Xu10j4rs block fitting an mi16 head

[Steven Wylie 0 1 Cars]

Hi so as titled I have an xu10j4rs block that’s  been machined and now running the k24 pistons gti-6 forged rods and dw12 crank and just after a bit of info on the options for heads I have an mi16 head that’s been ported sitting that I thought about fitting to it but I also have the standard gti-6 head but it would require work as a couple of the valve heads have broken so just looking to see what peoples opinions are. Thanks 

[SRDT 175]

Both XU9J4/10J4 and RS head designs are good.

[welshpug 1,657]

personally I'd go gti6, get the valve seats 3 angle cut, that will also clean up the throat into the ports.

[petert 586]

It's just a dollars thing. At the end of the day, if both are prepared correctly, they'll flow the same.

 

The RS head has a couple of advantages over the Mi16 head, in that it has double springs and already has a cam sensor fitted. I don't know what your application is and thus double springs may not be necessary for the Mi16 head. It will take a lot more lift before double springs are necessary. Having the cam sensor is a plus, as you can run sequential fuel injection. However, you can also upgrade an XU9J4 head to the same by fitting a thermostat housing from an XU10J4.

 

If using the XU9J4 head, you'll need to buy an XUD9 head bolt to use over the water pump. The other nine bolts can be XU10J4/R/RS.

 

Exhaust manifolds from both will require some form of modification to avoid hitting the firewall.

 

 

[Steven Wylie 0 1 Cars]

9 hours ago, petert said:

It's just a dollars thing. At the end of the day, if both are prepared correctly, they'll flow the same.

 

The RS head has a couple of advantages over the Mi16 head, in that it has double springs and already has a cam sensor fitted. I don't know what your application is and thus double springs may not be necessary for the Mi16 head. It will take a lot more lift before double springs are necessary. Having the cam sensor is a plus, as you can run sequential fuel injection. However, you can also upgrade an XU9J4 head to the same by fitting a thermostat housing from an XU10J4.

 

If using the XU9J4 head, you'll need to buy an XUD9 head bolt to use over the water pump. The other nine bolts can be XU10J4/R/RS.

 

Exhaust manifolds from both will require some form of modification to avoid hitting the firewall.

 

 

Yeah thats what I was thinking use the rs head for them benefits plus I already have the standard loom where as I would likely need to modify the loom to fit the mi16 head as I will be running my throttle bodies again so n/a application only thing is I have a maniflow mi16 manifold for a 205 but might see them if I can get another flange welded on to line up with the Rs head. Cams am not sure yet was looking into the catcams 109 for the RS head but will have to see what I have for clearance on the k24 pistons first. Thanks 

[petert 586]

I looked at that 109 cams for the RS. They're still fairly tame for the street and with the extra cc they'll be fine. Their suggested setup is less than optimal, however. Rather than 110º LCL for both inlet and exhaust, it needs to be more like 106º inlet and 109º exhaust. Thus you'll need to ask them for a revised lift @ TDC figure, when the inlet is set at 106º.

[Steven Wylie 0 1 Cars]

9 hours ago, petert said:

I looked at that 109 cams for the RS. They're still fairly tame for the street and with the extra cc they'll be fine. Their suggested setup is less than optimal, however. Rather than 110º LCL for both inlet and exhaust, it needs to be more like 106º inlet and 109º exhaust. Thus you'll need to ask them for a revised lift @ TDC figure, when the inlet is set at 106º.

Yes that’s what I was thinking. Oh right thank you that’s great to know I can get in touch with them and see. They also have 110 and 112 but again I would have to see what clearance there is on the valve reliefs as it’s just standard k24 pistons 

[IRISH_MI16 2]

On 1/22/2022 at 1:53 PM, Steven Wylie said:

Hi so as titled I have an xu10j4rs block that’s  been machined and now running the k24 pistons gti-6 forged rods and dw12 crank and just after a bit of info on the options for heads I have an mi16 head that’s been ported sitting that I thought about fitting to it but I also have the standard gti-6 head but it would require work as a couple of the valve heads have broken so just looking to see what peoples opinions are. Thanks 

What pistons did you use?

[Steven Wylie 0 1 Cars]

On 2/8/2022 at 9:11 PM, IRISH_MI16 said:

What pistons did you use?

Hi am using standard k24 pistons with the top machined down