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Hello all...has anyone successfully rebuilt the AJ16 engine?
I was chasing down some oil leaks on mine and during the course of it I had to replace the front and rear crank seals and reseal the oil pan. When I took off the oil pan, a job and a half in itself, I noticed bits of the timing tensioner floating in the oil! Anyway, one thing led to another and I checked the crank bearings and they need to be replaced
And that is where I am stuck now
I need the crank bearings, big end bearings for the connecting rods, bolts and nuts that hold it all together and piston rings. I have had no luck in finding anything locally and google searches haven't been fruitful. I know that you can reuse some of the hardware but apart from that I have made no progress. If anyone has been able to do successfully source parts, I would appreciate them sharing that info!
Bearings have been hard to find for many years now. The presumption, likely correct IMO, is that these engines are so robust that very few ever need overhaul and thus there's no demand for bearings. No demand = no supply.
However....
I'm nearly positive that someone here found a supplier 2-3 years ago. A few minutes searching the archives might do the trick.
Are you able to have the Jaguar part #s as the part #s needed from the ClassicJaguarParts website ?
I have some manuals on the AJ16 engine block / core hardware buildup that will take you around if you don't already have them , and shoot me back what you have to archive for others
Upgraded tensioner with the big arrow on the casting ? as I broke my upgraded tensioner interworking's ( brittle and easy to do ) but I caught mine visually before installing fortunately
Bearings have been hard to find for many years now. The presumption, likely correct IMO, is that these engines are so robust that very few ever need overhaul and thus there's no demand for bearings. No demand = no supply.
However....
I'm nearly positive that someone here found a supplier 2-3 years ago. A few minutes searching the archives might do the trick.
Others will chime in.
Cheers
DD
thank you for your reply
for an engine that is almost 30 years old and with almost 300k km on it, yes it did not look too bad. But there are signs that it is wearing. The pistons are splattered with black marks that point to oil consumption. The bearing surfaces show signs of loading
I took it to a local Jaguar engine builder and he told me that they don't work on these engines anymore due to the lack of parts availability. He also said that worse case scenario I could always clean everything up and put it back together but that is just kicking the bucket farther down...
Are you able to have the Jaguar part #s as the part #s needed from the ClassicJaguarParts website ?
I have some manuals on the AJ16 engine block / core hardware buildup that will take you around if you don't already have them , and shoot me back what you have to archive for others
Upgraded tensioner with the big arrow on the casting ? as I broke my upgraded tensioner interworking's ( brittle and easy to do ) but I caught mine visually before installing fortunately
Thank you for your reply
Yes, I managed to find the part numbers. There are part numbers on the bearings themselves but those do not collaborate with the ones on the ClassicJaguarParts website
So I did some research and found some stampings on the crankshaft. Those give me the correct part numbers for the bearings... see here (pages 13 to 16):
I have the workshop manual as posted in the reference sections of this forum and the parts catalogue (which is outdated so the classicjaguarparts website is more useful)
Yes big arrow tensioner. Sorry to hear that yours broke but good on you for catching it!
Last edited by someguywithajag; 08-17-2024 at 06:14 AM.
Reason: pages added
Go to the "crank grinder"....they know everything there is to know about cranks and the bearings to fit them. Most likely will be able to set you up with a ring supplier also.
Go to the "crank grinder"....they know everything there is to know about cranks and the bearings to fit them. Most likely will be able to set you up with a ring supplier also.
thank you for your reply
and yes, I did. They also said that they do not have bearings for them. They said that they'd just try to find something online and sell it to me with a 45% upcharge...
There are two companies in the UK that race and tune these engines so it might be worth contacting them as they will surly have had to rebuild their engines.
Being on the tale end of the ICE era, I imagine there won't be any aftermarket suppliers lining up to make all these parts but one can dream...
There is similar issue with the 1940s pushrod SSand Jag MK4-5 engines where bearings are getting harder after “only” 70 years.
3.5 litre “pushrods” have the same big end size as XKs for which there is a good supply and some rebuilders are using adapted Chevy mains on the basis bearings for these will be manufactured for a long time.
Things are. bit trickier for my 1946 1.5 litre engine which was also used in some Triumph Roadsters.
There are two companies in the UK that race and tune these engines so it might be worth contacting them as they will surly have had to rebuild their engines.
Funny, Tom Lenthall was the first person I ever contacted when I ran into this problem! I saw his YouTube video and it inspired some confidence but he said that he didn't have any bearings nor did he know where to get any :/
Nice find! It doesn't say what grade they are but looking at the listed dimensions and the document I posted above, they seem to be "white"...which is what I need. I contacted them and they are working on my parts, fingers' crossed!
