Xu7j4 / Xu9j4 / Xu10j4rs

[easypug 0]

Having recently followed 28Craigs engine build with a XU7J4 and XU10J4RS head I have decided to build some thing similar with the parts I have available.

 

Parts I have to hand:

• XU7J4 complete engine (i've not took this apart yet but I believe it has a XU10J4R head on)
  
• XU10J4RS Head complete with Cams
  
• XU9J4 High comp bottom end (1927cc)
  
• Newman PH4 cams
  

At the moment I'd like to build the following:

 

• XU7J4 Bottom end with the XU9J4 Crank, Pistons, Rods, Liners from Mi16 engine
  
• XU10J4RS Head with Newman PH4's
  
• XU10J4RS Sump (As I have a spare available)
  

In its final spec I would like to be running with 45mm bodies and suitable management.

 

Any thoughts, comments welcome.

[Cameron 16]

Big fat no to the Newman PH4's unless you're running a strengthened bottom end and rev limit of 8-9K. Have a look towards the end of my project thread and see the ballache I had with them at Emerald.

[24seven 104]

I may be wrong, but I think the XU7JP4's and 10RS both have the same baffled sump. This is exactly the engine build I want to put together for my 205 in the next year or two, possibly with some Mi16 liners in the XU7 block as I have a complete Mi in bits lying around.

[Anthony 1,003]

Why bother using the XU7 bottom end fitted with the XU9 crank/rods/pistons? Might as well just use the whole XU9 bottom end if that's the case IMO.

[Anthony 1,003]

I may be wrong, but I think the XU7JP4's and 10RS both have the same baffled sump.

They're similar, but not the same - XU7 sump is more like the design of the S16 sump and doesn't have the bulky cast "wings" that the GTi-6 and XU10J4R sumps have.

 

They are the same fitment however, and could be interchanged, and both fitted to Mi16's and 8v's.

[Cameron 16]

Why bother using the XU7 bottom end fitted with the XU9 crank/rods/pistons? Might as well just use the whole XU9 bottom end if that's the case IMO.

 

That's what I was thinking.. I'd prefer to use the XU7 bottom end in it's entirety, then you get a nice oversquare engine that should withstand abuse much better than an XU9 will. Then you don't have to try and fit the windage tray to the XU9.

[welshpug 1,661]

I'd use the XU7 block and liners, XU9 crank rods and pistons, 10J4RS head, unless your XU9 liners are oversize and suit your pistons.

 

that way you'd have timing belt covers and engine mounting brackets that fit without any messing whatsoever.

[easypug 0]

Big fat no to the Newman PH4's unless you're running a strengthened bottom end and rev limit of 8-9K. Have a look towards the end of my project thread and see the ballache I had with them at Emerald.

 

I've just read through your build and feel your right on that one. Looks like I'll be looking at getting them reground as you did or sell these and go for the PH2's. The car will be used on the road and I don't want to be revving the tits of it every where.

 

I'd use the XU7 block and liners, XU9 crank rods and pistons, 10J4RS head, unless your XU9 liners are oversize and suit your pistons.

 

that way you'd have timing belt covers and engine mounting brackets that fit without any messing whatsoever.

 

The liners are oversized which is why I was going to retain these. I've also read about the covers which although is only a small inconvenience for simplicity is the way I plan on going.

[welshpug 1,661]

xu7 timing belt kit is about £20 cheaper too