3.8 Litre E Type engine upgrade advice?

[andrewh]

I am just about to start on the rebuild of my 3.8 E type engine, and am wondering what to do, if anything at all, to "improve" it. I am a great fan of originality, and a genuine belief that the thousands of miles that Jaguar did when testing the car, arrived at perhaps the best compromise between tractabilty, performance and longevity. That said, I am also aware that technology has moved on and perhaps by doing a few things I can "push" the BHP and Torque towards where they were publicicsed as being when new. I dont want to go bonkers on cost, and I certainly dont want anything that can be seen from the outside, such as fuel injection or even electronic igintion (with external amplifiers). So the question is, what should I do. I am going to lead free the valve seats, and it may need a rebore, not sure yet. But any thoughts on cams and flywheel and gasflowing would be much appreciated, although I intend keeping the original exhaust manifolds and a standard looking and sounding exhaust.

[Heuer]

Andrew

It is a game of compromises. I have a VSE02 engine which includes gas flowing, higher CR, lightened flywheel, different cams etc etc and whilst the car is lightning quick the tick-over is very lumpy, but then how long do you spend at tick-over A lightweight flywheel will make the car more difficult to drive smoothly in traffic. My VSE02 conversion gulps air so really does not like the standard filter/can hence my research into K&N/ITG filters. Bear in mind the increased power costs in fuel consumption (super-unleaded is compulsory) and wear and tear on all components. I go through a rear set of Michelin XVS tyres every 8,000 miles. If you are going to fit a 2.88 diff (not recommended on a 3.8 ) you will need to increase torque to avoid bogging down. Increased power means you will have to fit a dual outlet oil breather if you want to hang onto your rear crank seal.

My advice would be to speak to Harry, Rob Beere and VSE and see what they say when you state your requirements. To be honest the biggest improvement you can make is to install EDIS/Megajolt (~ +10%) have a straight through as against baffled exhaust system (~ +10%) and do something about the air filter (~ +6%). A standard E-Type is already a quick car so addressing those three areas will make it great to drive. If you start to make changes without expert advice you could end up very dissatisfied.

Basically if you do not intend to really cane the car stick to original - little point spending that extra cash just for bragging rights in the pub

[Mark Gordon]

Pertonix makes an electronic ignition that is entirely contained within the distributor, so it still looks original but performs much better than a contact points ignition does. Ease of starting is particularly enhanced. I've been running these units on my cars (Volvo, Spitfire, and now E Type) for years with no problems. The only downside, as with all electronic ignitions, is that they don't slowly die like points do, but work perfectly up until the second that they die completely. That being understood, I wouldn't even consider leaving contact points in a driver, and I'm not sure that concours judges would be able to tell that a Pertronix unit has been installed.

[Dave K]

I fitted Pertronix to my 3.8 about 6 years ago along with a flamethrower coil and it has worked perfectly, as Mark starting is very easy.
Some upgrades I have done to my 3.8 include:
Big valve head.
Gas flowed.
Rob Beere crankshaft scraper.
Lightened flywheel (Mine is a factory lightened flywheel and came with the car)
XJ S3 cams.
Fluid harmonic damper.
Diaphragm clutch.
Engine vented to atmosphere as Heuer.
Rob Beere micro vee belt pulley system, Not an engine enhancement as such but it gets rid of the troublesome belt tensioner and uses good non slip belts.
Get decent spark plug leads, dizzy cap and rotor arm.
ITG canister style air filter.
Upgraded carb jets.
St.steel tubular manifold and straight through exhaust system.
I have set my inlet valves to open at 14 thou and exhaust is set 12 thou.
There is probably a lot more but I can't remember at the moment.

Dave

[andrewh]

thanks Guys, there are some really good ideas here....what is EDIS/Megajolt? I guess as I write this I should have done a Google!

I do drive in a spirited fashion, but would not be track daying the car, just pushing on when possible. I think for me its going to come down to a petronix electronic points set up. I reckon to keep a points and condensor in the car as a get me home, and perhaps a slightly lighter flywheel but without compromising the smoothness of the engine. Its a tricky one, I think I want the original experience, but with a bit of enhancement.

By the way what was the crankshaft scraper?

Reference the rear crankshaft seal, is this a rope type? I hate them if it is ! Presumably you are talking about increased power producing increased crankcase pressure hence the danger for the rear seal?

Ummh, decisions decision! a talk with Harry is a great starting point and maybe I can blag a drive of one of his set up from him! thanks guys

[christopher storey]

I really cannot advise strongly enough against fitting one of the lip seal kits for the rear main seal. A high proportion of the (admittedly small )number which I have known have failed, and this leaves you with a far worse problem than the minor weeping which is common on the rear seal when it is old . The problem is that the lipseal is irreversible because 75 thou has to be machined off the crank, and if you then want to go back to the tried and tested rope seal, you need a new crank . I can remember these engines when they were new , and rear rope seal leaks were never a problem that I can recall : it is when they go hard and friable with age that the leaks occur

