www.jec.org.uk

Has anyone replaced all brake pads and discs.

Hi eastendjohn and welcome to the JEC Forums,
I would think yes would be the answer.
Would be helpful to know exactly which model you are referring to.
Your title "Barn Find" implies you have found a car in a barn,tell us more if you can?
Good luck with your brake pads and discs.
Take care.
Andy

Hello AJP delighted to find my first venture into JEC. Yes barn find in the sense that it was a car abandoned for over a decade and a half. I have established its a 1979 vehicle from the vin and engine numbers but am confused as to the model. It (an Aristocat Replica) has three carburettors, which does not appear to relate to the series 2 that I'm am being told was the donor car! There is much to do with an entire replacement brake system (rotted to unsafe condition) upgrading to electric ignition, loosing the apparently troublesome AED though on mine its a strange baculite two wire object! So need to know how to find out the true donor model but DVLA does not go back beyond rebuild registration. Probably hit you with far more than you anticipated when offering to help, sorry. Many thanks John

That sounds very interesting John,I love things like this.
Trying to find out the history of a vehicle can be very frustrating at times(data protection does not help either).
You could try posting a question in the Replica section of the Forums.
There is a Sub forum for the Aristocat:
viewforum.php?f=394&sid=7d499f3dc6df2ce ... 41e80bc0c2
Although it seems that part of the forum has been a bit quite.
I think Autotune was the company that produced the Aristocat,they might be able to help.
Sorry I can't be of more help John.Perhaps someone with more knowledge on the Aristocat and Series 2 XJ will come along.
Try and post some photo's if you can,would be nice to see your find.
Take care.
Andy

The Bakelite thingy is the earlier electric cold-start device - it predates the AED. I think XJ Series saloons only ever had two carbs, but E-types had three. As the Aristocat is a self-build kit car (I've thought of building one myself, but never got around to it), the engines will vary, as will any tuning or other features applied to them - my guess is someone replaced the inlet manifold and carbs. Quite likely they also replaced the exhaust manifold too - the original cast iron ones tend to crack, and were designed for driveability rather than performance. If you have some swooping stainless steep pipes, count yourself lucky!

Thank you Paul very helpful. You have confirmed my guess at the 'cold start thingy' . The original builder made some interesting choices including triple SU carbs to add to my fun in getting the car fired up and back on the road. The designers of the Aristocat ( Carolyn at Autotune UK) are very helpful <mail@autotuneuk.com. swooping stainless steep pipes, might come later but the agenda is full taking the first steps with fuel delivery; ignition and transmission, brakes to sort out. One step at a time, for some time yet me thinks. many thanks again John

That sounds very interesting John,I love things like this.
Trying to find out the history of a vehicle can be very frustrating at times(data protection does not help either).
You could try posting a question in the Replica section of the Forums.
There is a Sub forum for the Aristocat:
viewforum.php?f=394&sid=7d499f3dc6df2ce ... 41e80bc0c2
Although it seems that part of the forum has been a bit quite.
I think Autotune was the company that produced the Aristocat,they might be able to help.
Sorry I can't be of more help John.Perhaps someone with more knowledge on the Aristocat and Series 2 XJ will come along.
Try and post some photo's if you can,would be nice to see your find.
Take care.
Andy

Hello Andy I have decided to take some advice by logging into the Aristocat group. It is pretty inactive, which is a surprise. I am not sure if raising issues in a general category can be then channeled to the Aristocat group to start bolstering the topics and thus general interest in the group. I have gathered so much useful information in the last week, since I brought 'Felix' home that I want to share with enthusiasts but wish to avoid it being lost in a general topic not to be discovered by the Aristocat fraternity.

The Bakelite thingy is the earlier electric cold-start device - it predates the AED. I think XJ Series saloons only ever had two carbs, but E-types had three. As the Aristocat is a self-build kit car (I've thought of building one myself, but never got around to it), the engines will vary, as will any tuning or other features applied to them - my guess is someone replaced the inlet manifold and carbs. Quite likely they also replaced the exhaust manifold too - the original cast iron ones tend to crack, and were designed for driveability rather than performance. If you have some swooping stainless steep pipes, count yourself lucky!

Hello Paul I have decided to take some advice by logging into the Aristocat group. It is pretty inactive, which is a surprise. I am not sure if raising issues in a general category can be then channeled to the Aristocat group to start bolstering the topics and thus general interest in the group. I have gathered so much useful information in the last week, since I brought 'Felix' home that I want to share with enthusiasts but wish to avoid it being lost in a general topic not to be discovered by the Aristocat fraternity.

A bit late to the party, but I have recently changed brake pads and disks. Last year went to Le Man and the car really struggled from several high speed (!) stops.. the noise was as worrying as the long peddle travel. I was going to look at a big brake kit as I have 16" fitted, but bulked at the price to upgrade just the fronts, so I bought some EBC crossed grooved and drilled disked (front & rear) and some yellow stuff pads. WOW what a difference, still haven't found a situation where I think I would need to upgrade the callipers, but then I haven't been n the track yet...

I took my XJ6 to a track day several years ago. Everything was fine until the time I went round and missed the "The chequered flag comes out next time" notice and so didn't have a cool-down lap. Parked up in the pits, and a cloud of steam (actually, boiling hub grease and burning pads) as the red-hot disks cooked everything. The brake pedal went nearly to the floor, and felt like a bath-sponge. The cool-down lap is crucial!

I got the same have driven the same car to Applecross in Scotland. The sole road climbs over a mountain. and something like a 1/2 mile 1in 4 decent back to loch-side, with the occasional gate. When we stopped to open the last gate, yes, a cloud of smoke from the front brakes...

For normal motoring, Series XJ brakes are fine (although pedal pressures are higher than current car norms). It's rapid motoring, like track days, when they show their limitations. In my experience, the rears overheat first, which puts even more strain on the fronts. In turn, the fronts can glow and stink quite nicely after only a few laps. Harder pads can help but the basic problem of solid inboard rear discs hidden away from decent airflow remains. I have had a set of wider rear calipers sitting on the garage floor for some years awaiting the time to work out which vented discs will fit. One day perhaps... In practice, I just drive slower these days and avoid the problem that way! Mike.

Do you think Dot 5 would stop the boiling of the fluid from the rears??

Tried that. The answer's, 'no!' The rear discs just get far too hot even for dot 5. Mike.

Maybe time to try F1-style ducting - or removing the rear seat and cutting some holes in the floor ...
Do I correctly recall there are a couple of access panels about 4 inch square in the boot? If so, removing them might help for race days.
Of course, for an Aristocat there are probably all sorts of other considerations.

Your description of the cold start device suggests that the inlet manifold and carburettors are from a Mk X or 420G which are a straightforward swap to the 4.2 XJ engine.
As for the rear brakes, Jaguar issued brake ducting diagrams in a booklet entitled "Tuning and preparation of E Type cars for Competition use", in the early 1960s. Since the XJ rear end is identical to that of the E Type, except for its wider track, this could be the way to go. Unfortunately my copy of the publication was stolen some years ago, so I can't help with the fine details, but from memory it involved a pair of rectangular ducts ahead of the differential, directing air to the callipers.