Results/Big idea: 20 degrees F cooler on double insulated side vs factory insulated side. 109 degrees F vs 129.


Trunk gets hot from the mufflers on my '77 XJ12L. Initial heat prevention included spraying the factory cardboard insulation with silver high heat paint, in addition to ceramic coating the outside of the mufflers.


Having removed the 12 cylinder and the factory fuel refrigeration unit, the 462 BBC continued to add heat to the fuel.


removed mufflers, shields, and cleaned and scraped off the factory muffle coat.


Added insulation per pictures, then reinstalled factory cardboard.

 

Interesting approach. With all the fancy insulation products available now why did you retain any of the factory stuff? Just wondering.

 

I am in the process of converting my Series 1 to fuel injection. Have one new S3 tank installed now and the other one in by tomorrow.

Since I plan to reroute the V8 dual exhaust under the IRS and am running new feed and return lines... what about the heat from the resonators or mufflers in that exhaust exit tunnel near that line shown in the photo?

Plus the tank feed line and return should be wrapped with foam and some high temp insulation.

You helped the gas tank already but my thought is there is now more heat going to the lines?

 

A nice fuel cell under the rear parcel shelf would be the go, weight removed from the rear end and put over the axle, old style tanks that can rust out are gone, one cell for fuel supply, no more issues with the twin feed/return setup, easy modification for more room for the mufflers resulting in better heat removal.

 

Steve, kept the stock insulation thinking more is better.


Roger,
My tanks are series 3 in a series two, also. Lines are insulated individually below the rear exit of the muffler. Feed and return inside the trunk, going forward along the spare are individually insulated. Feed and return lines under the hood are individually insulated.


Tunnel insulation is http://www.summitracing.com/parts/DEI-050503. ( no affiliation)


Individual line insulation is https://www.wirecare.com/products.asp?prodline=t6f (no affiliation) - great site by the way - as I used their products to recover the wiring harness' in the '77.


Thanks for looking and additional comments!

 

I like the sound of that. Do you know if that would pass a rego/engineering check in our part of the world. Common sense would say yes as its basically in the same compartment as the existing tanks and walled of in steel from the passenger area. I am never sure common sense is enough when dealing with Vic Roads /RTA etc.

 

Clyde
I like that line wrap you used.. will investigate it for my own use.

My plan for the trunk side but particularly for the gas tank - is to add the two tunnel insulation pieces (properly coated with high temp stuff) that are
double sided - from a Jaguar Sovereign. Guess Jaguar cared about the contents of "deluxe trunk" and insulated the trunk side in those cars? I figure twice the tank side insulation will not hurt at all.

My fuel change over valve (Pollak six port) will be in the trunk in the rear area behind the spare tire, along with all the hoses and the inline
fuel pump from FAST. All those lines will be wrapped when the conversion is finished (need to make sure no leaks first). Real fuel injection hose, AN
fittings on the pressure side and 37 degree flares on the hard lines. It will be mounted similarly to the LT1 that used the same concept with the S2 tanks, just
moved around this time a little and insulation.

My goal is to use as much GM stuff or new aftermarket stuff as possible and get rid of the old style Jaguar fuel stuff. All will be new from the S3 gas caps to the
throttle body on the engine. Next engine upgrade (if I live that long) will be a LS7 or LS9 (if it will fit under the stock hood?) and the fuel system will be ready to
support it - hopefully.

After the actual throttle body is on and lines run from the fender well, I will know the length of the coverings I will need.

 

I know modern regulations have changed from the past, but if a Datsun 1600 can have its fuel tank between the strut towers, I cant see how an engineer would fail you fitting a modern fuel cell, which are usually designed with motorsports and safety in mind, bladder inside the cell, foam filled to prevent fuel sloshing, adaptable to fit internal fuel pump setups a lot easier than an old Jag tanks. Venting the cell would require an external vent line, and it would need some solid mounting points.


Filling it would be the hardest task, making a neat solution from one of the filler caps might take a bit of ingenuity.


Removing the two tanks from the rear would also prevent potential fuel leaks from being rear ended, and a nice slim one to fit behind the rear seat would barely take up room, and make the car handle a lot better, no sloshing fluid upsetting the cars handling so far rear of the axle.

 

Roger,
Looks good.
Tin/fiber would not fit over my lines after I wrapped. I should have spent more time to make a replacement & covered same. Will do on the left as I still have to insulate that side. Got to keep every degree of heat as possible.
Products from wirecare.com have been top shelf.

 

I have put Be-Quiet insulation on the Jaguar floors, from the front to the rear package tray. In the doors and it will be put on the roof under the new headliner that is next. Helps sound and heat and keeps the car cooler as the early Jaguar AC was not the best... even though I have many modern mods.


My firewall has it on it and will try to put as much as possible in those exhaust tunnels... I did not even remember about those Sovereign tunnels being in my parts shed until I saw this posting.. will go back and do the left hand tank tunnel now. I had saved them for this job but it has been a long time since that car was scrapped.


They fit in the tunnel fine and I will notch them for the two fuel lines and the mounting bolts...


Could save a lot of time and money by just leaving my exhaust that exits under the rear valance alone.. but I really want to use my S3 curved exhaust tips and they look better coming out the normal exhaust holes (mine were welded shut by the PO).

 

Wouldn't you be gassing yourself though? from my understanding that's why they fitted the elaborate curved tips

 

I do not drive with the windows down... I use AC in CA about 250+ days per year. But, at idle with the windows down I think they do help a bit.

I like the looks of the shiny S Curved tips and they change the sound emitting to a softer sound but do choke down the V8 a bit due to their much smaller ID... overall they are not needed but "wanted" as I am way past performance at my age... "been there done that". My current tips are mounted down very low and I do not notice any exhaust fumes.

I have geared this car toward being a good daily driver with economy in mind.. lots of torque so it will move smartly. Changing to fuel injection for
consistent AFR and hopefully better overall mileage. With the rear end gears of 2:88 LSD and the 200R OD, I turn 1850 RPM at 65 MPH.. I will adjust the FI AFR at light cruise to around 15.0-15.2 and enjoy like my carb is setup now.

 

Glass pack resonators might just run cooler than straight thru conventional units. Smaller OD can help air flow.


A PO installed them in my car. I kept the Jaguar mufflers and through the cage system.


Nice sound. No issues with hot tanks or hot boot???


Carl

 

Good point, if the muffler isn't too restrictive, then the airflow will be much higher through it, resulting in less heat transfer into the muffler. Time for some straight through units!

 

Super 44"s are listed at Flowmaster's loudest street muffler. X pipe and rear exit keep the sound out of the cabin.

 

nice job.

those shields by the rear resonators are not cardboard, they are (or were) ASBESTOS! Watch Out!!

 

$ to a doughnut, you're right Jose. At no time did I do a taste test or grind on them.

 

i was worried about the heat problem when doing my XJS,SSOOO!

polypropolyne tank good insulation , and exhaust outside the car!

hey these Jag hot rods need some changes, yours seem close to a hot rod?

 

Ron,
yep, almost a hot rod
Street Slicks, skinny drag tires, and Full Moons
Headed for Turn One at Mid Ohio during HPDE
Auto Cross at Mid Ohio during HPDE - cone killer

 

have you got too much asbestos on the left side? it looks like it is leaning too much.