JP4 Head conversion

[renagademaster4]

Needing sum help guys , basically tax return time again so got a bit of money cuming my way , thinking of doing a jp4 head conversion on my vts , just wanted more info , a know i can use the cam from my vts and ave read up about the inlet manifold , anyway few questions .......

1) is it worth the hastle or am i better just spending the money on a decent cam ? what gains can a expect using my vts cam and secondly an aftermarket , say 708 type cam for the jp4 head ?

2) can i use the jp4 vts alloy inlet manifold and my vts j4 throttle body ?

any info atoll on this would be greatly appreiated :y:

[gd16]

2) can i use the jp4 vts alloy inlet manifold and my vts j4 throttle body ?


If you can get ahold of one of the C2 VTS inlets - as they're pretty hard to come by. You will need an adaptor plate to get the J4 throttle body working on the JP4 inlet. GMC sell these.

Not to sure what you'd do regarding the ICV though :S As i don't have to worry about that.

[Dboyvts]

If you can get ahold of one of the C2 VTS inlets - as they're pretty hard to come by. You will need an adaptor plate to get the J4 throttle body working on the JP4 inlet. GMC sell these.

Not to sure what you'd do regarding the ICV though :S As i don't have to worry about that.


Gmc also now do a full kit for the alloy inlet. Gives you bigger t/b think its 50-55 mm mounting plate and cable brackets.. will let you know what there like when i order mine

[renagademaster4]

is it only the 206 xsi that had the big valve head ? anybody know the engine code , can get hold of a cheap 1.6 16 VALVE -NFU from a 206 cc , this any good ?

[KamRacing]

I cant really remember much about doing the head swap but I think you need to change the pistons. The head lowers the compression but also the saxo valve cutouts on the pistons are not big enough...

Kev

[Andy_K]

Don't thinkl you have to change pistons, but its better to use a thicker head gasket (the saxo vts standard one is thicker than the jp4 iirc) to space the valves away from the pistons.

Lots of people recommend using saxo vts valve springs, especially when using aftermarket cams, as they are stronger than the JP4 springs.

Cams - saxo vts cams have slightly different lobe spacing to jp4. If you are buying new, probably go for proper fitment cams (cat cams do a range to fit the jp4), but if you have cams already for your saxo vts, they will fit. Several people have been running J4 cams in JP4 heads with no problems (including Tam in his AX as far as i am aware).

You would need cams to really benefit, as I dont think just a head swap would make much difference or be worth the hassle. As Neil and others say above, the alloy inlet is hard to come by and not a direct fitment. However, you can use the standard saxo vts inlet manifild if you redrill/tap hole to suit (not too big a job)