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Well its all down to cost and as Mr Davis (EX TWR Manager) said to me, where's your market!
I have brand new TWR head castings on the shelf and the problem is the cost of turning these into usable cylinder heads.
I'm getting there but I wont put my house into it!
I wonder if there are any 5 axis machines that can turn your heads into near-usable blanks in a single device. If each purchaser of the heads did not have to replicate that programming (if the heads came with a digital machine-work file) it would make purchase more bearable. I'm still hopeful with the advent of 3d printing that the cost of low-volume replica parts will continue to decline. Digital versions of a product might end up being more marketable than the physical item itself (especially if having said-items produced locally becomes more doable).
XJR5006, I assume when you mention £100K for top quality sand molds you're speaking of making them in the traditional methods. (I'm making some assumptions here about cost reduction, but what are your thoughts about the following example.) Reconstructing cylinder heads
Very interesting thread, posts from people with more experience and knowledge than me seem to be suggesting that costs are going to be astronomically large with the end result being improved volumetric efficiency via better cylinder filling from much larger ports, valves and camshaft timing / lift.
If more power and torque are being sought from V12 Jaguar engine my guess is this could be achieved less expensively via fitting modern turbocharger (extremely low lag), suitable charge intercooler with boost limited to 0.5bar (7psi approx).
Should with good map and larger fuel injector give easy 450 to 530bhp with massive usable torque throughout rev range to make superbly street friendly vehicle.
Upgraded transmission obviously needed.
there is a small company in Australia that has a V12 LS design engine up and running, posted on a YT site!
also i think some one has one up in Seattle USA area, on the net with pix.
to add back in 2007, i was at a BIG vendor show in Orlando FL, and GM had an LS cylinder head V12, along with a V12 aluminm block!
and look up GMs sweet sixteen Cadillac concept car, LS 16 cylinder engine, and it runs, beautiful work,god knows what it cost!
so seems a lot of ideas and about the LS series engines!
they are really good engines , i have owned some , and my pix in my gallery, 1985 Buick Grand National, with LS3 in it, along with built 4L80E trans, 3.73 rear LSD.
the best thing is they are low cost to buy, along with many combination of parts!
we have locally a vette with the LT5 4cam engine, but truthfully its not very fast or exciting,(shame most people dont know what they are looking at).
I have a 1992 v12 XJS I have driven a 1992 ZR1 LT5 ... if the power key is not inserted... she only has 220HP.... with the power key inserted about 400 hp... depending on which year 385 or 405... and the revs you have to get it up there... redline is 7?00 7200 or 7500 it has been a few years 1999 or 2000. now if the vacuum pump is broken it does not matter if the key is in or not.... unless like one owner did at a meet and used his wife's breast pump to sub for the broken vacuum pump.... so he could drag race it at the meet... the vacuum system opens up the secondary intake system above 3500 rpm and then that half the engine and injectors do their job...
now the impression I got from driving the car properly warmed up with the power key in place was AWESOME!... a much better car than the new 427's and the new super charged one I have driven them too and they are not as refined... a scalpel compare to a 20 pound sledge hammer. the newer ones are designed to appeal to the tire burning masses... same with the high HP dodges... the xjs I have I am just sorting out and I am finding that is handles very well in spite of the 104k miles it has on it... it will handle better as I go through all the worn out areas and address them...
Last edited by Jonathan-W; 07-27-2016 at 05:12 PM.
I wonder if there are any 5 axis machines that can turn your heads into near-usable blanks in a single device. If each purchaser of the heads did not have to replicate that programming (if the heads came with a digital machine-work file) it would make purchase more bearable. I'm still hopeful with the advent of 3d printing that the cost of low-volume replica parts will continue to decline. Digital versions of a product might end up being more marketable than the physical item itself (especially if having said-items produced locally becomes more doable).
