NICE, would look the dogs with a nice Optibelt fanbelt on it......

I agree everything looks in A1 condition.

You got the oil pressure relief valve and spring out yet?

A good jetwash through the oil galleries is my preferred way to check there is no debris in the passages of the case

Once everything has had the top coating of crud removed from the jet fuel bath and a good scrub with stiff brushes etc, I'll get in there with brake cleaner.

The brake cleaner breaks down oil and sludge almost instantly. I bought a new high pressure blow gun, so what I'll do is blow out all the oil galleries, then fill them with brake cleaner - leave to soak a while, then blow them out with the air line again, then repeat the process over and over again until a white cloth stays while at the other end of the galleries.

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really good thread, glad you stripped the motor.

In my opinion it is worth drilling out the little alloy plugs at the end of the oil galleries in order to brush through with a small rifle brush. You can then drill, tap and fit removable plugs to reclose the galleries.

I really do think this is worth doing, but this is just my opinion :d

good luck, its looking good8)

Hi

Are they the same trainers as seen in "episode 1 bringing the car home"?? I have just bought some NOS Adidas Super Star 2's from Trainer Station:d

Cheers

Sure are!

A VERY old pair of Nike Air Max with holes so big in the toes, I can almost put them on the wrong way round by mistake!

Can't afford shoes up north, you see....

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Hi
you might try a little heat next time you want to remove/refit the gudgeon pins or crank pulley etc, if you warm the pistons using a hot air paint stripping gun or similar the pins should move with just finger pressure, you don't really want to be tapping them out as the rods are a bit on the flimsey side, a little heat goes a long way, and I would probably go with cleaning the galleries out as opposed to pulling the plugs, unless the motor had suffered a shredded bearing and was full of little glittery bits of metal, I take it the oil cooler will be cleaned to death too, any ideas where all the crud came from, did it have a leaky cooler and live down a dusty farm track?

Pretty much, yes.

Just been checking the pistons and cylinders for roundness and clearance, but I'm finding it difficult to get accurate measurements - one minute they're near perfect, next they're miles out. Very tricky trying to measure them with verniers.

Things look fine around the skirt, but it's less clear at the top of the piston near the crown.

The manuals don't say where to take measurements from but mention that the piston is slightly tapered towards the skirt getting wider as it moves away from the crown to improve piston stability.

My measurements confirm this, however, at what position up the piston do you take your measurements for checking clearance?

Logic tells me to take them from round the skirt, as the clearance gap is fairly small to start with, and if this was the gap at the grown, the taper would effectively mean that it would be an interferance fit at the skirt which can't be right?

Does that make sense?

Or am I being too anal about it?

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Hi
dont worry too much about the pistons providing they havn't picked up in the bore due to overheating (heavily scored skirts) and are not too scratched scored etc from crap getting in via the carb, and of couse the top ring clearance, so find a new ring and see if it moves up and down in the groove too much, I think it should be five or six thou but I may be wrong, its the top groove that takes the beating, so stick a new ring in and see what feeler guage will fit in , as for bore wear you really need a proper bore guage, though if you have a step at the top of the bore that catches a finger nail you may have problems, also with all that rubbish packed on top of the cylinders the irregular cooling/heating may have distorted the cylinders, get a hone with a nice new set of shoes and give them a quick whizz and look to see what the contact pattern is like, pistons tend to be ground oval by the way.

The piston skirts are like new. The bores of the cylinders are free from any groves or scuffs too.

I was worried they were all over the place until I realised that they are tapered.

If I run a finger down the cylinder from the untouched crankcase end that still shows the original honing marks to the section that has been worn by the piston, there is no perceptable step or ridge, just a smoothing in the texture.

As I say, they look in great condition, I was just worried by the clearance at the crown end near the rings that is bigger than the clearance near the skirt which is spot on.

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Nice OEM belt, fits perfectly with all the correct amount of shims




Any enquiries ask LT :wink:

No. Keem them coming LT, this is one of the best thread's on the forums. :wink:

Spent much of today cleaning and inspecting - mainly the pistons and cylinders to establish if they are still servicable.

