I posted earlier that I’ve owned Chevy’s since 1955. The first car I worked on was a 1948 Chevy. My last truck was a Chevy that went 371,000 trouble free miles and 20 years. I raced a Corvette and owned 2. They are a fine value.
My problem with the swap is it’s expensive, time consuming, and not needed.
You blow up the engine in your Jaguar, why re-engineer the wrong engine in? Just buy a good engine out of a bad car. Rusted, wrecked, whatever. Dump it in and away you go.
I’ve collected 50 or so V12’s over the years. At first I was willing to pay $300 each for them but the abundance I was offered dropped that price down to $150 and I refused to accept HE’s. Those I took as a favor to the donor. Some from rusted cars ( I live in the rust belt) some from wrecks, a few because the owner was tired of issues, but a lot from engine swaps.
The guy doing the engine swaps was, well let’s just say a 305 looks just like a 350. And pressure wash and paint a used pickup motor looks the same as a new crate motor once it’s in the engine compartment and a few chrome accessories are added.

Some of those so called shot/junk motors merely needed new vacuum hoses or a loose wire tightened. Out of all of those motors only 2 were actually bad. One because an oil filter wasn’t tightened and the owner ignored all the warning lights. The other because leaves and trash we’re stuck between the A/C and radiator. He too kept driving.

I took them apart following the last recession sold the aluminum off one week, the copper off another. Steel the third week. In order to make my house payments. I only have 3 left. Plus a bare block to make a coffee table with.
But I know I can find a cheap used engine that would cost a lot less than swapping in a Chevy.
People don’t know how easy that part is.Hint, the engine was running in order for a car to get in a wreck, An engine fire ruins the wiring and some gaskets but not the mechanical things underneath.

 

MG you are aware of the most powerful V8 engines in the Universe,, Top Fuel engines , 2 valve pushrod , 8L , supercharged, very simple American engineering, based on 1950s Chrysler engine designs!

makes OVER 10,000HP , so no matter what you could ever do even with UNLIMITED Money, NEVER repeat NEVER would or could make a V12 Jaguar engine make 1/2 half that power, like 5,000HP, Nope never gonna happen!
we seem to be getting down to totally useless information, on this pissin contest about mine is bigger than yours, LOL.
ron

 

Are you absolutely sure? Never is a very long time. Ever wonder what would be powering those top fuel rails if they’d had a Jaguar V12’s to start with? The in line 6 that started the V12’ in the XJ13 are basic Hemi heads. ( minus pushrods and rocker arms ). That had 502 horsepower back in the early 1960’s. Since everything is milled from billets really how hard would it be to mill up 4 extra cylinders? Yeh it would be expensive. Probably what a top fuel engine costs. But I’ve forever right? Plus the same budget they used to develop all those top fuel engines.

 

And if we are comparing apples to apples, then let us not forget the P51 and P38's as well as the Spitfires that used V12's, they made impressive horsepower at the low rev range back in the 40's.

The V8 vs V12 debate will continue to rage, however this is a Jag forum, we love our Jags, some can afford to keep them original, some will convert, to each his own. I know which I prefer.

 

And i will have both. Nice work i say!

 

You're preachin' to the choir. I enjoy owning a V12. . Over the many years I've suggested a good used V12 as an alternative to a V8 swap. And I've oft thought that some gave up on their V12 a bit too easily, as you've alluded to, going straight for a swap when I'm pretty sure the V12 just needed some easy repairs.

But, still, I can understand that not everybody is fascinated by the V12. And until or unless you learn all the tricks they can be a PITA. All the talk about engineering sophistication, track use, main bearing studs instead of bolts, and the metallurgic composition of the oil pump housing isn't gonna change that!

There are upsides to a V8 swap. And SBCs are good engines. And swapping them into old Jags has made a lot of owners happy. They've enjoyed both the process and the end result. It's hard to argue against that.

Cheers
DD

 

While we seem to agree on most things, maybe my exposure to many decades of various repair shops gives me a more jaded exposure.
Let me explain my biases up front. Some owners are not any real prize. They neglect to do important things or cheap out and have untrained mechanics attempt to learn by working on their cars.

