I read somewhere that the standard liners can be bored safely to 92mm and Volvo pistons can be used.

 

Stock bore on both the 6.0 & the 5.3 is 3.543 (90) any bigger than 3.675 (93.345 )and you will need custom head gaskets made. Plus, Size of the pistons really doesn’t pick up a whole lot of power. Assuming everything else is the same, in this case maybe 3-5 more horsepower.
A serious increase in stroke is very straight forward and yields power in the more street friendly region of the RPM band without the need for serious head work.

Real affordable power is gained at higher RPM with intake ports opened up and straightened out. ( the exhaust already flows too much) Now add a serious improvement in the camshafts. Stock for all Jaguars is .375 (3/8ths) .500 is starting to get there. But duration needs serious improvement as well.
The intake ports are just too small to make power, Hand port work is too laborious and too prone to errors unless done on a vertical mill. I’ve spent over 140 hours trying to get the ports to flow enough and equally. First time I did it on a vertical mill I cut it to 20 hours and the flow numbers were better and closer to equal.

 

So Mguar you are advising that a 92mm bore can use a stock head gasket. If S10an needs new turbo friendly pistons and a rebore picking up another 0.3l ain’t going to hurt.

 

i other words a lot of careful machining and careful assembly! so a well equipped machine shop would be requierd ?
MG have you recently had any V12 camshafts made?
you may be in a shock of costs in todays market?

 

To get much over .410 lift you cannot simply reduce the base circle by grinding. You either have to build up the lobes by welding or start with a fresh Billet.
The later is too expensive for me to consider while the welding process is still going to be plenty expensive

 

That i agree ,costs in todays market have changed consisderably!
i used to buy Custom made piston to my specs for $75/80. a piece now they are more than $200 each , custom designed!
multiplied by 12 =,2400. plus shipping, without pins & locks!
ron

 

.
my cams measured .400 lift at specified lash! Hmm? Crane cams regrinds!
ron

 

.400 lift is still .025 more than stock. The lack of longer duration will still allow it to be civilized on the street.
But heck even my billet cams with monster lift and massive duration would sit there and idle smoothly at 750 RPM. the advantage of a V12 and it’s firing every 60 degrees instead of 90.

 

AAHH yes ,the smoothness of a V12 engine, MG i owned 2 Lincolns with V12 engines when i was 15yrs didnt run, and another when 16 yrs old(got my drivers license in it!
you were only around 2 or 3 yrs old!?
gotcha.

 

https://www.terrysjag.com/product/SA1771MSET.html

this sounds rather affordable if a reboore is not considered.
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in combination with HE heads the compression should be ridiculous low.

 

I just recently saw my first Lincoln V12. ( the famous Hot Rod Lincoln of rock and roll fame ) While I knew they existed I’d never seen one before.

Yes, I guess somewhere around that age. You’ve got 10-12 years on me.

I built my first V12 in the 80’s. Patterned after the Huffaker V12 roadster. It seems like I was paying in that $40 a piston from Aries. But I bought 4 sets well, 50 pistons to get that price. He let me change pins. pin heights etc. I also bought 12 gaskets sets. Heck, I bought a lot at bulk or distributor prices. I used those low prices to attract buyers who always wound up having me do the builds.
I’d rather make little or nothing on parts and get flat rate time on labor. I had a high school kid who worked with me cleaning parts. He was meticulous about cleaning parts and because he was extremely near sighted could see dirt or problems I’d need to use a magnifying glass to see.
Then when it was ready he’d lay everything out on white butcher paper. I’ve still got a picture I took because he was so obsessed about laying everything out just So!
In 2000 the last couple dozen V12’s I had had to go away. I was tearing down my shop, building new so I sold them all for scrap metal prices. ( I did keep 3. Plus a few nice parts.)

 

HEY time changes ALL things , and we havent seen anything YET!
some scary **** on the horizon of the world order!
ron

 

s10n that is a good price , BUT they are not custom designed for a hi performance engine!
also they are cast pistons, not recommended for BOOST applications!
HE heads are known to lose flow rate as rpm goes up, but just maybe boost could help that design push more air into cylinder(that is what we are trying to do?)!
ron

 

still looks pretty for 25yrs old

TORQUE APPLIED
quote " build it and they will come".
we all will be awaitin.

