Warning Alloy Block And Xu10 Head

[Cactus 1]

Excuse me if this has been covered before as I know there have been a few posts previously covering the various differences between heads. This difference is one I missed and it caused me a bit of a headache and I would hate it to happen to someone else.

 

If you put an xu10 head on an alloy block using xu9 bolts and bobbins you will punch a hole in the block above the water pump which you will then have have to weld up.

 

The reason for this is that the head bolt (no.9 I think) above the water pump sits about an inch deeper in an xu10 head.

 

To overcome the problem I simply turned a spacer to sit between the bobbin and bolt head.

 

I will say that as I was falling into this trap I did notice a slight difference in feel through the torque wrench but I put it down to the threads on the block being less than perfect as it was only very slight.

 

Ho hum you live and learn.

[Tom Fenton 1,542]

All the 8v heads are the same, this "issue" exists on all the alloy block 8v XU's, and the standard cars came with an extra spacer or around 20mm (I have never measured it) fitted to the head bolt you mention.

[Cactus 1]

You see, I just didn't know that but I sorely wish I had. I guess these sort of things happen when you are buying bits here and there and don' t have two complete engines to compare.

[Anthony 1,003]

For the sake of completeness for anyone who finds this whilst searching, there is a difference between the 1.9 and 2.0 Mi16 heads with this regard - the 1.9 has the spacer cast into the head, but the 2.0 doesn't.

 

Thus use a 1.9 head on a 2.0 block and you'll need a longer headbolt (VAG diesel IIRC) and if you use a 2.0 head on a 1.9 block you'll need to add an appropriate spacer to avoid winding the headbolt through the block.

 

As Tom says though, all 8v heads are the same in this regard and it's not unique to the XU10 head - many people have been caught out missing that additional head bolt spacer and punching through the block over the years, so you're not the first and unlikely to be the last!

[welshpug 1,657]

xud ant, with the head turned down a bit.

[wicked 103 3 Cars]

For the sake of completeness for anyone who finds this whilst searching, there is a difference between the 1.9 and 2.0 Mi16 heads with this regard - the 1.9 has the spacer cast into the head, but the 2.0 doesn't.

 

Thus use a 1.9 head on a 2.0 block and you'll need a longer headbolt (VAG diesel IIRC) and if you use a 2.0 head on a 1.9 block you'll need to add an appropriate spacer to avoid winding the headbolt through the block.

 

As Tom says though, all 8v heads are the same in this regard and it's not unique to the XU10 head - many people have been caught out missing that additional head bolt spacer and punching through the block over the years, so you're not the first and unlikely to be the last!

 

Sure it wasn't the other way around? Did punch it through the pump of an 1.9 Mi16 when I forgot the spacer... (long long ago....)

Edited October 9, 2014 by wicked

[Anthony 1,003]

You still need to use the ten "cotton reel" spacers (one per bolt) regardless.

 

It's definitely that way round though - 1.9 head has the additional spacer for alloy blocks cast into the head, whereas the 2.0 doesn't as that additional spacer wasn't needed on the iron blocks.

[wicked 103 3 Cars]

Think you're right..

[petert 586]

I also use one XUD bolt over the water pump and reduce the head diameter.

[DrSarty 90 1 Cars]

I had a load (10) of XUD head bolts all turned down ready for this scenario (XU10 head onto XU9 block) if anyone wants to buy any from me?

 

 

[£7.50 posted ea within UK]