. MG get it together, the bare block WITHOUT liners is 96MM,, liners bring it back to 90MM, and some can be bored to 92MM!

BUT also block bare block can be bored to 98MM and special liners installed, and bored to 94mm, and then some!

LOTSA money, the only thing that beats cubic inches is cubic money, OR BOOST!
ron

 

If Ron
Of course you are right. I brought my first V 12 (XKE ) out as big as I could, bore and offset ground crank. Weber’s and piper cams ported heads. 1.90 intake valves 1.50 exhaust
My 2nd V12 I took a stone stock junkyard motor that had sat for decades pulled the pistons and using the stock rings opened the end gap up and put everything back together. Then I put two Saab turbo’s (T2’s) under the fenders reclocked them and modified the stock Fuel injection and came within a whisker of 500 hp. ( with E85 I would have been over) That one I put a Jaguar 4 speed from a 4.2 XKE on . By Chumpcar rules I had less than $500 in the car.

My next V 12 using a early Flathead 7.8-1 compression I have a 250 cu.in. Roots type blower I’m putting on top of it with a Jaguar reversed and modified carb manifolds to hold it. I’ve already mocked it up and everything works and fits. On top of the Roots type blower I’m putting the big Holley 1200 CFM carb. Since I can have any grind I want made, I want to try to duplicate the one used on the last Offy Indy cars. The short stroke ones. Pull it back a little bit since I’ll only go to 7500-8000
but they made some monster power back then. Using Lots of boost. 800-1050 hp.
I’ll use gas filled O rings from the turbo charged Datsun Z cars. Since the bore will work. That’s going in my MGT series with Jaguar suspension and frame.

My final V12 will have the 6.0 and chopped off Fuel injection Manifolds. I’ll weld a piece of Aluminum angle on the end and put 3 Strombergs per side. Duplicate the Piper cams I used clean up the HE heads to somewhat reflect the Heads Lister used. XJS will be my track day car.

 

Hi Mguar your supercharged V12 project sounds interesting, can you please post up some pic of this engine and the turbo V12 engine. Thank you.

 

!

Hey MG , Stromberg Carbs. are you talking the Ford 2 barrel type Strombergs??.
ron

 

No I’ve got 8 Strombergs off Jaguars. ( side draft) I need to use those instead of the better SU’s in order to fit under the hood. I’ve got a few tricks to lower the engine. If you use the stock carb manifolds in a XJS the tops only clear the hood by an inch and a half on the front. That’s using the Dog Legs Jaguar used on the XKE which cost 30+ horsepower by themselves.
Huffaker used the Strombergs on their E type when Group 44 used SU’s. But claimed 50 more horsepower than Group 44 had. Tullius agreed that Huffaker had more power.
I’ll make sure they will work with alcohol by soaking all the rubber/plastic parts in 100% pure alcohol for a year to check.
I think I’ve still got a couple rebuild kits on the shelf.

 

The turbo XJS was sold, not fancy or pretty to look at. It was a cheaper rusty car built for Chump Car racing. Since there is no minimum weight I got extremely aggressive with a hole saw and a dimples. Anything not absolutely required was torched off or dimpled.
The windshield was the only glass and no chrome. The exhaust went from the stock Iron manifold up a U bend into the turbo and then straight into a hole in the inner panel to the manifold.
The super charger engine is parts but if you don’t mind dirty dusty parts pictures I’ll send you some. If that’s what you want.

 

Mguar, it was actually the supercharged engine I’m most interested in. Yes please post photos.

 

Rear view

 

Mguar, that is going to look very interesting. Will you be able to access the spark plugs with this configuration? What’s your timeframe?

 

Yes. I checked it out. My main concern was could I adjust the timing, while it’s awkward it can be done. However I’ll have to pull everything to re-index it.

