When it comes to tuning I’d like something that I can connect together and have it fire up. Then using my laptop tune it to my requirements.
I’m not the guy who tunes to the ragged edge of destruction. I built my Chump Car using used T2’s. Because the absolute most boost I could get was 8psi. I richened the whole mixture up and then using a $85 FMU turned on the cold start injectors as boost went over 2 psi aided by an after market fuel pump i
Yes it was crude

 

Smart is never crude.
Dave

 

If you try to run an HE on carbs unless you richen up the mixture you can get what called a stratified charge. Part ignites, part doesn’t and the ne t go around it will cause preignition. ( resulting in blown head gasket.)
richen the mixtures up and it doesn’t happen but fuel mileage suffers.

The HE gets better fuel mileage on carbs than the 7.8-1 so by comparison you’ll still get semi decent fuel mileage.
8-12 mpg compared to 16-18 on FE. But the early engine was often 10 or less

 

I’m afraid you and I must disagree. For a car that is original the EFI might be worth the battle. But not for a swap. The 17 extra horsepower and one mpg difference means you have to either learn to trouble shoot your EFI yourself or pay some mechanic to learn at your expense.
Carbs are lawnmower simple. Problems? If clean remove 4 screws in the dash pot, lift it up, buy a new rubber diaphragm, put it in place return dashpot and screws. Yawn, next?
Worn throttle bushings? Send them in to be rebushed, next?
Some of the problems with the EFI. Are vacuum leaks in the 20 gazzilion miles of rubber hose going all the way back into the trunk? Corroded computer board in the ECU. Defective sensors that are NLA, Defective hall pick up in the distributor. $249.00 Cooked wires in the valley of death. Misadjusted throttle linkage.
Shall I continue?
Plus the fuel available is different from the fuel it was designed to run on and there is no way to adjust it for that new fuel . ( it runs leaner on a system already designed to run as lean as possible)

The stock EFI cannot be adjusted to deal with performance enhancers. Camshafts exhaust system changes etc etc
The carb systems have been modified to make 450 horsepower with stock(ish). Manifolds. And 480 horsepower if 2” SU” are used instead of the Strombergs.
Do not bother with Webers. While they look sexy as all get out, the hood is too close to use IDA’s or even IDF’s ( less than 3/4 inch clearance) Side draft Webers stand a better chance but you’re on your own fabrication a manifold and tuning.

 

I own (or rather she owns me) a 1975 T/Stromberg 4.2L six cylinder engine. And while it took a couple of tries 10 years ago to iron out the Strombergs, It's been a flawless daily driver since. And I don't miss the learning curve of the EFI system. And... I think the cold side of the engine looks sexy as all get out!

 

Fuel injection versus carbs? There are good arguments either way. I've had good luck with both. And some problems with both. Generally I prefer F.I.

Carbs are pretty easy, generally, but dialing-in multi-carb set-ups has kicked my butt a few times. :-) Grrrr!

Fuel injection on older cars will be more challenging as the decades roll by because of gradual degradation of solid state electronics and availabilty (and quality) of replacement parts.

It's all part of the fun of running oldie cars :-)

Cheers
DD

 

new to the site and may not be heading the right way, but how can I tell what V12 and auto trans I have. I got this as a trade and trying to figure out what to do with it. I was told it is a mid 80's but not confirmed. I am new to Jaguar so any direction is appreciated.

 

That will be the V12 HE which is hooked to a GM Turbo 400 if you look on the drivers door jam the exact manufactured date will be printed.

 

All I have is the engine and trans. nothing else. no car.

 

Easiest way is to look at the sparkplugs on one bank. If 3 tilt forward and 3 tilt toward the rear, it's a pre HE. If they are the same it's an HE. If it's an HE, it will likely have a GM TH400 transmission, and it should have a plate on the right side of the transmission saying so. It will look like any other General Motors TH400, except for the bellhousing pattern, that is unique to Jaguar.

 

OK is the transmission case all aluminum? It’s a GM turbo 400 if the case is cast iron it’s a Borg Warner. And 1977 or older.
The GM Turbo 400 can be swapped for a Chevy 4-5-6 speed manual transmission very easily.
If the spark plugs point across to the other side then it’s an HE.
If the spark plugs have washers it’s a pre HE ( 1980 or older ) if they don’t and are tapered it’s an HE 81& newer.
Both engines have the same horsepower. The HE is limited to a max of about 450 hp. While the pre HE has potential for much much more.
Mechanically they rarely need rebuilding. I take a ratchet and turning the engine clockwise I make sure it turns over smoothly. Then I put it in the race car.
Stock they make 32 more horsepower than a Chevy 454 of the same age. & 102 more than a 350.
Extremely durable. The crankshaft is forged EN 30 Steel that following machine work is hardened. The rods are also EN 30 steel forgings. ( only rare Chevy engines are forged none have that quality of steel or are hardened post machine work.
They have SAE bolts of really I grade Do don’t pull out the metric wrenches. 1/2, 9/16th etc.
Don’t be afraid of EFI. Buy a Megasquirt MS 2 and connect the wires correctly . It will start and run. ( it’s self learning)
There are also carb manifolds available. 4 really simple single barrel carbs that flow as much air as a HOLLEY Dominator ( which is massively complex compared to the simple Strombergs. Honestly they are lawn mower simple.
Ask and this group will love to help you.
What are your plans for it?

 

Thank you very much for this information. I have no plans at this point. I need to check it out closer to see what it is. Whatever I do with it, could be fun. Not sure if it is something I want to hold on to, or trade/sell. It would be cool in a hot rod or kit car especially with a manual trans behind it.
Thanks,

 

Good luck whatever you do. About 20+ years ago I started collecting V12’s most I got were from a place that replaced them with Chevies.. ( ( 35 in total)
33 were in great shape mechanically everyone was just afraid of the EFI. One was ruined when the owner drove it home from an oil change that didn’t remember to put the oil filter back on.
The other was ruined because the owner allowed trash and leaves to collect between the A/C and radiator and ignored the temp gauge
The other 15 were donated from rusty cars ( I live in the rust belt ). Those were all in great shape.
For over 15 years I tried to sell them with a 1 year warranty for $995 each. Barely sold enough to pay for the ads in magazines ( pre internet days)
Prices eventually dropped to $395 with an occasional buyer. Most of them I took apart and sold them to scrap metal place.
I still have 3 complete engines and a few apart.
My point is people are terrified of things they don’t know about. You can typically buy 2 even 3 used Jaguar V12’s for the price of a used Chevy engine.
The early pre HE. Engine is starting to have a small increase in value by those who understand its potential. And the last 6.0 engines have a strong market because it makes 50 more hp than the 5.3 so people are grabbing them to increase performance.
Never buy one that has had an engine fire. Getting the heads off is a really challenging job.
With 29 studs holding each head on it doesn’t take much of a fire to make it impossible to remove.