What makes the SBC a “good” engine is it’s ability to deal with that neglect and ignorance and still keep running.
Even swapping in the SBC though doesn’t fix the poor HVAC system ( heating, ventilating, A/C ) that a low volume producer like Jaguar saddled the car with.
Nor will it deal with wiring issues. Luxury cars like Jaguar are cursed will complex wiring systems, one area where costs were definitely cut is in the wiring.
Another area is with regard rubber products. Water hoses, vacuum lines, seals around windows doors etc.

Often owners don’t understand that the reason they are having trouble with their car is not the engine but those three areas. Yet a perfectly good engine is yanked out and replaced with something inferior in a vain hope that will somehow make the whole car better.

Finally, dealers and mechanics. They want/need to make money so parts are replaced when all that was really needed is a wire tightened. Valve jobs done when an adjustment to the fuel injection system was called for. Engines rebuilt when a seal or gasket replacement would have resolved the problem.

 

MG ever think you wont live long enough to R&D a Jag V12 to make 5000HP , with unlimited MONEY!

it took old fashioned American hotrodders , 60 yrs to get to where they are today!
ron

 

gotcha beat on how long you been playin Chevy V8s you say 1955?

i was working at a Chev dealer 1954 , and low and behold December, a new Chev V8 came in skippin, only one there me, had the ***** to get at it!
pulled covers and a dead cylinder #2 right side , one rocker barely moving,, deeper into it,it wiped a cam lobe , GM/Chev already on the problem with some very early V8s!
SOFT cam lobes , immediate changes in factory surface hardening!
RON

 

mike great change of topic, i been debating this one for many years!

what was the better engine WW2 fighter planes ,, the Most Famous GB Spitfire RR Merlin 1650 V12 engine?

or the encredible GM/ ALLISON 1710 V12 ,used in Lockheed P38s, with turbochargers?

lottsa BS lies with big wigs, back in war years, my father worked at the GE(General Electric Lynn Mass) , one day brought home a defective small wheel , i said it looked like a small WATER wheel with fins on it! (Hey watcha spec from a 9 yr old).

anyway GE and its development of the 1st USA turbochargers that worked for pressurizing the inlet manifolds!!

read about the BS with G Britain saying they were junk and wont help for hi altitude flying, we sent some P38s over to England and they took the turbos OFF, and the planes would barely fly, much less be useful ?

then read about the Pacific war (Japan) the P38s cleaned house , changing the direction pf the war, with USA Lynn Aviation division turbos!

opps, anyway about the better engine i know the Allison was much better engineering, if anyone ever gets to see 1st hand the valve train rocker and combustion chamber shapes Allison!
, i upset some by calling the Merlin 1650 has Monkey motion rocker setup, and an almost square chamber , shame on them making a 4 valve from a 2 valve head assembly!
i,m gettin carried away here! youtube 2015 RENO Air Races , VOODOO plane making emergency MAY DAY landing, listen to cockpit audio of engine tearing itself .
apart!
yup a 1650 RR, OK **** happens they for all intents, again plenty of money for that class of flying, and i have not found out what letgo inside that engine HUSH<HUSH!

RON

 

Not sure Ron, I do know that RR brought out a bigger version again and the name escapes me at the moment, it was used in the Mosquito. My dad worked at CAC here in the 60's through to the 90's, and the aircraft made there are now sought after by collectors (P51, F86 to name a couple). I do know the Merlin was a 27 litre engine, the replacement was much larger, both made under license here in Melbourne Australia.

Mike

 

In 1955 I was only 7 years old, so pulling that engine even with a neighbors helping was a really big deal. He would point at what needed to come off and which way to turn the wrench, myself and neighborhood boys would tug and pry until we got it going then slowly remove it.
Eventually we had it in a wagon and spent one whole day getting it to the welding shop 6 blocks away.
No it wasn’t a V8 it was a 48 Chevy the owner had parked at the end of the street car line. The block filled with water not antifreeze froze and cracked.
He signed the tittle and left it in the glovebox.
We, well mainly me, worked on it the whole summer with the aid of a neighborhood hotrodder.
Mike had a 27Ford roadster hotrod named Wee Weary Will That to me was the coolest car ever! It had 4 carburetors!!!!!
Anyway the welder fixed the cracked block. I put it back in Mike helped me get it running. OK I helped Mike. Big grin.

