this otta expand this 500hp stuff!

if you want 500-750hp(as was other post,ICSA) just drop in a GM 572 cu in crate engine all built and tested, it will give 500hp& 500TQ, all day long months on end,

twin turb. you could be lookin at 750-1000hp, i'm willin to bet 90% of guys on this thread cant handle a 1K car,driven in earnest!

SO you say its gotta be a V12(i like that idea), check out an Audi V12 Diesel, factory stock, with just a remap and bigger exhaust ,MADE 600hp and encredible 850 ft.lbs torque, and its a smooth daily driver, in an XJS could get 30 MPG.

gotta think outta the box sometime! lot here are in that old 30-40yr old box.

and i have know concept what the drive train,XJS would do with that kinda torque, its torque that eats drive systems,, if i could get one of those engines with factory 6 spd auto, i just might come outta retirement!

they are sold all over the world (except USA). but if there is a will there is a way!!

 

GM 572 engine is 9.4L..

 

In the 80's we raced XJS'S and V12 Saloons in the XJ Championship. You could get a race winning engine by dropping the sump, flicking out the BE bearings and replacing with new; then putting the sump back on. INlet manifolds off then turn the engine over until the inlet valve was closed then open the inlet to the gasket with flap wheels and die grinders A vacuum got rid of the swarf. repeat on all 12 and consider wearing out 6 flap wheels and 2 die grinders. Took 6 - 12 hours work , we are talking lots of opening here. Then add the bolt ons, The exhaust manifolds would have been opened and opened and opened you knew you where about there when they started to go through and a mig had to close the break out. The down pipes needed the 2 into 1 removing and a good one added, often if you split one you would see 1 pipe almost closing the other internally so poor was the construction. Then came the inlets, band saw where the fins where then hog em out, A large washer on a rod would give a clue as to where and this could be a 2 week job to get right, the injector 'blib' needed removing totally internally. Again to the gasket. When finished bolt on and dowel then a flap wheel on a flexi to make sure of good head to manifold matching. Finally either weld the chopped phlenem back or used mastic (grey sickaflex was my preference) holding in place with the triangular end plates. Tuning was turning up the fuel pressure to 33 - 35 psi and advance until it knocked then back off 2 degs.
When you had the knowledge we went Cossie pistons -120 grams off the BE caps and race gaskets but by then it got expensive. Won the championship on and engine that cost £50 that way.
Hoping for 725-735 from an engine I am building and 750- 800 from one following.
You wont get a v12 to survive well over 6k unless you get serious on the oiling side. That seriously affects the realistic BHP because of the way the formula is calculated. Spark blows out at 4200 with 1 coil , piggying it can buy you another 1.2k dependant on set up. Marelli or coil pack is the way to go.
The good 6L engines are the XJRS ones those that followed had naf pistons and the last also had naf cranks (but good ignition).
TWR copied what Gp44 did, they bought the car I own and stripped and copied the engine albeit with cosworth pistons. The parts from TWR are interchangable with those on my car! Useful. And they should be too as the procuremant guy (Tom Seal) was the same guy. The parts came from the same places. You bet Bob was pissed. Then again if you dont negotiate a full time budget you aint a full time race team no more!.
The XJR5 chassis was obsolete soon after it won a race, the XJR7 was obsolete when designed. Full carbon was the way, stronger lighter cheaper and easier to make. Sad really, would love a full carbon 7.

 

what does one have to do to fix the oiling system?

 

My dad had a '72 series III E type with rebuilt 5.3 liter V12 with 6 Webers & lots of machine work. It takes $$ in machine work.
He also has a '68 E Roadster with a 4.2 with 3 carbs that makes 400RWHP.

I've seen lots of XJSs with V8 swap, one with a 502 BBC marine block and several swaps make 500+.
Most of these are not street cars and not as reliable the orig. v12.
The 5.3 v12 got a lot of bad press, but can be reliable with common fixes and coolant maintained these cars do 150K+ miles & don't overhead in 110+ degree AZ summers. Most of the problem cars have been overheated.

I've had Nitrous cars, supercharged and turbo cars and would not butcher a heavy smooth driving XJS. A co-worker put twin turbos on a v-12 SL-600 Benz and ended up spending $$$$ to get the thing to run well and drivable. It just doesn't make sense.

 

Cal have you got Allan's book? there is a picture in there of the last iteration of the Group A Wet Sump.

A simple way is to weld a square in the sump pan with hinged doors, the oil pickup will sit inside this. Have a look at this.

