Man I feel like such a Pest!

I found a place selling 199(4(5)) v12 6.0 JAG Long blocks for 1750.35
90 day warranty

would one just bolt it in place of the 5.3 with the correct injectors?

I need to file my tax return to see what I get back... it would be nice to have a 6.0 ;-)

 

Technically it will bolt in. It is the same block

That sounds like a lot after paying $100 for a 5.3, but I guess it isn't too bad.

 

Where do you find one for $100?
100 dollars that is amazing...


this is some company that
INCLUDES: Long Block Assembly, valve cover to oil pan (drained of fluid) DOES NOT INCLUDE: Cable Harnesses, sensors, hoses and bolt-on parts such as alternators, distributors, intakes, manifolds, pulleys, flywheel, etc may be included with the engine but are not warranted.

90 warranty

30 day money back no questions

free shipping in the continental US

 

also would be nice to bolt on a set of pre-HE free breathing cylinder heads.

and i feel bad about scraping 3 pre-HE engines complete,for $75. dollars, but sometimes you gotta do what you gotta do.

 

Pre HE's are the best to HOT ROD... a stage 4 can put out well over
600hp it just cost $13400 to build

 

I found a 100.00 5.3 within a day or two of asking about one. I bet it would only take 2500.00 to do a freshen up on it, lol.

I am about to put a 6.0 in my 89. It may be the same block, but man is it a lot different in other ways. Plus, if you aren't going to change your ECU to MS or some other programmable set up, you will need your 16CU reprogrammed to run the 6.0. From what I get, that runs 700.00+ alone.

Wish me luck, I'm knee deep at the moment

 

Craigslist. Was out of an 86 I think. It was cut out, so a lot of parts are still on it. Basically if you cut the AC lines, cut the exhaust off, and and unbolted the engine, that is it. The tranny was even attached.

I don't think it would take 2500 to freshen it up though. Completely rebuilding doesn't even have to be expensive. Parts are parts, the engine doesn't care. Is a proper compression piston for a 5.3 100 dollars or more? Yeah. Does the engine know if it is a jaguar piston or some other high quality piston with the same measurements? No.

Just measure everything and buy what you need. Even the bearings can be overpriced for the 12, but I guarantee I can find ones elsewhere that don't say jaguar for less money. It just isn't really necessary. Yeah there are 4 more parts than the average v8, but it doesn't need to cost 10 grand to rebuild the V12 like so many like to claim.

 

The 6.0L block has a different transmission bolt pattern it will NOT bolt to the 5.3L TH400. You can have the block drilled to fit as the bosses are still there.

The differences between the 5.3L and the 6.0L are:

* O ringed injectors removing the rubber hoses from the fuel rail.
* Serpentine belt for accessories.
* Better flowing heads.
* Depending on market full flow oil cooler.
* Different crank snout.
* Same 1 piece rear main seal as late 5.3L
* Early 6.0 Marelli and EN40 forged crank.
* Later 6.0L coil packs and cast crank.
* Different transmission bolt pattern.
* Sanden AC compressor with different mounting.

Otherwise it is bolt in. Engine mount bolt holes are the same even though the XJ40 and X300 used different mounting the XJS mounts bolt straight to the 6.0L block.

 

Apologies but please let me correct: no 6.0 XJS come with the coil packs, those are only applied to X305.

 

Depending on time and ability, I'm sure the Jag V12 could be freshened up for a lot less than 2500. However, just for starters, the tensioner is now pretty commonly over 300, unless you know better. Then go out a find a machine shop willing to do a valve job on a V12 Jag head. My last V12 rebuild needed ALL 12 of the exhaust valves, do to the stems being so worn. Throw in a seat, guides, and I'm thinking I spent about 6-700 on the heads alone. We now are at a 1000.00, and haven't even started looking for gaskets, rings, pistons, shims to adjust valves, .......

 

\
the awful price I listed above covers them doing all that machine work porting new cams that are nickel welded line boring, balancing, new rods pistons ect, and the whole thing reassmled and ready to drop in producing over 600hp...


and a warranty...


speed is just how much you can afford....


my v12 cams to piper cams in England and back here would be about $730 US mild road 2200- 7000 cam
I am checking with them now about any nessary head mods or a change in valve springs... ect...


