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ozzie831
ozzie831 New Reader
8/7/19 1:36 p.m.

In reply to frenchyd :

Oh ok. I didnt know that. But that does make sense. 160 sounds way better as a marketing tool haha.
But i know those 4.2s pretty well. My first car was a 1990 XJ6. I used to drift it around my High School parking lot haha. My buddy had a 1989 E30 with the 2.5L Inline 6. It was funny to compare the 2 different sizes. 

Im not too worried about resale value. I just really needed a project. Stop sitting on my butt so much. Found this bad boy for $1500 so anything I do to it will only be an improvement.

 

frenchyd
frenchyd UberDork
8/7/19 2:16 p.m.

In reply to ozzie831 :

I’m glad you’re bringing the Jaguar back from the dead. Those are handsome, elegant  cars and for the price you paid you sure got a great deal.  You’re right it’s your car, do as you wish. 

If it were mine I’d put a V12 in it and slide the suspension from the same sedan underneath.  It will fit and work nicely.

 As far as gross and net horsepower the XKE claimed 265 horsepower from that engine but I never saw much over 200 and some of those had cams, pistons and Weber’s.  

The only trouble with the early 4.2 Jag motor is it doesn’t like high revs.  Factory redline was 5500. With that long stroke ( 4.17 ) that was really screaming.  Later newer engines tolerate high revs much better.  

 

ozzie831
ozzie831 New Reader
8/7/19 2:34 p.m.

In reply to frenchyd :

They guy I bought it from had a couple old jags. He had a Rallye version Mark VII that he had restored. Im pretty sure he took the engine and transmission out of this car since it was the M version with the more HP and manual transmission. But he also had a couple other cars including a Mark 1 that probably got sent to the crusher since he was moving. That's how I got this car.

I just want something a little newer with some more juice. This is a suuuper heavy Yacht. Also I wanted to get some newer stuff like AC.... It gets pretty toasty here. Especially since its supposed to be a comfortable cruiser when its done

Vigo
Vigo MegaDork
8/7/19 2:42 p.m.

The engine is fine but the transmission is on the weak side in the GM Trailblazer, Envoy, etc. 

They're not weak, they just need to be built to take big power. But, we're not talking about big power. Any 4l60 derivative in any  kind of good condition is going to take 4.2L of naturally aspirated torque until the end of time. 

As far as love for the trailblazer engine, the reason more people don't think about them in my opinion is that not that many enthusiasts have gotten into a 6 cyl trailblazer and rode it all the way to 6000 rpm. The thing that makes it cool is that it already starts with the shape of powerband that v8 owners are replacing camshafts and manifolds to get to. If 4L of torque and 300hp on the top end is good enough, it is a very pleasant engine!

Brett_Murphy
Brett_Murphy UltimaDork
8/7/19 3:51 p.m.

If you want a 300HP inline 6, you could always import one of the Ford Falcon engines with forced induction from the Australian market.

I'm in the keep it all jag camp. FrenchyD can probably offer lots of advice.

dherr
dherr HalfDork
8/7/19 4:03 p.m.

I got your drive train right here.... NMNA but found this in Facebook this morning.

https://www.facebook.com/marketplace/item/411418402922166

MotorsportsGordon
MotorsportsGordon HalfDork
8/7/19 11:25 p.m.

Small block chev is probably your easiest option. Here is a jaguar x120 with a 350 and th350 transmission.

frenchyd
frenchyd UberDork
8/8/19 12:46 a.m.

In reply to MotorsportsGordon :

An unaltered XK 120 is worth north of $150,000 

 

frenchyd
frenchyd UberDork
8/8/19 1:08 a.m.

In reply to ozzie831  I was going to mention that. The heaters in those were marginal in extreme cold and no there never was a factory A/C  

For that I would suggest going to the hot rod aftermarket. They have simple and really efficient compressors,nice controls and dash units.  

Then use the modern insulation kits to deaden sound and keep the cool inside.  

You will be surprised at how much Jaguar sedans of the 70’s-80’s & 90’s weigh, a lot more than that 1955 sedan does.  The little XJS COMES IN OVER 4600 pounds!  With the XJ12 over 4800 pounds.  Plus people, luggage,  and fuel!   

