In reply to Keith Tanner :
Sort of. Who would be so different as to take a engine conceived in the early 50's to go against a engine created almost 50 years later?
Then using a roots type blower against modern turbo's?
Finally topping it off with a carburetor? instead of EFI?
I could make the excuse that they are all things I already own and have been paid for for decades. Or on a fixed income I can't afford to buy new.
The real truth is I'm convinced I can turn all that junk into a fun car that will perform surprisingly well. Much better than the costs involved
In reply to frenchyd :
What's going to break if you put the combo together and it fails? Probably won't hurt the blower or carb. Likely a piston if the tune is off or the bottom end (rod or bearing) if you push it too far. Are do you have spares ? Will you be heart broken if it blows up? If those answers are yes and no then why not try and report back?
In reply to 1SlowVW :
The bottom end is stronger than you would ever believe. The crankshaft and rods are forged EN 40 steel and then hardened. V8 crankshafts tend to weigh in that 25 pound range while the V12 is 78 pounds.
The block is all die cast aluminum. Topped with 34 studs per side for the heads. Many of those studs go all the way into the crank web. The main caps are forged steel with 4 studs per cap.
Most V8's that size have about 2.00 rod journals Jaguar uses 2.30 and 3.00 mains even though the stroke is only 2.75. Compared to about 3.50 for V8's Rod bolts have 12 point nuts made of high grade steel.
It is unbelievably strong. If you've ever seen a 9000 horsepower top fuel block from the inside it looks like that with 4 extra cylinders.
I right now am down to 3 spare V12 engines. But since I pay a max of $300 for a good one. It's not a big deal. Jaguars tend to be reward cars. Successful businessmen buy it as their last car drive it carefully and maintain it by the dealer. When they pass it may sit with low miles for 20-30 years before it's sold for peanuts because they can't get it running.
Oh, and in all of my racing since the late 60's I've never lost a Jaguar engine. In fact I can often get 2 decades or more before I need to freshen them.
frenchyd said:
In reply to 1SlowVW :If you've ever seen a 9000 horsepower top fuel block from the inside it looks like that with 4 extra cylinders.
One of the customers I used to deal with had a bent top fuel rod hanging behind the counter in his shop...maybe it's a reminder that no mater how good your gear you still can't get greedy.
It sounds like the only problem area may be pistons? I would start with the low compression combo only because it gives you more room for error in tuning. Once you have it tuned put the high compression motor in pull a few degrees timing and put the meth to it and film the burn outs for us.
What do we need to say in this thread to get you to put this monster together ?
In reply to 1SlowVW :
I like the way you think. The best head/pistons are the 1971-1980 versions. 7.8-1 compression but fantastic flow.
The later 11.5-1 compression motor makes the same power but gets about a Mile per gallon better fuel mileage ( combined with other improvements works out to be about 5 miles per gallon better.)
The early one is what all the race cars used. And they made over 830 horsepower on French pump gas for the 24 hours of LeMans. The later ones were meant to meet California smog laws. ( although the bottom end is just as stout.)
Stock pistons tolerate over 8 PSI boost without issues.
I have less than I year before I finish up building my house. At which time the chassis jig is coming out and I'll start building my last race car.
The latest episode of engine masters has a supercharged BBC making 1500hp on e85 and nitrous. Only 8.3:1. Food for thought.
In reply to barefootskater :
In reply to yupididit :
In all honesty, it was a BIG shot of N02, but still. Made over 1100 without. I'd be willing to bet that's more power than frenchy needs. More than I need, anyway.
barefootskater said:
The latest episode of engine masters has a supercharged BBC making 1500hp on e85 and nitrous. Only 8.3:1. Food for thought.
I'll never make 1500 horsepower. Not when my total budget on the engine will be $100, hopefully less.
Oh, I do intend to use all the junk sitting around but I am a crafty old geezer with more than a few tricks up my sleeve.
But making flash numbers on a dyno isn't anything I'd care to do. I realize it's all the fad now. Then I look at costs involved and wonder how long it could sustain that level.
My goal isn't to make flash readings on a dyno. Rather to spend the tiniest budget and have the resulting engine perform well at various race events and go back on the trailer in the same shape it originally was repeatedly.
In reply to frenchyd :
Reusable on a budget usually means low stress, which is just another reason to opt for lower compression.
Im just excited to see what you end up putting together either way. I've only ever driven one jag 12, and it still sticks in my memory as one of the best sounding engines I've ever heard.
And I'm with you on not seeing the light in regards to dyno queen engine building. It should be noted though that the engine in that video was used to set several records at bonneville and then screwed up to 1500hp. Pretty neat stuff.
barefootskater said:
In reply to yupididit :
In all honesty, it was a BIG shot of N02, but still. Made over 1100 without. I'd be willing to bet that's more power than frenchy needs. More than I need, anyway.
I get a big kick out of finding cheap or free ways to increase power.
Jaguar's V12 is designed to be smooth. Balancing a coin on an engine at idle is a common way to show off. But to do that Jaguar puts a balance pad on the top and bottom of their connecting rods. It adds nearly a pound per connecting rods.
Yes you can buy racing prepared connecting rods. And save more than that pound. But I've made a simple jig that I can use my drill press to remove those pads, saving that pound. ( times 12)
With that weight gone more than 18 pounds can be removed from crankshaft counter weights. While that requires the use of my lathe to carve that off and since that would take nearly 18 hours because it's a small manual lathe.
But for zero dollars I made my engine lighter and able to rev quicker. Running numbers through the computer program Tells me that a more radical cam profile can be used. Since my local cam grinder can give me any profile for the same price. That promises me an additional 34 horsepower over the 62 extra horses my first shot at regrinds would have yielded.
He has a profile used on turbo Offenhausers that if I have enough lobe to copy will yield another 18%
He charges me the same price as grinding any 6 cylinder engine times the two cams that need grinding.
In reply to frenchyd :
A luddite that runs numbers through a computer program to calculate what cam profile he can use. 
In reply to yupididit :
You got me. But to be fair in the 1960's & 70's I'd buy whatever Cam was the latest thing in Hot Rod magazine. Put it in and see if it was faster. Surprise surprise a lot of those were just advertising.
When the 80's brought computers along I started learning how to use them and started making my decisions based on what the computer told me.
In those days I'd build an engine and take it to the dyno shop. Once the dyno shop consistently confirmed an engine within 2% of what the program said. I stopped using the dyno shop. I kept using their flow bench to get flow numbers until I could repeat flow numbers myself with my shop vac and unisyn.
By the late 90's I was pretty much done doing cars and engines for others. But I kept most of my stuff.
Having spent more than 20 years building my house I'm ready to build one more car. While I know the potential is greater using turbo's and Fuel injection. I don't have those.
so I'm being a Luddite.
