Gti6 Head Or 306 Xsi Head

[wardy18 33 1 Cars]

In your opinions, which would be better:

 

a GTi6 Ported/Cammed head

 

or

 

a 306 XSi Ported/Cammed head

[Bakes100 20 1 Cars]

Bit of a no brainer isnt it?? Gti6 head every time?

[B1ack_Mi16 67]

Bit of a no brainer isnt it?? Gti6 head every time?

 

Depends, if the XSi head as mentioned is a XU10J4R it's almost the same head as the GTi6, but actually with bigger inlet valves.

The XU10J4R head is very good and gti6 exhaust manifold and inlet etc can be bolted straight on it.

[wardy18 33 1 Cars]

the one im looking at is the 1.8 XSi which is the XU7, the 2.0 XSi is the XU10 isnt it!?

 

Sandy said this head with some work gives great results but then im being told by others not to bother with this head and to go with a GTi6 head

 

grrr what do i do!!!

[wardy18 33 1 Cars]

is the GTi6 and the s16 head the same?!

[24seven 104]

S16 is different to the GTi-6. the 1.8 16v is the XS, the XSi 16v is a 2.0, but the heads of both those and the GTi-6 come from the same casting. Apparently it's not uncommon to use an XS or an XSi head when building a full race spec GTi-6 engine, because although initially the ports and valves are smaller, there's more material to work with in order to get the ideal port shape for the build. Money no object, this would be the better way to go. That said, the gti-6 head is more than suitable for the majority of applications, and is a good alternative to shelling out lots of money getting the perfect spec head. At the end of the day, it depends on what you want to achieve from the engine.

[wardy18 33 1 Cars]

yes see this is why Sandy recomended the XS head because it has more potential for your own port shapes rather than working with large ports already

 

i think im going to stick to the XS head and go with a proper port job on that one to get the ultimate set up and this way seems much cheaper to source the engine itself, GTi6 engines seem more expensive to get hold of and plus the XS has teh 1.8 internals which i may decide to use next year in the hillclimb class

 

if they are from teh same casting and lterally teh same head apart from the ports then i would prefer to start with more of a blank canvas as in the XS head!!

[24seven 104]

in that case I'd do the same also. apparently the 1.8 bottom end is one of, if not the most reliable of the XU engines, but don't quote me on that . Sandy is definitely the man to talk to about the XU7. It's his fault I'm doing what I'm doing with mine

[wardy18 33 1 Cars]

what you doing with yours?! im intrigued................

 

im not sure whether to try and stay in my 1801 and over class with running a standard xu9 1905cc bottom end with the XS head on or frop down to up to 1800cc class with the XS internals planted in a XU9 bottom end

 

not sure yet!!

[24seven 104]

nothing outstanding. Sandy posted about a 309 goodwood he had with an XU7 underneath, GTi-6 cams & exhaust manifold, with carbs or bodies (can't remember) and I think it was the standard head. 130something bhp I think he said, but then I've read in a couple of places that with gti-6 manifolds, 6 cams and a 6 head can achieve 150ish bhp with a decent remap, so I've got my sights set on something similar. all I need now is the head and remap.

[wardy18 33 1 Cars]

I haven't even thought about cams an manifolds yet, will leave this to sandy what he recommends, i think i can use my 8v carbs inlet mani on the xs head once port matched but i have no idea, gotta get the engine first then go from there

[wardy18 33 1 Cars]

What xu is the 306 xsi engine?

 

i keep hearing xu10j4r and xu10j4rs, which ones the 306 xsi engine an whats the difference/gains etc?

[carbers205 1]

the xsi 16v is XU10J4R, the RS is the gti.

xsi is 135bhp as standard, as with XUs lots of bits are interchangeable.

Thought you were going 83mm bore and therefore the 1.8xs head?

[wardy18 33 1 Cars]

Ive managed to pick up a xsi head on the island for nothin so wont bother gettin the xs engine, i can always pick up a xu7 crank etc if i do go down that route but for now i can jus fit the xsi head as standard on my 1905 block, at least then i can get the expense of the conversion done an then build the spec from there, if i do have any spare cash after sortin my house out an buyin a new set of slicks for next season then ill either go for a set of cams or do some block work!

 

thanx for the info

 

are gti6 cams good enough for a race engine or would get a set of catcams?