Side note: I am beginning to see a pattern. Most of the well known parts suppliers seem to be getting their parts from some German company called "limora". In the past I have bought parts from various North American suppliers and the customs paperwork always lists "limora" as the supplier. The curios thing is that all the known suppliers offer the same "limora" parts for different prices but when I myself go to limora's website, I see extremely high price points, I wonder if there is some sort of backdoor deals the big players get. Anyhow, this listing also pointed to "limora" after I contacted them...
if they don't have them, I think the next logical thing would be to find a lower mileage engine from an auto yard...or have custom ones made, which is likely uneconomical, even if it was offered
There is similar issue with the 1940s pushrod SSand Jag MK4-5 engines where bearings are getting harder after “only” 70 years.
3.5 litre “pushrods” have the same big end size as XKs for which there is a good supply and some rebuilders are using adapted Chevy mains on the basis bearings for these will be manufactured for a long time.
Things are. bit trickier for my 1946 1.5 litre engine which was also used in some Triumph Roadsters.
Thank you for your input, very interesting
One of the local British engine builders I took my engine to said that if I can't find bearings, which he said may be a fool's errand, the next thing I can do is to have the block bored to accept Chevy mains. Which he said would be very expensive but would be a permanent solution given how common parts for LS engines are and are expected to stay popular until the ship sinks on ICE
You sure do have a lot of challenges on your plate with that 1.5L...wish you good luck with that!
I am rebuilding now, too. Is there any parts interchange opportunities from the AJ6 / XJ40 ?
Can we search and match piston rings by diameter?
I also need a couple of intake valve guides.
I am rebuilding now, too. Is there any parts interchange opportunities from the AJ6 / XJ40 ?
Can we search and match piston rings by diameter?
I also need a couple of intake valve guides.
Not sure to be honest how similar the AJ6 and AJ16 are. But I think the main bearings and the big end bearings are the same since they have the same part numbers (depending on the grade). The crank is the same itself. I think the top end stuff is slightly different but some parts may carry over, like the valve guides. Those are the same
If you need the dimensions of the anything from my end, just ask me. I have the entire block stripped (not so much the cylinder head)
As far as my research can tell, AM used the same same lower end stuff (block, crank etc) but not the pistons. They had different ones but I don't know the dimensions of them so I can't say if they used the same rings or rods. I imagine the big end is the same. But unlike Jaguar, AM doesn't have a graded bearing system so not sure if things would carry over
I did buy the crankshaft sprocket from these guys because mine has worn down (it rotates twice as much as the crank so it wears the quickest). Haven't received it yet so can't say more yet. I would try the main bearings from them but unless I know for a fact that they are the ones I require, I wouldn't bother
For the sake of general interest and reference. I took some pictures. Any notes on the post mortem are welcome
steering pump aux shaft and the intermediate idler gears. Not showing many signs of wear crankshaft sprocket. very worn in comparison chain tensioner guides. most of them are worn. one even had the plastic bits peeling off. those are the pieces I found in the oil pan bearing surfaces are fine. none of them spun. some sludge here and there. some coolant passages had gunk in them but mostly fine front side of the engine cylinder shows signs of fowling. maybe running rich (the ecu is programmed with the advance and the supercharger pulley was upgraded to a larger size, or maybe oil in spark plug wells) cylinder walls still have a good cross hatch pattern...impressive pistons don't look so bad. the horizontal lines are from a manufacturing process. the vertical ones are normal wear crank journals look good. also impressive the pistons are black from oil burning. the rings are likely worn (didn't do a compression test so cant say definitively) outside of the centre, piston big end and main bearings. notice the oil sludge buildup in the oil pathways inside of the centre, big end and main bearings. the big end bearings are worn. the centre and main ones, although worn, could likely be reused on the first balance weight on the crank there is the code stamped for the bearing grades. F = front. The first set is for the main/centre bearing. the last group for the big ends the pistons have a front and back orientation close up of the piston rings
Last edited by someguywithajag; 08-22-2024 at 04:07 AM.
The 3.2L used by Aston Martin DB7 is a modified AJ6 engine. The only parts that are the same as the AJ16 are the crank and everything that goes on it (i.e the bearings are the same except AM uses numbers to grade their bearings vs Jaguar's colour grades but I have no idea how they match up). Except for the connecting rods, which are the same as the ones in the Jaguar 3.2 AJ6.
The pistons are Aston Martin's own (I assume the piston rings are also unique to the AM but not certain). Even if the pistons were the same as Jaguar's 3.2 AJ6, they would not fit the 4.0 AJ6/AJ16
08-16-2024 | 06:21 AM
engine rebuild