 

I know I'm sick and getting old, but I'm not interested in boost or large-scale horsepower increases, nor am I interested in haunting junkyards for pre-HE heads or a crash course in programming to make a Megasquirt setup work. I'm interested in minimizing cost. I'd like to use as much of what I've already got as possible (5.3L HE engine with a few bad pistons/liners, Marelli ignition, factory cams) and minimize the amount of machining required. What's getting hard to source are pistons and liners. Sounds like the word is now that Chevy 305 pistons won't work without 6.0 liners and block machining or a custom crank - so that's out. Any other ideas?

 

Alcohol picks up more horsepower for lower cost than anything else. Switch the injectors. Right now the good premium gas costs $3.15 a gallon. E85 is $2.09 Gas is 92 octane but gets you stock horsepower. E85 is 100 octane and gets you 10% more. Kent /Piper cams will throw that combination up another 35-50 depending on if you can gear the car to use it. Nope, not gonna be any automatic or most gearbox kits
You don’t want to go scrounging for early heads, OK I’ve got three sets, make me a decent offer. but only if you promise to buy a set of proper Cosworth pistons.
If you use those early heads take them to a good machine shop with the right ball mill and go to work on the intake ports. If the shop knows what they are doing they will put them on the vertical mill and you’ll have spent about 20 hours ( leave the exhaust port and valves alone).
The proper set of headers ( not something off someone’s shelf ) will pick you up 5%. If the back end is big enough with the right mufflers.
So far everything is streetable.

 

Found a set of forged pre HE pistons that will give 9:1 in a American version. Since pre HE are flat heads I guess it would be same in European versions. Question is what this would give in a HE.
replacing the cylinder liners with aluminum liners would increase heat transfer and it would be possible to increase the cylinder pressure slightly without experiencing knocking.
alcohol has way lower heat value than petroleum so either needs increase injector duration, higher flowing injectors or increased fuel line pressure. Fuel consumption will increase, but it's much more tolerant towards knocking, engine will run cooler. It can run much richer since the fuel itself brings oxygen atoms into the combustion. 1,5 times the amount is needed for same power.

 

From that I assume you are in Europe rather than US.
game changer.
Can you find an affordable source for Ethanol alcohol? If so you can still pick up the power. Incidently here in America, serious race cars like Indy cars or NASCAR. Etc use ethanol alcohol for added power.
Alcohol also burns so much cooler. And cleaner. After a while season of racing there would be zero deposits in the combustion chamber

Yes you need bigger injectors. That’s why it was one of the first modifications I listed. More power= more fuel.
Don’t mess around with aluminum liners. GM tried it Mercedes tried it Jaguar tried it. Nobody succeeded.

Don’t whatever you do use Methanol alcohol. It’s nasty stuff, splash some on your clothes and your skin will absorb it, attacking your internal organs. Splash some in your eyes and bye bye seeing. It attacks aluminum if left for more than 24 hours( plus other metals. Oh, if you drink some? You die!
Ethanol on the other hand is what’s in beer wine and booze. Drink some and you get foolish.

 

If you want the feeling of much better performance you’ll have to change 2 things. The rear end to a post body restyling rear end with the outboard brakes, Not for sake of the brakes, ( although they are much better and far easier to work on),but because instead of your 2.88-1 rear end ratio you will have a 3,54-1 which you need for the next change. Dump the automatic. Sorry, you need a clutch pedal because you’re going for the 5 or 6 speed gearbox.
Then pull your ECU out and send it to AJ6 engineering. Tell them you’re going manual.
The only other thing you can do inexpensively is get the car lighter. Stock it weighs nearly 2 & 1/2 tons! In stock configuration you could make another 100 horsepower and barely feel it!!!

 

well that's a truth with modifications.
about all racing two strokes use aluminum liners.
all f1 cars of the 80's turbo area except BMW used it. Unless you really need to get rid of lots of heat they are hardly necessary. If I'm not mistaken lots of liners got bad quickly because some countries had sulphur content in the fuel that was high enough to be harmful to the coating.