Hi Bob, great information! I'm binge watching your channel now that I've discovered it. I'm putting a Pre HE V12 into a XJ6 that I purchased that is missing an engine and tranny. I live in NW Iowa, glad to hear you're "in the neighborhood" I just picked up the engine two days ago, so I'm in the beginnings of cleaning, inspection and ultimately, testing. I love your engine stand...you should sell those, but with a geared handle for easier rotation. Cheers!
Very informative video and something to consider whilst buying a V12 jag. Are there any warning signs of both the aluminium corrosion and overheating to consider?
Thank you for the kind words. As far as corrosion in the block is concerned, the only indicator that I can say is reliable is the overall condition of the vehicle. If they can't vacuum the interior they aren't going to do the regular maintenance. If a car has had several owners that likelihood increases. Overheating can be witnessed only by driving the car though I will say if the oil it's been leaking is baked onto the side of the crankcase(hot oil being the source of many overheating issues) it's probably been overheating. Which opens up a whole other can of worms.
These engines must have thermostats with "jiggle pins" to bleed air from the coolant. Most parts stores are unaware of the small but important difference.
I've got a few thoughts on the cyl head repair. 1. would pre-heating the cyl head before welding help. 2. Would stitch welding this help... i.e. welding just a pool on one side.. then the other.. and spacing it out so that not so much heat is applied at one time to one area. 3. Why not just muggyweld it... braze that sucker with some 800F filler rod after cleaning the pits out.
Preheating the head would definitely help. But it’s hard to find someone with a big enough oven. Though I could have bought one for $600 a couple of years ago. No room for it. 😬
Hi, could the voltage between the coolant and any proper ground be an indicator how well the system is protecting. 0.3 volt is ok above 1 volt is the danger zone for 6 cilinder jags.
Shops do it all the time, but in my opinion there are plenty of other issues in the engine bay besides head gaskets that are more easily handled with the engine out of the car. Everything is so much easier engine out.
Great video,but going to have to disagree on your conclusion.Ive had many cylinder heads,engine blocks,intake manifolds welded and I've always had good results. In fact my current xjs project has had the cylinder heads welded.
Prior to 1980, the combustion chamber was in the top of the piston like common diesel engines. After that, the HE engines had the chamber in the head. The 6.0L engines combustion chamber was similar but a bit bigger.
thither is a YT guy with engine machine shop built his own gas grill head modified straitening rig not all that hard and it works well .makes sense to me
May’s simply copied the Buick fireball head of the 1930’s. Yes. Because it was a lean burn engine, it got better fuel mileage. About 1 mpg. Better.*. The real reason for adopting the Fireball head was about air pollution. California was adapting increased restrictions on the amount of pollution an engine could emit. Loss of the California market would have bankrupted Jaguar. * The extra fuel mileage came from other sources such the more efficient transmission ( GM turbo 400 ( with 2% slippage) replacing the Borg Warner (5% slippage) plus a change in final drive ratio from 3.31-1 or 3.11 to 2.88 . Also improvements in the EFI the first system ( Bosch) to later systems. Changes every 3-4 years.
Hi Bob, great information! I'm binge watching your channel now that I've discovered it. I'm putting a Pre HE V12 into a XJ6 that I purchased that is missing an engine and tranny. I live in NW Iowa, glad to hear you're "in the neighborhood" I just picked up the engine two days ago, so I'm in the beginnings of cleaning, inspection and ultimately, testing. I love your engine stand...you should sell those, but with a geared handle for easier rotation. Cheers!
Good luck with your project. Keep us informed.
Excellent information sir. Thank you.
You are welcome
Thank you for this excellent content Sir!
Very informative video and something to consider whilst buying a V12 jag.
Are there any warning signs of both the aluminium corrosion and overheating to consider?
Thank you for the kind words. As far as corrosion in the block is concerned, the only indicator that I can say is reliable is the overall condition of the vehicle. If they can't vacuum the interior they aren't going to do the regular maintenance. If a car has had several owners that likelihood increases. Overheating can be witnessed only by driving the car though I will say if the oil it's been leaking is baked onto the side of the crankcase(hot oil being the source of many overheating issues) it's probably been overheating. Which opens up a whole other can of worms.
seen your issue in australia as well - it is a maintenance issue clogged radiator not enough inhibitor lots of oxide = no cooling
These engines must have thermostats with "jiggle pins" to bleed air from the coolant. Most parts stores are unaware of the small but important difference.
Correct.
I've got a few thoughts on the cyl head repair. 1. would pre-heating the cyl head before welding help. 2. Would stitch welding this help... i.e. welding just a pool on one side.. then the other.. and spacing it out so that not so much heat is applied at one time to one area. 3. Why not just muggyweld it... braze that sucker with some 800F filler rod after cleaning the pits out.
Preheating the head would definitely help. But it’s hard to find someone with a big enough oven. Though I could have bought one for $600 a couple of years ago. No room for it. 😬
It should still be restrained regardless.
Hi, could the voltage between the coolant and any proper ground be an indicator how well the system is protecting. 0.3 volt is ok above 1 volt is the danger zone for 6 cilinder jags.
good question to look into this coming season.
Wondering how realistic it would be to replace the two head gaskets while the V12 is still in my 89' XJS?
Shops do it all the time, but in my opinion there are plenty of other issues in the engine bay besides head gaskets that are more easily handled with the engine out of the car. Everything is so much easier engine out.
Once the heads are off, if their is anything I can reasonable do to increase the horsepower?
The $100 V12 Overhaul Challenge series shows some porting clips.
Great video,but going to have to disagree on your conclusion.Ive had many cylinder heads,engine blocks,intake manifolds welded and I've always had good results.
In fact my current xjs project has had the cylinder heads welded.
Did they restrain the head?
I’ve had minor welding done without a problem. But these pits were halfway through the head in the middle and took a ton of welding.
welder just went too fast
What engine did the cylinder heads that have the larger combustion chamber in it?
Prior to 1980, the combustion chamber was in the top of the piston like common diesel engines. After that, the HE engines had the chamber in the head. The 6.0L engines combustion chamber was similar but a bit bigger.
Is it possible to have one of those heads cmc Machine?
I'm currently looking into it but it's looking expensive.
So JB Weld is not a solution?
It is often the solution. ;-)
thither is a YT guy with engine machine shop built his own gas grill head modified straitening rig not all that hard and it works well .makes sense to me
worth a look.
May’s simply copied the Buick fireball head of the 1930’s. Yes. Because it was a lean burn engine, it got better fuel mileage. About 1 mpg. Better.*.
The real reason for adopting the Fireball head was about air pollution.
California was adapting increased restrictions on the amount of pollution an engine could emit.
Loss of the California market would have bankrupted Jaguar.
* The extra fuel mileage came from other sources such the more efficient transmission ( GM turbo 400 ( with 2% slippage) replacing the Borg Warner (5% slippage) plus a change in final drive ratio from 3.31-1 or 3.11 to 2.88 .
Also improvements in the EFI the first system ( Bosch) to later systems. Changes every 3-4 years.
How about restrain and use some of the low temp Aluminum braze alloys like ruclips.net/video/fKIKsDfRAcs/видео.html ?