205freak 7 1 Cars Posted June 17, 2007 Hi guys, is it possible to take a XU5J head from a later 1.6 and use it with Mi bottom end or this is a really stupid question???? if it was possible what would be the gains??? Share this post Link to post Share on other sites
Baz 421 Posted June 17, 2007 Pretty sure it's possible as lots of 8v race engines use Mi blocks, they're isn't really a gain power-wise i wouldn't have thought, the block has extra ribs so i can see it being better for strength etc. Share this post Link to post Share on other sites
petert 585 Posted June 18, 2007 Why not? I've done it before. Free revving, high compression. Share this post Link to post Share on other sites
Hilgie 16 2 Cars Posted June 18, 2007 it's possible...like Peter says. the otherway around is also an option (XU5 bottomend + XU9J4 head = XU5J4) Share this post Link to post Share on other sites
205freak 7 1 Cars Posted June 18, 2007 thanks for all the replies, as petert said the benefits of using the mmi bottom end is free revving, high compression....if i use skimmed/ported/polished head what would be the result using a 270 reprofiled cam???? Share this post Link to post Share on other sites
Hilgie 16 2 Cars Posted June 18, 2007 I guess around 140bph or maybe 150bhp on carbs/throttlebodies. Share this post Link to post Share on other sites
oli-pug 6 2 Cars Posted June 18, 2007 ive heard of rally boys using the mi head on a xu5 bottom end and thats supposed to bring very good results! anyone know where there's a good amount of info on the xu5j4?? Share this post Link to post Share on other sites
Baz 421 Posted June 18, 2007 ive heard of rally boys using the mi head on a xu5 bottom end and thats supposed to bring very good results! anyone know where there's a good amount of info on the xu5j4?? Do a search there was a thread aboutit not too long ago, i don't think it's as straight forward as it sounds iirc. Share this post Link to post Share on other sites
oli-pug 6 2 Cars Posted June 18, 2007 thanks baz, i was sure i'd done a search on it before and nothing was found! but ive just found a good few threads and the conclusion an xu5j4 = lots of money Share this post Link to post Share on other sites
Baz 421 Posted June 18, 2007 Yeah sounds about right, would be an interesting build though. Share this post Link to post Share on other sites
24seven 104 Posted June 18, 2007 I was talking with veero about an XU5J4 earlier. I'll have a spare XU5 soon that I've nothing to do with, and it's not worth selling on. I'm thinking maybe an Mi1600, then find a car to put it in. Share this post Link to post Share on other sites
Baz 421 Posted June 18, 2007 Yes but as i say, find the thread(s) where it was talked about previously, i think you'll soon change your mind as the oil/water ways don't match up or similar. I'll have a look now actually... Share this post Link to post Share on other sites
24seven 104 Posted June 18, 2007 well, I'll need a project to work on when I'm in uni. could always do something with it then. Share this post Link to post Share on other sites
Hilgie 16 2 Cars Posted June 21, 2007 Oil/water ways do line up. Only issue is an extra tensioner. The hole is already there, just needs some thread in it. Share this post Link to post Share on other sites
welshpug 1,656 Posted June 21, 2007 do it do it!!! should be an interesting engine, shorter stroke with higher flowing head should give characteristics close to the TU5. Share this post Link to post Share on other sites
ginjaspeed 0 Posted July 1, 2007 Hi all, if anyone would like info on a xu5j4 build, i have one sat in my garage that i built myself. Correct it is not an easy straightforward build but does produce some good results. Share this post Link to post Share on other sites
Mandic 0 Posted July 1, 2007 Well I'm interested and I think I'm not the only one, so if You dont mind, You can post some pics and describe more about it in this topic. Cheers & thanks Ziga Share this post Link to post Share on other sites
ginjaspeed 0 Posted July 1, 2007 Sorry i havn't got any pics (destroyed with my old computer, but thats anouther story). The engine is an mi with a 1600 crank and rods. Pistons are JE high compression bought from france (they have these on the shelf), First problem comes with the conrods as these have to be modified to take a bushing as per the mi rod. The next problem is the fact that the block needs to be decked to take up the space that the new piston and rod combination leaves in the bore(at TDC). this needs to be done properly to not upset the seating of the liners in the block!! Even with this the CR is still to low, so the head needs a fairly major skim to bring the CR up to an acceptable level, i've got mine to about 11.5/1. A set of vernier pulleys is now a must as with all the skimming of the block and the head the standard pulleys dont make the right timing for the cams! the rest of the build is more conventional, i added a set of std sizr gpA valves as the standard mi valve size is more than enough for a 1600, some cams sourced for me by a man that used to work at Ravic engines. I converted my cam followers to solids, put her on a set of webber 45's and a maniflow exhaust manifold. Share this post Link to post Share on other sites
Mandic 0 Posted July 1, 2007 Thanks for that, nice spec btw, do You have power&Tq printouts? What about solid lifters, did You buy new ones or? Cheers Ziga Share this post Link to post Share on other sites
ginjaspeed 0 Posted July 1, 2007 the solid lifters can be made out of your hydraulic ones in your engine. You bang the hydraulic part out, then have some shims made to suit the required valve clearence, makes it much cheaper than buying normal solid cam follower! No power printouts i'm affraid, the rolling road i use hasn't got a computer connected to it. I've had two engines on the same rollers, the first was a 1.9 8 valve on carbs and some decent mods which put out 150 at the wheels, the mi1600 put out 175 @ 7400 on the same set of rollers. Quite happy with that. Share this post Link to post Share on other sites
