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to answer the OP question , a big NO , the Jag 5.3L perHE pr HE , cannot be made to make 500hp without spending a rediculas amount of money, far more than most think, because the engine was never designed for HI-performance in the 1st place!
did spend way more than i anticipated, many engine mods, and best wheel dyno ever was 355WHP, most times only making a repeatable 335WHP, have no idea what crankshaft HP would be?
i had lowly Chevy V8s making 400 hp back in early 60s!
ron
Becasue every great automotive engineering effort starts with "All you need is a cheap..."
LOL... Low compression isnt the only thing you need for boost. The early chamber has no tendency to swirl, and has a dish piston with no squish area. The design is optimized for ease of production not boost. The early V12 chamber is a compromise. It's very poor from a combustion stand point and needs lots of ignition timing becasue the flame has to travel so far becasue of the flat wide dished chamber in the piston. Jag new this, the XK head with its pentroof chamber, flatter pistons, and central spark plus was a much better design. The V12 needed to be smooth and easy to produce not win races like the early XK needed to do with the 120, 140 etc.
I understand the Romance a V12 offers. The mechanical and symphonic dance of 12 pistons and 24 valves smoothly going about their business is very alluring. I own two V12's myself but weight and packaging cripple high performance potential unless you have an exotic budget and since you're here and used the word "Cheap" I know you dont. It's very expensive and difficult to get world class performance from a V12 and I promise "All you need is cheap" will not get it done. Porsche bet the company on the 917 V12 project and it was close to putting them under. They pulled it out in the end but it's a mistake they wont make again.
The V12 strength is smoothness. Best to leave it there. Tinking at the margins..., making it the best it can be, yes. I had a V12 with a 6 speed and it's a very rewarding driving experiences. I will build another. The world has moved on but Romance will never die.
Yes smoothness is part of the V12 and indeed romance but not everything. First the HE head design basically followed the much earlier Chevy Six fireball design in an attempt to fire a lean fuel mixture and still pass California's Tough emissions laws. Loss of the California market would have been the death blow to Jaguar.
As far as swirl the front and rear cylinders have the best swirl but even the center cylinders aimed the intake towards the cylinder walls effecting swirl. Turbo charging forces the mixture into the chamber with a lot more energy than normally aspirated does.
When I put a pair of turbo’s I used old junkyard Saab units I paid $35 each for. The FMU was admittedly a kludge job and no way was it ever suitable for street use. It would have been fine for the Chump Car goal intended. But yes I had a car that met their $500 limit. I’d call that cheap.
I accept that no 2 valve head can develop the same power that a modern 4 valve head will, but Group 44 was able to beat the Corvettes in the national championship race. Yes a modern LS V8 can make more power than our beloved V12 but that Chevy is like belly buttons. Everyone’s got one. The person who puts the most money into his Chevy LS is going to win. Yawn!!!! What’s new?
But I get an awful lot of race quality parts in a V12. Parts that will cost you dearly for a Chevy.
So yes they are cheap! I paid as much as $300 for most of the V12’s I bought while a lot of them came to me the result of rust and cost me nothing more than the labor to get them out.
The biggest flaw of our XJS is its weight. 4600+ pounds is too much to be quick. However it can get down under 3000 if you are intent. Less, if you are willing to do the work. 2700 pounds is the lowest I got but requires your willingness to make molds and work with fiberglass. You don’t need to spend the money for prepeg and autoclave or even vacuum bag carbon fiber. No it’s not formula 1 quality but it doesn’t cost formula 1 money either.
Racing can be terribly expensive. Or really affordable. In 1986 I went to The Bahama’s for their vintage speed week. I didn’t win my class, Sir Stirling Moss did. Driving the factory Aston Martin DBR2 recently freshened up and upgraded ( according to the two factory mechanics in attendance) I finished 2nd. In my Jaguar powered Black Jack Special. I did manage to beat Sir Stirling in the Autocross event. And he was beaten in one event by Steve Kline in the Echidna.
