True, although the average difference is only 12 Deg C difference (which is close to the delta you’d expect between a hot and a standard tuned engine. The big thermal problem here is brake fade (Looooong downhill stretches with lots of hairpins).
I doubt there’s much to the bonnet landing strip thesis, but it should be easy enough to check - just run a strip of 1" (paint friendly) tape across the gap at the rear. The landing strip is only a few feet wide, try taping off the whole section between the corners and see if it helps.
Hi: good thread here, I miss you guys.
I think if you pull some vacuum at the top of the float bowl you will raise the fuel level there and close the float valve. I can not picture what would happen to the fuel level in the jet but your float valve will be shut until things straighten out.
I have no idea how anything works in my 2006 x type. There is no dipstick for the auto trans even, it cost me $200 to get the level and quality checked, and to replace 6 qts of the stuff, and it took 3 weeks to find a mechanic to do it. Everything else is computer codes translated by a German into Greek.
P. Smith, Carson City
Jaguar itself suggested this if the air filter is removed, but this was presumably primarily for performance purposes:
"small number of sensible alterations can be done as Jaguar suggested when new in its excellent ‘Tuning & Preparation of E-type Cars for Competition Use’. The recommendations include: ■ Removing standard air-filter assembly and replacing it with mesh covered trumpets and replace needles with SU UO (all available from Burlen Fuel Systems)"
Like your conversion, Ian ! How did you attach the filter, and what sort did you use ?
Doing some work on our engine at the moment & have polished the cam covers etc so, like you, I’m reluctant to cover it all up again !
And what’s the flexi pipe - for a woodburner stove ? Have an alternator with power steering pump on our l/h side, but probably still enough room to find a clear route.
Why Jaguar did not make holes in the inner wing and have the air supplied to the carbs from the wheel arch we will never know , I did think about going down that way , but I don’t like to make holes hmm !
Any way , I used Semi rigid Aluminium ventilation pipe , attached the filter to the pipe with a plastic gutter drain pipe with a 112.5 offset bend 68mm pipe , the other end of the pipe is fixed to the Jaguar air intake with a Silicon rubber reducer
I used threaded bar to attach the bend to the front sub frame , using a hole already there , and just clipped a spring on the front of the filter to keep it in place , as I could not do the nuts up too tight in the plastic !
Once I got the Jaguar air intake size , I found all the other parts on e-bay , the down pipe bend I had , and it was just the job !
My guess is that Jaguar did not want to have the air intake in a location that could pick up a lot of road dust. Also, very low intakes have been known to suck in water when wading through somewhat flooded streets. The results can be disastrous if sufficient quantity is sucked in, hydrolocking the engine with major internal damage.
On your setup have you eliminated the "pancake air filter assembly entirely? If this routes to one of the nozzles of the regular air cleaner I would see the necessity for new needles in the carbbies. Or do you still have to use different needles because of restriction differences?
Can you post a picture of the upper connections going to the carbbies please.
Hi The_jag_man , if you go back 22d , your see a pic of my car under bonnet , yes its a bonnet , a hood you put on your head lol
Not sure what needles are in the carbs , as I have never had them out , Engine starts runs smooth and pulls like a train !
Nice setup Ian, I have made a similar one for my car, except I don’t mind cutting holes, especially when they help exhaust some heat soak from the engine compartment.
My 3.8 I had a 2 into 1 pipe fabbed by a motorcycle shop, connected to a similar ducting hose out a hole in the side of the engine compartment, fitted to a similar cone filter. It really woke up the engine and stabilized the idle. The original setup would lose power and the idle would drop more and more as the engine compartment heatsoaked. With the cold air it was totally different.
I just had a 4.2 built to replace the 3.8 and it has the same issues. The pancake filters are choking the engine (not flowing enough air) and sucking hot air is killing the power.
There’s a lot less space with a 4.2 and HD8’s than my original motor so I’ll have to be creative in fabbing some kind of air box, but it’s my #1 priority with the new motor.
The problem with the MK2 is , there is no room down the carb side of the Engine bay , ideally I would not of run the alloy pipe over the Exhaust manifolds , but being shiny alloy it reflects some of the heat !
I did think about going down the ram air road , 2 air scoops just under the bumper , 2 feed pipes going in to a air filter box under the wing , but like I said , I don’t like making holes lol
I am getting a 3.4 XJ6 Engine ready to drop in my MK2 , that has HS8 carbs at the moment , on a XJ6 manifold , so I may go with pancake filters on the carbs , or stick with the carbs I have now !
Not sure how much difference 1/4 of a inch would make , as my car is a she , that 1/4 of a inch may make all the difference lol
The usual reason an auto mfr. pulls heated air is to help cold engine running. It may be at the cost of some performance at the higher end but cold problems at start up are more noticeable to the drivers.
Well like I have said before , I put the original fan back on my MK2 , yesterday we went to Headcorn Aerodrome Kent, it was a very hot day , I never had to put the electric fan on once !
The fan must make a lot of turbulence at 40-50 mph ,
We was treated to a air display by this old biplane , for a good 20 mins , as well as the skydivers , micro lights and other planes about , there is a bit of a Battle of Britain museum there to , well as a café , if your passing well worth a call in !!
Another real world vote for a cold air intake. I’ve been working through all the issues and road testing the rebuilt 4.2 S3 in my mk2. The first iteration had small pancake filters on the carbs. It was an absolute pig. I spent the day yesterday building a steel box to pipe air in from under the fender. First drive last night confirmed suspicions - more, colder, air has woken this engine up. It pulls HARD now.
My plan, subject to re-direction / correction from you all, is to keep the existing pancake filter arrangement, albeit with a free flowing K&N, and then attach foil tube from the trumpets to take air from the lower front area of the engine bay. Reasoning;
1.The volume of air the engine takes in is pretty big / fast so as long as it starts in a cool place, should still be cooler than existing set up at the intake.
The carbs are set without air cleaner in place, get them just right, only to effectively ‘choke’ the engine and enrich the the mixture with an obstructive air filter. K&N circular model E-3032R (non-oiled) should fit if possibly a little under tall by a mm or so; I can soon make this up with a bit of closed foam strip if needs be. (I suspect the latest incarnation of ‘made to original specification filters’ are guilty of over choking, having previously run generic filters for some US V8 of some sort).
Easily reversible and doesn’t’ involve the cutting / welding / fabricating I am not able to do.
I’ve been thinking the same thing, and putting reflective foil under the pancake assemby to keep some of the radiant heat out. Please share the details as you pursue this. I will do the same.