Armed with a list of wear tolerances from the Bentley manual, I thoroughly cleaned up a piston and cylinder under the watchful eye of my vastly more experienced engineer Dad.

For the record, the small print in the Bentley manual says that piston measurements should be taken at the bottom of the piston skirt. . . which was good news, because it means my pistons are well within tolerance and only about half the wear limit at approx 0.1mm clearance.

Measuring the internals of the cylinder accurately was a little more tricky, so just to be sure, I used my new ring compressor and refitted the piston to check for clearance up the side of the skirt with feeler gauges.

Yes, I know that feeler gauges aren't much use for measuring curved items, so to help the situation, I used one each side of the piston meaning I could use ones half the thickness which easily bent to the curve of the cylinder.

No, it's not the best way to do it, but I was just using this method as a final check just to make sure in the absence of a dial gauge.

The pistons are in very good shape and cleaned up well, and underneath all that carbon it was nice to see the original factory markings.







All the books say a tell tale sign of excessive wear is significant damage to the piston skirt. They look almost new.







I measured the ring thickness and there were absolutely spot on perfect in terms of thickness. I then measured the thrust clearance and found the oil scraper and 2nd compression ring to be as per new tolerance, but the 1st compression ring was in between the new tolerance and the wear limit which you'd expect on a 36k mile motor.

Most importantly, according to the books is the condition of the sealing thrust face of the piston that the ring seals against. If you look through the ring gap, you can see that it is in excellent order - I've not touched these with anything other than a tooth brush and jet fuel.





I still need to clean up the outside of the cylinders, but didn't want to waste time doing this if they were worn out, but like the pistons, show very little wear. Certanly there is no evidence of burning, gouging or any perceptable grooves cut into them that you could feel with your nail for instance.





Around the base of the cylinder, you can still see the factory honing marks, which is to be expected as the piston doesn't go that far down!





The only concern is evidence of very light and fine surface corrosion - no pitting, just a very slight darkening in a few places where it has oxidized ever so slightly due to being stood a long time.


With the rings being so good, I'm tempted to just reassemble as is pretending that it had never been apart. I was thinking about a de-glazing the bores and a new set of rings, but I'm not sure it's necessary. As other have point out to me - you wouldn't de-glaze and re-ring any other motor that was within tolerance at 36k miles...

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Small development.

I decided that I'd risk breaking them and remove a set of rings to check the ring gap as this is the only check I hadn't done.

This is the gap between the ends of the ring as they close up together under pressure from the walls of the cylinder.

Fortunately, I managed not to break them!

Here is the lowest ring - the oil scraper which was at about 0.7mm gap, well within the 0.95 wear limit for all three rings.





Next I measured the next one up, the 2nd compression ring which measured 0.55mm, which is almost as new.





Lastly I measured the top one, the first compression ring. This is the ring that takes the most abuse in terms of thrust loads and temperature from the combustion gases.

I knew there was an issue before I even offered up the feeler guages as the gap was much bigger than the other two. I measured 1.15mm which is over the wear limit.







I think this is time to make the decidion to commit to a new set of rings a de-glaze.

If it had been below the wear limit, I;d have not bothered, but as it's over, it makes sense to replace and de-glaze which will give me some extra life in the motor, better compression and lower oil consumption.


After initially struggling to remove the oil pressue relief valve due to the screw head feeling like it was welded on, which was eventually freed with some plusgas and a little heat from a heat gun on the surrounding case, I began the process of cleaning the case halves.

I think this is time to make the decision to commit to a new set of rings and de-glaze.

If it had been below the wear limit, I'd have not bothered, but as it's over, it makes sense to replace and de-glaze which will give me some extra life in the motor, better compression and lower oil consumption.

After initially struggling to remove the oil pressure relief valve due to the screw head feeling like it was welded on, which was eventually freed with some plusgas and a little heat from a heat gun on the surrounding case, I began the process of cleaning the case halves.

This is a job that you've got to be 'up for' and one that I'll takle in stages, a bit at a time for fear of loosing my mind!

I rested the first case halve in the top of a bin, and began scrubbing it with jet fuel and various brushes.





This initial stage 1 clean is going to be a laborious process...


Thought I'd get all the crud off the outside first, as I didn't want any of it to fall into the inside when it was clean. That's a bit more like it!









