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All I will caution is to make sure that the machine shop is very familiar with Jaguar engines and is in a position to thoroughly and correctly evaluate all the parts.
Does this 3.4 block come with its original timing cover ? Reason I ask is that if not, then a prospective replacement needs to be bolted up to the block to assess whether it is level with the block deck. If it isn't and there is a protruding lip, a light pass over the deck to level it off is necessary. The timing cover forms part of the deck onto which the head goes and if there is a lip, it's likely the head gasket will leak at best, or the head gasket fail at worst due to lack of crush loading from the head studs.
Where there is a recessed lip, the head gasket is likely to leak at the timing end of the engine.
Does this 3.4 block come with its original timing cover ?
As I know from experience, putting the wrong cover on the block results in the coolant going straight into the oil. I had filled a freshly rebuilt engine with fluids and left it for the night. Came back the next morning and wondered why the oil level was so high. Turned out 6 liters of coolant went right into the oil pan through the timing cover.
You don't need to tell me about that as I had a similar problem when I rebuilt my engine. Put the engine back together using a generic gasket set from SNG that covered the 3.4, 3.8 and 4.2 engines. Filled it with fluids and started it up for the first time and had a slight oil leak with the old style original oil filter. Stopped the car to rearranged the oil filter seal and notice water in the oil. I had to drop the subframe and remove the oil pan to get all the water out.
Then I pulled the head off the engine thinking it was a head gasket fault but found nothing.
Sat for half an hour after I had stopped crying and thought about where the oil and water could cross over. Pulled timing cover off the engine and found a gasket that I had fitted which was for the 4.2 engine rather than the 3.4. See the photos.
When you offered the gasket up to block side it was a perfect match but on the back of the front cover side there was a subtle difference that allowed water to go into the timing chain area and down into the sump. My mistake but I offered the gasket up to the block first then put the timing cover on.
Engine had to be completely disassembled. Radiator, water pump, timing cover, front pulley, sump, ancillaries, subframe. All cleaned and reassembled but this time in the engine bay rather than on the bench which was a bitch of a job all because of a £1 gasket.
Top gasket for 3.4 engine. Middle gasket for 4.2 engine. Bottom is the back of the timing cover plate. This is the 4.2 gasket on the 3.4 timing cover showing the tiny hole the water got through. Correct 3.4 gasket in place on the timing cover.
Last edited by Cass3958; Oct 21, 2022 at 12:08 PM.
It may seem a bit excessive and a waste of time, but it's good to check gaskets against both the surfaces that are going to seal against it and also think hard about how new parts are going to line up with old ones. I've bought so many parts that don't fit that it's possible I'm becoming obsessive.
It may seem a bit excessive and a waste of time, but it's good to check gaskets against both the surfaces that are going to seal against it and also think hard about how new parts are going to line up with old ones. I've bought so many parts that don't fit that it's possible I'm becoming obsessive.
Just like me! You're not a Virgo by any chance?? It's good advice.
Last edited by Glyn M Ruck; Oct 22, 2022 at 06:24 AM.
No, I'm fine with near enough is good enough, but near enough means fits and works, not vaguely looks like and is useless without a huge amount of work.
Glynn wrote:-
The problem with the 4.2 is cracked blocks as we have discussed here frequently. Some of the figures Fraser Mitchel gives are frightening. He quoted a number of 8 out of 10 in one case
This interesting article obviously has a lot of experience behind it but I think it would have been made clearer to add pictures or diagrams ti show what the cracks look like.
As the Chinese say:- A picture is worth a thousand words.
I'd agree with Bruce's link. I'll blame young engineers with too much CFD and FEA and not enough thinking combined with the ancient machine tools and lack of weathering in the production of the blocks. The relative merits of old 3.4 and 3.8 engines are reflected in secondhand prices. If the 4.2 had a good reputation, shouldn't it, as a more recent, larger displacement version, be worth a lot more than the old engines?
The relative merits of old 3.4 and 3.8 engines are reflected in secondhand prices. If the 4.2 had a good reputation, shouldn't it, as a more recent, larger displacement version, be worth a lot more than the old engines?
I wouldn't go that far, as relative scarcity comes into it as well. The 3.8 ceased production in 1967 and the 4.2 was made into the 90's and far more of them. It's much easier to get a 4.2 than a 3.8/3.4 and that can account for the price difference. I'd rather have a 4.2 simply because it's less prone to detonate due to the larger bore size.
