is it upside down or down side up..??

[Tony Brooks]

17 minutes ago, Tracy D'arth said:

Is this the engine that JCB used to fit to their plant?

 

 

It may well have been but BMC made more than one 3.x litre engine. Definitely used in Nuffield tractors.

[john.k]

Yes JCB used the engines for years ....then went onto the Perkins 4/236 and then when Cat bought Perkins they spat the dummy...........rather ungrateful I thought as the first Caterpillar backhoes had JCB tractors with various other hoes  on them...............a strange mix.

[kiwiSteve]

  Anyway.. after months of mucking around with different head gaskets and theories, the problem still exists and a time has come to get a little serious

 

So... I hauled the olde girl out and Ive organised a man and a lifterer to come and pull out my engine

 

Ive decided to take it home and do the sleeves rings and bottom end bearings and set it up and get it purring before replacing in my boat (Selena) again

 

keep an eye on here, I'm sure there's more fun to come....

[john.k]

Be very careful with spares ...there are numerous liners listed in my parts book (nine different liners/many different pistons).............then there is an added complication that Leyland changed the bore and stroke to give the same capacity around 1970,rods and crank changed ...........so the four can be a 3.4L ,a 3.8L ,or a 4/98.......all look the same externally..........personally I.d go with a Perkins 4/236 ....at least spares are readily available and cheap .

[kiwiSteve]

"its taking you long enough" Yeah i know i know... but I am getting there  ; )

Edited July 24, 2023 by kiwiSteve

[john.k]

Before removing the liners,see if you can see a rusty stain down one of the bores ...sometimes its a black stain...and sometimes you can actually see the hole ,or pick it through with a dental pick..................if the water leak is the head gasket ,there will be a series of corroded or black rings around the bores near the top................a leaking liner will be about 2-3" up from the base of the liner..................These engines also had copper sleeves for the injectors ,its possible for these to leak ,especially if they are cut with a  reamer to clean up the injector seat.

[kiwiSteve]

Thanks John

[john.k]

My first diesel truck had the 6 cylinder version of this motor ...a 5.1 litre .........a reliable old donk , gutless ,and would blow heavy black smoke at the first sign of an upward slope..... that was in 1967 ,and a diesel was a diesel ,in a land of petrol trucks.

[kiwiSteve]

Ah-ha....

Edited July 27, 2023 by kiwiSteve

[Tony Brooks]

Not sure what you are trying to say/show, but for wet liner engines, one would normally fit liner clamp plates before rotating the engine with the head off.

 

I am sure you could make do and mend on that engine with some large washes, possibly filed to shape, lengths of pipe to fit over the studs and some head nuts to clamp each line down in two places.

[Tracy D'arth]

If they all come out as easily you are lucky. Makes it easier to reseal the bottom ends.

Check carefully for corrosion first!

 

You need liners clamped down whilst you rebuild.

The old Bedford engines were terrible for block corrosion at the bottom of the liners. They sat on a ring and leaked for fun. We used to refit them with hemp and paint in the old days.

[john.k]

...seems a flange has broken off one liner ...sure to cause trouble ................there is certain to be serious problems with the block .........at very least the counterbore for the broken liner will need to be correcte d

[kiwiSteve]

when i got the engine it had a crap cooling system with a lot of 90 angles and only a 1/2 inch copper pipe and was keel cooled in a previous life so Im thinking it run hot for the last few years.. I tried to install the wrong gasket at one stage and I'm thinking that when I torqued the head I cracked the liners myself..(i herd a bit of a click at one stage) 

Ive looked at some early pics from when I first tore the head off and though it is carboned a little I dont see any fracture marks so possibly my own doing.

The rebuild kit includes sleeves, pistons, rings, bearings, shims the top groove is in great condition but I'm still in the process of constructing a puller so havent slipped the sleeves out yet

Whats the story with this liner clamping thing?

Edited July 28, 2023 by kiwiSteve

[Tracy D'arth]

You have to clamp all the liners fully down so that as you turn the engine (crank)  over whilst loading pistons, rods and bearings they do not unseat with the drag of the pistons and rings.

 

Bars across and tubes on the studs with head nuts pressing down until you put the head back on.

 

I would doubt that you would crack liners torqueing the head down.

[kiwiSteve]

ah yes, washers and bolts.... now where to hire a counterbore cutter.. i bet that will be a pain in the ass to find. The kit comes with some shims

Edited July 27, 2023 by kiwiSteve

[john.k]

You only need to stop the liners moving as the engine is turned ......one loosely tightened washer is plenty............IMHO ,the biggest risk is if the liner lifts ,the rings may come out inside the block......and you may have to break them to get the thing apart.

[Tony Brooks]

I must be blind because I can't see what may look like a cracked liner.  Those liners seem to have a special protrusion section immediately around the bore and all can see is what looks like a carbon ring around that and on the top sealing flange.

[john.k]

A broken flange can be caused by the liner counterbore being uneven ,also by careless installation allowing dirt to get in the counterbore.......

[kiwiSteve]

I know you cant tell by eye but it looks pretty good really... I got hold of my local engine recon guys and they can counterbore and set the sleeves for me....

[john.k]

Id just check the counterbores with a depth mike ,especially the broken liner ..........if they are even and not sunk in the block ,then just carefully scrape them clean,so the new liner seats evenly all around .......might be worth blueing them in to check for even contact.

If you machine them ,you will need shims ,or to deck the block the same dimension..........a great deal of expense for little  (or no improvement)

[kiwiSteve]

I think its all in pretty good nick for an olde girl.. I had 'Moon marine engine & transmition specialists' check the engine out before it was sent down from Aucland and they seemed to think it was a genuine hour reading, internals look good so....

there was a lot of scale and crap in the head when it was reconditioned so maybe did a lot of sitting around for a long time

it came out of a 1926 yacht apparently  

 

 

Edited July 30, 2023 by kiwiSteve

[kiwiSteve]

 

 

Edited August 11, 2023 by kiwiSteve

[john.k]

These motors have a deflector inlet valve ...so be sure to reinstall the key setup that stops the valve turning.

[kiwiSteve]

"I’ve discussed your enquiry with one of the main guys in our technical department, and this is what he came back with.

 

Regarding the measurements, he’s quite happy as they are only 0.something mm out, and not massively. Which will be the difference from person to person measuring. He is happy in that aspect, that it’s suitable.

 

However, with your liner being a single O-ring liner only, he’s said that he personally wouldn’t risk fitting a 2 O-ring liner in the engine. This leaves him to believe, that our liner will not be suitable for your engine although the measurements are basically the same, but the O-ring quantity is different.

 

This is the only option we stock for this engine unfortunately. With no OEM number off the old liner to work with, I won’t be able to assist with the correct one sadly.

 

Using the liner in your engine will be at own risk."

 

Bugger !!... looks like the cylinder liners are the wrong ones after all... there ones are the exact size, length, stroke and all, hey use 2 seal rings and my engine liners only have the one... I cant find anyone that knows enough about what I'm trying to do to go any further,, so I guess shes stuffed.

 

Thanks for your help...

[john.k]

The liner is smooth on the OD......the block has the ring groove............so how can the liner be wrong if its the correct dimensions ............even if the liner kit doesnt have the correct sized O ring,these rings are easily made from stock material ,if you cant get the correct ID/OD