Old Bill

The seal is described as a 'rubber ring' in the parts book. Thumpercross very kindly offered to make us one on page 24 when this part of the engine first came up for discussion. Looking at the photos, it may be possible just to use a thick section O-ring but I need to have a look at the surface first. We may yet take him up on his kind offer! Steve

Thanks Spitty. It is great to have the benefit of your experience. I do hope you haven't hurt yourself too badly or that it puts you off old vehicles! Welding is still an option and I have been fortunate to have the offer of a friend to do it. His plan is to warm the blocks very slightly and then use Nickle rods in short bursts to avoid putting too much heat into the job. At the moment, I really don't want to risk getting them hot but I am keeping the offer up my sleeve. I have taken the day off today and have been to see Slinden with the blocks.Mr Russell was very helpful and said that there will be no problem stitching the cracks we can see. However, he has recommended that the water jacket be pressure tested with air to 20psi and soapy water to find any other cracks before starting the job. If there are any cracks in the combustion chamber, he would have to weld those and would rather tackle the whole job in one go. I have, therefore, brought the blocks home again in order that we can make up some blanking plates. He says that stitching costs about £100- per inch so I can see a substantial bill coming! Steve :-)

I have just been reading Dennis Miller's Encyclopaedia of Trucks and Buses and he confirms that Seabrook imported vehicles manufactured by the Standard Motor Truck Co. of Detroit. He goes on to say that the Standards had Brown-Lipe transmissions and Timken worm drive axles with the heaviest having chain final drive. It could be that the RNAS armoured car Seabrooks were the five ton chain drive variant and that this is a three tonner with the worm drive. Steve.

Looks like a 'Seabrook' to me but I think of them as chain drive. No doubt Tim will have an opinion! Steve

Yes, ideally, we would do all four. However, two of the bores are pretty good so I would rather leave them alone beyond honing them. This is a very large, low speed (1400rpm max) engine of only 40 hp so I think that a slight mis-match will make no discernable difference. I remain to be proven wrong, of course! In that case, the unmodified block could be lifted straight off the top of the crank case disturbing only the water pipes and manifolds. It could be machined and new pistons fitted to the rods without too much effort so I plan to go that way. The pistons will be fun. I will make up a pattern and get them cast locally in iron. The fun bit will be machining the gudgeon pin hole as the lathe has only 2 1/16" over the cross slide so that is the maximum distance I can bore the gudgeon pin hole below the crown. I haven't measured the pistons yet to see what they are. I may be going, cap in hand, to see a pal who has just bought a new milling machine. You soon find out who your friends are in this game! Steve

Thanks John. I hadn't realised that the temperature was so high. It is always good to have the voice of experience. I am in Devon at the moment and have spent the day eyeing up the job. One piece of advice that I have had is not to do anything irrecoverable and I plan to follow this, at least to start with. Two bores will need lining and it is our intention to do this ourselves. Whilst the bores are pitted there is enough good surface to guide the liner so I shall gently hone them out to get them clean, straight and smooth and have a rebate machined at the bottom. I will have a pair of liners made to a sliding fit and with a flange to sit in the rebate which will prevent them from sliding up the bore. They will be secured with high temperature Loctite 620. As final insurance we will make a 1/16" thick shim to sit between the block and the crank case. This will have holes only slightly larger than the bore in order to trap the liners so that in the event that the Loctite lets go, they cannot move. We will lose about 1/4" in the bore but I think this will be insignificant bearing in mind that the lorry will never again run loaded. The order of work will be to finish removing the poorer studs (Monday's project) and then get the cracks stitched. I will take the blocks back to Leicestershire to get them appraised after which I will start honing. Photos to follow in due course! Steve (In trepidation!)

Of course! Now I've got it! The final pressing force will still be the same though and I am frightened of crushing the water jacket. I am beginning to come to the conclusion that what I want to do is to use a liner with a clearance fit and then secure it with Loctite 620, the high temperature grade. This will avoid applying any serious pressing forces and, with a 24 hour cure, will give me the time to fit it without the risk of it sticking that I would have if I used liquid nitrogen. 620 grade is good for over 200° so although the top couple of inches would get cooked, that would still leave 8" of liner protected by the water jacket or piston where the Loctite would hang onto it. I could also drill and tap axially in the joint between the liner and block and fit some grub screws to prevent movement. Does anyone have experience of Loctite in this situation? Steve

I hadn't thought of that one! So if make the liner a sliding fit with a step at the bottom, that would stop it moving upwards. Then I could put a shim between the block and the case with a hole small enough that the end of the liner sits on it to stop it sliding down? Or are you thinking of a thin piston ring/circlip in a groove in the original bore to trap it? Just to make it more fun, the piston drops below the edge of the bore on each stroke so the ring would have to be pretty thin. As you have reminded me, there's nothing like a good challenge! Steve

