3 1/2 Litre engine part recommendations?

Yeah, and it went with a loud ”BANG!”

:smiley:

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Hi Pekka, I have a handful of new old stock C.438 and a handful of used C.438. I also have a gaggle of pushrods.

For the pushrods, please look at photo here to determine which type you wish. These were taken out of Mark V engines. You may see the slightly different end designs. Also one design is about 1/16" longer than the other, 11 9/16" versus 11 10/16". I’ve not measured them carefully in this moment. Plenty of used in either type.

I will send you an email in the next day as I have some unrelated questions to ask you. You can think about what you need and reply back to my email.

I have had the same problems in the last days. Maybe it’s a 14.3 thing, I thought it was me but they are correct on phone and laptop.

Yes, I know, irritating isn’t it.

Cheers!

Hi Roger,

Great! Sure, I was also wondering if you read my previous PM, as it took me a few days to respond due to our small trip through Northern Europe.

I have the upper type of those two in the photo. I haven’t measured mine, perhaps this is related to the tappets? The new ones I got from Ed down under are of the same type (of tappet) that I had and that you sent me a couple last year. So actually I now do have a set of good used pushrods and a couple if extra valves. Two inlet valves on mine were bent, and one exhaust valve was broken off. I got all new exhaust valves from Worcester Classic Spares UK and used the old original inlet valves that were true and not worn or pitted.

Cheers!

Hi all,

I am returning to my old engine rebuild thread as I believe some of you were interested in the engine block data, before it was bored and relined with cast iron “top hat” liners.

Regarding the “post mortem” I don’t think anyone can ever find out what really had happened, but the signs would indicate that the reason for the failure was lack of lubrication upstairs due to some of the valves not getting any oil as the rockers had old wicks some of which were hard as a rock and very black. So the theory that hell broke loose when the exhaust valve in cylinder number four had started to stick to the (non original cast iron) valve guide and eventually broke and then the loose steel valve dish inside the running engine broke the piston and the wall from cylinder number four into the water jacket etc.

The shock after the 18 month rebuild was complete and when adjusting the valve clearances after the first startup and retightening the cylinder head nuts and noticing that one valve wasn’t closing and the piston would not move to TDC when gently turned by hand was a big one. But luckily I was able to remove the head, remove the steel debris (those two pieces of I believe a broken non-original cast iron valve guide) AND also I used a magnet in a long flexible arm to “fish” around the passages in the cylinder head and found some more iron / steel bits. :frowning:

Using rags and to finish it off with a lot of compressed air I believed that there were no more loose bits inside the cylinder head and put the head back on and everything has been well after that.

Here are some pics of the broken bits, the small ones in the first shots were found inside the cylinder head and the large ones are pieces of the piston and cylinder wall of what used to be cylinder nr. 4.

Also I am attaching a photo of the 1947 LHD MKIV engine block #SL2199 after it had been bored and before the new cast iron liners were fitted.- Perhaps the positioning of the cores for cylinders 4-6 was less than ideal when it originally was cast? Or possibly just within the normal tolerances, after all the original bore on the 3 1/2 Litre was only 82mm.

Cheers!

Ps. In the bore-photo the boring machine is in cylinder nr. 3 and we can see inside the cylinders nr. 4 and nr. 5 already bored to accept the new top-hat liners.

That old tappet is there just to give a sense of scale / size.

The thinnest piece of old cylinder wall measures at 2.77mm thick (or thin) and the part of cylinder wall nr. 4 which was found inside the water jacket measured at 3.64mm so maybe it would have been ok unless the valve broke off?

Plus the liners being fitted: (ignore the incorrect numbering, it’s just the engine shop, I know that cylinder nr. 1 is the one closest to the flywheel and firewall. :slight_smile: )

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Thanks for posting these photos and numbers. Do you happen to know the cylinder bore size before the carnage?

When I did the rebuild on my Mark V, I chose to go with a 70 thousandths-over bore and custom pistons. This was making a bet the cylinder walls were thick enough to handle that oversize and that factory parts stocking issues are what constrained the factory recommendations on bore limits. With your numbers I can get an estimate range on remaining cylinder wall thickness in my block.

Hi Roger,

Well the pistons in there were +0.030” oversize 8:1 compression 83mm XK pistons.

And I don’t know the outside diameter of the new liners, but I could see that the boring did not go through at all in cylinders nr. 1 and nr. 3. Nr. 2 just and just went through on the inlet side, BUT cylinders nr. 4 nr. 5 and nr. 6 all went through to the water jacket on the upper exhaust side, towards the flywheel side.

If your custom pistons are 82mm +0.070” oversize you are quite close to the same bore I had.