I drive it to work... the more I drive it the smoother it runs... second tank of gas now....

 

Yes you are correct I was talking about the 6.0L engine not the XJS

 

Unless the engine is really neglected you will not have to touch the bottom end.

When I dismantled my spare 6.0L the oil was black with a lot of contaminants, the crank does not even need a polish. I bought it to use the crank in my engine so was always going to dismantle it.

Check the oil and if it is in good condition you are way ahead.

I tried to CC the heads just to determine chamber volume and EVERY chamber leaked from either valve, one very badly from the exhaust valve.

 

If you produce 600hp in a Jaguar V12 without forced induction all you will achieve is moving the power curve higher in the RPM range. The car will be slower off the mark.

a good 400-450hp V12 with out accelerate most from the traffic lights, due to its excellent low end torque.

Cams are a waste of time for a road engine unless you want less torque low in the RPM range.

INTAKE MANIFOLDS is what is important. Either make a set of manifolds like the AJ6 or cut the plenum off a stock set and open out the runners then add a 100mm box section with the Throttle body on the front.

Port match the intakes and blend the horrible 45° cut Jaguar made in the intake on the head.

3 angle valve job and bolt it together.

 

I am not looking for a lot...
just a little...
it seems to run out of breath too soon and the stock air-filter housings necking down to that little tiny straw to breath through seem like the fist place to start...

now when you get into the head mods you have to remember that you need to look for swirl and tumble... a good swirl and tumble design goes a long way for part throttle response and fuel ecom.

I will most likely end up with QuickCat™ intakes and the mild road cam...
as far as torque goes... I too easily fish tail leaving the gas station entering the road... (part throttle) moving the torque up the rpm band a little is ok... the cam is only good for about 25hp gain... do not expect a race car out of this just a few more revs... ( remember I used to own a high revving sprite...)

A little more exhaust noise would be ok too....

 

OK,

where do I find the information on the FULL FLOW oil cooler conversion?

I live in Florida... it is hot here and I would like to do this as it makes no since to me to only cool oil when the pressure is high and in bypass...

that is not when it needs cooling....

 

It's your $$$. My build will focus on the intakes and valve seats this is where the power is. Polish to a shine the exhaust ports and chambers, these will be carboned up badly.

I will be using the stock cam, throttle bodies, pistons and rods. Rods will have the pad in the BE removed and balanced. Stock TB's flow 630cfm each so 1200cfm these do not need large bore, waste of money. Then if funds allow ceramic coat piston crowns and low friction coating on the skirt and bearings.

400hp is easy for a 6.0L with ported stock intakes and a valve job. Add an intake like the AJ6 and now you are at 450hp.

 

I don't mean to sound dumb, as I have worked on, rebuilt fully two Jag V12s, and lost count over the years of repairs. But what happens, or can it even be done, to put a set of pre-HE heads on a 6.0 without going really crazy on money?

 

supertr6, it can be done, but you would need to change to pre pistons, myself id order custom pistons 10-1 ratio,you want the chamber in the piston not in the head, better heat control , any good USA piston manufactuer, will help you with design! porting and polishing is your choice, but expect little in perfromance. you would need to do some smaller other type work, tuning,etc. big exhaust system.

and for cams,you would need to make a choice, 6.0L makes good mid range torque, pre 5.3 cams make more top end power. pre heads ,6.0 cams would give the best combo for both together.
or custom cams ,but most are all about extreme top end, which we rarely use(how often do you drive around town at 5000-6000rpm?)
factory cams and valve springs are good for over 6500-7000rpm anyway.

you would do yourself a favor if you buy book by" Allen Scott, TWR and Jaguar XJS," a world of information!

XJS are a heavy car,i like mid range torque, i like to pass a car quickly, and be done with it, after all now he has to get by me! hehe.

 

your starting to get it about the Jag V12s, go for the full flow oil cooling system.

i think these engines are around 25-30% cooled by the oil, so when its bypassing its not cooling the engine!

the Allen Scott book goes into a lot of detail about oil cooling.

course the ultimate would be a DRY SUMP sysytem. lot of money tho.