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Nathan JansenvanDoorn
Nathan JansenvanDoorn Dork
10/25/16 5:58 p.m.

Mark, you stated (generalized): "I think either you like one or the other. Don't think many would like both." I think many here would like both - that's what Cotton was replying to.

HappyAndy PowerDork
10/25/16 6:02 p.m.

This is silly

Cotton UberDork
10/25/16 6:06 p.m.
markwemple wrote:
Cotton wrote:
markwemple wrote: In terms of sound, I hate a US v8, other then a gt40 for some reason, and all v12s are wonderful. Chevys are cheap but Im biased against them. Personally hate the old LS swap. I think either you like one or the other. Don't think many would like both. Opposite ends of the scale.

I don't know many that shun one or the other. I like both and have both (v8s and v12s) along with many other types of engines. Not sure why some 'car guys' feel the need to be so single minded.

So I have to like the sound of a v8 to be a car guy. WTF! We all have opinions. I also hate the sound of a Merc v8. Audi and BMW v8s are ok, except the BMW V8 in the current US endurance races.

What are you going on about now? I was talking about the comment you made in regards to people liking one or the other in reference to v8s and v12s, but 'don't think many would like both'. That just seems odd to me.

Regarding sound, I do find it funny that a guy that's into AC VWs, as I am, complains about the sound of other engines, but like you said we all have our opinions.

markwemple SuperDork
10/25/16 6:22 p.m.

Sorry I misunderstood your reference. Its kinda like f1 and Nascar. I know some like both but its usually one or the other.

Nick (Bo) Comstock
Nick (Bo) Comstock UltimaDork
10/25/16 6:28 p.m.

It's very rare that I find an engine Note that I don't like. I like most V8s, I4s, flat 4s and 6s, straight 6s, V10s, V12s sound good but very very few V6s sound good to me.

Out of the Chevy V8 vs. Jag V12 I don't have a front runner. If be fine with a V12 Monte Carlo or a V8 XJ.

frenchyd Reader
10/28/16 11:41 p.m.
Flight Service wrote: Is there a question here or just a statement as to why you are conflicted? Chevy Pros: Cheap Easy to find parts cheap almost receipe book easy to make power cheap common so help at the track is easy to find cheap V8 sound cheap Chevy cons: V8 sound common V8 vibrations Jag pros: V12 smoothness V12 sound exclusivity Jag Cons: Power down compared to weight costs not as much support In your examples, the Jag had a better setup/chassis and suspension. Despite all the bragging from the US/Vette/Bowtie faithful, the C3 and C4 Vette were E36 M3 in the chassis department and needed all the help it could get from under the hood to be competitive.

I find Jaguar V12's all the time around $300. Many times for less. Occasionally I'm just given a broken or rusty sedan with a good engine (or one that needs very little to be good).. The early (1971-1978) V12 had a horrible Borg Warner transmission. The cost of rebuilding one of those transmissions put plenty of good V12's in the junkyard.. But those early ones had the best heads.. Heads all the racers want because they flow so much better than the later H.E. heads.. Parts are readily available from several sources such as XK's Unlimited and on par (price wise)with any decent performance part for a Chevy V8 Power to weight? Well yes and no. The V12 was first introduced at 317 horsepower or 271 or 242 depending on which pollution laws it had to conform to.. Same engine just different rules.. However it originally used carbs rather than the fuel injection it was designed with. In order to fit the carbs under that swoopy bonnet the manifold wanders around up and down like a drunken snake. Chop off the worst of the manifold and pick up 50 horsepower. Replace the Strombergs with S.U.s and there is another 25 horsepower..

OK The Chevy small block does weigh in over 200 pounds less. But power wise you need the Big block (454){and then the weight does get much closer} to equal the torque and due to pollution requirements most small blocks were decidedly weak compared to the V12 especially the late 70's 1980's and even into the early 90's

frenchyd Reader
10/29/16 12:11 a.m.
edizzle89 wrote: In reply to frenchyd: you are also talking about teams that, even though they only had a few months to sort there engine, still had a lot more money then you or I (I assume) to make it fast and reliable (the whole 'pick 2 of the 3 thing') So really it would come down to, do you have the means to make a jag v12 push ~450 hp and still be reliable? At the end of the day pretty much anyone who has ever done a basic engine rebuild could make a 450 hp SBC with the right combo of parts, and its always going to be easier and cheaper then getting 450 hp out of the v12. Not trying to knock the v12, its hard to knock the sounds of a smooth running v12 at full tilt. If i had the means i would do a v12 over a SBC, but the small block will always be the easy button over the v12

To make a stone stock V12 1981 or newer make an honest 450 horsepower you would only need to replace the injectors, and replace the distributor with the early carbureted distributor.(even better would be to find a 1980 European spec distributor) Now run cheap E85 pump gas.. Price wise I can buy V12 engines cheaper than small block Chevy's In fact I've paid as little as $50 for a good one. $300 is my upper limit.