83mm +0.030” = 83.762mm
82mm +0.070” = 83.778mm

I still think the only reason my engine broke down was that the exhaust valve in cylinder nr. 4 snapped and the dish broke the piston and cylinder wall.

Cheers!

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If I got this calculation right, my cylinder wall thickness is now 0.089" - 0.123" thick (taking 20 thou more off the thickness of your two samples at 3.64 mm and 2.77 mm. 0.125" thick is common for new liners, so I am running a bit less than liner thickness but no cylinder troubles seen in the first few thousand miles. I do have one head bolt which will not quite reach full torque specification, causing some steam after engine is warmed (this will get addressed as the tranny change advances).

Hi Roger,

I don’t remember what your MKV looks like do you have it on www.saloondata.com?

What do you mean with “will not quite reach full torque specification”? Does that dome nut bottom out? is that stud fully seated?

Having torqued the head quite a few times now I do remember what brother Nantes (Ed) said about the 2 1/2 Litre cylinder head being more ideal. He is definitely right, having three rows of head bolts evenly spread and allowing higher torque would be really really good. Especially if one would like to raise the compression a bit more or run a supercharger! :smiley:

Cheers!

Ps. Once I have my engine properly run-in and hopefully having cured all the oil leak issues, double checked the rockers and pushrods I would like to take the car to a dyno just to see what the AFR is, adjust timing and mixture accordingly and see how much the larger bore and higher compression would add to the original 125 British ponies! :smiley:

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Hi Pekka,

Head bolt labelled “4” on shop manual Plate B.22, page B.27 starts to go plastic at about 59 lbs-ft, less than the 62.5 lbs-ft shown on the shop manual page B.37 and which holds for all the other head bolts. I had hoped that slightly-under torque would not matter, but the head gasket does leak coolant into the number 2 cylinder now after engine running about ten minutes. Was fine for at least the first thousand miles, but is not okay now and torque wrench gets the same plastic feel in the fingers when reaching that limit while the others still can take the full 62.5 lbs-ft from the wrench. This is not an issue with the head bolt nut bottoming out (I learned to watch out for that problem a while back). Either the bolt has lost elastic response or the threads are losing it in the block.

Norman Dewis Mark V Chat 2007

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Hi Roger,

Lovely photo! A classic MKV Saloon in Black, like most of them over here originally were. A very rare sight nowadays!

And Norman. :slight_smile: He was such a nice bloke and he got around amazingly much.

I think and hope that the stud is just tired, AFAIK they are not that expensive or hard to get. Of course if the threads in your engine block are damaged then that may be a little bit more difficult to solve. :thinking: Helicoil? Maybe not in that place. A slightly deeper new stud and running the threads deeper? Anyways it would require taking the head off so may take longer than one weekend, now that I have removed the head already three times on the MKV it does not feel so challenging anymore, although I am hoping I would NOT need to do it again anytime soon. :smiley:

Cheers!

Ps. A couple of pics of Norman in various places:

Saanen, Switzerland June 2011 (from left: me, Norman, Aulis Pennanen FJDC)

Cernobbio, Italy 2014

Goodwood Revival, England 2017 (Bristol Blenheim in the background)

I never got to meet Norman but I did get to park next to a car he drove. (After it was rebuilt.)
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Beware of thread inserts with liners.

Peter

Hi Peter,

Very cool cars you both drove! :smiley:

And ouch, no it does not look good with those thread inserts. :frowning:

Take care!

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Hi Pekka,

I don’t know what was cause and what effect in the horror photo above. When I came to take the head off I found that the studs had been tightened to ridiculously high torque. It is possible that the previous “restorer” didn’t know what a torque wrench was and after initially failing to prevent water ingress to the cylinders ripped the studs from the block and then fitted the inserts and only after that cracked the top deck by strong arm tactics.

Peter

Hi,

From a couple of other threads (“Most miles” and the “MKV Oil Filter cartridge”) back to this one as noqw I know I need at least one of these circlips: C.491

I had not looked for one as my engine apparently has not had one in many many decades. :frowning:

But now (as I didn’t have the Spare parts books with me) I checked the MKIV “Jaguar Service Manual for All Models” 1946-1948:

As my engine is #SL2199 PLATE 8. on page 28 shows this all.

So in that diagram / drawing the part I did not have (and still do not) is “84 Circlip on Shaft” and jaguar part number is C491. None of the usuals seem to carry it and I did now also ask Worcester Classic Spares UK, lets see.

Cheers!

I can’t remember the exact profile but I think you will be able to determine the id/od and thickness now that you know what it’s for. I think if you search for snap rings you will be able to track one (or many) down.

Peter

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Thanks. Yes, mine did not have that! :-o

So now I know why it’s rather important.

Cheers!

So you want part C491 circlip?
If we can get a size I can probably get it easily here in the land of inches.