XJR5006, I assume when you mention £100K for top quality sand molds you're speaking of making them in the traditional methods. (I'm making some assumptions here about cost reduction, but what are your thoughts about the following example.) Reconstructing cylinder heads
i suppose anything can be done, if you have the money and time , plus mind set to complete a project!
only time will tell!
at the same ORLANDO vendor show back 2007, way back in a corner of the show hardly seen walking by, was this funny machine buzzing along ,back ans forth, doing something like i had never seen before.
i asked what is it , CHINESE guy said a 3D printer, it was making a plastic gear, and other small objects,, they had started a new company in China and came to show USA, but very few were interested.
i walked away and had no idea it would become an encredible new way of doing things(still dont know full potential), but it sure is coming!
i thought CAD/CNC was spaceage stuff, now look at the custom BILLET cylinder blocks being made, and endless new beautiful products!
i suppose anything can be done, if you have the money and time , plus mind set to complete a project!
only time will tell!
at the same ORLANDO vendor show back 2007, way back in a corner of the show hardly seen walking by, was this funny machine buzzing along ,back ans forth, doing something like i had never seen before.
i asked what is it , CHINESE guy said a 3D printer, it was making a plastic gear, and other small objects,, they had started a new company in China and came to show USA, but very few were interested.
i walked away and had no idea it would become an encredible new way of doing things(still dont know full potential), but it sure is coming!
i thought CAD/CNC was spaceage stuff, now look at the custom BILLET cylinder blocks being made, and endless new beautiful products!
I personally have receive a cad file that can be used in a 3D printer to make a new sun visor clip for my convertible...
... and was used by the person would gave it to me to make one for his....
Last edited by Jonathan-W; 07-27-2016 at 09:49 PM.
Some very interesting posts,
My lad has redesigned the race cam carriers and made a far better job than TWR ever did. Big statement that.
I now have a Le Mans engine to rebuild , mainly as I have the tooling and it needs new cam carriers etc and I have the parts; I am sure.
But and its a BIG but; I will be using castings from the original tooling, we have made boring jigs for the cam follower and made a CNC line boring machine for the caps and carrier. We have worked out what TWR did wrong and will machine the carriers correctly with vastly superior castings. I will not ,sadly, be using the new design at this time. Its all down to cost. Pattern making will be about £10K (we are working on this but thats the bottom line at the moment)
I cannot justify this cost and cannot recover it especially as I have something that although not as good is original and does the job.
Personally I find this sad.
We will however be remaking the Heidegger pumps; but folks will want the cheaper and less efficient US units like Weaver / Johnson et al.
Heads we can make and can /will redesign I have the original TWR drawings etc, later in the year BUT as Mr Davis said , where is the market. How do I even start to recover the costs?
Making files available? yes thought of that BUT what do you do when someone then sells on the files for 1/2 of what you were charging?
Its a problem.
We also cannot get away from the machining costs on heads; CNC on the ports is about £100 per port ish but there are 24!
But the other problem is the castings; if you have castings suitable for all inlet bore sizes you have a huge amount of material to remove if you go for the large ports. ie 36mm upto 42mm. This effectively almost doubles the porting costs even with CNC. Its a time thing. If you have the big ports cast in you loose the main market which is for the 'smaller' big ports. Would love to be able to print what was needed needing only light porting to clean up. Really fancy honeycomb structures for supports and to assist cooling in the waterways but the cost would be high AND the machining would still be needed. I am also told they dont last too long!!??
Machining the heads is also a huge job and we have found the original now old boys who did them. They will do new heads for a relative pocket money but its still well more than 4 figures per head and its not repeatable like on a CNC machine, but they will make changes to suit the castings if there are problems. Dont forget to factor in in the guides and seat too , make sure they are good ones as these engines deserve much better than engine recon stuff.
If you want to see where we are take a look here https://www.facebook.com/groups/1432458440324391/ really like the redesigned cam carrier vid on CAD Cam although my lad thinks its a bit corny. Cant upload the vid onto the forum , unless someone knows how?