I’m still building my house ( and I do mean I’m ) and as soon as the punch list is finished I’ll lay out the car on the chassis jig. I’ve done enough scratch built cars to know that this will take me about 2500 man hours. It seems the more equipment I have to do the tasks faster, the more complex the job becomes ( because now I can do this and this, oh and this too!!!!! )

 

that supercharged set up looks for a inline 6 cylinder?
ron

 

Good eye. I bought it because I was tired of so called Vintage Chevy powered car that had recent NASCAR Chevy 350’s under their hood. Try as hard as I could the most I could pull from my 258 cu in six was slightly over 300 horsepower to some 650+ horsepower. I adapted the blower to fit my Jag motor but was later forced to sell. The new owner wasn’t prepared to buy the supercharger, so I kept it.
I’ll yank off the SU’s and weld up a new manifold. Presto chango something over 500 horsepower in a less than 2000 pound car

 

Superchargers only need cooling if•••• the boost goes much over 6 psi. The rpm of the supercharger is more than 5% over crank speed.
You can effect cooling most easily by supplementing charge with windshield washer fluid. ( water and about 10% methanol ) GM sold it for their turbo charged engines in the 1960’s.
Or using E85 gasoline. 85% Ethanol 15% gasoline. Ethanol adds about 10% power gai. dramatically cools the inlet charge* and has 114 octane rating compared to premium gasoline at 92- 93 octane. * on a cool evening frost will form on the intake.

 

If you want bragging rights buy something new. Whatever you’d like. But be prepared to accept that anyone with a decent credit rating can have its duplicate. Plus the joy of ownership is quickly surpassed when the next big thing comes out.
Several people here recognize how Unique a V12 is and have put their heart and time into making it better or at least fit their goals.
My goal isn’t some number, my goal is a result that I create. I have three Jaguar V12 engines. Given to me free out of wrecked rusted or transplanted cars. Sitting on my shelf are a few sets of gaskets from when I bulk bought when I was racing. ( they’ve been collecting dust since ) hopefully a set of rings and grind the valves. I’ll be out of pocket a little over $150.
One car was a $500 Rust free Southern California car. That’s going to be my track car goal is to have it on the track under $2000 total
The other I’ll weld together out of scraps of metal to resemble a MGTC. ( with a supercharged V12)
since I’ll want 19 inch wire wheels that might be more expensive.
Really it’s about how much can I do with how little.

 

really its about how much YOU can do for so little??

like the old sayin,"how fast do you want to go EQUALS how much money you want to spend".

 

Yup!

I've always admired to know-how and enthusiasm needed to make the big HP numbers.

Personally, and now more than ever, it's SO easy to simply go out and buy a car that has tons of performance, I'm less inclined than ever to spend thousands re-engineering an engine . For less than $10k (sometimes much less) you can buy a car that is as quick/fast as track cars and high-end exotics of not-that-long ago. Nowadays, Grandad's Toyota Camry V6 will outrun any of the cars in the magazine article !

I'm just getting old and lazy, I guess

Cheers
DD

 

Nothing wrong with that approach. Most people do it. Only weirdos like myself and a tiny handful of others even know how.

Post WW2 that’s what started the hot rod movement. Few guys who wanted to go fast on modest budgets. That turned into the sportscar craze and led to muscle cars etc.

Few young people will even see performance cars as crowding turns transportation from freedom to a chore. My grandchildren will wake up tell the computer what time the car should arrive and where they are going.
“Oh look dear, they sent a green one again”.

 

think you guys need some quad cam heads for your v12,

 

At the risk of sounding brash, is this thread dead? I've looked it over in general and it seems that we have yet to see anyone that has made any real power from the street version of the v12 except Ronbros and Warrjon. Without being insulting there seems to be a lot of speculation with nothing to really benefit the individual who really just wants to get the most out of their engine without a humungous outlay of cash.
Can we forget about comparing our v12's to everything else? Can't we stop comparing apples to oranges? Everyone seems to want to compare an engine that came out in 1972 with 2012 standards, does that make any sense to anyone?

