.

thanks xj. good info, cost dont look to much, shipping to another country could make or break the purchase, unless you could gett FREE shipping,, Amazon ,etc.

my engine has Crane cams Nitrided, been fine for 21yrs , but if i ever did change cams i would opt for a milder profile, they sound great at 4000 on ward but blubber and not smooth below 3500(no matter how i retune fuel or ignition sttings). sound like a big V8, they american hotrod guys love it.

when i got them from Crane Co. Daytona FL.(helps to be 5miles from Crane Factory).LOL. they cost $300. USD, springs from Lanky,Tulious racing Grp. 44.

 

I agree about the cams. My engine is away being machined for a 95mm bore kit 6.7L when I get it back and on the advice from my engine builder (very experienced Jag V12 guy) I will be running stock 6.0L cams, multi angle valve job and re-profiling of the 6.0L chamber ( I need to enlarge the chamber 12cc to keep CR to 11.5:1) This engine will make monster torque. My engine guy said another 6.7L he built for a Targa Tasmania XJS twisted both halfshafts on the dyno, tubular hafshafts then blew the diff at Targa.

 

when chambers are finished could you post pix of them, be nice if supercharged would post pix also.

be interesting info ,for sure!!

 

I'll start a new thread when I'm finished and post all the details including pics

 

That is kinda how I feel about the pics. I priced having it done by a shop that would make a bit to cut the combustion chamber per my request. It was simply outrageous!
So, I had a little help. It turned out great, but the machine marks show where it was moved around to accommodate the milling. I really feel this isn't a concern, as the original combustion chamber (still in the exhaust pocket too) has a rough sand cast finish. I feel I am wading into unknown waters here, and would love to see it work before I say much more. It may sink to the bottom if you know what I mean.
I like to consider myself somewhat of a daredevil when it comes to my projects, and one of the things I just caught was not installing the steel cups? that go against the head under the spring. Thank goodness I caught it. That would have been a catastrophe relatively quick I imagine.

 

one of the best things about aluminium heads is you can TIG them and re-machine if you make a booboo.

The shop I spoke to re doing the chambers said - If I do 1 chamber they will run the CENTRIOD over it and CNC the other 11 including recutting valves and blending bowls was $3k.

 

OK if i had to do HE heads for lower compression, i would open up the area around the exhaust valve larger(unshroud exhaust valve,and lower comp.).

something like the 6.0 chamber but larger, using a custom shaped Ball mill cutter, then some fine hand work, rough edges!

now after some thought on this head, i would just flat mill surface cut the whole head surface down to the edge of the INLET valve seat, that way you would still have the Quench area intact,I consider it very important on a forced induction chamber.

but lets look at how much deeper the inlet valve unshrouds and protruds into the cylinder bore, using any type cam, remember we are trying to get more air into the cylinder(not the chamber).

then a nice thermal barrier coating of the complete head surface, and exhaust port coating, to reduce heat transfer into the coolant jacket, trying to reduce V12 overheat problems!

that is exactly what i did to my heads 21yrs ago, pre HE flat chamber, unshrouding both valves go deeper into the bore,(something like a higher lift cam).

, other day here in central TEXAS 102F ambient, out for drive for 1 hr, check digital gage while driving,standalone ECU readouts, 180/185F, cruising, some city,some hiway!
when pulled in and stopped engine temps went up to 210F after 10 minutes Oil heat soak,twin elec. fans on for few minutes, kinda wish i had the Craig/Davis pump system, and better oil cooling system,(but hell been 21yrs all ok).

i can only speak from my experiences, others may do something different!

give it some thought just maybe be of some help!

 

I am using a 6.0 engine, heads and all. I looked at opening up the exhaust chamber side, but stopped when I felt around inside the water ports, and really feel that the head is super thin around the exhaust chamber recess. I still am going to CC these heads, and now that I have milled only the combustion chamber down to the inlet side valve seat. My goal is to lower compression, and milling the entire head down to the inlet valve seat would dramatically raise compression. Once I CC the heads, I will have a absolute compression ratio. The stock pistons have a .280 crown thickness in the center (PLENTY). Chadborn Bolles has built a V12 for the flying mile, and actually cut the piston tops by .100, and used longer Chevy rods to get his compression UP to 14:1 and used longer duration cams with more lift. He assured me that 14:1 lives on in that engine, even after cutting .100 from them. That will be what I will have to do if I don't get down to around 9:1. I understand quench, but from what I read, combustion volume is what becomes important here. To lower compression by cutting the pistons would decrease quench much in the way I have relieved the combustion chamber, would it not?
I really appreciate the interest shown in what I am attempting, so all thoughts considered.

 

The stock 6.0L has 29cc in the head and 4cc dish in the piston and has 2mm (0.080") squish. Each 5.5cc drops CR 1.0.

Machining the top of the piston down will decrease Squish. Doing this can decrease the engines detonation threshold hurting power potential. I would machine the piston under the exhaust valve/spark plug.

Squish and Quench are not the same, squish is the distance between piston top and head at TDC and Quench is the flat area between head and piston. Have a look at the difference between the Mercedes 3.2L NA and AMG C32 supercharged engines (the AMG Mercs run IHI twinscrew superchargers), the chambers are the same as the NA the CR reduction comes from the dished piston, retaining the squish pads on each end of the piston.

