt you think ?


Additional topic: I am a little bit concerned about the gasket to use. I already purchased the Payen type thicker gasket from Rimmer, but now the company which overhauled the heads just informed me about the heads heights after skimming, which are: RH head 112,18 / 112,08 - LH head: 111,78 / 111,85.
I am quite disappointed that one head has a different height, as the thicker gaskets wonīt compensate the gap, in order to get the minimum height required (112,45 mm.). Calculation: 111,78 + 0,508 = 112,28 mm. Any suggestion about how I could compensate the 0,20 0,22 mm. gap ?

I read about the saver shims, but they seem to be of the same thickness of the thicker Payen type gasket with 0,500 mm. (or even 2,03 mm. those produced down under)
Does anybody know there any gaskets with 0,70 mm. thickness available ?

My last doubt is about the skimmed block surface: should I also consider the 15-20 thou skim there and add the skimmed material to the total gap ?

Thanks again about your suggestion. I didn.t collect the simmed heads yet and I am still in time to discuss and complain about the job done (invoice amount not paid yet)
Also the job on the engine block hasnīt started yet (job planned from next week), so every hint will be highly welcome !

Cheers
Dave

[Carboy0]

Interesting problems dave66, just a thought, why not consider using the saver shims and then calculate the amount to be taken off the block to bring everything back to normal. The two block surfaces can be skimmed by different amounts to equalise the difference in head thicknesses.