Glynn wrote:-
The problem with the 4.2 is cracked blocks as we have discussed here frequently. Some of the figures Fraser Mitchel gives are frightening. He quoted a number of 8 out of 10 in one case
This interesting article obviously has a lot of experience behind it but I think it would have been made clearer to add pictures or diagrams ti show what the cracks look like.
As the Chinese say:- A picture is worth a thousand words.
Bruce
I agree but do not have pics among my thousands. Fraser Mitchel might be able to help as he has the background in the UK with the man behind that article. It's actually a UK article used by the Tasmanians. Fraser's man made the 8 out of 10 comment. All I can say is that our club members comments echo the article.
I post more pictures of my personal experience than any other on this forum. You should have witnessed them all over the place if you are a regular here.
Peace! I agree with you & the Chinese. A comment I frequently make.
Suggest you PM Fraser. He knows the whole 9 yards and backed the first time I posted the article years ago or search.
Last edited by Glyn M Ruck; Oct 22, 2022 at 02:18 PM.
Glynn wrote:-
The problem with the 4.2 is cracked blocks as we have discussed here frequently. Some of the figures Fraser Mitchel gives are frightening. He quoted a number of 8 out of 10 in one case
This interesting article obviously has a lot of experience behind it but I think it would have been made clearer to add pictures or diagrams ti show what the cracks look like.
As the Chinese say:- A picture is worth a thousand words.
Bruce
See here. Sorry it was 7 out of 10. I'm getting old. Read from post 8
There's a photo by Fraser Mitchell in the thread linked above. You have to look very closely to see the crack especially in a photograph, which may be why there aren't many pictures.
I apologise in advance if I am doing this wrong, but I couldn’t work out how to submit a new post of my own.
I have been trying to track down the specification of the alternator that is in my 2013 Jaguar XJ 3.0 Diesel Portfolio. The Jaguar part number is 2CD36987 and costs circa £723+VAT, which I am not prepared to pay. Searching the internet I can’t be sure if it is 150amps or 180amps or indeed some other rating. My local dealers couldn’t (or perhaps wouldn’t) tell me and, much to my frustration, neither could the Jaguar Customer Experience Centre. It really beggars believe that no one whom I have contacted at Jaguar can tell me the specification of my alternator.
I apologise in advance if I am doing this wrong, but I couldn’t work out how to submit a new post of my own.
I have been trying to track down the specification of the alternator that is in my 2013 Jaguar XJ 3.0 Diesel Portfolio. The Jaguar part number is 2CD36987 and costs circa £723+VAT, which I am not prepared to pay. Searching the internet I can’t be sure if it is 150amps or 180amps or indeed some other rating. My local dealers couldn’t (or perhaps wouldn’t) tell me and, much to my frustration, neither could the Jaguar Customer Experience Centre. It really beggars believe that no one whom I have contacted at Jaguar can tell me the specification of my alternator.
Hence my plea for help please.
Regards
Madaboutjags
Someone might have the info on this thread but you are in completely the wrong place as this part of the forum is about the 1960s Jaguar Mk2 and its derivatives. You need to go on to "Jaguar Models Modern" and post on "XJ (X351)" which I believe covers your car.
I apologise in advance if I am doing this wrong, but I couldn’t work out how to submit a new post of my own.
Your car is known by the factory code of X351, the forum is here: https://www.jaguarforums.com/forum/xj-x351-53/
On a desktop, there is a red button that says "new thread", click that and start your thread.
Regarding your alternator, if it has failed I'd go to an autoelectrical specialist and get it rebuilt. Aftermarket alternators are often not nearly as reliable as the OEM ones. I suppose from Jaguar's point of view, you replace a part by the part number, there is no need to know a spec - replace like with like and that's all that matters.
after about three and a half months my engine rebuilder has thrown in the towel (or maybe it could be said that I've thrown the towel at him, whatever...) and i am now forced, yet again, to find a new-to-me 3.4l engine for my '67 mk2.
i am in california, the rebuilder will now be, at best, an engine installer only, as the car is sitting in limbo in delaware, ohio. the newly formulated plan is to have Bill Terry of TTraceengines.com sell me a rebuilt engine, have it shipped from illinois to ohio and have it installed by the shop where the car has been residing for the past three months.
i have had verbal and written correspondence with the proposed builder in illinois USA. the website is "ttraceengines.com". he has stated, via email, that he is able to provide a short block and a head if necessary. any information on him and his enterprise would be most welcome.
