Destroking A Xu7 Down To Xu5

[Dylan l 0]

As title really.

 

Has anyone tried or attempted the project and is it feasable or should I just get a 106gti engine?

[Henry Yorke 269 3 Cars]

Much cheaper to get a 106 GTI TU engine I think. They are more modern with their management and come with more valves so technically have more horses per cc. Fitting will require some driveshafts matig up but that is not a massive issue I believe.

[welshpug 1,661]

XU5 is lighter than the TU5 IIRC, not sure if a 16v XU5 would be, but at least its bolted to a decent gearbox.

 

XU5 J4 has been done with MI16 heads, I don't know if anyone has done it under an XU7 or gti6 head yet.

 

 

most 16v XU5's have been XU5 cranks and rods with special pistons in an MI16 block, nothing stopping you doing the same in an XU7 block at all.

 

there are two threads discussing the XU5J4 build on here

[RossD 44]

BE4 swap onto a TU is a doddle, so I don't think that the gearbox reason can be used as an excuse really

[Batfink 201]

XU5 is lighter than the TU5 IIRC, not sure if a 16v XU5 would be, but at least its bolted to a decent gearbox.

 

XU5 J4 has been done with MI16 heads, I don't know if anyone has done it under an XU7 or gti6 head yet.

 

 

most 16v XU5's have been XU5 cranks and rods with special pistons in an MI16 block, nothing stopping you doing the same in an XU7 block at all.

 

there are two threads discussing the XU5J4 build on here

 

Its been a long time since I did any calculations but to use on an mi16 block I worked out that you needed custom longer rods to save having to deck the block.

If I could magic some money together I would be building one (damn this recession). Longer rods are going to be lighter than thicker pistons so would be less stress on a standard 1.6 crank.

 

Kev

[welshpug 1,661]

just some custom pistons on stock 1.6 rods would suffice, though as you say if longer rods were used you could use a lighter piston, does one counteract the other?

 

taller pistons aren't thicker though, just taller, heavier of course.

[Dylan l 0]

With the xu5 crank with custom pistons or custom rods it is possible,but at a cost of £500.OTTOMH.

 

Is the xu7jp4 capable of constant high revs without a dry sump or as the mi block end in doom.

[Baz 421]

Uh-ohhh...

 

 

 

[Batfink 201]

With the xu5 crank with custom pistons or custom rods it is possible,but at a cost of £500.OTTOMH.

 

Is the xu7jp4 capable of constant high revs without a dry sump or as the mi block end in doom.

 

You cannot destroke and use cheap parts.

The Mi copes fine with high revs, just has a very high oil capacity in the head which can potentially be a problem in corners. The newer heads have a different design which seems to cope better, but then it has other issues...nothing to do with de-stroking and covered relentlessly in the past so a search will bring a wealth of information.

Edited June 30, 2010 by Batfink

[Dylan l 0]

BE4 swap onto a TU is a doddle, so I don't think that the gearbox reason can be used as an excuse really

 

Is it just the bell housing thats different or are internals different as well?