But the real point is while there is really nothing wrong with a Chevy small block, it's hard to get excited about one unless the owner has spent a lot of money with the pretty and go fast stuff. To make a V12 pretty, remove the pollution stuff and polish all that aluminum! It's already got forged crankshaft, 4 bolt mains, forged con rods with floating pins, etc. etc. no need to replace all those parts. Plus the camshafts come indexed so you could advance or retard them 1&1/4 degree per tooth!!! It even comes with a tool to set the cam timing properly.

As for easy? A V12 isn't hard to work on.. No push rods, no rocker arms, carbs so simple little boys can work on them.. and for those who have difficulty counting all the way to 12, Jaguar doesn't.. it's 1-6 left and right bank. In decades of working on those engines I have yet to see my first ridge worn into the bore.. If you did you can slide the iron liner out and slide a new(er) one right back in place.. no need to re-bore. Unless you want to make it bigger Yep you can take a little 326 cu.in. engine out to 500 cubic inches without buying a new crankshaft or doing anything to the block

frenchyd Reader
10/29/16 12:24 a.m.
Stefan (Not Bruce) wrote:
frenchyd wrote: I like Chevy small blocks. I prefer Jaguar V12's. Aside from that prejudice you should know all my life I've been a racer and that is the perspective I view the conflict from. In 1974 the Corvette small block met head to head with the Jaguar V12.. S.C.C.A.'s run offs in Atlanta The best Corvettes in the country took on 2 independently prepared Jaguars. The Corvettes came in with decades of development by thousands of racers from Factory efforts to backyard guys.. However the engines had been developed in Trans Am, Can Am, NASCAR, IMSA, NHRA, Indy Car, Sprint Car, and many other venues since 1955. Group 44 and Huffaker only had a few months to sort out their Engines and develop the chassis for racing.. In the end Group claimed 450 horsepower to Huffaker's 475.. yet there in the front of the pack were two Jaguars.. And yes The Jaguar won the run-offs that year.. Group 44 also won the I.M.S.A. title in 1977 & 1978 and again chased a Trans Am title in 1981

Sure about that?

Looks like it wasn't until 1975 that Tulius and co were able to beat the Corvettes at the Runoffs (or Champion Sparkplugs Road Racing Championship as it was known then):


Basically they showed up without much development time, lost to more experienced teams/had some bad racing luck, worked on the cars for a year while campaigning them and when they came back, they were much better. Shocking.

1974 Showdown

A brief history of the Bill Jobe Corvette (which wasn't a 1974 model with its smog restricted V8):

1969 BP Corvette

An excerpt from a brief history of Group 44 racing:

Bob Tullius, Group 44

Into the ’70s Tullius and Group 44 raced a variety of British Leyland cars including the TR4, TR250, TR6 and GT6, adding to the trophy case with success in SCCA regional and national events. But as the TR6 became less competitive in its class, Group 44 looked to the V12-powered Jaguar XKE in the B Production class. It took time to convince Jaguar to take the car racing, but the company finally decided to back Group 44 on the East Coast and Joe Huffaker on the West Coast.

It took Fuerstenau and crew chief, Lanky Foushee, 3500 hours to turn the E-Type into a racer. In its first race in 1974, Tullius was leading at Watkins Glen with three laps to go when the gear shift lever broke off in his hand. But he won the next five races in a row and just barely missed the championship win.

The following year, Tullius had to face off against Huffaker Engineering’s factory-backed XKE at the SCCA Runoffs. Lord Donald Stokes, managing director of British Leyland, came to witness the showdown. But the other XKE met its demise on the pace lap, and Tullius went on to take the championship.

Tullius then took Jaguar to another series, SCCA Trans-Am racing. They claimed the season championships in 1977 and 1978 in an XJS.

