What To Do With Xu10 Top On Xu9 Engine?

[martin81 1]

I apologize my English...

 

I need to know how much is needed to be grinded off the XU10 top, so that the compression is ok, for the XU9 buttom??

 

I have a 205 1.9 CTI, which has the same engine as a 1.9 rally.. It's a DFZ engine with 102bhp..

 

My plan is to put that top on, which has larger in and out valves, and then a standard gti cam for starters. Ill buy a sportcam later, or ill get the gti cam reprofiled(cheaper )...

 

but how many milimeters is needed to be grinded off, to get perfect kompression??

 

Anyone??

Edited February 21, 2008 by martin81

[martin81 1]

any1??

[tony perks 1]

Not sure how much to remove from head but make sure the oil return holes in the gasket at the gearbox end line up or you will get an oil leak, we use this head on a class 6 autograsser i will have to find build sheet and let you know but we used mi16 pistons so cc's wont be right for you.

[petert 588]

The DFZ head has big chambers and small dished pistons (like a 1.6L GTi.) So putting on an XU10J2 head will see an immediate increase in CR, probably around 10.5-10.8:1. I'd cc the XU10 head first before doing anything. The DFZ pistons have a 9cc dish and 37.50mm compression height. Thus zero deck height.

[martin81 1]

But the CR is 8,4:1 compared to 1,6 gti's 9,6:1 standard.. Doesn't that make a diff to the CR with the XU10 head fitted??

I mean if the CR is high (eg 10,5:1) when fitted to a GTI, then wouldn't it be around 9,5:1 when fitted on the DFZ??

The pistons are also different from the GTI! which causes the low CR on 205 1,9 rally/ CTI(DFZ engine)

 

Can't I just use a standard gasket, when fitting the Xu10 head? never heard about the oil holes shouldn't fit? But if you say so, i'll make sure thx

[petert 588]

The DFZ piston has a 9cc dish and the chamber is approx. 47cc. On an 83x88 combination this gives 8.4:1. If you put on an XU10J2 head, which is approx. 36cc from memory, you'll have 10:1. Perhaps I have the volume wrong on the XU10 head?

 

Are you using a compression ratio calculator?

[wardy18 33 1 Cars]

the xu10 head and xu9 are the same heights (or so Damir told me)

 

ive attatched a sheet showing the height etc