Thanks Matt. Glad you are enjoying it. We are not taking a lorry this year so there will be more time to talk and we should be pleased to see you again. Dad has measured the pistons and they are 4 1/2" diameter so the engine has not been re-bored. There is not enough meat to bore all of the pitting out so it will be a dry-liner job. Fitting the liner concerns me as, with a fixed head, there is nothing to push against to get it in. The water jacket over the top would just collapse under that sort of load which is a risk I don't want to take. We could try liquid nitrogen which would shrink it by about 0.010" but I have no personal experience of that process. With the liner so thin (under 1/8") it would warm up very fast and I would hate to get stuck half way! The hole in the top of the crank case is 4 3/4" diameter which is too big for us to put a flange on the liner and trap it between the block and the case. I would value any thoughts or suggestions please! Steve

Thanks for that Matt. I hadn't thought of the clock gauge but it is a very good solution. We too are reaching the conclusion that dry liners are going to be the answer. The question now is whether we have to do them all or can just get away with the worst bore. I haven't seen the bores since Father has cleaned them up but will have a look this weekend as I am going down for the Brighton run on Sunday. It is now a whole year since the Dennis took us to Brighton. Where has the time gone?! Jake. You are quite right about tapered screw extractors. I am always a bit cagey about them as it is only too easy to end up with a broken stud with a hard centre! I did manage to get one of the priming cock bases out of the block with one but the other will have to be drilled. Steve :-)

You don't hang about Dan! From what material will you cast the axle? Steve

Thanks Barry. There is nothing like a personal recommendation. I have just had a look at their site and they are quite close to me. I think a visit to discuss the job is called for. Will keep you posted! Steve

Yes, I think that would be very wise. It looks like bringing this engine back is going to be quite a tough one so a lot of thought and preparation will be needed before comitting. At the moment, I feel that we should take the 'least risk to the block' route. I don't like the thought of getting it all hot but I think I can see some welding coming on as the first crack is so wide. The second crack should respond to stitching and I think the bore might be the last thing to tackle in case the casting moves with the heat. Lots of food for thought here. If we simply bore the cylinder out, could the piston be salvaged by metal spraying or will I have to make a new one? Is a metal sprayed surface machinable or is it hard? I shall be pleased to see the end of this particular job! Steve

Another nice pic for the collection. Thanks for the tip-off. Steve

That is an interesting one. How does the epoxy cope with the heat? I have tried looking at the JB Weld website but keep getting a German dating agency! Steve

The pitting is a ring just level with the top of the piston. Unfortunately, the piston was on the down stroke with the crank at about four o'clock so although the scraper ring will remain below, the top rings will run over it every time. The pitting is quite deep so a +30 thou cut (60 thou on the bore) might not take it out. There isn't enough metal there to re-line it to orignal size as it is only around 1/4" thick just below the water jacket and we don't know what the corrosion has done inside. I must have a word with the cylinder coating people mentioned by Thumper above and see what they can do. I don't think we can metal spray the bore but it might be possible to build the piston up to match. I know there is a metal spraying expert on this site who might be able to offer some advice. This job is going to need some serious consideration before cutting metal! Steve

The bus in the far background is an LGOC K-Type from the early 20s and has done the Brighton run many a time. It has been in the current ownership for longer than the LGOC had it and the time it spent as a caravan combined! The one closer is an LGOC B-Type which should be out in the next two or three years. Still plenty to do on that one. Steve

Looking good, Ben. Well done! I'm pleased to see that you are not wasting your day off and are making an early start! Steve

Hi John. Nice to hear from you again! It was a good day out! Steve

Definitely not too much detail! I always want to salvage original parts rather than make new, if I can, and I like to see the detail of how you have done it. Always something to be learned. Steve

Never mind. Every job is just one piece at a time. That's what we like. Attention to detail! Thanks Rob. Steve

All very nice. It is great to have finished parts put away ready for a reassembly exercise! Incidentally, when did Tecalemit type grease points come in? They are far superior to the Stauffers that we have all over the Dennis. Good show! Steve

You have a nasty problem there! As Father says, nearly all of this old aluminium won't weld due, I believe, to excess zinc in the mix. (Put me right somebody!). However, just occasionally, you get a batch which is OK so it might be worth having a gentle go at a corner to see what happens. If it looks promising, you could make up some lumps to weld on and then machine them back. Failing that, I would feel inclined to dress back the broken area to a nice flat surface and then make up a steel replacement to bolt on. It will be a really weird shape and will have to extend in all directions to give you enough bolts to spread the load into the case. I would also dowel it onto the case as well. It will be a very painstaking exercise to get a good fit as the box is such an awkward shape but you will be able to do it with care. Look inside the box to see what space you have for bolt heads. Also, I would recommend split pinning the nuts to avoid any risk of them coming loose and falling inside the box, potentially spoiling the gears. This case is not beyond hope but it will take a lot of care and persistence to bring back. Good luck! Steve

That's it! Plenty of info there now! Steve