Couple of corrections, First it wasn't the Jaguar factory that sponsored Group 44 rather the US importer. As far as 3500 hours to convert a stock XK-E into a race car, that's about what I spent on mine, in fact that's about what I've spent on getting every race car race ready.. Now granted I had the advantage of following Group 44's lead. On the other hand I'm no where near as professional nor do I have the same level of equipment they do.. Third rumor has it the reason the Huffaker car broke it's rear end is they failed to put oil in it.

yupididit HalfDork
10/29/16 12:26 a.m.

I'm going to just go ahead and say this; I think Frenchy smoked too much jaguar v12 exhaust these past 40 years.

frenchyd Reader
10/29/16 12:32 a.m.
NickD wrote: In reply to Flight Service: That V8 sound is subjective too. I personally rank that as a pro, V8s are the best sounding engine. But yeah, same points other than that.

V8's have two problems. The first is the second order harmonic (roughness) caused by adjacent cylinders being from 90 to 270 degrees apart in the firing order. Unlike the smooth firing of a 60 degree V12. Second you don't hear 8 cylinders in a V8 you hear 6 and a stumble.. With a V12 you hear all 12 cylinders because of it's even firing. That's why when you hear one unmuffled you'd swear it's turning 1400 RPM but a glance at the tach will show 650rpm

patgizz UltimaDork
10/29/16 8:28 a.m.
wheels777 wrote: I guess I'm going to be kick out of the club. I love listening to all engines....V8, V6, V12, V10, V2, V4, Straight anythings, Hit and Miss, Steam, Diesel, Flatties, Subies, all. The only engine sounds I don't like knocks, pings, grinding and silence.

+1000. Except 4 cylinder hondas with ebay cannon mufflers

Robbie UltraDork
10/29/16 3:48 p.m.
patgizz wrote:
wheels777 wrote: I guess I'm going to be kick out of the club. I love listening to all engines....V8, V6, V12, V10, V2, V4, Straight anythings, Hit and Miss, Steam, Diesel, Flatties, Subies, all. The only engine sounds I don't like knocks, pings, grinding and silence.

+1000. Except 4 cylinder hondas with ebay cannon mufflers

I even like those when I'm driving em!

bearmtnmartin Dork
10/29/16 5:46 p.m.

I think it is great that gt can pump the tires of a non gm product. Makes me want one. They are all great motors, but variety is the spice of life. Chevys are done to death.

Hey frenchie/mguar, you wouldn't be GT from the Sideways Technologies site would you?

frenchyd HalfDork
9/13/17 12:55 a.m.
kanaric said:

I am not a huge v8 fan either. I prefer straight 6 engine and SOME V6 engines sound. V10s as well, they actually might be #1 for me.

However I wouldn't say v8 is a con lol. It is one of the better sounding engines.

A LeMans GT40 just had a 289, same as a Mustang, so...?

He must like how long tube headers sound or something lol.

The reason a V8 has the sound it does is because the interference . adjacent cylinders fire from 90 to 270 degrees apart

jag V12 on the other hand fires every 60 degrees so you hear all 12 cylinders not six and a stumble 

at an idle the V12 sounds like it's at 1500rpm but the tach will tell you it's at 600

yupididit Dork
9/13/17 8:52 a.m.

Do you just like search the forum for v12 and reply to these post, my man?

Im going to annoy the hell out of you when I finally get me a v12 Jag!

frenchyd HalfDork
9/13/17 3:41 p.m.

In reply to yupididit : I have spent a great deal of time messing with Jaguars and MGs 

i read a lot of other postings but can offer little or nothing .  I wish I could figure out how to post pictures because they say a picture is worth a thousand words 

then my postings would be few words and a picture 


yupididit SuperDork
9/13/17 4:02 p.m.

I'll post your pics of you can't figure it out.  


I upload to imgur then go to share links. 

frenchyd HalfDork
9/15/17 7:50 a.m.

In reply to Flight 

Well I hate to ruin a good myth but power on the Jag V12 is very comparable to the Chevy of the era.  

First it has more torque than the Chevy big block even though most were only 326 cu in  The reason?  A V8 will have two con rods at or near 90 degrees while a V12 has three!  

Second the firing order of a V8 forces adjacent cylinders to be anywhere between 90 & 270 degrees. That causes an interference on both the exhaust and intake side.  