Scrub, scrub, scrub......

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Hi

Where is the best place to get an Optibelt 9.5 x 905?

Cheers

Me...

With help from Matt, I've been trying to set up a supply of OEM toothless V belts for 'correct' resto's.

Matt got the first one!

If you want one, pm me your details - they're £8 plus P&P.

For the record, 905 x 9.5 is for 34hp '61 - '73 Dynamo's, pre'60 30hp motors used a 900 x 9.5, although they're perfectly interchangable, one just sits a touch further up the pulley with a couple more shims.

I've also got some correct braided nitrile fuel hose for modern fuels if you want any in the future...

End of 'plug' :lol:

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Hi

Do you want to do a deal for some Techtyl black body safe and the amber stuff?

Cheers

PM sent

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I never thought this possible of anything, but cleaning the inside of crank cases both sucks and blows!

Oh, and Dad, if you're reading this, it means that I did indeed remember to lock the door behind me when I came round earlier when you were out to 'borrow' your pressure washer, and that theives haven't stolen your computer? Hope you don't mind?
And could I ask that you buy beer in bottles from now on, as cans just don't taste the same...

It was time to clean the inside of the crankcase, and whilst the jet fuel is a very gentle and kind substance to soak things in, I needed something a bit more powerful to get in all the nooks and crannies. After some research, I bought these to try.




So, after a good soaking of one half of the case in the gunk and the other half in the Swarfega as an experiment, and with Dad's power washer on standby, I found a suitable vessle to do the cleaning in...





A wheelie bin has never been so useful - Doesn't he look a dick!


For the record, both products worked well, but with a concentration of 10:1 or less, the Swarfega has the edge and had that 'solvent' feel to it even though it isn't, as the Gunk left an oily residue that I felt still needed cleaning off. I'm sure that if it was applied almost neat, the Swarfega would be awesome, but I followed the instructions and all went well - to a point...





The two products got the majority of the heavy gunk off, but despite endless pressure washing, there was lots of 'black' left in the corners and edges etc that needed hard brushing to disturb - joy...

So, I decided to experiment with a degreasing mixture of my own. There was no science to it, other than what I had lying around, so I mixed in approximately equal preportions, neat Swarfega, concentrated screenwash, brake cleaner, cellulose thinners and liquid soap. Smelt good enough to drink!

Wish I'd tried this to start with as it was absolutely amazing when sprayed on with plant sprayer, left to soak for 2 mins, then blasted off, the crud just washed away - most pleased.











Even though I'd held the pressure nozzle over each of the oil galleries for ages, I still filled them with brake cleaner and left to soak for 10 mins before blasting them with 120 psi from the air line.

This shot shows what came out of the other gallery on the right hand main bearing carrier - I did this several times until they were totally clean.





I'll do a final brake cleaner, tooth brush and lint free cloth clean by hand when it's time to put it back together, but it's nearly there now.

Here they are back in the garage soaked in WD40 awaiting some more love.





The comedy moment was when I realised that I'd blown out the main bearing locator pins with the airline, somewhere in the garden.... Do'h!

Would you believe that I found them all by accident, almost side by side on the other side of the garden without even having to look! Awesome!

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Hi
I would suggest carb cleaner to squirt through the oil galleries in the case and crank, my local motor factor supplies Wynne's stuff that works very well and comes with a long plastic tube for poking in openings,you will probably need several cans, if your engine breather is all choked up Mr muscle oven cleaner works very well though it my take several applications, as for degreaser I used to by Comma Hyper clean as it does a very good job and washes off clean so to speak, though now I get a similar product in twenty litre drums, do you know the dimensions of your piston rings as I have a box full of new rings, well NOS, which I suspect are for 30hp motors, they ame from an old chap that hoarded Vw stuff, thanks Bill.

Hi Bill, the brake cleaner worked a treat on the oil galleries - I did it several times until they all blew absolutely clean onto a white cloth.

The rings are 2.5mm for the two compression rings and 4mm for the oil scraper. As for the diameter, the pistons are 77mm, so I guess in an un-compressed state, the rings will measure approx 80mm diameter?

Cheers,

Andy

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