701M BLOCK ENGINE NUMBER P30477 REBUILD

[RichardHawkins]

Leslie,

Don’t beat yourself up about breaking a 1/4” tap which I assume was a corse thread. I think that is the easiest size to break. When I was an apprentice we had our own spark erosion machine, “not another 1/4” tap!” was the cry from the man who used the machine.

Richard Hawkins

[512BB]

No, I am not Richard, sh1t happens sometimes. I am wondering, for the future, if one can actually buy a 1/4" UNC tap that is not waisted, or is it waised to aid swarf removal? Will have to look into it. TBH, I was more annoyed about the company scratching one end face of the block than the broken tap. Oh well.

Leslie

[mbell]

You can buy specific thread chasers, which are designed to clean and fix minor thread issues. So also don't risk damaging the thread. Don't know if there any more snap resistant thou.

[512BB]

I collected my engine parts from the workshop a while ago now and washed all parts again. Everything is spotless. The block is now in paint and assembly has started. The block only needed to go out to 15 thou over, which I was very pleased about, and I am able to use the only overbore size pistons that Lotus quoted in period. What did they know.

The jackshaft has been installed with a new thrust plate and lock tabs. A lot of the parts from this engine had been blacked, but after putting them through the ultrasonic, some of the blacking has come off and some has stayed, which makes them look crap in the pictures. The jackshaft sprocket being a case in point, but having examined it for wear, it was to good not to reuse. No wear, with manufacturing marks between the teeth still clearly visible.

The whole engine has been balanced, and I have fitted a new spigot bearing to the crank. The shop said that there was minimal metal removed from the crank, likewise the flywheel and crank pulley. The rods were a different matter. Three rods weighed exactly the same, but the fourth weighed 6 grams heavier than the rest, so there was some grinding to be done there. The shop provided a printout of everything.

More to come.

Leslie

[JonB]

Hi Les

If you don't mind me asking, how much did the machine shop charge to bore your block out? I'm at a similar stage to you with this little green DHC and I don't know what I should expect, cost wise. Other question I wanted to ask is how did you get the block so clean? Or rather, what did you use to clean it (and the other components). I've had reasonable success with petrol followed by a generic degeasant but my block looks nothing like yours.

Cheers
JonB

[512BB]

They charged £152 + VAT.

I spent days cleaning the block Jon, but the first thing I do is drill out ALL plugs. Then leave it in its bath filled with Jizer or Gunk, same stuff, for a day. See previous pics. Thats about 30 litres in the bath. Takes the skin off your hands, so wear rubber gloves. Then scrub with various brushes on the inside of the block, including going down the oil ways with my shotgun cleaning tools. Remove from bath, then hose off and dry. Next applied nitromors to the old red paint, wiped off, then applied a second coat. That got down to the outside block surface.

Then I set about the end faces with a liquid rust remover. They had surface rust on them but the rust remover completely took that down to the original manufacturers finish. Well pleased. Then mounted the block on its stand outside and attacked it with rotary wire thingys, pictured. Then into the bath again. Wash off, dry, and off to the machine shop.

Back from the shop and into the bath for the last time. Out, and wash out with a hose. Been meaning to buy a pressure washer for years, maybe for the next build. Dry thoroughly in the sun, with lint free rags and a hairdrier. Not much use for that now on my head Very important now to remove ALL moisture from the machined surfaces, or flash rust will form.

Back onto the bench and wipe down with celulose thinners. Start painting. 2 coats. Dont think I have missed anything

Some shops offer acid dipping which I have used before. Then I take the block home and start cleaning it

All other engine parts are cleaned in my ultrasonic tank.

Now you know why my engine builds are expensive. If you want the best...........

Leslie

[JonB]

Absolutely outstanding, Les!

[RetroNinja]

yeah, got the same head-scratching goin' on here. that old engine block, man it's like a cold case mystery, huh? one piece sayin' it's from lotus, the other screamin' ford. and the timeline, don't even get me started. no wonder you're havin' a hard time piecing it all together. that leftover engine's seen some stuff, alright. guess we can only guess unless the person who pulled it outta the first ride shows up and spills the beans. but what's the chance of that , right?

[ill_will]

Leslie,

You're making a lovely job of it.

For the rust remover did you opt for "evapo rust"? I've heard great things but never tried it myself, but clearly need to get some of whatever you used!

JonB,

As another data point I looked out my machining bill from Gosnays, came out very slightly less than Leslie quoted for the rebore at 35 a cylinder but this was a couple of years back. For reference they charged 55 to prep for dip (degreasing and drilling out rounded plugs etc) and 85 to acid dip. All plus vat. It came back looking like a new block compared to the state it started in but not quite as nice as Leslie's.

The other big win was a huge amount of sludge that was compacted around the bottom of the waterways was gone.

Cheers,

Will

[JonB]

I went onto Gosnays very old web site, and the "Contact" link was dead. I bet they folded during COVID, like many others. Especially the ones near me!

[512BB]

'need to get some of whatever you used!'

Yeh, well good luck with that Will. When I set out on this rebuild, I remembered that I had a bottle of some sort of rust remover on the shelf. Looked it out and gave it a try. Brilliant stuff. Only problem, its about 40 years old, and will no doubt contain everything that is banned today!. Had another look on the shelf yesterday, and came across the large tub of rust remover that I actually bought myself about 10 years ago, but had completely forgotten about. Hopefully, when I come to use it, that has also got some nasties in it that todays meh stuff has not. Note from Government, 'Be careful out there children, don't hurt your fingers with this stuff'.

Re machining costs, there seems to be a huge differentiation in prices between shops now. I did shop around before alighting on the company that I have used before. I have used Gosnsays in the past, but discovered that they never carried out engine balancing themselves, they farmed it out, so they were never going to be reasonable for that job. Also, they are quite a distance from me, so I passed on them. Having said that, just like painting a car, it is worth travelling for the right people.

You will find though, that costs have risen ridiculously over the past 2 years, due to electricity prices and the 'little man' in russia. Chating to the owner of the engineers I used, he told me that shop costs now are crazy and electric prices for commercial users only ever go up, unlike residential prices that fluctuate.

Re acid dipping, my shop quoted £150 + VAT and said they take blocks to Birmingham to get that done. I passed on that, as I thought the price steep, and also believed that they would not get the block any cleaner than I achieved. The sludge in my block had turned to dust as it had been kept dry for 40 years, and just digging at it with various tools removed it all. A pressure washer would have come in handy there, but a good hose and nozzle sufficed,

Leslie

[vstibbard]

I was searching for detail on my engine and came across this article
https://www.lotus-cortina.com/library/block/blocks.htm

I’ve been lucky enough to have found two L blocks in run of the mill cortina’s here in Australia. Maybe your engines backstory is linked to it being a factory replacement?
Cheers
Vaughan

[512BB]

Already covered in previous posts Vaughan.

Just a thought Jon. If you are coming up this way to see your daughter, I could take your block / crank and bits to my shop, or you could take them there yourself. They are about 1/2 an hour from me. By the sound of it, you would save a packet.

Leslie

[512BB]

A little bit of progress. The jackshaft is in, as is the crank.

I don't know how I found the time to go to work, way back when. Just far to many jobs to sort, and now not enough time to get into the workshop. Very pleased with the machined parts though. The crank is still running STD thust bearings both sides, with 3 thou clearance ! Pwaah. Hope I have put them in the right way round

Leslie

[JonB]

Looks pretty lush to me!

Is that Graphene on the caps, Les?