3 1/2 Litre engine part recommendations?


Yes, it’s in a MKV DHC, but the engine is from a MK IV, I think a LHD Saloon exported to USA (but do not know for sure) engine nr. SL2199.

What do I need? A LOT!

Well technically only a few parts are damaged, but as one part is the engine block itself (cylinder nr. four has a large hole into a water passage in it. :frowning: so I think it would be better to renew some other parts at the same time.

Only one valve took a hit (and broke to pieces, the exhaust valve in cyl nr four.)

One piston fell into bits and pieces, all parts were found in the sump, together with 10 liters of cooling fluid. :frowning:

As I will HAVE TO remove EVERYTHING from the block for fitting liners and possibly some welding should be done as well, I think I may take Ed’s route for the resurfacing of the crank to use Chevy bearings.

So is it just Chevy mains, that is the seven main bearings for the crank?

If so, which Chevy parts? Or for which Chevy engine?

And the big end and small end and con rods and wrist pins?

The engine currently has, or had XK 3.4L high compression pistons in +0.030" oversize.
The con rods seem all fine, nr. 4 has a sign of some part hitting it, but very small and the rod is straight.
They have part number C7017 * 5 on them.

Although it ran great, I would not recommend that to anyone, as I can see now, in cylinder number four, why boring beyond standard +0.030" like they say in the factory service manual, is not good, but new liners should be fitted. The block may break!

So standard 82mm pistons, from where?

I guess I should have the new pistons at hand before having the engine block welded and fitted with new liners?

Photos will follow once I figure out my password again and can log into form my phone or find the time to move the photos to my laptop etc…

Or does someone happen to have engine block with number available??? (my car’s original engine) :slight_smile:


Pekka T. - 648194

Sad news indeed.
Since you are not really committed to that SL block, you may want to look around for a Z block. A few have come on ebay in the past few years.

Chevy 350 cubic inch oversize main bearings are the usual choice. It involves line boring the mains in the block.

Con rod C.7917 was used in XK140 and Mark VII-IX saloons.

I have block Z3133 but it is probably worse than yours; a piston exploded and the steel rod whipped around for awhile before it went through the side.

Hi Pekka,
Really horrible news about your engine. When I had my 3.5 rebuilt for my MKV, I went down the 350 Chev bearing route. I have the build sheet somewhere and I think it details what was used. I think there was conrods from a MKVII in the mix too. I will try and find the sheet and send it to you.

Regards. Jon

Hi guys,

Thanks already for that. It’s not really that bad, but as the rebuild will mean taking out EVERYTHING from the block I might as well try to do it as well as possible.

Z3133 would be close, my original one was Z2453. But I think all my block needs is only some welding, boring and new 82mm liners fitted, right?


Pekka T.

Ps. The photos, cyl nr 4 and the piston and con rod.

Hi Pekka, sad moment, sympathies to you.

A different block may well be in your future.

Can you do some forensics on the cause? Do any of the pieces show evidence suggesting failure cause(s)? It is hard to judge surface coatings, scoring, and other variations on the photos posted. The piston side and ring parts suggest stuck rings? Temperature or rpm contributors?

What is the thickness of the punched wall material? I ask because I have been running at 70 thousandths oversize on a Z block for a couple of years without issue, but I think I drive with less vigor than you. I figured the factory recommendation was merely to limit the replacement stock variations needed to be kept on hand. But experience often is worth more than figuring.


I’m very sorry that you have had this problem. I don’t know if this is relevant to identifying the cause but many years ago I had a similar failure (in a totally different car). In my case I also found that the piston had disintegrated and there was a triangular chunk taken out of the cylinder wall. Where my case differs is that there was no damage to the valves. I suspect that what initiated the problem was the break-up of the piston and cylinder wall damage was caused by the gudgeon pin.

In my case I was storming up a steep hill in second gear and probably over-reved the engine.


Apologies for the poor quality photo.

Hi Pekka,

When my block was done, the following was used:

Regards, Jon.

The original pistons were split skirt [ for quietness] But these are weaker
We always go for solid skirt
FRom memory Standard sized 3.4 XK pistons are about =.030" from std Mk IV/V and because few XK owners can use standard pistons, they are cheap, I got a set cheap from XKs unlimited a while ago. The 7:1 are flat top but alot[ well a number] of pushrod engines have run well with 8:1 XK pistons The fuel is much better now.
I would certainly just replace the block rather than welding. Although if it’s only a hole in the bore, you could put a liner in it.

You might need to get the crank thoroughly tested. Z series blocks are not hard to come by [ S series are ] but Z had steel rods which didn’t break so much]

Hi everyone,

And thanks again for all the sympathies and good advice.
Where I am there are no blocks available, they could be bought overseas but shipping and cuustomes and VAT (24%) add up.

