Yes ~ CAN Networks require full integration. We have big trouble with this at MBWorld and the fiddlers.

 

WBO ~ we know your engine is worn. Just taking it back to full original spec will help a lot.[/QUOTE]

You are right Glen. I have been quoted $8000 AUD for a full rebuild. Its probably cheaper than all the work necessary to modify a worn engine up to the same output as an unmodified new engine

 

You are right Glen. I have been quoted $8000 AUD for a full rebuild. Its probably cheaper than all the work necessary to modify a worn engine up to the same output as an unmodified new engine[/QUOTE]

That comes out to around £4400 British Pounds which in the grand scale of things is not too bad. You could reduce that price by doing a lot of the work yourself and sourcing the parts yourself. My engine was very worn at the point of my rebuild so I pulled the engine myself, stripped it down to empty block and head with valves and cams still in. Not difficult with an empty garage floor and a basic set of tools. I located a local engine builder and delivered the block and head to him with all the new parts I had sourced a lot of which were new old stock parts I had found over a couple of months on E Bay. For £1500 the engine builder did a good clean of all the oilways and oil pump, re bored the cylinders, fitted new 9:1 compression pistons and rings I supplied, new big end shells which he supplied, polished the crank and fitted new main bearing shells which he supplied. He stripped the head and fitted new valves where needed which he supplied having re cut the seats then shimmed the cams. Skimmed the head and then gave it back to me in the same stripped down condition I had given it to him. Back to the garage where I reassembled it with new gaskets. The parts on E Bay cost in the region of £1000. Worst mistake I made was when I delivered the engine and parts to the engine builder he asked when I wanted done by and I said there was no rush as the body was still being stripped and then it would need painting. Nine months later I returned to the builder to check on my engine as I had not heard from him to find it was still on the garage floor untouched where I had left it. When I asked what the score was he said "when do you need it?". A week later it was done and back with me at home. Moral of the story is always give them a time scale when you want it completed or it will as mine did just sit in the corner unloved.
Not sure if the £4400 you have been quoted involves the removal and reinstalling of the engine but you are talking about 8 to ten hours of labour for this alone. UK garages are charging anywhere from £70 to £230 (Main dealers) an hour so the cost of taking the engine out and putting it back could be between £700 to £2300 alone so shop around. Maybe get one garage to take the engine out and another to do the rebuild.

How much do UK garages charge per hour?
Overall, the UK average labour rate – combining main dealers, independent workshops and fast-fit outlets – is £67 an hour.
...
Garage labour rates hit as much as £230 an hour. Region Average hourly labour rate London £77.42 Worcestershire £77.16 Berkshire £76.77 Buckinghamshire £76.65

Whilst you have the engine out I would have the gearbox rebuilt at the same time. My car was not running when I bought it so no chance of checking the gearbox. Once the car was finished and on the road within a month the gearbox started to slip. (BW35 Auto). I had to have the gear box removed which with some fiddling can be done from under the car leaving the engine in place and had it rebuilt. Cost another £1000 but it had to be done.

 

WBO ~ with the viscosity of oil you are having to run in that engine (SAE 25W-70) for decent oil pressure I think you are going to find it severely worn unless you have a duff oil pump (unlikely) or pressure release valve.

I think with a new stock rebuild you will find the old girl quite sprightly. I'm quite surprised with mine and my daily driver is considerably more powerful. I never feel I'm driving a lazy motorcar with the Jag. The 3.8's midrange torque is what makes it so driveable and why it will leave many of those tin boxes behind once on the move. They will give you a hard time at the traffic lights if they are any sort of hot hatch. But once on the move matters change.

 

You've probably been over this before, but for low oil pressure in these engines, I'd consider sender, gauge, relief valve, pump in that order before bearing problems. That's unless there's other evidence against the bearings. I think your gearbox is MOD. The manual gearbox part is less likely to need a rebuild than an auto. You've already discussed the overdrive.

Aus$ 8000 isn't bad compared with what a lot of 'specialists' ask. As Cass wrote, you can save a lot by collecting parts and doing as much as possible yourself. If you do, keep in mind patience and cleanliness.

 

Peter. This is all covered in a long thread with WBO some time back.

But it's always a good remender. WBO tried a synthetic & had no oil pressure with an oil which would have achieved a good SAE 40 at operating temp. Previous owner admitted the engine was well worn. Hence 25W - 70. Aussie oilco extrapolating.