As far as mods are concerned, again, be very careful. The 3.8 has a much lighter flywheel than the 4.2 in any case ( about 19lbs against 26 lbs) and except for racing where heightened throttle response between gears has some advantages , further lightening is not likely to do much for you . If you want electronic ignition ( I never have , being a Luddite) the latest 123 has the undoubted advantage that the ignition curve need not be predetermined but can be mapped for both mechanical and vacuum advance using a laptop . I really cannot advocate doctoring the head : the ports are already of ample size and well shaped and bearing in mind that 95% of your time will be spent below 4000 rpm, what you want for road use is a good fat torque curve between about 1200 and 3500 rpm . Playing with the head, and indeed the exhaust , has a notable tendency to rob you of mid range torque . Despite the pronouncements of Dr Samir Klat about combustion efficiency , who was very bitter that Jaguar would not listen to him , Jaguar ( and Harry Weslake ) knew what they were doing hence the 5 wins at Le Mans with an engine and head fundamentally similar to that of the road cars apart from increased valve angle , , and I would leave well alone

[Heuer]

Andrew

Get yourself a copy of Des Hamill's "How to Power Tune the Jaguar XK Engine" and do some reading. As Christopher says the rope seal, properly prepared and fitted, is not a problem providing the car is used fairly regularly. High crank case pressure can cause the seal to start leaking however (my own experience ) hence the desirability of fitting the double breather on hard driven and tuned engines. I had big problems with fitting a bigger exhaust system with tubular manifolds which caused a torque dip between 2,250 and 2,750rpm and in the end I went back to the cast manifolds and am now getting rid of the big bore silencers in favour of standard sized ones, albeit 'straight-through'. As regards EDIS try here: http://etypeuk.com/forum/viewtopic.php?t=437

Any tuning you do will increase BHP at the top end and move the torque curve up the rev range - exactly the opposite of what you want in a road car but great on the track. The Jaguar quoted 265bhp at the flywheel was done on a dyno with open exhaust ports and no air filter which is why you will only see ~225bhp in the real world. You can reclaim some of that 16% by carefully choosing you exhaust system and air filter. I found the EDIS improved torque on my engine by about 10% as measured on a rolling road. Sad news on the EDIS/Megajolt though as Ray is having difficulty sourcing the connectors so the next batch could be the last he makes.

On balance I really like my VSE02 engine's performance (250bhp & 270lb/ft at the wheels) and I would not go back to standard because it is so much fun to drive.

[Dave K]

Just like to add that had I been doing my car now I would have added the 123 ignition and not gone for the Pertronix but because my car runs so well I feel it's best left alone.
The crank scraper sold by Rob Beere fits between the block and the sump and scraps the oil off the crank as it spins round and is supposed to lighten the crank and give the impression of a dry sump crank.

Dave

[andrewh]

Gosh, there is a lot of knowledge here. I dont know where to start really!

I had a hot Aston which was breathed on by RS Williams, what he does is go for Corillo Rods and Cosworth pistons plus I went for the steel billeted crank which stroked the engine up to 4.7 litre. The BHP went to 360 with 390 ft lb torque from memory. The car was awesome, but as someone said earlier the fuel consumption went down accordingly. That car was on high left cams and 45 DOCE webers so was a bit of a street monster anyway, the E is rather a different kettle of fish from new and this is why I am wondering how far to go. I am also keeping, at least for the time being, the MOSS box, so you have to wonder whether all my new found acceleration will get lost on the gear change.

Thank you all very much for the advice, and it certainly arms me for a discussion with Harry or others. Ummh.........

[Dave K]

Gosh, there is a lot of knowledge here. I dont know where to start really!

I had a hot Aston which was breathed on by RS Williams, what he does is go for Corillo Rods and Cosworth pistons plus I went for the steel billeted crank which stroked the engine up to 4.7 litre. The BHP went to 360 with 390 ft lb torque from memory. The car was awesome, but as someone said earlier the fuel consumption went down accordingly. That car was on high left cams and 45 DOCE webers so was a bit of a street monster anyway, the E is rather a different kettle of fish from new and this is why I am wondering how far to go. I am also keeping, at least for the time being, the MOSS box, so you have to wonder whether all my new found acceleration will get lost on the gear change.

Thank you all very much for the advice, and it certainly arms me for a discussion with Harry or others. Ummh.........

Andrew,

If you want a serious engine then you really need to have a chat with Rob Beere, you will get what you want but it will cost you.
I had a Moss box for the first 10K miles and found it fine, as long as you have a good one. It does take some getting used too and the gear changes can catch you out even when you get used it.
There are various knacks of getting it into first gear etc and it does whine a bit in first but this is part of what these cars are about.

Dave

[andrewh]

Funnily enough the first gear whine is one of the reasons, as you say, that I want to retain the Moss. There is an old boy near me in Kent, with an absolutely lovely old 3.8 he has owned for 40 years. He comes to a few old car do's locally, and I love the whine when he motors off after his half pint of shandy. Its actually that noise and the look on the old cross plys which for me transcents the old school world with the new world. The early E crosses that divide so well. On the one had it looked liked a space craft but still wore upright tyres like an old model T and whines like an old pre way Bentley..........lovely.

[adam]

Hi mine is still fitted with a moss box, I love the whine in 1st! I have also just fitted Dunlop RS5 crossplies, much prefer the look of the skinny tires.

The only upgrades it has are Coppercraft front brakes and a 123 distributor so it stops and starts reliably. It still has its lawn mower fan blade, dynamo, cast manifolds etc.

Try Harry's upgraded car and see if you prefer to the standard car.

Adam