Search found 271 matches

by Tom W
Sat Feb 15, 2020 6:22 pm
Forum: Technical
Topic: Space saver spare wheel
Replies: 16
Views: 580
Great Britain

Re: Space saver spare wheel

You’ll soon get good at packing and travelling light!
by Tom W
Sat Feb 15, 2020 5:00 pm
Forum: Technical
Topic: Space saver spare wheel
Replies: 16
Views: 580
Great Britain

Re: Space saver spare wheel

The C-type never had a boot, just a huge fuel tank and a spare wheel compartment. Are you using the correct 16 inch wheels, or 15 inch? A space saver is only going to save on tyre width, not overall diameter. C-type tyres are pretty thin as standard (6.00x16 I think). To go thinner, you’ll need to b...
by Tom W
Sat Feb 15, 2020 3:47 pm
Forum: Technical
Topic: Standard camshaft max lift
Replies: 18
Views: 520
Great Britain

Re: Standard camshaft max lift

If you have slack in your timing chain, the cam timing will be both retarded, and also prone to wandering. Accurate cam timing and correct tensioning is critical to getting the most out of an engine, that’s why Jaguar specified a vernier arrangement on the drive sprockets. Over a high mileage, the t...
by Tom W
Sat Feb 15, 2020 9:26 am
Forum: Technical
Topic: Standard camshaft max lift
Replies: 18
Views: 520
Great Britain

Re: Standard camshaft max lift

John, 235 degrees does sound like a typo on the Rob Beere website. I would expect somewhere between 252 and 282 of the cams above and below. I’m surprised Rob or Kent cams can’t qualify the duration. This is inherent in the cam design for a given valve clearance. The point at which the valves open a...
by Tom W
Sat Feb 08, 2020 8:19 am
Forum: Technical
Topic: Distributor curves
Replies: 23
Views: 608
Great Britain

Re: Distributor curves

It can be a bit confusing trying to correlate distributor curves into what’s measured on the crank pulley. What you want to end up with is the curve plotting crankshaft degrees relative to TDC and engine RPM. The numbers in the manual are usually distributor degrees and distributor rpm. They certain...
by Tom W
Fri Feb 07, 2020 6:37 pm
Forum: Series 1
Topic: Brake system-Refreshed and No pressure
Replies: 44
Views: 1078
Great Britain

Re: Brake system-Refreshed and No pressure

I imagine the pictures were hosted on photobucket. It used to be free to host photos on there. They’ve now introduced some sort of pay wall, so everything is fuzzy until you cough up some money.
by Tom W
Fri Feb 07, 2020 6:33 pm
Forum: Technical
Topic: Distributor curves
Replies: 23
Views: 608
Great Britain

Re: Distributor curves

22D6 is a generic family of Lucas distributors. What makes it unique and tuned specifically for a given engine is the maximum advance of the cam, the strength of the 2 return springs, and the travel and strength of the vacuum capsule.
by Tom W
Thu Feb 06, 2020 9:07 pm
Forum: Technical
Topic: Distributor curves
Replies: 23
Views: 608
Great Britain

Re: Distributor curves

If you’ve already had the car set up on a rolling road, it should be very close. Unless of course, they returned it with a list of things that need fixing before they could set it up properly. If it’s just general tweaking, I think you’ll struggle to make any improvements that you’ll notice or measu...
by Tom W
Wed Feb 05, 2020 9:14 pm
Forum: Technical
Topic: Distributor curves
Replies: 23
Views: 608
Great Britain

Re: Distributor curves

Hi John. What’s the spec of your engine? If it’s modified , it’s unlikely one of the factory curves will the optimum. Your plot looks like what I was describing. Are you sure you’ve got the lower values right on 1&2 though? It’s unusual for advance to start at 500 rpm on the crankshaft. With this, y...
by Tom W
Wed Feb 05, 2020 7:01 am
Forum: Technical
Topic: Distributor curves
Replies: 23
Views: 608
Great Britain

Distributor curves

All I did was to use the pages from the manual as Steve’s shared. These are the specs for testing the distributor on a bench. You need to double the RPM figure to get the crank RPM for that point. You need to double the number of degrees advance, then add on the static advance figure. Do that for ea...
by Tom W
Tue Feb 04, 2020 6:05 am
Forum: Technical
Topic: Has anyone got a Winspeed (Guildford,UK) Electronic Ignition - Thinking of a purchase
Replies: 11
Views: 483
Great Britain

