V12 4 valve. Quad cam. C Deuce quad cam. On you tube. Questions answered if possible
A link would be good: maybe you are referencing Neville Swales recreation of the XJ13?
Hi Peter- Are you the guy behind 1956ct on YouTube that built the Ford with the Jag engine? Some of those videos are seven years old, so I guess my question is how well has everything held up and what would you have done different? -John
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Ah…the AJ6 head conversion: had forgotten about that one…impressive!
Yes john that’s me. In this video it’s all together and running. Yep hobbies take time Was just browsing Internet and saw some negative comments. So thought I would put something up there
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If I built again would I do different no. But would be easier to chain drive cams than to external belt drive. I am a hot Rodder so looks are important as well
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Peter which heads did you use AJ6 or AJ16? What are your specs, hp, tq, max rpm, boost, compression ratio, etc? Have you had any problems?
There is really a lack of info about this type of conversation so your expertise is very much appreciated. The only negative stuff I’ve read about this type of conversion is http://www.jagweb.com/aj6eng/stretching.php
“Then there is the structural integrity of the engine to consider. The V12 open deck cylinder block is heavily dependent on having the heads attached in order to achieve adequate torsional stiffness. On the other hand the block of the AJ6 engine was intended to allow for a possible diesel variant so was designed from the outset to be extremely robust. Putting what was essentially a V12 HE head on the stiff AJ6 block, as Jaguar did to create the 2.9, is relatively simple. Trying to do the reverse, putting a head designed for a stiff block onto one that isn’t, could invite trouble.
An associated complication is that the V12 cylinder liners are designed to stand 0.005" above the block face to ensure correct “nip” on the gasket for gas sealing. Supplementary studs around the outer water jacket give additional rigidity to the structure and seal the coolant joint. The same arrangement was used with Jaguar’s prototype 4 valve heads and the later ones designed by TWR. It is difficult to see any way of accommodating these outer studs with the AJ6 head, designed as it was for its own rigid decked block.
Probably the only way of achieving adequate rigidity without the outer studs is to weld a deck structure to the block which would entail converting to slip fit, dry liners inside aluminium sleeves. This of course is how the original twin cam hemi V12 prototypes were constructed.
Then there is the provision of a reliable camshaft drive. The single chain arrangement of the standard V12 is not at all practical in this context because of the torque fluctuations that can arise in a twin cam four valve layout. In fact the two stage timing drive of the AJ6 engine was never totally free of problems and Jaguar’s later V8 has acquired a reputation for trouble in this area. A simple chain drive to each bank might work in the short term, but a two stage drive is probably necessary to achieve reliability. Certainly that was the conclusion reached by Jaguar, TWR and KRS (see below). Some very respected engineers have suffered a lot of frustration trying to solve unexpected problems with camshaft drives. There is a saying “all camshaft drives can work and all camshaft drives can fail”. At least the difficulty of accommodating a distributor drive can be resolved by use of a modern coil-on-plug engine management system.”
Wow John what a message. AJ6 heads. Head studs retapped out to 9/16 Bored the aluminium block out to accept new aprox + 5mm liners. Stock crank and rods. Utilising stock aj6 cams Although turn around head had to lengthen cams. Shrunk fit piece on. Where outer head studs ( smaller ) ones. Machined and fitted dowels. Then machined aj6 heads with coresponding hole positions this keeps outed block from moving Oring machine new liners stainless mig wire fitted. And copper head gaskets were made. Getting the cam timing was interesting on turn around head you have to take into consideration the valve splayed angle int consideration This can to me at 2 am in morning while asleep true Engine management is 2 Holden 909 Ecu s. With real time Kalmaker. Cheers for now Pete
One other thing John. The timing belt is a gates racing series 32 mm wide. I think it also fits an Audi Quattro This thing is never going to break. However if ever a bearing idler ever gave out and caused belt to shift might be different. I would have liked to machine the valve clearance into Pistons deeper so no crash condition even if Pistons were at TDC and valves open But to much would have to be machines from piston tops My static comp is 9 to 1. And 10 lbs of boost 1000 cfm single throttle body. Pete
Thanks Peter. You seem like a bloke with skills. Got to love the ‘32 Fords. One of my best mates has one in Perth with a supercharged sbc.
I guess the core questions for many V12 enthusiasts is how durable is, how much work and what are the end results assuming naturally aspirated.
The durability has been called into question (for me at least) by a Roger Bywater writings question block integrity with these heads and the timing chain. I’m guessing timing chains are stronger today than 40 years ago and with a 6000rpm limit probably fine. I know you used a belt solution.
The work I guess is flipping one of the heads, custom intake and exhaust manifolds on top of the normal V12 hot ridding mods, aftermarket ECU, striker crank, bigger liners, pistons, etc.
Results is a guess but the 4.0L with an over square bore/stroke made about 240hp at 5000rpm from memory. So a 7.0-7.5L V12 with a 6000rpm redline, extractors and a proper intake should be around 500hp I would guess.
Anyhow your thoughts would be appreciated.
Do you operate a commercial car workshop?
Hi john. I used to own Centre Tooling in Melbourne. I retired 10 years ago. My sons own it now. Lots of CNC machines. There are lots of pics. If you search Maguires MotorEx 32 roadster V12 we even made the wheel centres We based the tuning on 500 cc per cylinder which is 6 ltr. 12 injectors Ford AU Sound like a jet with the B&M supercharger 4 DFI coil units to get ohms correct wired to BMW coil on plug Reliability will never know. Until something breaks Revs to 7500 steady. I have set ECU
limit to 5900
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Peter that’s a beautiful car with a unique engine. I have watched your videos now and I’m amazed by the engineering required. Yes it sounds like a turbine. I see some guys in Oz are making a V12 LSX now and last year I saw a V16 LSX at the Miami boat show. All big bucks.
Do you know roughly what would it cost to flip around one AJ6 head with standard cam drive gear to suit the V12?
Hi there is a lot more work. To do. Rocker cover. Oil to cams. Drain back to sump. Front cover alter single chain drive. Idler as to drive top cams at 2:1 List keeps going. And going. To plonk head no and weld ends back on is just the start. Integrity of Dowling side walls of block back to heads Larger head studs Oil to feed cams on both heads The hole thing is a project Hundreds of hrs
I am BLOWN away by the engineering, and quality of fabrication/problem-solving!
I gues that’s what hobbies are all I out. I remember close to 20 years ago. I met a guy called Peter Jenkins. He owned the one that was on eBay I machined many parts for him. He never finished it . He helped me with learning the Kalmaker tune. Very smart guy. That loves jag stuff if you ever get time. Look up jenkin engineering. I think there is also an early pic of my engine there as well. Did you know that you can machine all the counterweights from the v12 crank he did. On a racing engine. Best regards. Pete
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What a great project Peter.
And superbly executed !
Aristides
I had stumbled across your amazing build on YouTube a while back burn only a short video. As has already been said, that is beautiful work! Have you driven it much or do you keep it as a show piece? I usually lean towards liking cars that see the road but I can fully see not wanting to take the risks associated with sharing the streets after all you have put into it.
Amazing work! Glad you joined up and hope to see more of the engine and any other stuff you have done.
Thanks. Been finished for a few years now. Shows now finished. And planing now to enjoy it on the road more
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I’ve long held that most of the things men do – golf, fishing, working in the garage – are simply excuses to get away from the ol’ lady for a while. Dude, you wife must really nag you a lot! 