Examining a 1961 MK2 Engine
 

Evening all -

As you may know, I already have a 1965 MK2....but (and this is a secret, because some people get really bent out of shape over it) my car doesn't have its Jaguar engine or transmission. It came that way, was too hacked up to put back, so I just improved on the existing condition - enough said. However, I've always wanted to have an older Jaguar with the original equipment and I have the opportunity to look at a '61 Mk2 with the 3.8 engine, automatic transmission. The car is supposedly in reasonable condition, but has not been on the road nor in regular use for many years and the current owner does not appear to have much knowledge or history beyond the last 2 years. The car does run, and I'm told it will drive, though likely needs a few things before being strictly road-worthy. I'm familiar with most MK2 systems, but obviously the the engine and transmission are new to me, and I thought I'd ask your advice on tips and techniques for assessing engine health on a car I likely wont be able to test drive.

My initial thoughts are as follows:

Compression test, dry and wet. What sort of compression is typical? Any idea what numbers I should look for and does the 10% +/- difference between cylinders still hold as the red flag for the XK motor, as it generally does for the venerable small block Chevy?

Oil pressure - what is typical here?

Smoke and such from the exhaust - Does the XK give you indications of health from its exhaust? For example, a puff of smoke on start-up, if a small block Chevy, but otherwise no smoke, often means valve guides are worn, more smoke, more worn out. Does the XK 3.8 have similar tell-tale signs to look for?

How about vacuum readings - what is typical for the 3.8? and...where would I connect a vacuum gauge to full vacuum?

Any common issues that can be detected in a static run - i.e. engine is running but no drive test?

Anything else you can think of? The whole point of getting this other car will be to have the Jaguar engine and transmission, so I'd like to have some way of assessing at least the engine's health, given that I won't be able to test drive.

Appreciated,
Allan.

I don't know all the values you are seeking, but if the car is on anything like 100k miles it really needs an overhaul. If the current owner knows nothing about the car then really you should budget for a complete overhaul of the engine and much else besides, as it would appear he didn't really look after it or he'd be only too willing to show you invoices and so on for work done. These cars, like so many of the 60s, are notorious for rusting away, so it is essential this aspect is checked, (unless you're just buying it for the engine and transmission, of course).

The the true mileage is unknown. It is known that the prior owner replaced the braking system, generator / power steering unit, complete wiring harness front to back, and cleaned out the fuel system, including the tank.
The current owner does not appear to have done anything in the two years he's owned the car, but if the claims are to be relied upon, the owner before him did. As for invoices and records - I can count on one hand, and not use all the fingers, the number of times I've saved a record. I always mean to, but they get lost or I forget, and I've restored, modified, resurrected and ultimately sold many cars over the last 20 years. I view a lack of records as normal, and the presence of them as an unexpected surprise.

No, my '65 has gone too far over to "the dark side" of modification and change to ever again hold the original engine and transmission. If it were feasible, I might consider it, but the car was modified long before I owned it and the modifiers made some interesting choices - some good, some not, and I dare not think of what challenges I might face trying to put the jaguar equipment back in. If all goes well, my '65 will continue to be the faster, more comfortable, and likely more reliable Resto-Mod Mk2, while the '61 will be carefully restored to the best version of original that I can achieve, while doing the work myself.

Compression needs to be around or over 150psi, oil pressure at least 15-20lbs at idle and 40lbs at 2000rpm and above, but wear in the oil pump can also show low pressure as well as the pressure sender and oil gauge, so you must use an accurate pressure gauge to check this, do not rely on the instrument gauge.

If you can do a leak-by test that will give you much more information than a compression test, if it passes the leak-by test then you know that most things are in reasonable order.

Smoke checks are as per any standard engine, but the leak-by test will also give you most indicators you need.

These engines notoriously leak oil from the rear crank seal, it has a rope seal originally, this can be converted to a proper oil seal, but requires the engine and gearbox out and the crank out to do it, this also applies to the rope seal so if there is oil at the rear of the sump suspect the oil seal is gone, you can live with this and just keep putting oil in it will not effect the engine as such unless the oil gets too low.

Noisy timing chains, this can be worn timing chains, worn timing chain guides, blocked hydraulic tensioner (there is a tiny filter in the block behind it) or just adjustment, leaking core plugs, corroded waterways are also an issue if incorrect or no antifreeze has been used, this results in poor water flow and overheating, check the colour of the water after a run, if it is brownish then the engine would benefit from a good flush through.

The engines themselves are pretty damn good, it is only lack of use or poor maintenance that causes issues. If the engine has done 100K miles or more it would benefit from a rebuild, but if it has been well maintained it would be good for 150K plus, many of these cars were laid up for many years, and it is often that together with poor re-commisioning that leads to failure, usually overheating and a blown head gasket !

Agree wholeheartedly ~ A Leak Down Test is by far the best way! :icon_toast:

Thank you for the feedback everyone. I went ahead and bought the car.

Good luck Allan ~ enjoy.

Thanks! it will be a new adventure, since this is the first I'm dealing with the MK2 running gear.

