This was an empty case, I have looked in my 16CU and the pcb takes up whole case. Apart from the wiring this is as it will be.

 

..


now you make me envious, i'm far better at engine building and machine work!

electronics has always made me uncomfortable. like said earlier my ECU system is SDS, it works OK, somewhat dated (1994),upgraded 3 times tho.

time 1&2 used same PCB modded, 3rd time complete replacement of PCB, that really brought it up, closer resolution, and easier to tune.

same case as original! pix of ECU, and hand held unit.

 

Hello warrjon
Did you measurement volume of the combustion chamber?
What volume?
I got 31cm3 ???
Piston in liner is 15cm3
Am I right?
It is all std 6.0L
stroke 78.5mm
bore 90mm
piston cm3 15
comb camb cm3 31
gasket cm3 8.15
CR is 10.2 ???
Where did I go wrong?

 

Warrjon
I have been thinking about your chamber shape, having re-read and tried to grasp Roger Bywater's points about chamber shape in his book on engine technology, and I am interested in your thinking. I know nothing about this subject, so this is a genuine enquiry, not an "Are you sure you are right" veiled criticism, I assure you.
I can see that de-shrouding the valves will help ultimate gasflow potential of the head. I can see that with a longer stroke or a bigger bore engine CR will not be a problem and that removing metal will give no problems on that score. What I am wondering about is this (as far as I can see your pics and understand the HE system): In effect the HE head forces all the mixture into the small pocket by the plug that has the exhaust valve at its top. There is almost no space round or below the inlet valve at TDC. The bit of metal between the inlet and the exhaust forms a wall that forms one side of this pocket, and the notch in its profile through which the mixture is forced adds a "squirting" effect to the mixture as it is forced through it, and this adds swirl which helps combustion efficiency by homogenising the mixture.
Bearing all this in mind, my question is: If my understanding of your bit I have highlighted in blue above is correct, and this "wall" is removed or reduced, and no other changes are made, presumably the combustion chamber will burn mixture less well as the squirting effect and its swirl will be reduced? So are you aiming to compensate for this with (eg) a special sort of piston shape (or something else) to give a more uniformly shaped combustion chamber space to promote good flame propagation etc etc that the books say is important? Or how else (if at all) are you aiming to get extra swirl or tumble into the mixture, or is this something that you hope will remain sufficient even with a bit of the "wall" removed as the extra chamber volume will compensate to a degree?
Greg

 

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i thought the 6.0L engine came factory, at 10.5 ratio anyway, 10.2 is close enough, with so many numbers it would be easy to mix up a couple tenths ratio!

without CNC machining you will not get every chamber perfectly the same, beside it being an N/A engine , it is not that important, couple tenths.

and then you have to deal with getting 12 pistons all the same.

i would like to see a bowl in piston crown , not just a flat cut off the top.

Warron not much worried about the Fireball turbulence chamber, believe me it will run and alot better than some think!

 

When I CCed the chambers I got 29cc, in Australian spec the 6.0L was listed at 11:1 CR so you are close

 

Good question Greg.

I have read a LOT of info by Darin Morgan, Grumpy Jenkins and David Vizard on head porting and chamber design (even though most of this is SBC related the theory is valid), so I can not remember who wrote that the Jaguar HE chamber was one of the best at burning lean mixtures at high CR at part throttle.

And YES I did think about the loss of the FIREBALL effect. But I think the bit of metal between the Ex and In valve is a potential hot spot and could cause detonation not to mention the shrouding it provides to the In valve.

My goal is to increase torque significantly (capacity increase) and hopefully power not just in the 2000-4500rpm range but also peak power (combustion efficiency/breathing). So I am not too concerned about losing the pocket in the exhaust valve area.

One of the objectives is to (hopefully) improve the efficiency of the burn in the chamber. With the pocketed spark plug the propagation of the pressure wave is severely limited by the pocket and the bit of metal between the exhaust and inlet valves. Removing this and profiling the pocket should help this situation (in theory). The spark plug position in the HE even though it points to the Ex valve is not ideal as it is not in the centre of the chamber, the pre-HE is better in that the plug is central in the chamber. Laying back the chamber walls opposite the plug should also help with pressure wave propagation across the bore. I may not be able to full lay back the exhaust pocket as it may reduce CR too much, this will be trial and error.

Too much swirl is a bad thing as it can centrifuge the heavy fuel out of suspension and the fuel ends up stuck the cylinder walls then as the piston reaches TDC it ends up in the crevice (between the top ring and the piston crown) where it remains un-burnt. I will be running a much tighter squish than the stock HE at 0.040” and flat top (apart from V8 valve reliefs). This should help with mixture at part throttle. Full throttle is not so much a problem as the air speed helps keeps the fuel in suspension better.