Unlike the V 12 which has a firing order that allows an even 60 degrees between firing.  

You can hear it in the exhaust. At idle a V12 sounds like it's turning 1500rpm because you actually hear all 12 cylinders with a V8 you hear 6 and a stumble. 

As far as weight goes considering how easy it is to take a V12 out to  big block size weight is very comparable to a Chevy big block 

Some other facts,  put away your metric wrenches, that's right standard American SAE size hardware.  Also the transmission and rear end are also American.  Early auto's were Borg Warner Then GM turbo 400 and finally A GM 4 speed overdrive.   Since the turbo 400 line-up pins are the same as a manual transmission it's easy to make an adapter plate for American 4-5-6 speed manual transmissions 

finally if fuel injection and computers scare you,  they make and sell a manifold that takes two Holley four barrels.  

As far as costs go, no it's not expensive  especially considering what you get.  A good rebuildable core sells in the $300-500 region while running engines are $1000-1500.  

To get the same thing in a Chevy you'd need a whole bunch of ARP bolts, studs, and fasteners.  Plus an Aluminum block strong enough to handle well over 800 horsepower An aftermarket forged crankshaft  Aluminum heads Aluminum timing chain cover Fined aluminum valve covers etc etc etc 




7/9/18 8:40 p.m.

In reply to frenchyd :


In reply to frenchyd :  I know it's been a while since this post but I have a few questions.  I am planning a project for my wife (in her her mid fifties).  It will be a 1956 Ford F-100 (her choice).  At first I was planning a cop car frame swap but it looks like everyone has done it so it would be nothing new or different.  


I've loved the Jaguar V-12 since I was a kid and now I'm exploring the possibility of using a Jaguar V-12 along with front and rear suspensions in my truck project.  I will be doing most of the work myself except for specialty stuff.  I was an auto trans mechanic for many years a long time ago although I will be making this a manual five-speed.


I want to make good power and don't mind stroking to 427 (like that number - it will look good engraved somewhere) and want to use two or four turbos.  Looks are as important as power.  My wife will be the only driver and it will never be raced of course.


My questions are:


1.  What year would be a good donor car?


2.  What size turbos would work for a two or four setup?


3.  What stuff could be eliminated?  The truck's battery and brakes are under the floor board.  I want a good clean look under the hood.  I plan to ultra detail the engine.


4.  Can I stick with the stock cam if it's stroked to 427?


5.  I read you recommend early head on a 6.0.  Will valve sizes need to be changed?


6.  Is it possible (easily) to transplant from and rear suspensions?


7.  Any other suggestions you might have?

frenchyd SuperDork
7/10/18 10:08 a.m.

In reply to MARKUSA :

Great questions each one of them!!  

Donar car year?  Let me lay out the good of each batch of engines plus the bad.  

1971-1978( mid year) Transmission is Borg Warner( yuk!) what’s worse  the alignment dowels are too small and none of the holes line lup so it’s the hardest to fit a manual transmission to.  

Late 1978-1997 all used the GM 400 turbo or overdrive version so adapting a 4-5-6 speed is easy. No the Chevy and Jaguar  bell housing is different so you will need to make a adapter plate but that is just about transferring hole locations. Uber simple to do!  Ask, I’ll walk you through the steps. 

Pistons.  1971-1972 9.0-1 compression. Good to turbo. Late 1972-1980 7.8-1 compression great for turbo’s 

1981-1991 11.5-1 compression. Very hard to get good enough fuel to keep from burning up the pistons.  

1992-1997 11.0-1 compression. Marginally easier to run on E85 pump fuel. 

Heads. 1971- 1980  the best heads for power but if used on later engines custom pistons must be made!!! 

1981-1991 recessed intake and exhaust valve.   11.5-1 compression with stock pistons.  

1992-1997 recessed intake and exhaust valve.    11.0 compression with stock pistons. 

Distributor. 1971-1980 good basic distributor  nice advance curve. 1981-1987 same basic distributor but designed to retard under certain conditions. Very handy when under boost 1988-1992 different design some reported issues.  1993-1997  crank fired ignition

I’d use the stock cast iron exhaust manifolds  they only weigh 4 pounds each (4) and unlike a V8 engine headers only give a slight power gain because of the even exhaust pulses. 

recommendation?  Well in a perfect world I’d take a 1978( late) 1980 That way you can avoid buying pistons and still have a good transmission. 