:icon_worthless:

LOL, yes, agreed. I only have a few so far - so you get a shot of the stable-mates, the tag on the fire wall, and what to me looks like a dipstick showing way too much oil.....(perhaps that's why it smokes a bit)


https://cimg1.ibsrv.net/gimg/www.jag...3363c20ddf.jpg
https://cimg2.ibsrv.net/gimg/www.jag...e802118b02.jpg
https://cimg3.ibsrv.net/gimg/www.jag...85392edbb3.jpg

Is that an optical illusion on the picture or is the car sat really low at the back ?

No, its a fact - its very low in back, funky squeaking sound and very little (if any) action from the shocks. I didn't notice it sitting so low at first, but once I got it home and off the trailer, was pretty obvious. I am hoping for a weak / broken leaf spring. Worst case of course is that the spring mount has broken and or rusted off - but given how generally rust free the rest of the car is, and the fact that you can drive around in it without a spring hanging off, I'm hopeful nothing is catastrophically wrong. I will get it on the lift today, and take a look......fingers crossed.

As it's a cantilevered leaf spring let's hope it's not the mount as it sits in a box at the end of the chassis leg ! Hopefully broken spring/s rather than a rusty spring box /es.

Well, upon a quick inspection, I don't see anything significant. I couldn't figure out what was making the squeak, but if there is a broken leaf and I just can't see where, thay would probably explain it.


https://cimg4.ibsrv.net/gimg/www.jag...4b5189aec3.jpg
https://cimg5.ibsrv.net/gimg/www.jag...b786ac698b.jpg
https://cimg6.ibsrv.net/gimg/www.jag...d71d46ff8a.jpg
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As you say on initial looks, nothing appears out of place, can you post a pic of it on the ground from the side with a spat off.

Springs maybe weak, you can measure them off the car but that is a bit of work to do right now. It also looks a little high at the front, this could be due to it being low at the rear, but may be a contributing factor to the low rear, a view from the side would be easier to see.

Also check the rubbers in the rear torsion bars, if these are shot the axle will rotate a bit and change the ride height.

See you have a 9:1 compression engine, they are more sensitive to the quality of the fuel, so make sure you use the highest octane best quality fuel you can get at the pumps.

Yes, I'll get that later today

I didn't get a shot of the Torque arms, but I did note that most rubber under there looked pretty bad - may even be original. The car was from Louisiana except the last 2 years, and I imagine the heat did little good for rubber parts.

I think what I have is engine with a head gasket problem, potentially anyway - will do some testing today, but yes I always put in the best grade fuel, which around here is 92 Octane, unless you want to pay for the racing fuel, and I don't ;-) . The engine code says it is a 9:1 compression motor, but the head stamp looks like it is 8:1 - the numbers are really hard to read.

It would be a good idea to re-build the rear suspension with new poly bushes, at least you know it's all sorted, and you can measure the leaf springs to check if they are potentially weak at the same time.

The compression is changed by the pistons rather than the head, can't think at the moment where the compression is marked on the head if it is at all, they all used the same head as far as I recall.

Why do you think you have a head gasket problem ? These engines do usually take out the head gasket if they overheat too much, common problem is they are not re-commissioned properly as the waterways often silt up giving poor water circulation and hot spots in the system which overheat.

The car is far, far, too high at the front, and I suspect the wrong springs have been fitted, or poor aftermarket ones. This will tend to force the back of the car down. Photos show everything in pretty good order for a car this age, with very little rusting.

Yes, part of the plan for sure.

A few things, but mostly the 1/4 cup of water I gathered from the tailpipe in around 20 minutes. The car has not run regularly in years, and I already see improvement just from being started, brought to temp and used a little, but a few things point to a potential head gasket concern. The first is the classic white smoke - not clouds of the stuff, but enough. In a telling sign, there is no smoke upon start-up, but after a minute or so, you start seeing the white smoke. Although hardly unusual to have a little something until things get warm, in this case, the smoke continues - even 20+ minutes after start. I noted water on the ground and so sat a tub under the tailpipe - I gathered approximately 1/4 cup +/- over 20-ish minutes.In a video I took, you can see water dripping from the exhaust. The car does not overheat however - its actually hard to get it to heat up.....oddly enough...and I did not see evidence of exhaust gases in the coolant. So just based on the smoke and water collected, I suspect a head gasket.

I did run a compression test, expecting to find a low cylinder or two, but the readings were oddly consistent, and good. 160, 160, 160, 163, 160, 165 - front to back.

I also noted what I believe is piston slap.....sigh.....still, could be worse. Its most noticeable at cold start, gets progressively "better" and once warmed to operating temp, only detectable with your head over the block. In the video below, recorded shortly after start, it is most noticeable at 0.26


Here are side shots with spats off, and a comparison to the red '65. Also a shot of the spark plugs - running rich, but consistently so across all cylinders.

https://cimg9.ibsrv.net/gimg/www.jag...17153c7a5c.jpg
https://cimg0.ibsrv.net/gimg/www.jag...b9f645f936.jpg
https://cimg1.ibsrv.net/gimg/www.jag...e0ad21971d.jpg
https://cimg3.ibsrv.net/gimg/www.jag...9f8546b5e5.jpg
All dry, very sooty, consistent condition.

How is the oil pressure hot? That knock is quite pronounced but if it lessens as temperature rises & clearances normalise it's unlikely a bearing. Your diagnosis is probably correct.