You know that the XK120 bypass is internal, right? There is no bypass hose to the sump. There are three holes behind the filter mount: 1) unfiltered oil in, 2) filtered oil out and 3) excess pressure bypass to the sump. On XK engines without the bypass hose the overpressure relief just sprayed in on the spinning crankshaft, aerating the oil, which is very undesirable. The later filtering scheme bypassed to the sump below the oil level via the hose. If you put a bypass hose style filter mount on an early block that originally had the internal bypass, you need to plug that third hole with either a plate or a plug. I “think” most of the later 1950’s blocks had threaded plugs in those holes, but I would not swear to it.
LOL - Just add beer!
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Ron, are you in the USA? I have one I don’t need. It’s been sitting in its box on a shelf for about 10 years.
GM, 80 amp, one wire hookup. Zero miles on the full rebuild, black powder coat. Comes with the oversized NASCAR grade CV Products aluminum pulley, the original chromed steel standard pulley and a new spare solid state regulator. If you’re in the USA, PM me and I’ll make you a deal.
Chris - thanks for the offer but I’m in the UK. Plenty of those around here but no shipping required!
I certainly know a helluva lot more about spin-on oil filters than I did at the start. Feel well prepared for that adjustment when I get around to it!?! This must be a hot topic.
I’ve made my choice - thought I’d share it. the runners 1) a G series Type C engine and transmission that was on ebay. Was rebuilt 15 years ago and has never been in a car. Pristine. and based on the stamps a real c type. (it’s still available). 2) a 3.4 from a Mk1 or Mk 2, or 3) a 3.8 or even a 4.2.
I went with a 3.4 head off a 1957 mk 1 sedan that was a runner and was just pulled of a car while the original head was rebuilt. Apparently the mk1 sedan heads were ported, whereas the base 140 heads were not. So a bit more power I hope. Married to a Mk7 “M” block, again out of a runner that the local jag mechanic had driven and would vouch for. Again, loaned to a car while the original rebuild was underway. The “m” block has the same sump and oil pump configuration as the 140. Drops right in. So I’ve never heard either running but the vendor does a lot of race prep for xk’s and e’s and he will warranty them.
I wanted a period head from a 3.4 as it has a direct connect to the tach, which is manual cable Seems like a better bet.
Still open on the transmission but have ruled out the original moss box with OD. Going with a syncro’d later model, or a new 5 speed. Thoughts on the gearbox still welcome.
Other decisions I’ve made: new high torque starter, alternator and electronic ignition. Will go with headers vs. original enamel exhaust which I hear create a lot of back pressure. Again, maybe a bit more power.
Observations welcome and appreciated.
What is the engine number on the head? You can look it up here:
http://www.jag-lovers.org/xk-lovers/library/engine_numbers.htm
One of the oddities of Jaguar in the late 50’s and early 60’s were the 240 and 340. Inexplicably, both had straight port heads and were stamped with the 7J prefix.
Thanks again Mike! I machined a thick aluminum plate to exactly fit the ports as traced from the original filter assembly. Used an aftermarket die-cast spin-on screw plate. Could never convince myself that there was really pressure going to the bearings. Your scheme is exactly what I was looking for. I will try to procure the adapter assembly from Barratt.
Mike , I posted my example as an alternative choice. With any change from the norm, personal preference is just that. When and if a preference
is bad practice it is worth pointing out. If you observe the bypass hose
on my installation it has a slight bend. As both connections attach to
the same mass, straight or with a bend, makes no difference as long as there is no strain in the connection. When the hose runs, from say the engine to a cooler mounted on the chassis, in a straight line, I agree ,bad practice, but I do not need to work in a high hazard enviroment
to work that out. Obviously I prefer my installation on neatness and
functionality, note the use of a quick drain fitting. I agree the red and blue fittings are a bit " modern", 15 mins on a buffing wheel will sort that.
BTW looks like you have used the MK2 rear rope seal housing, is this the case?
Peter B
Yes sir, I did. rope seal in the back, S3 XJ6 Teflon in the front.
We did several similar things in slightly different ways. I just like more flex in my hoses.
If I understand correctly, you are not using a filter mount with a excess pressure bypass? You can do that, but you need to be very careful with the throttle before the oil warms up. Absent the relief valve, the oil pressure can be higher than the oil filter canister can tolerate. Most of the guys who run that way have heaters for the oil sump so they start warm.
This photo shows the plugged bypass port circled in red. On this block the port was already threaded, and it think this was a 1/2"-20 plug.
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Mike, ideally you need this rear rope seal housing with the early “E”
sump. See the thread in the E type section.
3.8 to 4.2 rear main seal question.
Peter B
Thanks, I’ll look into it. I didn’t have any issues getting to to go together.
EDIT: I see. The early sump has a male tongue in the rear seal area and the later ribbed sump has a female groove. I recall that I ordered the rear sump seal for the early E-Type sump, and I don’t recall having any issues fitting things together. I have a photo of the sump I used before it was installed and I still have a 4.2L sump to compare it to. The 3.4L block I used has a 21-10-64 production date. It had the labyrinth and rope seal, not the scroll seal.
Mike the rubber seal is the same for both types,but, as will be obvious to you, ( remember best practice) it is more secure" in the groove" so to speak.
Peter B.
Ha ha! I well EARNED that comment!
What I need to do is take a look at the Mk2 sump that was original to the engine, but it is in storage, not here at the house. This is the best photo I have of what is in there. I’m sure it was the Mk2 seal because it had to match the crankshaft.
By 1964 MK2s were fitted with alu sumps so the detail re the seal
is the same as your 4.2 sump. Are you using the 3.8 sump, without the
fins , as a lookalike 120 sump?
You are going to town with the main studs and rods etc. good to see !
Just received a site message stating after 3 replies please continue
by PM. As this thread might be of interest to others, surely a bit daft.
But i conclude.
Peter B.
That pulley is too big for street use: it will turn too slowly.
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Not true, about the cast iron manifolds causing “too much back pressure,” , and steel headers are often too BIG, which WILL cost you low-end torque.
Any of the modern porcelain coatings will not last long, and the electronic ignition is one of the best things you can do!
Yep, leftover from the vintage racer plan.
Yes, I’m in WA State. I’ll pm you. This is what my alternator conversion looks like, so it takes a standard pulley and needs the right configuration of mounts. As I recall there are three different ways the case can fit together on these.
Good job! As to the transmission, take your time to consider the possibilities, but the 5-speed is the most straight forward for your situation if you have the budget for it.
FWIW, I’m using stock exhaust manifolds on my hi-performance 120- engine. Seems fine so far, but the car is only running, not roaded past my driveway.
Be careful, and get good advice from your engine builder for the spin on conversions, as there are nuances, such as - the oil ports on my 120 engine are not the same as on the photos posted here - make sure you know which one to blank and that you have oil pressure before firing it! If your xj6 adapter comes from a car with an external cooler, you must use it, or no flow.