Thread even showed a pic of sender location & how to remove. All was well until oil change. I'm not surprised on that treacle. Jaguar never recommended over an SAE 40 in torrid summer conditions. 20 in winter, 30 in summer, 40 in torrid conditions.

Synthetics are just fine for a rebuilt XK engine that is to spec & will extend it's life. A lot of nonsense is spoken ~ 20W-50's were for Alec Issigonis transverse common sump engine/transmission units & soon sheared to below a true SAE 30 (range & typical midpoint). Very much a British carryover, for Mini to Landcrab. (Austin 1800 etc.). The gearbox did a fine job of chopping up the VI improver.

 

You are right Glen. I have been quoted $8000 AUD for a full rebuild. Its probably cheaper than all the work necessary to modify a worn engine up to the same output as an unmodified new engine[/QUOTE]

That is a very good price if the rebuild engine is done with all new bearings, pistons, valves, etc. instead of a low buck rebuild where they re-use most of the parts and just change piston rings and not put many new parts in the engine. The one good thing you have going for you being in Australia is the labor is way less than the US or UK so you should check around and find pure engine machine shops that only build engines as the price for rebuilding the old engine may be better if they do all new internals. Not all rebuilds mean the same, there are often a lot of false advertisements.

Then, you might consider finding out what the extra cost of increasing the intake/exhaust valve size with a simple 3 angle radius and a mild cam. If you have more funds then look into the extra cost for them to port the head. That is the time to get the most value on performance is to do internal upgrades. Your country has many very highly skilled engine builders so do some research to make sure as internal mods are always the best...

 

That is why for my personal preferences the GM LS V8 is a clear choice not just for the better power, weight, reliability, but for the ease of so many people, aftermarket parts, etc. for ECU's and ECU tuning of stock and aftermarket parts to make is so easy.

 

I don't think you need to mod this car. If it was me I would go mad ~ all or nothing on the engine. Probably not wise & certainly expensive. I'm not racing it.

If you mess with cams keep them mild as Primaz says. You do not want to do anything that disturbs Jaguar's turbine smooth idle. The minute performance cams cause rough idle they cause layshaft/inputshaft rattle in the gearbox & other irritations. Keep it smooth. One of the delights of the XK.

Flow benching the head (even with stock valves) is always a good idea which is why I had it as No 1 on my list above not that that list was intended to be in any order. Mass production never achieves perfect flow with misalignment, flashing etc. etc..

Reminder:

Flow bench the head
Increase carb size & tune inlet length (e.g. 3 twin side draught Webers & tuned length tumpets from a filtered plenum.)
High performance cams with suitable valve springs
Fit largest valves possible ~ cut 3 angles on the seats.
Balance crank & flywheel. Lighten flywheel. Forged lighter, weight matched, rods. Fit short skirt pistons if you don't mind the noise. Increase rev limit.
Maximise compression ratio without knock or up octane of fuel used.
Tuned exhaust manifold & freeflow tuned exhaust system.
If money is no object increase capacity as Eagle does.They have build some greater output models for clients but standard ~ Capacity is enlarged to 4.7-liters, enough for an output of 380 horsepower at 5,750 rpm and 375 pound-feet of torque at 4,000 rpm. 0 to 62 mph under 5 secs. Top speed over 175mph.
Fit a 123 Ignition distributor that allows accurate ignition curves. There are other high energy ignition solutions. Curves must be repeatable & accurate.
Ensure adequate fuel line sizes,
Forced induction.
Friction modified synthetic oils.

 

Glyn,

I'd maybe go to a twin 2" carb but no more. I have seen an E Type engine on a dyno and under full throttle the pistons on the three carbs do not lift to their full height, so that engine is over carburetted.

Based on my experiences with my DS420, I am a fan of the HIF44 carbs. I had put a wideband AFR gauge on the car, and those carbs did a very good job of keeping the AFR's near the set point, I was impressed with their accuracy and how they changed the AFR from cruise to full load exactly where I would have wanted it to be. I did need to reset the mixture when going from sea level to 5000' elevation, but no carb can compensate for that automatically. 1/16 of a turn on the mixture screws and it was where I wanted it to be.