Let's compare apples to apples shall we. 1974 FI v12 Jaguar puts out what, 270 hp and the HE version put out 290? Something like that and Chevrolets premier sports car of 1974 put out 195-250 hp depending on the version of 350ci that you chose and if you bought the big block you got a whopping 270 hp. Wow! I'm sooo impressed (NOT). Let's move on to 1982 for comparisons. We know what the HE v12 put out, how about the Chevy? A whopping 200hp across the board. Fast forward to 1990 and the standard vette has 245hp and finally you have a ZR1 that gives 375hp with a 32 valve twin overhead cam engine to get it there. These figures are from the Corvette black book that I have.

Funny that someone a while back mentioned the Buick Nailhead as I happen to own one of them too. So I guess I have two obsolete engines. But I have to say that I don't agree with the idea that a sharp curve in the exhaust port kills the flow. Exhaust is under pressure and can turn some pretty tight corners my exhaust ports flow 177 cfm at max lift and that's a lot considering the tight curves that it has to follow. (has anyone here ever seen a nailhead exhaust port?)
With due respect to XJRxxxx I likewise don't accept that what TWR or Group 44 had done with respect to intakes and heads is the end all of making decent improvements on these engines. It takes a total approach, albeit a reasonable one to make these engines come alive, be competitive, be satisfying and reliable at the same time.
Maybe we should make a new thread asking "what have you ACTUALLY done to make good power from your v12"
I think virtue, if I got his name right has a good intake setup, warrjon has what looks to be reasonable modifications to an HE cylinder head and others have good ideas about ignition mods, especially using a megasquirt setup, which I do have myself. I have yet to start something with the 6.0L that I have but I do believe that there are plenty of things that can be done to improve the breed as it is.
Perhaps some can share their practical improvements that have worked for them without all the theological outpouring of the shortcomings of the engine, as that is a useless exercise. The fact is that any engine can be brought up to more modern standards to make it much improved over the old tech that used to make it run. Case in point: the flathead ford, who knew? right?
As I see it, the items that are within reach are: lighter rods and pistons, proper intake length, better camming, better exhaust, exhaust tuning, injectors, ignition, proper gearing, maybe a mild stroke of the 6.0L crank using arggghhhh (gag me) chevy rods and perhaps a manual trans. I forgot, slight head modifications.
Of course this isn't necessarily all to be done at once but can be done progressively. Can someone else add to this list? Or tell us your success in doing some of these items.
I'm interested in knowing if warrjon has finished his 6.7L engine yet and how it is working out for him. I think that all of us are interested in what works, is tried and true. And I don't think that we are interested in engine swaps as this is the wrong forum for it. That comes under lumps, take your LS over there (nothing personally against them)
Let's keep it real and maybe naturally aspirated too, as I don't think that many here are looking for boost (nothing wrong with it) we just want good running, decently powered up v12's.
I'm sure this will generate some backlash but we need facts and proven combinations not philosophies and conjecture. Of course scientific approach with regard to applicable modifications is good, even necessary. We just need them to be of help, not explain why something doesn't work, that's not beneficial. The breed can be improved, that's a fact. Let's all get it there.

 

We need definitions and explanations. For example what does cheap mean? $500, $5000, $50,000? And does that include labor, or is it DIY?

What does easy mean? Sit on your easy chair and push the Red Button? Strip the car and put it on a rotisserie? Something in between?

Finally what is the purpose? Nice drive on a sunny Sunday afternoon? Or diving inside a competitor in an out braking maneuver ?

With regard to horsepower, Your comparison with the Chevy and Jaguar isn’t correct. One is gross or advertised horsepower while the other is DIN net horsepower.
When talking about horsepower please remember the difference.
Finally, your summation is pretty complete but to really be complete you point out what each costs and nets.
For example lightening the rods makes the engine more responsive but no additional horsepower. That’s not theory, I’ve built race motors and put them on the track to prove their validity.
With regard to costs, it really depends on a whole lot. For example I took the stock rods made a jig and milled the counterweights off the rods.

I don’t know what that would cost to have done, I do know the finished rods while good weren’t particularly light or strong. While they held up ( and are still are last I saw) but to be fair the engine was turbo’d not normally aspirated which puts greater stress on rods.