Re: Has anyone got a Winspeed (Guildford,UK) Electronic Ignition - Thinking of a purchase

Yes, that’s right. Next challenge is to make sure the advance curves (both vacuum and mechanical) match your original. Not every distributor that’s marketed for a Jag actually has an advance curve that matches properly. I’ve plotted the original curves in the manual against the 16 available in my 12...
by Tom W
Mon Feb 03, 2020 8:12 pm
Forum: Technical
Topic: HD8 carb issue
Replies: 67
Views: 3536
Great Britain

Re: HD8 carb issue

If anyone wants any further reading on this, I can recommend “The scientific design of exhaust and intake systems” by Philip H. Smith and John C. Morrison. It’s not specifically Jag focussed, but XK engines do feature in a few examples. Notably there’s an illustration of a Jaguar 6 cylinder inlet ma...
by Tom W
Mon Feb 03, 2020 7:54 pm
Forum: Technical
Topic: Has anyone got a Winspeed (Guildford,UK) Electronic Ignition - Thinking of a purchase
Replies: 11
Views: 483
Great Britain

Re: Has anyone got a Winspeed (Guildford,UK) Electronic Ignition - Thinking of a purchase

Some electronic distributors (the 123 with vac-option comes to mind) don’t have a vacuum capsule per se. They do have a port to connect the vacuum hose to though, it’s just connected to an electronic pressure/vacuum sensor. Those with a vacuum capsule usually apply the vacuum advance mechanically, s...
by Tom W
Mon Feb 03, 2020 2:15 pm
Forum: Technical
Topic: HD8 carb issue
Replies: 67
Views: 3536
Great Britain

Re: HD8 carb issue

I don't disagree with you. In my first post, I did qualify by saying not exactly true, rather than wrong. Really, this comes down to the semantics of how the balance pipes are considered in the explanation. In mine, I discount the balance pipe, which isn’t correct, but makes the explanation of intak...
by Tom W
Sun Feb 02, 2020 9:32 pm
Forum: Series 2
Topic: E-Type series 2 1969
Replies: 5
Views: 528
Great Britain

Re: E-Type series 2 1969

Possibly the clutch, gaskets, the rear crankshaft seal, plus likely several other areas beyond what you’ve already covered. Some underseal has asbestos in it too. It’s scary how prevalent it can be in old cars.
by Tom W
Sun Feb 02, 2020 7:38 pm
Forum: Technical
Topic: Sill Rubber Seals
Replies: 4
Views: 264
Great Britain

Re: Sill Rubber Seals

I glued mine in with contact adhesive.
by Tom W
Sun Feb 02, 2020 7:36 pm
Forum: Technical
Topic: HD8 carb issue
Replies: 67
Views: 3536
Great Britain

Re: HD8 carb issue

I’d already written my reply to John when you posted your reply Christopher, so I’ll answer your points in a separate post. 120 degrees is for the purpose of explanation, not what an xk, or any other engine has for that matter.. I did state it’s ridiculously short. As I explain above, on an engine w...
by Tom W
Sun Feb 02, 2020 7:20 pm
Forum: Technical
Topic: HD8 carb issue
Replies: 67
Views: 3536
Great Britain

Re: HD8 carb issue

Yes, the statement on the intake alternating between the front and rear carburettor applies in a scenario where the front 3 cylinders are fed by one carb, and the rear three are fed independently by the other. With the firing order 1.5.3.6.2.4, you can see that the intakes alternate between the fron...
by Tom W
Sun Feb 02, 2020 8:25 am
Forum: Series 1
Topic: Brake system-Refreshed and No pressure
Replies: 44
Views: 1078
Great Britain

Re: Brake system-Refreshed and No pressure

I should also add to the above list of attributes: Total braking performance. Can you lock the brakes? Once you can lock the brakes, the system you have is already capable of stopping the car as quickly as possible. To improve on this, you’ll need tyres with more grip, or to shift the brake balance ...
by Tom W
Sun Feb 02, 2020 8:11 am
Forum: Series 1
Topic: Brake system-Refreshed and No pressure
Replies: 44
Views: 1078
Great Britain

Re: Brake system-Refreshed and No pressure

So to confirm the system is not just a bias linkage but should result in autonomous braking by the alternate MC if one should fail? Unfortunately that’s wrong. There is nothing autonomous about it. What happens on the standard system is in the event of one circuit failing is the other should remain...