XJ-SC Modifications

 

I was planning on doing that warren, I was actually going to do that as well as make the pan about an inch deeper and the pickup longer

 

The other thing they did on the Group A cars was to lower the sump into the airflow under the car and add fins, apparently this dropped engine oil temps considerably.

I don't know about your car but my engine oil cooler looks very ineffective, it’s a bar and plate cooler but the fins are very small I will be replacing this when I do the engine with a newer more efficient oil cooler.

 

i was almost thinking of doing an oil cooler mod like Robert Knodt did on his race car with a larger one in the place of the AC condenser since i dont have AC

 

Ok it's time to get involved in this conversation and tell you all about what I am building. My 5.3HE had a blown head gasket and a noisy big end on start up, so I am having a new engine built up and will have it on a dyno within the next couple of weeks. What i have done should give me a strong reliable engine and address a number of the oil and cooling issues.

Here is a list of what I have had done.
I am using a later model block and crank with a lip seal
Replaced the rings and bearings.
The heads have been ported to match the inlet gasket size
Valve seats pined
Cams reground
Stainless steel Headders
Inlet manifold has extended runners (AJ6 style)
Throttle bodies have been opeded up to 2.875inch
3inch cold air induction
Autronic SM4 ECU with a crank position sensor in the bottom of the distributor
Aulminuim Radiator and dual thermo fans.
Full flow oil cooler
Oil accumulator (Accusump)

The full flow oil cooler and oil and Accusump should address the cooling and oil surge issues, with the Accusump as soon as the oil pressure starts to drop up to 3 litres of oil is forces streight into the oil journals.

The pourpose of the build is to have a strong reliable motor for track days and tarmac racing.

Once I get this on a Dyno it should answer the $64,000 question, what can you get from a 5.3L HE , any guesses.

 

thanks owen, you results should open things up, because everyone is guessing HP.

on an engine dyno, i'm gonna say 410 bhp. torque numbers will be of most interest for me.

if you car is light enough it should be a respectable performer!

 

some numbers for race engines , an F1 race engine makes 800hp, torque is around 250 lb ft.

that F1 couldnt pull a hat off a greased ball head.

most diesels like Audi v12 TDI stock makes 500hp and 700tQ, its almost the only logical way to go.
if smooth performance is an important factor!, along with low fuel consumption.

 

I am putting the car on a chassis dyno. And hoping to get between 270 to 280 RWHP. If I get more I will be very happy.

 

ported and cleaned up it should be around 310-325 to the wheels. im iffy about the cams since when I had mine going the power band was high enough already. the only reason I went with bigger ones was because im using more displacement.

I know an engineer from ford and.he was telling me that cars are rated as BPH now adays but the power is estimated rear wheel horsepower. so if the car says 330 bph brand.new on premium gas it should make 330ish on the wheels. but it's rated as BPH not WHP so idk doesn't make and sense to me.

 

Figures
Well moded 5.3 better inlet and better exhaust 350-375
6L with extruded exhaust and .415 cam 450
decent inlet and bigger cam will crack the 500=525
Full wack 6L with exhaust and inlets on .45 cam 601
Full wack with bigger cam .54 635
6.5L with the lot 701
7L with the lot 735-750
7.3 (i'll let you know)
7.4L torque engine 700 ish with .54 cam but big torque and better fuel consumption
7.5 with bbc mains and sbc be + .6 cam and everything else 750-765
7.7L with everything 775-?
Inlets are 1.8 to 6L and 1.9 above.
Accusumps work, you can run the opposition out of their engines on long corners. As for Group A TWR cheated, simple as that, then agains so diid BMW and the rest, just TWR did it better and more extensively.

 

xjr are you talking about pre he or he heads. cus I've got 6.5 with 10.7 compression and cams.

jeeze now im getting over excited

 

how does one make 7.4 liters? I saw some articles that a guy did it from a 6l motor

 

96mm bore and 84mm stroke will give a smig under 7.3L. So if you offset grind a 6.0L crank to 2.1 journals 84mm is attainable without having to weld the journals.

I was thinking about the low sump and in a road car there is a chance of damaging it on speed bumps. I think a better solution would be to fin the sump, keep it slightly above the front subframe and add a duct to channel air over the fins.

I have also added a TWR front bar and removed the front lower sill panels. This leaves plenty of room for oil coolers away from in front of the radiator.

 

wow! xjr5006,, what does it take to put a .600 lift cam on a jag V12 head???

 

What are the best mods?

I drove a '90 XJ-S v12 that had an aftermarket cold air package that deleted the air horn intakes. The intake sound and HP was one of the better mods. I doubt exhaust mods would do much.