The whole week cost me less than $900 including everything. Costs in excess of $30,000 were rumored to have been spent by both of my chief competitors.
longjohn those are NOT factory pistons, they DO have some squish turbulence ,top and bottom of chamber shape!
Aftermarket pistons do offer some potential gain. Especially in fuel efficiency and reduced smog. A well designed combustion chamber will give an improvement in power output and likely less tendency to “ping” on marginal fuel( or with timing advanced ).
The main power comes from bigger. The cylinder sleeve in Jaguar’s can be dramatically increased, that combined with offset grinding the crankshaft can increase the engine from 326 inches to well over 430 cu inches.
The rod journals are 2.300. NASCAR uses engines with rod journals down to 1.940. Accordingly there are plenty of inexpensive aftermarket rods that can be adapted. You don’t even need to have custom pistons made if you go that way.
My 6.7L uses 95mm liners so block is bored. 6.0L crank and Chev 305 KB pistons. Stock rods have small end re-bushed for Chev pins. Engine is ready to put together.
I have just been busy with the house which is nearly finished, so I'll get back to engine shortly.
Aftermarket pistons do offer some potential gain. Especially in fuel efficiency and reduced smog. A well designed combustion chamber will give an improvement in power output and likely less tendency to “ping” on marginal fuel( or with timing advanced ).
The main power comes from bigger. The cylinder sleeve in Jaguar’s can be dramatically increased, that combined with offset grinding the crankshaft can increase the engine from 326 inches to well over 430 cu inches.
The rod journals are 2.300. NASCAR uses engines with rod journals down to 1.940. Accordingly there are plenty of inexpensive aftermarket rods that can be adapted. You don’t even need to have custom pistons made if you go that way.
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but Mg can a 5.3l make 500hp without forced inductions?
we do know that turbo's cam make encridible power! GM 4 cylinder Ecotec 2.2L can actually be bought over the counter
but Mg can a 5.3l make 500hp without forced inductions?
we do know that turbo's cam make encridible power! GM 4 cylinder Ecotec 2.2L can actually be bought over the counter
A 6.0L can. This is a 5.3L with big bore kit 95mm liners, flat heads, Chev valves and custom pistons. 500hp @ 7500rpm in an XJS
My 6.7L uses 95mm liners so block is bored. 6.0L crank and Chev 305 KB pistons. Stock rods have small end re-bushed for Chev pins. Engine is ready to put together.
I have just been busy with the house which is nearly finished, so I'll get back to engine shortly.
You can do as I did, offset grind the crankshaft and use 6 inch Chevy small block con rods to pick up stroke. Jaguar rod journals are 2.300 Chevy is 2.100 so you pick up slightly less than .400 stroke. Then the pins are already at Chevy sizes. No substitute for cubic inches.
Shrug... Do us all a favor, put down the keyboard and pick up a V12 and wrench, go build something, make it work and be able to put the power down, stop and turn. Then post some picts and some performance data, ma be even prove it works on a track and post some picts and video. The world needs less pontificating and more wrenching, I've done my part now go do yours.
Forget "faskKat" He abandoned his project and sold off the parts before completion. I spoke to him,,,he went with a different car, a Pontiac G8.
I have been actively racing since 1971 ( I recently paused to build my house) on a tiny budget that means I have to do all the work myself. Because I can’t afford to just buy parts and bolt them on I’ve found cheap affordable ways to achieve my goals.
There are two basic ways to make more power. Either make the engine more efficient in the RPM you need it to make more power, or make the engine bigger. ( I suppose you can do both)
the stock linings will go out safely to 96mm. You can offset grind a stock crank to pick up almost .400 stroke. Actually .600 with the right rods.
Aftermarket pistons do offer some potential gain. Especially in fuel efficiency and reduced smog. A well designed combustion chamber will give an improvement in power output and likely less tendency to “ping” on marginal fuel( or with timing advanced ).
The main power comes from bigger. The cylinder sleeve in Jaguar’s can be dramatically increased, that combined with offset grinding the crankshaft can increase the engine from 326 inches to well over 430 cu inches.
