My Lucas data base shows:
Both 3.4 & 3.8 CR 9:1 1966 Jaguar with 22D6 # 41064A distributor, with a {5/12/8} vacuum unit.

Give these guys a call, for recommendations on best distributor specs, for your compression ratio and fuel octane available.
They can overhaul and update your distributor for your planned configuration/application.
British Vacuum Unit
Canterbury, NH 03224
(603) 731-1788
​For orders or info, use our web "Contact Us" or email us direct at
​https://www.britishvacuumunit.com/lu...ibutors-1.html

This thread addresses some options:
https://www.jaguarforums.com/forum/x...xj6-s2-250183/
Rgds
David

 

8 to 1 CR = Lucas 22D6 ~ 41063A ~ on all 3 of the cars I had to restore my S Type. Monster Lucas Data Base .pdf that is too large to attach here shows the same. Seems the different CR has a different advance curve. (Another Service Manual mistake)

 

Just a few of them. Lucas made a bucket full of different spec distributors. First 20 pages. I chopped up the .pdf. Much missing data.

 

There no vacuum ports on the intake or carbs. I prefer not to drill any holes to add a vacuum port. Unfortunately, I haven't found many distributors without a vacuum advance. Mechanical advance only distributors have a different advance curve.
Is there a specific reason why some engines came with mechanical advance only?

 

Quote:

Originally Posted by jayd2

There no vacuum ports on the intake or carbs. I prefer not to drill any holes to add a vacuum port. Unfortunately, I haven't found many distributors without a vacuum advance. Mechanical advance only distributors have a different advance curve.
Is there a specific reason why some engines came with mechanical advance only?

PERTRONIX D171600 FLAME-THROWER ELECTRONIC DISTRIBUTOR CAST BRITISH 6 CYL PLUG AND PLAY WITH IGNITOR II TECHNOLOGY NON VACUUM
( Tailored advance curve for optimal performance and drivability)

Amazon price $285.00 Added matching coil Pertronix 45011 Flame-Thrower II 45,000 Volt 0.6 ohm Coil , Black price: $62
or (a Lucas DLB198 ignition coil, price $42 Moss Motors)
Note: you must use Electronic Ignition spark plug wires. Any Parts store can supply correct wire sets, if you ask for 1984 XJ6 S3 jaguar wire set.

I have not heard anyone comment on this unit, many Jaguar owner are happy with the Vacuum advance version. I installed Vacuum version on my 1968 XKE and it worked well. The Lucas distributor I removed was non-vacuum; It was a smog distributorto deal with lean burning at all RPMs, and like the carburetors were made to be tamperproof.
Rgds
David

 

My Moss 4 speed has a what looks like a threaded hole in the top cover. The manual shows a small dipstick in the exploded view of the gearbox. Is this hole for a dipstick? Did they all have a dipstick? There is a threaded hole in the side of the main case for a plug, I assume that you fill the transmission to that level.

 

I purchased a new Pertronix non-vacuum on Ebay for 175.00. The car I fabricated, the one the 3.4 is going into, has a SBC with a Pertronix. I've had the SBC Pertronix for about 4 years with no problems.

 

I've been researching oil for a Moss 4 speed. It's a little confusing, some say it must be a GL4 oil, all GL4 I've found is multi-weight, like 80w-90 gear lube. Other's have stated not to use multi-weight oil. Moss sells Redline MT-90 for manuals. Some post state specifically not to use synthetic oils, Redline is a full synthetic oil.
What is a proper lubricant for a Moss 4 speed with white metal?

 

The original spec was SAE 30 motor oil. I have had good luck with the RedLine MTL ( not the gear oil). I suspect a synthetic 30 wt engine oil would also work.

Glyn is the oil expert and can give better advice.

 

Moss gearbox with or without OD = SAE 30 Engine oil.
Jaguar all synchro gearbox with or without OD = GL4 90 (for easier shift when cold GL4 75W - 90)

 

I'd go with the MT-90 oil, in fact I did and I notice a better shifting experience. Just saying.
Schmitty

 

It's all in the viscometrics. You will probably find that the MT 90 is in fact a SAE GL4 75W - 90 ~ there is no magic way of improving change with additives.

 

Refresh page for edit.

 

Additives can make virtually imperceptible differences that the average driver would never notice.

 

Our MT fluid was an ISO 32 that we got away with due to the film thickness of the additive used.

 

I'm looking for spark plugs for a 3.4. It's bored .030 with a "B" type head, 8:1 compression and 2 SU HD6 carbs. What would be the correct heat range for 88-91 octane fuel? Champion shows a heat range from 6-9 for engines with a "C" type head, no listing for a "B" type head.

 

My 3.4 is bored .030 with a "B" type head and 2 SU HD6 carbs. Are there several cams that can be used with a "B" head? Is there a significant HP difference between the cams? I've seen 3.4 HP ratings from around 160 to over 200HP. What's approximate HP range with the "B" head?

 

Is there a hose fitting adapter for an early sedan (GR-4252-364) slave cylinder to convert to NPT or AN fittings?
What is the factory fitting thread size?

 

I have used NGK BPR5ES with good success. I do know that Champion and NGK have different heat range scales. Champion recommends N11YC

 

The early XK120 cars were designed for immediate post war low octane fuel, so were 7:1 compression. Later cars were 8:1 and some versions were 9:1. The pistons will determine the compression ratio and the height of the dome.

The power ratings then were gross, not net like is used now, and some of them were rather optimistic. I have tested my 3.8 with an actual compression of 8.6 and I measured 164 hp.

Some of the XK120, Mark VII, XK140 and Mark 1 2.4 had 5/16" lift cams, and the later engines all the way to 1992 has 3/8" lift cams. An engine from a Mark 1 3.4 should be 3/8" lift.