skauldy Posted April 11, 2014 Share Posted April 11, 2014 Why was the 4.0lt block cross bolted and the 4.2 wasn't. Seems a bit strange the larger capacity wasn't touched. Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted April 11, 2014 Share Posted April 11, 2014 4.0 later..wad 3.o zero. ..majority of 4.2s earlier and v belts Quote Link to comment Share on other sites More sharing options...
skauldy Posted April 11, 2014 Author Share Posted April 11, 2014 Would it be worth my while cross bolting it. Quote Link to comment Share on other sites More sharing options...
garrycol Posted April 12, 2014 Share Posted April 12, 2014 I understand that the 4.2 is a stroked 3.5/3.9 block where the 4.0 block (while the same capacity as the 3.9) is a beefier block to take the larger diameter crankshaft of the 4.0/4.6 and as such amongst other things, has the 4 bolt mains. Will drilling the mains of the 4.2 main bearing caps weaken them? Garry Quote Link to comment Share on other sites More sharing options...
skauldy Posted April 12, 2014 Author Share Posted April 12, 2014 I was looking at the 4.2 main caps last night and where the bolts that currently in the main caps hold the crankshaft in are pretty far out to the sides. So there's not much meat to thread for cross bolting. I must look at my 4.6 block and caps Quote Link to comment Share on other sites More sharing options...
garrycol Posted April 12, 2014 Share Posted April 12, 2014 4.6 crank and conrods in a 4.0 block and main caps. Quote Link to comment Share on other sites More sharing options...
skauldy Posted April 12, 2014 Author Share Posted April 12, 2014 Measured 4.6 and 4.2 and there would be the same amount of meat on them. Quote Link to comment Share on other sites More sharing options...
Darren Roberts Posted April 17, 2014 Share Posted April 17, 2014 How about instead of cross bolting having a strengthening plate fabricated across the whole block and then fit the sump on top of that. In the Rover V8 book by the same guy that does the Range Rover / Land Rover books shows an example. Quote Link to comment Share on other sites More sharing options...
skauldy Posted April 17, 2014 Author Share Posted April 17, 2014 Like what is in the Td5's Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted April 17, 2014 Share Posted April 17, 2014 A girdle I believe... http://i34.servimg.com/u/f34/11/14/83/96/p76lad10.jpg I would say you don't really need to worry too much on the RV8 with the bottom end until you get well north of 250BHP. Quote Link to comment Share on other sites More sharing options...
Darren Roberts Posted April 18, 2014 Share Posted April 18, 2014 Yep Bowie, a girdle.......forgot the proper name for it.... Quote Link to comment Share on other sites More sharing options...
Ash.Witty Posted April 20, 2014 Share Posted April 20, 2014 The late Gemini blocks from 93/94 onwards or all the 3.9 and 4.2 serpentine engines can be cross bolted as they have the extra material and late main caps enabling it to be done like on the TVR 5.0 v8. Quote Link to comment Share on other sites More sharing options...
skauldy Posted April 21, 2014 Author Share Posted April 21, 2014 The shop I was going to drop it into still hasn't got my lt230 output housing done. It's coming up on near 4 months I think I'll leave it as I now need this on the road ASAP Quote Link to comment Share on other sites More sharing options...
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