The rod journals are 2.300. NASCAR uses engines with rod journals down to 1.940. Accordingly there are plenty of inexpensive aftermarket rods that can be adapted. You don’t even need to have custom pistons made if you go that way.
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MG: NO one can do all those mods CHEAP, that type machine work in todays world will be expensive, no matter what you may think!
have you recently been to a shop that is CAPABLE of those mods, its all custom machining(like offset grinding a V12 crankshaft), and destroying the surface hardness, and finding some good shop to RE NITRIDE the surface and then rebalancing it all the components that go with a complete rotating assembly! then you have just a V12 shortblock assembly!
NA preHE heads are and always be flow restricted, forget HE heads they were always terrible for breathing,YES i know we could do this, that and the other, but in the end limited breathing!
almost forgot ancient history;; the Chevy Fireball chamber you speak about was actually a Buick design,and GM bought Buick in 1927 just to have that chamber design, for there NEW 6 inlne engine for chevy,, plus many small perks that go with a takeover business deal! pic of Chevy shows turbulence inlet area, and deep ressessed exhaust valve,(very close resemblence to the HE Jaguar FIREBALL, the Swiss guy copied from GM).
comon guy get real!
by the way good seein you back in forum ,used to be Jag/lovers back in the day,! LOL remember Kirby, me and him went round more than once , mostly about he says HP was most important, and I said give me TORQUE in the mid range , and i'll pass you every time commin off the corners!
ron
MG: NO one can do all those mods CHEAP, that type machine work in todays world will be expensive, no matter what you may think!
have you recently been to a shop that is CAPABLE of those mods, its all custom machining(like offset grinding a V12 crankshaft), and destroying the surface hardness, and finding some good shop to RE NITRIDE the surface and then rebalancing it all the components that go with a complete rotating assembly! then you have just a V12 shortblock assembly!
NA preHE heads are and always be flow restricted, forget HE heads they were always terrible for breathing,YES i know we could do this, that and the other, but in the end limited breathing!
almost forgot ancient history;; the Chevy Fireball chamber you speak about was actually a Buick design,and GM bought Buick in 1927 just to have that chamber design, for there NEW 6 inlne engine for chevy,, plus many small perks that go with a takeover business deal! pic of Chevy shows turbulence inlet area, and deep ressessed exhaust valve,(very close resemblence to the HE Jaguar FIREBALL, the Swiss guy copied from GM).
comon guy get real!
by the way good seein you back in forum ,used to be Jag/lovers back in the day,! LOL remember Kirby, me and him went round more than once , mostly about he says HP was most important, and I said give me TORQUE in the mid range , and i'll pass you every time commin off the corners!
ron
I didn’t know that story about the Buick head. I remember in my youth working on the old fireball head Chevy and thinking what an awful head design. Only later did I read why that design and why it made Chevy outsell Ford.
With regard torque vs horsepower. I have to agree with you the old 3.8 Jag six with the long 4.17 stroke would keep me even with some pretty powerful engines even though I was a hundred or more horsepower down from them.
Once past my competitor the Old Black Jack got very wide and Those brakes would allow me to get much deeper than my competition. Anybody trying to out brake me, I’d let by because I knew they’d go off, or be so out of shape it was easy.
The first thing I did when I built my racing V12’s E type was offset grind the crankshaft. Back then it was only slightly over $200 including rehardening the crank. Then I bought two sets of Chevy H blade type racing rods from Jegs. Forged pistons only cost $63 each from Aries. I narrowed the width of the Chevy rod base to fit the Jaguar journals and narrowed the bearings to fit on my old converted flat belt drive vertical mill. Both projects didn’t even take a whole morning to do.
Porting by then I’d figured out how fast I could do it on the vertical mill. The hard part was figuring out the XY axis so it was a straight shot with the ball mill. Straight shot down from the top of the intake port to the intersection of the feed up from the valve seat. Then blend together the intersection by hand. I used 2.02 Chevy intake valves I modified to fit on my beats.