While we are talking about it, both the front crossmember with springs shocks steering rack, swaybar etc. and rear suspension cage simply unbolt.  

Want modern world class ride and handling? vented disk brakes, rack and pinion steering, swaybar shocks, etc. unbolt and slide it all under your MK8. Then do the same to the rear cage.    It’s been done already,  both in England and New Zealand. You can’t tell from the outside it was done!  

The MK 8 has 5x5 inch bolt pattern same as older Cadillac, Buick, Oldsmobile. But 16 inch rims.

Later XJ6 & 12 plus XJS use 4&3/4 X 5 wheels same as Corvette and Camaro  first 15 and later 16 rims.   

The V12 is really narrow. Anyplace you can fit a six into will take a V12.    And while it’s heavy it’s 30 pounds lighter than the 4.2 six. ( it’s all aluminum )  plus the post 1977 versions used the GM  turbo 400 the heavy duty version found in ambulances and tow trucks. 

 

 

 

frenchyd
frenchyd UberDork
8/8/19 1:16 a.m.

In reply to Vigo : I sure agree that that motor really pulls nicely until about 3500rpm at which time it comes alive!  It really loves higher RPM  but apparently not the transmission. 

Mine went a little over 120,000 miles before dying. It was dealership serviced per their schedule. I used it as a traveling salesman and racked up about 85,000 miles a year.  I normally get 250,000-300,000 miles out of a transmission before rebuilding. 

In the shop doing mine were three others. Conversations with other owners indicated failure at less than 150,000 miles was common.   To be fair this was the early days. Later ones may have been beefed up?  Although I find many junkyard ones have bad transmissions. 

Maybe it’s the deep snow we get or the added strain of 4WD? 

Curtis
Curtis UltimaDork
8/8/19 7:42 a.m.

I would genuinely consider a Jag V12.  The engine itself is pretty bulletproof, but the injection or carbs and the electronics were the troublesome parts.

Everyone does a V8 swap, so if I were doing a V8 I would make it something really oddball but still can get parts.  Rover?  IH?

If you want oomph, do a slightly warmed-over 4.9L Ford I-6.  It came in carbed and EFI variants.

Another oddball would be a slant 6.

Atlas is nice, but I really don't like them.  They have a VVT system that I hate.  The cam advances in steps, so during part throttle acceleration there are surges as the cam steps up.  They also sound like a vomiting sewing machine.

Any of the 80s-90s Toyota inlines would be bulletproof.

Opti
Opti Dork
8/8/19 9:58 a.m.

I'm not gonna lie I didn't read anything but the first post so this may have been mentions, but atlas 4.2 all the way.

 

Around here you can pick up ratty trailblazers for a few hundred bucks and can hear then engine run.

dropstep
dropstep UltraDork
8/8/19 10:17 a.m.

Ford 300 i6 with header and a 4 barrel intake would be my choice. If you want too get real rowdy you can do a cam swap and big block Chevy 1.6 ratio rockers. Not to mention fordsix.com has every bit of information you could ever want about them. Durable as a rock and commonly backed by the Ford c6

nimblemotorsports
nimblemotorsports Reader
8/9/19 5:12 p.m.

Subaru Flat 6 is the only answer...that is sure to be the wrong one.   OK, a porsche flat 6 is even wronger.

Other than that, my advice is get a whole nother car and swap the body onto it.

stuart in mn
stuart in mn MegaDork
8/9/19 11:20 p.m.

The Jag V12 seems like a good choice to me.  

cdeforrest
cdeforrest Reader
8/10/19 12:44 a.m.

My vote is keep it Jaguar, whatever the generation. That's the least of your problems. Based on your username, I'm guessing near Santa Cruz, CA? If so I could point you to local resources. 

frenchyd
frenchyd UberDork
8/10/19 3:19 a.m.

In reply to cdeforrest :

You are absolutely right. Over 50% of Jaguars total production wound up in California.  The state and area is a rich resource for all things Jaguar with the added benefit of their smog laws.  Plenty of good solid cars can’t meet smog requirements because few people really understand how simple the Jaguars are.  