But if you’re going to rebuild it?   I wouldn’t, Take it apart to check on things?  Sure but most parts likely can be reused if you are careful.   Early 1971-1980 heads on a 1979 or later block.   

I’d use 2 T3 turbo’s with built in Waste gate  last E bay price was $127 each.  

Get rid of the air pump and lines. , I’d also loose the Lucas alternator. Use one of those tiny Japanese alternators instead. If you are not going to A/C the truck get rid of that big ugly York compressor. If you are going to A/C I’d still get rid of that ugly thing and replace it with a Sanyo.  

The Power steering pump is just a GM but racers use the pump body with a remote tank for a little cleaner look. 

If you plan on a pair of Turbo’s I’d take two butterfly assembly’s off the Jaguar 4.0 six  and adapt those. Then to make your life simple in the future I’d dump every Jaguar fuel injector sensors and switch to GM plus I’d use the fuel injectors off the Chevy/GM 5.3  with flex fuel.   ( get 12 of them or two used sets from the junkyard about $35-45 a set)  you’ll have to get creative to adapt  them but down the road you’ll never have to wait for parts) 

Dont waste your time using the stock Jaguar ECM  no way to tune it or make changes.  Buy a mega squirt or other aftermarket ECM.  

But fuel injection and turbo’s aren’t the only answer.  I’m putting a roots blower on mine. Relatively straight forward to do and you can use one or two Hollies  for simplicity. Very traditional hot rod look with an interesting twist. 

frenchyd SuperDork
7/10/18 11:17 a.m.

In reply to MARKUSA :

Yes the stock camshaft will still be fine. Even if you stroke it.  Personally I’d build it stock.  Then either turbo or supercharge it.  

Twin turbo’s stock you’ll be making 550 + hp. And 650-700 ft pounds of torque

Supercharged with say a GMC 671 type blower the numbers will be slightly less but still awesome. (ps, Holley makes carbs set up for supercharger). 

frenchyd SuperDork
7/10/18 11:32 a.m.

In reply to MARKUSA :

The front and rear suspensions unbolt and can be a real  straight  forward  mount on a truck. Bolt pattern is a Corvette/ Camero 5x4&3/4 

careful though, the final drive ratio on most Jaguar is  2.88.  That means it will be hard on the clutch to get rolling especially with taller truck size tires.  And in 6th gear you’ll be doing 60 mph at an idle!  

In other words it will seem bog slow!!!!! 

Jaguar sedans and XJS have the same basic assemblies.  Pre 1980 most will be 3.07 a few were 3.31. After 1992 they went to the better 3.54 but any XJS 6 cylinder had a 3.54 and any 6 cylinder sedan after 1988 also had a 3.54 

Brakes. Wilwood makes calipers that bolt right on and they are cheaper than new Jaguar calipers and not that much more than the cost of proper rebuilding them. Inboard  disk brakes up to  1992 outboard after.  

frenchyd SuperDork
7/10/18 12:00 p.m.

In reply to MARKUSA :

How much should you pay for a Jaguar?  A rusty unrunning roach is worth 3-$500 tops. It’s been more than a year and prices might have gone up.  But anything over a grand keep looking.  

Yes buy. the whole car. you’ll need the tachometer for sure and it’s nice to have all the instruments matching.   The seats on a Jaguar are really nice and comfortable.  Don’t worry if the leather is hard they can easily be cleaned with leather conditioner and then treated with Leathereque. It might take 3-4 applications but each time it will get closer to that original buttery feeling that is so beloved.  

There are plenty of undamaged seats out there so don’t waste time on badly torn or worse seats.  Minor stitching issues ( mines got two) are a cheap and easy fix. And a color change isn’t that hard for a skilled upholstery guy

rslifkin UltraDork
7/10/18 12:01 p.m.
frenchyd said:

In reply to MARKUSA :

Brakes. Wilwood makes calipers that bolt right on and they are cheaper than new Jaguar calipers and not that much more than the cost of proper rebuilding them. Inboard  disk brakes up to  1992 outboard after.  

Unless you get the rear end out of an XJ40, in which case the outboard brakes start in 1988.  

frenchyd SuperDork
7/10/18 12:53 p.m.

In reply to rslifkin :

You are correct. Hard  to list every variation without getting too confusing.   But if going with Wilwood you can use their rotors or go from the normal .83 to 1.25  

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