The exhaust port stock flowed 90+% of the intake stock so those remained untouched even after I did the port work on the intake side. since exhaust only needs to flow 80% of intake.
The first thing I did when I built my racing V12’s E type was offset grind the crankshaft. Back then it was only slightly over $200 including rehardening the crank.
. The crank grind was cost me nearly $3000. I bought a 6.0L engine for about the same cost.
. The crank grind was cost me nearly $3000. I bought a 6.0L engine for about the same cost.
Part of the advantage of knowing which machine shops are capable of doing work is I doubt even today that work would cost even 1/4 of your cost.
With a $3000 budget I’d go buy a wrecked/ or burned 6.0. Whole car, part it out, and sell off what I don’t need.
Yes for a week or so I’d have an extra car in the shop, but that’s the cost or racing on the cheap.
The reason I ask is the earlier oil pumps are not big enough to handle additional stroke at high RPM
about 1990 Jaguar increased the size and rerouted the oil. Since I was racing I just used a big Weaver 4 stage dry sump pump. I doubt you’ll want to go to that effort and cost. Rob Beere sells a bigger oil pump to take care of that issue.
Last edited by Mguar; 09-03-2019 at 07:33 AM.
Reason: Additional information
Part of the advantage of knowing which machine shops are capable of doing work is I doubt even today that work would cost even 1/4 of your cost.
With a $3000 budget I’d go buy a wrecked/ or burned 6.0. Whole car, part it out, and sell off what I don’t need.
Yes for a week or so I’d have an extra car in the shop, but that’s the cost or racing on the cheap.
The reason I ask is the earlier oil pumps are not big enough to handle additional stroke at high RPM
about 1990 Jaguar increased the size and rerouted the oil. Since I was racing I just used a big Weaver 4 stage dry sump pump. I doubt you’ll want to go to that effort and cost. Rob Beere sells a bigger oil pump to take care of that issue.
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MG a 4stage dry sump pump and tank fittings(TODAY is over $2500. bucks, times have changed) and you cant buy an old Jag with that stuff already in it(unless you are a mirecal worker)?
and that RB oil pump is very expensive also!
ron
Part of the advantage of knowing which machine shops are capable of doing work is I doubt even today that work would cost even 1/4 of your cost.
With a $3000 budget I’d go buy a wrecked/ or burned 6.0. Whole car, part it out, and sell off what I don’t need.
Yes for a week or so I’d have an extra car in the shop, but that’s the cost or racing on the cheap.
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Problem is I'm in Australia and 6.0L cars are rare. I bought my engine from Norman Lutz who is also doing the wrenching as he has the machining contacts and knows these engines well.
6.0L jaguar cars are very rare in Australia. In all the time I have kept a eye on the obvious website here in Aust, today was the very first time I have seen one advertised Presently for sale in Esk (QLD) on Gumtree.
MG a 4stage dry sump pump and tank fittings(TODAY is over $2500. bucks, times have changed) and you cant buy an old Jag with that stuff already in it(unless you are a mirecal worker)?
and that RB oil pump is very expensive also!
ron
Back when I bought the Weaver pump the 6.0 hadn’t come out yet, but by around 1990 Jaguar had put that bigger pump in the 5.3. European bound Jaguars especially German. Had a revised oil system but I don’t know when that began.
Used wrecked or burned 6.0 sell for as little as $300
Yank the engine out and there’s your solution. Then you’ve got all sorts of parts to sell off. With the floods Texas had there were plenty of flood cars. They donate great engines. Some that were sold, sold for scrap metal prices ( about what burn cars sell for ) while the upholstery and wiring are trash the sheet metal and mechanicals are usually decent. ( can you say race car? ) 😁
We have both major insurance auction places here, plus I watch the local dealers like a hawk. There is a spot where they roll cars with estimates too high to be repaired. Most of them know me by name, a couple seem to have me on speed dial. A transmission is usually scrap point on sedans. Or major electrical suspension or sometimes just brakes etc.
08-31-2019, 11:27 AM
