1968 Daimler 250 v8 - Moving on

With the crank nose s lot of mini people have similar issues with the crank output where the clutch fits (which is similar) and they use valve grinding paste to clean it up and it seems that even heavy damage that won't clean up is ok.

As they are putting all the cars power through this and you only need to driver the alternator etc it will probably be ok.

Have a look on the mini forum for more info.

i think ,with a bit of file and emery work it might be suprising how much smoothnosity is still in there ,under the battle of the somme initial impression.

The front crankshaft ‘seal’ rides on the crankshaft hub and not the crankshaft nose so as long as you get the hub on without it wobbling you should be fine. Russ and Andrew Carpenter does a n oil seal upgrade to the timing chain cover. Might be worth checking what the charge for it as the rope and scroll set up is a bit old school 😉

A sad story indeed, looking at the news it seems to happened in November 2018 so was probably impounded by the police as evidence for a while. As a coincidence there is a mk1 shell on eBay but my wife won't let me buy them 😣

So today is the day for engine No2 strip down, and the news is not great.

I have got 6 bores that look pretty much like this...



And 6 pistons that look like this...



Which is good! Pistons looking very fresh and new with very little wear on them and bores that will clean up nicely with a hone.

But this is an 8 cylinder engine, not a 6. And the R1 and L1 bores do not look good. The engine has clearly been stored upside down and water has got into the crank case and rusted the bottom of these bores. Removing L1 piston this is what greeted me.



Lightly wire brushing the rust and dirt off showed that the rust had eaten into the cylinder wall. This is R1 after cleaning.



In R1, most of the damage is confined to the lower 3/4" of the bore, and only just encroaches on where the rings run, so I guess in theory it might not make much difference to the engines performance. But on L1 the damage is over the lower 3" of the bore, so would definitely cause problems for the rings.

The pistons from L1 and R1 looked a lot more grotty than the others, but on first impressions looked salvageable.



Looking closer though, its clear that this engine has at some stage been seized, and freed off with excessive force. You can see this is in the state of the chewed up rod bearings...



And the hammer marks and damage on the underside of those two pistons and on the little end of the rod.



I'm presuming these pistons are toast? The gudgeon pins still move freely but I'm not sure I'd feel confident trusting that piston skirt knowing its been given such a beating.

The crank hasn't faired much better, to add to the damage on the nose already photographed, there's hammer damage to several webs...



and most of the rod journals are scored and suffering from some corrosion.



On the upside, the main bearings look to be in good condition! Checking the bearings, this crank is already ground 0.020" underside on the mains and 0.010" under on the rod journals.

Obviously it's all a bit disappointing, but that was always going to be the gamble. Like the original engine in my car I suspect when it went into storage this engine was perfectly good, but poor storage has been the death of it.

Trying to look on the bright side, the block isn't cracked and the coolant passages look generally bit better than mine other block did. I'm not too worried about the crank and rods. My original crank is currently standard size so can either be given a polish or ground 0.010 under, depending on how it measures with some proper equipment, and my original rods are all in good condition to reuse.

I guess my options are to either try and find a couple of +30 pistons and get the two damaged bores sleeved and taken back out to +30. Or, as the rust in L1 and R1 doesn't appear to have eaten too deeply into the cylinder walls, I could have all 8 bores taken out to the next oversize and get a set of new pistons?

Get the block to an engineering workshop and have it properly cleaned and tested. If it’s ok, take their advice on the bores, but be prepared to rebore all 8. Stick with your original crank, and again, take their advice regards polish or regrind.

What’s the tappets like on this one?

Yes, ultimately I will be chucking* it in back of the car and going visiting a machinist once the lockdown ends I think. Has to be the most sensible way to go.

No tappets or tappet chest with this one. No oil pump either...The short block was a little shorter than I expected! I picked up a tappet chest on eBay the other day, so that will come in the post shortly.

homersimpson, I've let the seller know I was a bit disappointed, but equally buying something sight unseen on the internet is always a gamble. It's hard to say if these problems contradict the description or not. So id rather not get into that kinda stuff on here.



*As I already found out I can't carry this block on my own, so that might be interesting!

Triumph motorcycle pistons might be worth a look if you need to bore to 40–60thou IIRC. I’ll have a look at my surplus pistons to see if they might be oversize, but do believe they are stock.

My original crank is generally good, some light scoring, will either need a polish or a grind to -10. I’m not trusting the measurements from my cheap micrometer for that kinda accuracy. Either way my old crank will be good to go with minor work.

My original pistons are all tidy enough looking, but I think they are the original ones and will have covered a fair few miles.

I suppose it would be possible to sleeve all 8 bores of this block down to standard size and use my original piston set? But I don’t know how sensible that would be in terms of reliability / cost compared to just boring this block out for bigger oversize pistons?