You do not need to mill the head down to inlet seat. All you need to do is take a carbide and cut a 45° angle to the seat making sure there is 0.20 of the diameter of the valve (about 8.3mm) between the edge of the valve and the chamber, this will effectively eliminate geometric shrouding caused by the recess.

 

Regarding deleting the distributor, the later 6.0 V12 in saloon (sedan) had Nippon denso ecu for injection and ignition, no distributor but an additional sensor on camshaft for ignition timing to distributor less coil pack

 

The donor car was a very early 1994 XJ12 with Marelli ignition.

 

Megasquirt direct ignition control and 2x GM DIS ignition coil modules. Remove the guts from the DIS and install the 3x BIP373 ignitors inside. I have mine on the bench ATM, just need to buy the DIS modules.

 

warron ,i think supercharge wants to do away with the distributor completely, and use a crank trigger wheel on front, plus some type coil packs,etc.

pic of a 6.0L in 1986 XJS ,OP bought new, uses the GM 4L80E trans, 3.54 rear gear.

oic shows coil packs in Vee ,no distributor, block off plate for hole!

 

I have already purchased the TEC3r for this project. I have yet to determine how I will mount the coils. The mount base for the supercharger has already be built. I am really wanting to post pics, but want to get it assembled. The supercharger is literally squeezed into the valley as far back as I could. It is turned up on its side. I can't run a distributor at all. I am holding out hope that the 6.0 valley cover can be modified to cover the front half of the valley, as well as wrap around the supercharger. This could hide the coils and the long snout that has yet to be fabricated.

 

I realize that, the GM DIS V6 coil packs 2 of them and run wasted spark, the pic on the left looks like 2 GM DIS modules

https://www.diyautotune.com/support/...stomer/gm-dis/

http://www.mye28.com/viewtopic.php?t=68448

I would remove the board from the base and install the ignition drivers on the aluminium plate

 

I definitely am running wasted spark as the TEC3r can't run sequential fire on a V12. I hope to run 6 coils if they will fit. The valley is very crowded indeed at the rear of the engine, and the drive snout is going to take up room in the front half of the valley. Its a very interesting project, that's for sure.

 

Been reading up on this squish and quench. Seems there are more opinions than people who actually know for sure. I even went so far as to find that the Dodge SRT-4 (turbo) had .340 squish, and runs like crazy. Open chamber big blocks that produce crazy HP. For what its worth, it seems combustion volume is more important on a forced induction motor than anything. I may have made a big mistake removing the squish from my 6.0 in a effort to reduce compression. Then again, I may not have, because the HE head still has the pocket for the exhaust valve. Either way, you guys will find out at some point. I am assembling the engine now, although slowly. I already have everything for the 5 speed conversion including the ABS pedal box.
Then I get to remove my 5.3, clean it all up under the hood, and install. I have no idea of a time frame because I still have to look into moving my AC compressor, as well as the supercharger drive extending out to align with all the other pulleys. Its a big job full of challenges, but any and all comments suggestions appreciated.
On the aluminum soldering rods....has anyone actually used them? Successfully? I bought some at Harbor Frieght, and haven't had much luck with those. Please jump in, because that could save me a lot of time and money.

 

[QUOTE=superchargedtr6;1499183On the aluminum soldering rods....has anyone actually used them? Successfully? I bought some at Harbor Frieght, and haven't had much luck with those. Please jump in, because that could save me a lot of time and money.[/QUOTE]

I have them, It's the same as soldering you need to ensure the metal is clean VERY clean and apply the heat to the part NOT THE ROD. If you are joining 2 parts tin both surfaces then join them.

Have you given thought to turning the SC backwards so the drive is at the rear of the engine you could then run a shaft forward, there are a few LSx kits here that run the SC this way.

 

When I post pics, it is very easy to see that running a shaft from the rear would be even more cumbersome. This is a 3.3L supercharger. It really is a big supercharger for a 6.0 engine. A 2.3L would have been fine, but it would have been about the same challenge I think. I got a screaming good deal on this one which is one reason I'm using it. I am making everything with removal of the supercharger being not much different than removing the AC compressor, as that is the only way I'll get to the last 4 plugs.

 

.

super, on the GM BBc open chamber(i have owned and built 5 engines,closed and open) 396/427/454/ 468 cu".

the socalled open chamber does have a squish area(1 side, the closed has 2 squish areas). squish on one of my aluminum engines 468", .020 thou. and no problem spinning 6700rpm, i also modded the open chamber tilted slightly for some addional swirl/spin. all were N/A engines!
mant tests and drives , closed has more low end torque, open can spin to 6500/7000 rpm, but lose some down low.

best street engines i have seen(using modded factory heads and manifolds), was closed chamber opened a little on both sides of chamber, and using the OVAL port inlet manifold.

dynod 540HP, with 600 lbs.ft. at the wheels. 1989 3rd gen camaro, much built drive train!

just little heads up on chevys. great motors still competitive 50yrs later, not many engines out there can say that!


yes it seems lately a larger initial chamber for forced ind. should hold more volume at TDC, logic says velocity would be higher in chamber with air being forced in to it, so mixing air/fuel along with pressure, would vaporize/homogenize mixture to produce a smooth burn, and reduce chance of detonation.