TheNeedForZ Posted September 21, 2005 Share Posted September 21, 2005 I was reading the Jaguar V12 history yesterday. On page 9 at the middle, the author said it is possible to attain 8.1 liter or even 9 liter displacement with increased bore/stroke. http://www.jagweb.com/jagworld/v12-engine/page9.html However, on page 2, from looking at the picture of the engine block it seems the cylinders are made of liners rather than holes cut into solid casting. http://www.jagweb.com/jagworld/v12-engine/page2html Is the author talking about a version of engine different from the one on page 2? You can't possibly "bore out" steel liners, not from 90mm to 98mm. Some other sources indicated the existence of 7 liter race engines and one company is capable of producing 8 liter Jaguar V12. http://217.37.193.161/rdcsite/pagesronart/rpower.html Is big displacement Jag V12 doable??? Quote Link to comment Share on other sites More sharing options...
dot Posted September 22, 2005 Share Posted September 22, 2005 Boring the engine would not be that difficult. Remove the liners and make a new set the desired bore. Put a shoulder on the bottom half of the liner so it sits in the block. Bore out the block to fit the liner. There is a lot of space between the liners but I think the 98 mm you mentioned is about as big as you can safely get with out making to walls too thin. This can be done by local shops and pistons can be sourced. Head gaskets are an issue. Stroking is another matter. You will have to source a crank. You might find aftermarket rods but the crank is an issue. I have had my head into this far a while. It would be more economical to find a rare six liter engine or just boost the bastard 5.3. I have found the mildly cammed 5.3l to be adequate for the Z. Quote Link to comment Share on other sites More sharing options...
datsunlover Posted September 22, 2005 Share Posted September 22, 2005 Just a thought on the crank.. would in not be feasible to re-grind the crank journels, giving the effect of stroking? Basicaly, grind them smaller, but offset from their original 'center line' therefore ending up with more piston travel, even using standard pistons, although the con-rods would need smaller ID bearing sizes... My engine builder friend has talked about this (actualy, I think he called it offset grinding), and from what I gather it's been done with V8's for years.. If the jag crank is a stout as they say, I'll bet it would be ok to take a bit of meat off... Quote Link to comment Share on other sites More sharing options...
TheNeedForZ Posted September 22, 2005 Author Share Posted September 22, 2005 Thanks for the inputs. Yeah if this is doable then I'll keep this at the back of my head. Crank...I'll see, if it's not thick enough then I think it is also possible to weld more metal then grind off the excess. With offset grinding, it is possible to grind the journals down to the rod size of popular engines. Like dot said the main difficulty is cost; everything has to be done 12 TIMES. Head gasket....how does one modify a HG? hmmmm... an all Canadian thread. Quote Link to comment Share on other sites More sharing options...
Chewievette Posted September 22, 2005 Share Posted September 22, 2005 About the only other option to offset grinding the crank is having a new one turned from billit. From the research that I have done this is the only practical way to have a one-of crank made, casting and forging are better for full or limited production. Just remember that you can do anything you want as long as your pockets are deep enough! Personally I think a bit of boost on the stock engine would do wonders. But thats just me. Quote Link to comment Share on other sites More sharing options...
Dan Juday Posted September 22, 2005 Share Posted September 22, 2005 Personally I think a bit of boost on the stock engine would do wonders. But thats just me. Excellent idea. The problem is real estate. It's tough enough to fit a turbo or supercharger in a V8Z. Add four more cylinders under the hood and you're out of room. Maybe in Chelle's stretched GTO you might have the space. Hey, is she thinking...? Quote Link to comment Share on other sites More sharing options...
Sven Posted September 24, 2005 Share Posted September 24, 2005 NeedForZ, I'm pretty sure someone makes a copper head gasket for the Jag v12. Actually, I'm positive- PAECO makes one for anything odd or foreign. Machining the copper gasket is do-able, and I've read about it being done for unorthodox bore sizes. With that being said, I wouldn't want to be that one that had to do it... Quote Link to comment Share on other sites More sharing options...
Chewievette Posted September 24, 2005 Share Posted September 24, 2005 The problem is real estate. It's tough enough to fit a turbo or supercharger in a V8Z. There is always a way, you just have to get outside that box first! You might have to relocate the brake booster and the battery to make room, but like I said there's always a way. Also thinking along the same lines isn't there a bit of room between the inner and outer fenders, yes? Even more if you have flared fenders, it'll make the tubing longer but at least you wont have to worry about heat. I'd say that's most definately outside the box. Once you get the engine mocked up into the bay and start thinking about it you can find someplace. Quote Link to comment Share on other sites More sharing options...
dot Posted September 25, 2005 Share Posted September 25, 2005 If I were to up grade, the boosted motor sounds tempting, A boosted motor could be built form a low compression 5.3l bottom end from the seventies. They had about 8:1 compression. The block has four bolt mains from front to back and the rods are fairly stout. For the top end the swirl port heads from the late eighties would be best. An aftermarket Fuel injection system would top off the long block. A pro charger system similar to Drarius’ system here could be jammed into the front left side of the engine bay. I think that Dan is right that there isn’t enough real-estate for turbo(s) but a centrifugal type super charger could be a way to go. Sven, I’m not that crazy on having copper against the aluminum head for TheneedforZ's big displacement V12 but if it is the only way there might be a sealer or something to stop the corrosion. Quote Link to comment Share on other sites More sharing options...
Chewievette Posted September 25, 2005 Share Posted September 25, 2005 I'm not familiar with the jag v12 so I dont know but, would an o-ring seal be possible? I know a lot of the high power race motors use that and I'm pretty darn sure you can get an o-ring in whatever size you want. Quote Link to comment Share on other sites More sharing options...
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