I recommend you go with Pertronix D170618 distributor and 45001 coil.... simple direct fit, use Pertronix installation and initial advance settings, not the book jaguar static advance for engine. Finding a good XJ6 S3 distributor is going to be expensive and you will need an amplifier, between distributor and coil.
Use ignition wires for a 1984 XJ6 S3, not the wires recommended for a 1975 4.2 engine.
D170618 has modern (conservative) advance curves matched to lower compression and lower octane fuels
Rgds
David

 

Available at Barratts.

 

I've completed the design and fabrication of a 1930's style race car, it currently has a SBC and a T5 transmission. I always planed on using a Jaguar engine. I've got two engines a 3.8 and a 4.2 and a Moss 4 speed. The 4.2 is from a wrecked XJ6, and it's up and running. The 4.2 also has early emissions components, mostly intake and carburetors, but does have a basic points distributor. The 3.8 has all new internals and has never been started, but has some minor rust in 3 cylinders. I'm currently dismantling it to see if it can be saved. Hopefully one of the two will be going in my car, along with the Moss 4 speed.
Since the car is not a Jaguar or even an original car from the 1930's, it has a limited market and is not very valuable, it's priceless to me. There's a 1929 Ford Sprint car on Marketplace with thousands in the engine alone and its been listed for months at $26,500 with no sale, that might cover the engine build cost.
It doesn't make much since to throw thousands at my build. I'm making do with with I have and only replacing parts that are absolutely necessary.

 

I was able to solder the broken connection on the cam oil feed line.

 

I would order free catalogs from Moss Motors for Series 1 XKE for the 4.2 engine and Mark II 3.8S catalog for the 3.8 engine. These models are well supported with OEM or after market parts. Both engines are strong in themselves, the 3.8 will have less issues than the 4.2. All accessories like carburetors, distributors etc. should be from 1967 or older. These were pre-smog engines... you do not want to get smog carburetors and non-smog distributor mixed together.
My choice would be to try to resurrect the 3.8 if you can (hone cylinders) ; Pre-smog carburetors, SUs (2") or de-smog'ed ZSs (1 3/4") and modern after market distributor, matching the 1967 OEM advance curves; since it seems you are going for common sense reliability and parts availability, as apposed to max performance.
The ZSCD175 carburetor is easily de-smog'ed, replace fixed needle with same needle, but adjustable, you may added adjustable main jet as apposed to fixed, close off the temperature compensator pathway and you will have ability to tune carburetor properly with out lean misfire somewhere in the range.
Rgds
David

 

Hey David,
I'll be going with the 3.8. I pulled the head today and the cylinder rust can be cleaned up, not perfect, but better than having to sleeve it or junk it.
Got any idea what model are the SU's in the photo?
Where's the model located?

Thanks Jay

 

I found a tag with what looks like AUC896. So they're SU HD6 models, correct?

 

SU H6 CARBURETORS 1 3/4" throat. A detailed picture of water rail and manifold will help identify what Cylinder Head you have. My 65 3.8S was a B head.. Manifold will be matched to Head. Also casting or part numbers in forward part of the Cylinder Head will help others identify. If the are no markings on top of piston a picture and bore diameter will also help. Since it was overhauled, piston compression ratio is important to know.
Rgds
David

 

Here's some photos.

 

Those looks like HD6 carbs. The device in the middle is the"Auxillary starting carburettor", which replaces a choke. It adds fuel for starting, and was operated electrically by a solenoid. There is an otter switch ( the one with the 3 bolts) right behind the thermostat that switches the carbs off at 35°C

The other sender that points to the side is for the dash gauge.

 

They are SU Carburettor HD6 ~ 1 3/4" Thermos.

 

The 3.8 has a B type head; the 4.2 has a straight port. If the 4.2 head is in good condition and is complete with 2 inch SU carbs, there might be a small performance advantage in using it on the 3.8 block. Where the rear end overhangs the block, leaving the water passages exposed, the water hole can be drilled, tapped and blocked by grub screws.

 

Three of the cylinders had some silver metallic paste in them, it looked like paint. Along with a super thick clear oil. I don't know what it was that had been poured in the cylinders. There were mud dauber nest all over the internal engine surfaces, especially on the timing chain and in the water pump. The engine was sealed except for the water pump and the cylinder head breather hose connector.

 

The car the 3.8 is going into, weighs about 1300lbs. It doesn't need a whole lot of HP to get it moving. A three carb setup would be nice.

 

Are there any issues with the front and rear crank shaft seals on the 3.8? Is the Moss head gasket set a good choice?

 

The triple carb would be mainly for aesthetic value? Triple carb manifolds (from Mk X, 420 G, E-type, XK150) exist for the straight port head. There aren't any OE ones for the B type and non-OE are extremely rare.

Issues with crank seals will be typical ones with seals from that era and much the same for both engines. The rear rope seal is sometimes replaced with a modern type, but that involves machining the crank. I'd leave well alone and make sure the crankcase ventilation works.

I've no knowledge of Moss parts in the US.

 

Moss US bought out "XK's Unlimited".

 

I've not had great experiences with either XK's or Moss. I prefer to buy from SNG in the UK. Shipping is DHL and comes in 2 days. I find buying from teh UK is generally more price advantageous than from the US, assuming you're not ordering 2 screws and then paying for shipping.

 

3.4 is 83mm bore, 3.8 87mm bore... stroke is the same 106 mm.

 

i would find it unusual to NOT have something molded into the block or head indicating the displacement. but i don't know where.