 

SO MG you were only 7 yrs old????

i kinda doubt thats true!
ron

 

Mike i dont think they put the bigger engine into Spitfires !
also some of those engines 1650s were made in USA by Detroit PACKARD motors, brass plate on side of block,like 60,000 thousand! there is a U tube Video out there !
and pilots who flew with Packard engines said they were smoother and seemed more dependable! slightly better fuel consumption.
ron

 

one of the changes of Packard USA , was in the drawings and specs , was getting rid of the Whitworth thread stuff(donno what AUS, used).
and Packs all threading was done to much simpler USA SAE threads! faster and far more accurate, for part interchangabilty !

slight off topic here, TODAY the RR Merlin engines have upgraded the connecting rods, to (of all things ALLISON con rod designs)?LOL.
ron

 

In my mind the weight issue is the big ugly here. It changes how the car preforms. I had an XJ6C with a bad engine. put a 454 in it. WOW

 

cant beat torque, horse power is a number , torque turns the wheels and gription gets things done!

for instance , an F1 engine makes around 800hp , but only around 200 lb.ft. torque, so would an 800hp engine push a Jaguar down the road!?
NO way! the transmission would be larger than the engine! old pic 1989 Camaro BBC 467" torque monster NO gription!

 

Hence the LSA -

 

If you put a Chevy 350 into your Jaguar you are giving away nearly 100 horsepower. Chevy engines from the Mid 1970’s to the 1990’s had 160-190 SAE net horsepower. Yes the rare earlier ones claimed 350 horsepower But that was Advertized or gross horsepower. Not actual in the car

Jaguar from the Mid 1970’s to End of Production had 264-319 horsepower 264 was only in America the rest of the world enjoyed 299
Now that is DIN net which you need to multiply times 1.0139 to get. SAE net.
299 DIN = 303 SAE.

 

Yes, I'm a purist. Still can't understand why someone would want to go through all the trouble of swapping someone else's engine into an XJS when he could buy a perfectly good Camaro (or a Mustang, but nobody talks about putting 4.6-4Vs into XJSs), save himself the shop time and the headaches and go driving.
Top Fuel Hemis have a life expectancy of...what? And that after 60+ years of no-expense-spared development? Any BBCs (or LSs) running in Top Fuel these days? If not, why not? Bruce McLaren had 650+HP aluminum-block 494 BBCs that would last a whole Can-Am race before the block warped to the point that they couldn't be rebuilt around 1970. For that matter why not use a V12 aircraft engine like an Allison (unlimited hydroplanes did)?
Think one of those 10,000 HP Hemis could run the Le Mans 24, or would it detonate after the first lap? The horribly unreliable Jag V12 somehow got one or two overall wins at that event. I don't think an LS motor has done that yet. SBF's done that, BBF too, but not many of those going into XJSs for some reason or another.
Hemi cylinder head is a copy of the P&W cylinder heads from the engines Chrysler built for Ford's B-24s.
IIRC, Bob Tullius won two Trans-Am titles with Jag V12s, once in the XKE and once in the XJS. Might he have beaten a Detroit V-8 or two in the process? Naaaaah, couldn't be, eh? He then won a race or two in IMSA GTP with the V12, and when he lost, generally he lost to Porsches rather than to pushrod engines of any sort.
Bigger Merlin was called a Griffon. Went into Spitfires late in WWII, Avro Lincolns and Shackletons afterward.
P-38s didn't work out in ETO because RAF controlled the fuel supply and saved all the good stuff for themselves. Turbo Allisons needed reliably 100 octane fuel, not "we say it's 100 octane, and pump it through a rag to knock the big chunks out before you fly" 100 octane. P-47s with their turbocharged R-2800s were more tolerant of junk fuel. Now, wait a minute, did that mean that the Allisons were unreliable, like a Jag V12? In the Pacific, USAAF controlled the fuel supply, so the P-38s got the good stuff, ran fine and destroyed the enemy. How could that have been? Didn't we just prove them unreliable, like a Jag V12? Oh, wait a minute, maybe they weren't unreliable, just mistreated. Kinda like a Jag V12?
Canadian Mosquitoes got Packard Merlins from Detroit. Didn't think AUS went through with building Mosquitos because the wooden construction wouldn't stand up to the climate in the South Pacific - USN had the same trouble with PT boats. Had they done so, I'm sure they would've used Packards from Detroit - shorter trip than from Ford UK in Dagenham. Oh, you didn't know that, though they said "Rolls-Royce" on the valve covers, they were built by Ford in Dagenham, home of the Cortina and Formula Ford engines? I think AUS-built P-51s got Packards, but post-war.