With shop labor over $150/ hr and plenty of padding because of owners ignorance.  Paying someone else to keep your toy running gets stupidly expensive.  

There are several great and free sources of information, Jag lovers website, U tube etc.  and the cars themselves are wonderfully engineered with amazingly stout components.  

If you open enough junk engines up you’ll quickly see how strong and well made they are.  High mileage engines with absolutely no ridge wear in the cylinders. Bearings sized 40-50% larger than required.  The forged crankshaft made of EN24 steel( same as Cosworth F1 engines ) that are tuft hardened to an astonishingly hard number.  I’ve seen an engine that had actually melted the bearings when the owner drove it without oil.  Not only was the crankshaft not junk it didn’t need to be turned!!!!!!!!!! 

So called “ experts “ want to remove a 284 horsepower all aluminum V12 to replace it with 160 horsepower Chevy 350 because that’s an engine they think they understand or can find someone to fix it for them.  

yupididit
yupididit UltraDork
8/10/19 8:58 a.m.

In reply to frenchyd :

If "few people really understand the simplicity" of Jaguars, then are truly simple cars? Or are they simple TO YOU because you have so much experience with them? Just think about that. 

Also, modern engine swaps aren't taking out the v12 for anemic 160hp sbc 350's. LS series engines are the Chevy v8 flavor to swap in. 

You gotta stop polluting every jaguar thread with your opinions as facts. You provide some true knowledge of these particular cars and that's awesome. But then you ruin it by adding in some old man dribble about made up nonsense. 

frenchyd
frenchyd UberDork
8/10/19 11:04 a.m.

In reply to yupididit :

If an old geezer like myself can figure out the system , can it really be that complicated? If you want there are several U tube programs on the system to watch that do a nice job of simplifying everything. The rest is nut and bolt stuff. ( even American sizes )  the ignition works the same as any car, just 12 spark plugs instead of 8-6-4  

The nice thing is you don’t have to figure out rocker arms, push rods, or hydraulic lifters.  Plus even the worst carburetor used on them is massively simpler than any 4 barrel. 

As for swapping in the new style Chevy engines. They require fuel injection.  If you can figure out how to do that why would you swap one system for another? With the stronger market for Jaguar it Pretty much eliminates a lot of swaps. 

As far as cost of running, used Jaguar engines sell for about what modern Chevy’s do. Then you’d have the added  cost of adapting one to another. A Corvette with a Ford motor won’t sell for as much as a Chevy motor will. Neither  will a Jaguar with another motor 

yupididit
yupididit UltraDork
8/10/19 11:28 a.m.

In reply to frenchyd :

Nope! Not going back and forth with Frenchy. I said what I said.

Antihero
Antihero SuperDork
8/10/19 11:58 a.m.

I came in here to say Cummins or other diesel swap, make it a high class rat rod. But since that's off the table....

 

I say i6, the ford 300 is an awesome smooth engine and would be easy to find. Maybe turbo it for more fun?

frenchyd
frenchyd UberDork
8/10/19 12:20 p.m.

In reply to yupididit :

Sir,  I bow to you.  With 27,356 postings that makes you #6 on the list, I lag almost 23,000 behind you.  

With only Jaguar and MG T series interests I will never catch up.  

Yes I’m willing to share information on Jaguars and having worked professionally on them. Successfully raced them for decades and owned many  cars and around 50 engines I might be in a better position than you when it comes to knowledge. 

yupididit
yupididit UltraDork
8/10/19 1:48 p.m.

In reply to frenchyd :

I'm not SVreX he's #6. 

 

Daylan C
Daylan C UberDork
8/10/19 1:51 p.m.

TIL I have more posts than yupididit. I am now really confused by frenchy's post.

captdownshift
captdownshift PowerDork
8/10/19 6:59 p.m.

I'm glad that you don't want an I6 Cummins as I was thinking 4BT before you got to what you were looking for. It won't have the HP you're targeting, but it will have the torque and will last 400,000 miles 

 

If not wanting to go diesel, I'll say a 2.3L Ecoboost

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