 

I'm a Weber man so all my comments relate to Weber DCOE range. Seen them on the dyno many many times & 3 is the way to go. Easily set up for any engine. Choke per cylinder. (Proper Schenk Dynos in properly IAT etc. controlled rooms) Sasol's Dyno rooms are even altitude compensated. We see the F1 guys out here from time to time. Sasol's Dynos are at 1,753 metres & can pressurise to just below sea level)

That Aston DB4 GT above is a rocket. 3 DCOE's. Don't remember the size any longer.

 

For the triple cut valve seats, nowadays, quite a few machine shops have carbide cutters that give a smoothed out multi-angle cut. It shouldn't cost much extra and can well give a 5 to 10% increase of power across the whole rev range. It's good to have the back of the valve cut to about 30 degrees. Also the lapping in lines should be close to the perimeter of the valve head. All this stuff is to help the flow to go around the corners of the valve and seat.

When Glyn wrote 'flow bench the head', I think he meant smooth out any casting flash and check and correct the alignment of carb to manifold, manifold to head and head to exhaust manifold connections.

If you go to 2 inch SUs, you might use a 420 manifold and a series 3 XJ cylinder head. The latter head is considered the best of the road car versions. It has bigger valves and straighter ports. The latter might or might not be beneficial (depends who you ask).

Triple SUs, Webers or Dell'Ortos may be difficult to fit in the available space. Jaguar themselves did experiment with a manifold with long inlet runners that looked more like something for fuel injection with twin SUs feeding the plenums. It's said to have been extremely good. But, given the effort required, you could as easily make a fuel injection manifold. Especially as carburetors are expensive and possibly not always of the quality of old ones.

 

Whats the difference between the 420 manifold, which is twin carb on straight port head and the manifold on 240 and 340 which is also twin carn on straight port head.

Or the twin carb manifold on the early xj6 twin carb cars?

Apart from that some are manual choje, some are asc and some are aed.

 

I'm not 100% sure, but the 420 is sized for 2" bore carbs, The 340 for 1.75" carbs. Not sure what carb size was used on the 240. A Series 1 or 2 XJ6 carb manifold should also be 2" and would work.

This assumes UK market, the USA market XJ6 had smaller Stromberg carbs.

 

The 420 and 4.2 XJ (carb) manifolds were the same and equally applicabe to twin 2 inch SU on a straight port head. The 240 and 340 will require at least some opening out for the larger throat.

 

The 240, well mine at least, has hs6 with manual choke, so 1.75".

I recently won an ebay auction for a 420 motor that I was planning to put in my 240, but the bloke has cancelled the sale, he thinks he can get more. Nevermind.

If I understand it right, I could get a XJ6 S3 engine, fit my manifold and HS6's with new needles. HD8 or HS8 and opening up the manifold vould be a next step.

Or efi.

 

Yes, you could do that. Keep in mind that there are various opinions on different vintages of the 4.2 engine block and the 4.2 in general relative to 3.4 and 3.8 blocks. My plan is to keep my 3.4 block and fit an XJ series 3 cylinder head. However, there's a lot of bodywork to repair first.

 

I guess any 3.4/3.8/4.2 bottom end with my 240 SPH and HS6's can work.

But if I'm gonna do it I might as well go 4.2....go big or go home!

BTW I was reading pistonheads last night and noticed a Peter3442 username.

 

Be aware that the Series III XJ6 EFI manifold will not fit in a small saloon, it hits the bodywork near the pedal box. A relatively easy spot to cut out and weld in a filler section on a LHD car, not sure if it would be possible on a RHD car.

To get around that, my plan for a modified EFI setup is to use the intake manifold from the 4.2 powered tank, and then use the TBI assembly from a late 80's-early 90's Chev/GMC pickup with a 350. I have the TBI assemblies, and a friend in the UK has the manifold for me, I just have to get them both on the same side of the Atlantic to make it work.

 

Indeed & increase diameter slightly & smooth all air flow. With practice & a tube you can hear it's correct on a good flowbench, measurement is not always king. Called porting by some. Different countries use different jargon. Syd Stacey came to work for me on our racing program. He was Kork Ballington's race engineer. I used to call him the "midnight porter". He was very good. A matched set of inlets, carbs, manifolds, heads, exhausts from him flowed to perfection. His valve jobs were a work of art. Over time I had both Trevor Tilbury ~ Kenny Roberts snr & Ballington's race engineers work for us. We had dynos howling every night.