Just a quick update on the problems with Jag/Group 44/TWR V12 heads and remaking them.
Seriously looking at a new method where I can design and make individual pairs of heads, port size designed in, not made with so much metal you can cut the ports to what you want, cast to what is required with a deigned in wall thickness. This can be different from one pair to another. Gonna take quite a while, its got to slot in behind 3 very special engines I have to rebuild, I say rebuild but the 1st one is so bad it may be more correct to call it build!
Long live the Jag V12. They may not be the best engine one could use to make power, but for those of us who love mechanical things, the Jag V12 is maybe as big a draw to us crazies as good bait is to a fish. Once hooked, its hard to get away, lol.
V12 on hold atm. just rebuilding the 496BBC for my boat. even though everything is ex us for this motor its sooo much cheaper than my costings for the V12. Still going to embark upon the project but soooo many things to pay for not enough coming in...
finish the boat, get some summer enjoymenthave a look at the Jaguar again mid to late next year.
Love the renderings xjr5006 your boy is talented... still want to talk to you re your manifolds and cam carriers... will call after christmas. They keep deleting my facebook accounts which annoys me to no end...so ill call you when time and resources allow...
Well at the risk of resurrecting an old post we have decided to go the new CAD head route. The why is very simple; with proper port flowing to TWR works spec going to cost £1800 per head + the initial cost of a program to do the work we have managed to find a route to make new heads with ports custom manufactured to what a customer wants, No machining just a nice run over with flap wheels and extension shafts. With this goes the chance to re design the waterways inside the head to increase surface area and hence cooling. We are also looking at water flow analysis to get those 6 outlets made to balance flow along the head; I am working towards removing the possibility of entrapping air inside the heads by design rather than having additional bleed pipes to clear such hot spots, we shall see if this is possible as the project develops.
One thing is apparent, the head construction is not so very well thought out, we have copied the original design but now will have to re do this having realized how poor the water system actually is.
Pics to follow.
Well at the risk of resurrecting an old post we have decided to go the new CAD head route. The why is very simple; with proper port flowing to TWR works spec going to cost £1800 per head + the initial cost of a program to do the work we have managed to find a route to make new heads with ports custom manufactured to what a customer wants, No machining just a nice run over with flap wheels and extension shafts. With this goes the chance to re design the waterways inside the head to increase surface area and hence cooling. We are also looking at water flow analysis to get those 6 outlets made to balance flow along the head; I am working towards removing the possibility of entrapping air inside the heads by design rather than having additional bleed pipes to clear such hot spots, we shall see if this is possible as the project develops.
One thing is apparent, the head construction is not so very well thought out, we have copied the original design but now will have to re do this having realized how poor the water system actually is.
Pics to follow.
Great news, I do hope you get there. Please keep us up to date.
Well at the risk of resurrecting an old post we have decided to go the new CAD head route. The why is very simple; with proper port flowing to TWR works spec going to cost £1800 per head + the initial cost of a program to do the work we have managed to find a route to make new heads with ports custom manufactured to what a customer wants, No machining just a nice run over with flap wheels and extension shafts. With this goes the chance to re design the waterways inside the head to increase surface area and hence cooling. We are also looking at water flow analysis to get those 6 outlets made to balance flow along the head; I am working towards removing the possibility of entrapping air inside the heads by design rather than having additional bleed pipes to clear such hot spots, we shall see if this is possible as the project develops.
One thing is apparent, the head construction is not so very well thought out, we have copied the original design but now will have to re do this having realized how poor the water system actually is.
Pics to follow.
What are the max ratings of the stock pre he heads? What rpm does it run out of air stock vs porting? How much could it handle with stiffer springs? Could you get 400hp? 500hp?
I would be interested in something more of this nature. I don't think many people are looking for the full race 700hp engine. But if we could see a 450hp motor on stock heads that are modified I think that a lot more people would be interested in that no?
07-27-2016, 03:21 PM