To help with fuel atomization I have a set of Denso (Ford) 12 hole injectors from an X Type V6, these have fuel droplet size (50um) 3 times smaller than (150um) 4 hole injectors and who knows how much smaller than the OEM Jaguar injectors.

Bravely going where no man has bravely gone before…………..lol

 

Norm is doing the pistons KB143 with 0.040" machined off the top.




Once I have decided on the shape, I plan on making patterns so I can get the chambers as close as possible to the same. They will be CCed to within 1cc of each other.

 

Thanks for explaining your thinking Warrjon. Very interesting and it makes sense to me (for what that is worth). The new injectors should help efficient atomisation a lot, I would think, and give better full throttle economy. As your pistons will go up to 40 thou of the head, what is the OEM gap, out of interest? I can see that if this works and a decent bit of mixture still ends up being concentrated in the (albeit modified) pocket, a leanish mixture will still ignite properly, therefore part throttle economy should not fall off a cliff. The danger being, I presume, that a sufficiently lean mixture for decent part throttle economy will not ignite nicely? I guess that with luck there will be enough of the pocket shape left to get the leanish fuel mix sufficiently concentrated round the plug to get decent part throttle combustion without having to add more fuel. If that does all go well, I can see that more power and torque should be a definite goer when you give it the beans. All too exciting! When do you anticipate getting the beast running?
Greg

 

The OEM squish is about 0.040" as well, but the pistons are dished which effectively reduces squish to about 0.060-0.080"

One of the things the HE head did well was make power with about 24° of advance I think the pre-HE was 38°. This is a good indication of a fast burning chamber. The later GM LS engines also have fast burning chambers. So I have been looking closely at how I can use what GM did and marry that with the HE chamber.

The biggest issue with the HE chamber is the relatively low valve lift (lift is only 0.23D of the intake valve a stock LS is about 0.27D of intake) and the shrouding of the intake valve due to the small recess.

I think about 6 months to get it all up and running. While I have the engine out I will tidy the bay and do a complete re-wire.

 

Aren't you having the camshafts remodeled or are they staying the same? I'm sure a bigger lift should contribute to a better performance. Might be worth checking the carb'ed V12s. From memory, carb'ed engines normally got a higher lift on the intake compared to the EFI cars (this though is looking via my experience wirh Volvo Redblocks and Ford Kent/Endura/Zetec engines)...

Do you intend on making the engine a lean-burner? Unless of course the pedal is fully depressed, allowing for loads of fuel to be dumped in If so, then maybe a relobe to a sloght atkinson cycle would improve burning but it would sacrifice a few ponies but gain some torque (IIRC)...

 

Are you planning to dyno it? It would be very interesting to see how the BMEP compares to a standard engine.

 

Camshafts will be stock, at initially. Depending on how the engine runs, I am not looking for maximum peak power, a wide power band is what I am after, ie flat torque curve.

This car is a toy so I am not too worried if fuel economy is not as good as a stock V12, In fact I expect it not to be. As long as it's not like my brothers Shelby Mustang 10mpg at best lol.

I need to get it on the dyno to dial in the advance curve. I am lucky the next town (40km away) has a shop with a chassis dyno. I'll tune it up as best I can with my G-Tech before the dyno.

 

Before I started I checked the CC again 28.8 or 29cc with the spark plug installed.

First chamber roughed out, 31cc so I removed a WHOLE 2cc.

I have left a message for Norm to discuss if it's better to take another 5cc from the piston by cutting valve reliefs for the V12.

 

down right beautiful!

 

Picked up my 36-1 crank wheel the other day. This was laser cut to fit in the OEM 3 tooth wheel location. I will need to bend the teeth around the damper and cut one tooth off once I decide which tooth.

 

Warren, just by postimg those pictures, you managed to answer a question even Jaguar couldn't answer: does the pulley fit in one or many positions? Going by the picture from behind: one position! YAY!

 

If you mean the 3 tooth trigger yes it is pinned. This is a 6.0L damper and is different from the 5.3L I have not had the damper off my car yet so I don't know if it is pinned.

 

I actually meant the damper itself... In the same position as the pin is a kerb in the harmonic damper. That is what I had been wanting to see since about May

 

The dampers are keyed to the crank, as I said this is a 6.0L damper and is a slip fit with a single key. The 5.3L damper uses a collet arrangement and 2 keys so the hole through the damper is tapered. Both dampers will only fit one way.

5.3L damper the hole is bigger and tapered.