If I get a good Z block sure I could sell the S (or SL) block to someone who wants it with liners fitted.

Ed, on mine the rods were also 3-4L XK that is MKVII / MKVII M or XK140 rods and the pistons are XK pistons in +0.030 oversize.

So yes, Roger and Peter may be right, perhaps a (gudgeon?) pin, or piston pin like we call them.

Oil was fine, temperature was fine, it wasn’t particularly hot, but yes, the failure occurred right at the top of a looooonng but not very steep hill on a highway doing ca 65 mph. I just felt a very small, loss of power, shut the engine off. And I should have left it that way (the damage might have been smaller) BUT I did restart the engine and then it made a VERY BAD noise and I immediately shut it off again, the the engine was stuck (the rod and pin in cylinder nr four were stuck) and we rolled in neutral to the side of the road to wait for a flatbed (my first flatbed ride EVER in 34 years of motoring.)

Peter, is that four cyl engine also an SS or what? Seems somewhat similar.


Pekka T.

Nothing like an SS. It was in a Reliant Kitten. It had an alloy crankcase with wet liners. The engine was just a two person lift. We lifted it out in the street and I bought it a new liner and piston and fitted them in my back porch. It ran fine after that, so much so that, sucker for punishment that I am, I bought another Kitten very cheaply because it sounded as if it had suffered the same failure. Sure enough, it was exactly the same, even to having the same triangular chunk knocked out of the liner and in the same cylinder. I repaired it and sold it on to augment my modest income.


It could have been incorrect clearance in the bores or ring gaps or…???

One could take a motoring holiday to Uk and ’ surprise’ someone left a Z series in the boot… Do they charge duty at land crossings…
In any case the value of a bare block isn’t very much.

Hi Jon,

And thanks, very interesting list. I will ask for those at the local US parts store.

My cyl head was done two years ago and I think it worked great, although the valves seem to be 70+ years old (original Jaguar part numbers). Interesting to fit viton stem seals, probably not a bad idea, although unlike the XK engine, there is no oil pressure really to speak of in the pushrod cylinder head.

The cam bearings are also of some interest as I believe that original cam bearings are NLA.

The con rods and bearings (small end and big end) are and should be the same as 3.4L XK, right?
That’s what I have.

The existing rods could be tested for trueness easily and perhaps also inspected regarding any fractures, yes, no?

The next big question is what size of liners and pistons I should get.

The smalles available XK 3.4L pistons? (Standardssize)


Pekka T.

Hi Ed,

Well, anyone’s guess, I am sure the rings were what happened to be on those XK pistons back in the 1970´s. Remember I had one “failure” because they did not push the lock plates on the tab for the camshaft sprocket bolts. And it lasted fine for ca 40 years!

Oh well, before Brexit I would not need to pay any customs for any second hand part from the UK obviously, but shipping can be expensive and I don’t think I will be driving there myself before the 2020 Goodwood Revival. Of course someone could. We could also rent borrow or steal a van or a pick-up truck with a Jag Nut friend and make a quick tour of the UK. :slight_smile:

But from AUS, NZ and USA / Canada both shipping and the added customs and taxes would make it most likely more expensive than just repairing and fitting new liners into the existing block.



Neverheard. :slight_smile: But ok, a Kitten is a small cat, like a 4 cyl SS sorta is. :slight_smile:


My reason for buying the Kitten starts with a rather rusty Sunbeam Alpine. Fed-up with rust I replaced the Alpine with a Ginetta G15 in 1974. It was great fun and with a glass fibre body, rust free. When our daughter outgrew her carry-cot (that fitted behind the seats in the Ginetta) I looked for a four seat GRP car and replaced the Ginetta with a Reliant Rebel. It was quite nice to drive but had a gearbox weakness causing me to replace the layshaft twice!. The Kitten was the Reliant replacement for the Rebel and had a much better gearbox but after the piston failure I decided that these small Reliants were just too fragile for my driving style.
As to the Ginetta, it’s still in use today which is more than can be said for any other car that I have ever owned.


I rebuilt the Continental engine, of a 1925 Kelly-Springfield fire truck: needless to say, I had to have everything manufactured, including the valves.

Egge Machine, in California, specializes in such: you might check them out. I’d also wager that somewhere, there are cam bearings that can be made to work.

Egge made the ones for “Kelly,” out of bronze, and they worked fine. Any decent machine shop could make them.

Didn’t Lofty England work for Reliant for a while?

Well, leg room in the small Reliants was probably better than in the E type.



a 3.4L Block popped up for sale here in Germany for cheap, I‘ve sent you pm with details.

But probably didn’t catch as much [ if any] crumpet : >)

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