16v Heads

[Pug_101 0]

I was wondering how to tell the 3 different types (I guess more than that if counting both 1.9L & 2.0L) of 16V heads appart GTi6,Mi16 and S16.

I have tried to find this info using the search but no luck.

Has anyone got photos & part numbers of each type that can be posted showing the differences. Also what other hidden differences are there between the heads such as valve sizes, cam profiles, inlet bore sizes etc.

I will soon have a 2.0L 16V from a ZX and also have another 16V head which I believe is from a 2.0L S16. I do not know the differences or which is the better head. So i would also like opinions on which is the best head and why.

I would hope this thread turns into a good resource for people doing the modified engine conversions inthe future.

Thanks

[Baz 421]

Do they have cam covers on them etc? Thats the easiestway to tell straight off!

[Pug_101 0]

Do they have cam covers on them etc? Thats the easiestway to tell straight off!

 

My spare doesn't, The ZX should though . What I do know is that it isn't a GTi6 as there's only 4 ovel shaped exhaust ports.

Cheers

[jochem 0]

The gti6 only has 4 oval shaped exhaust ports. And it has RS written on the gearbox side.

[PumaRacing 1]

The 1.9 and 2.0 heads are very similar. 7mm valve stems, 34.6mm inlet valves and 29.6mm exhaust ones.

 

The Gti-6 is quite different with 6mm valve stems, 34.1mm inlets and 30.6mm exhausts. I prefer the larger inlet and smaller exhaust valves of the other heads.

[petert 550]

1.9L XU9J4 Mi16 - 9 exhaust studs

2.0L XU10J4 1S16/Mi16 - 10 exhaust studs

[dazEmad 0]

I do believe both heads will be exactly the same i have seen pic's before of the engine in a zx 16v and looks identical to the S16 / 2.0 mi16v

 

 

my spec

 

brand new S16 engine (catcams inlet cam) still running in. (covered 70 miles so far)

[Pug_101 0]

1.9L XU9J4 Mi16 - 9 exhaust studs

2.0L XU10J4 1S16/Mi16 - 10 exhaust studs

 

Ok it's got 10 exhaust studs so 2.0L then.

 

 

 

The gti6 only has 4 oval shaped exhaust ports. And it has RS written on the gearbox side.

 

I've seen a head with 8 ports and took it for granted that was the GTi6 head so was I wrong? Is the GTi6 head the only one with 4 exhaust ports & 10 studs?

 

Cheers

Edited June 1, 2006 by Pug_101

[pug309twin40s 1]

im positive the zx16v, s16 and 405 2lt 16v are all identical engines. 155bhp mi16 engine.

[Hilgie 16 2 Cars]

thats correct

[Pug_101 0]

Ok it's got 10 exhaust studs so 2.0L then.

I've seen a head with 8 ports and took it for granted that was the GTi6 head so was I wrong? Is the GTi6 head the only one with 4 exhaust ports & 10 studs?

 

Cheers

 

 

im positive the zx16v, s16 and 405 2lt 16v are all identical engines. 155bhp mi16 engine.

 

Sorry Hilgie which one of the above statements was correct.

[Baz 421]

I think Hilgie was referring to the second statement about ZX16v, s16 and 2.0Mi being the same. This is what i had always thought too.

[Pug_101 0]

Thanks for the replies so far.

I am already a bit confused, so I've cleaned the head up a bit and taken so photos

 

Intake

 

Exhaust

 

Cams

 

Face

 

Pulley End

 

Dizzy End

 

Hope this gets it indentified, all in all does not seem to be in bad nick, are they Vernier pulleys

[petert 550]

I think it's GTi6. Look at the top RH exhaust stud. Note how it's offset, compared to all the others, meaning you can only fit a GTi6 manifold.

[pug309twin40s 1]

yep thats a gti6 cyl head.

[Pug_101 0]

Wow thats a result although it's missing the spray bar.

This should mean I'll have a choice of which head to fit GTi6 and Mi16/S16

My spec so far is looking like this.

2.0L block, Diesel crank (1.8L 88mm stroke unless I come across 2.1L crank), New pistons with better squish design. new ConRods, Finned sump, Best of the 16V heads (GTi6/Mi16/S16), Custom exhaust manifold, standard or shortened intake manifold (later to fit bike throttle bodies and ecu Megasquirt).

I don't want a race engine just a good flexible road engine with plenty of power & torque

Any coments on the above spec?

 

So this now leads on to the question of which head to use.

 

Pumaracing you said that you prefered the Mi16/S16 heas in favour of the GTi6 head. Is that your opinion in standard spec, tuned spec and race spec or all three spec's?

As the GTi6 is the more powerful engine in standard trim how much of that is down to the head? or are other factors like the camshafts resonsible for the better power

I like the exhaust port design of the GTi6 head and also it's better in preventing the oil surge problem, but I'll take advice on this one.

 

I don't really want to do much to the heads, but if theres some work that's well worth doing I will consider it.

Are the camshafts mixable from GTi6/Mi16/S16 and what would be the best combination for road use.

[jochem 0]

Im inclined to say its not a gti6 head. I think its an xu10j4r head, found on a 406 or a head from the 1.8 16v (306xsi?). It should say RS on the gearbox side and it should have the spraybars.

Also i dont really see the mounting point for the cam position sensor, but that might be a problem with my glasses ;-)

Edited June 2, 2006 by jochem

[Pug_101 0]

Im inclined to say its not a gti6 head. I think its an xu10j4r head, found on a 406 or a head from the 1.8 16v (306xsi?). It should say RS on the gearbox side and it should have the spraybars.

Also i dont really see the mounting point for the cam position sensor, but that might be a problem with my glasses ;-)

 

 

Done some checking, bore is about 83mm, Can not find RS on casting, gearbox end or otherwise & no cam sensor.

Therefore would agree most likely 1.8L 16V head

BUT surely good head for 1.9L block 8V to 16V conversion though

 

Ok this heads not much good to me for now as I need 86mm bore for the new pistons

Can the cams and verniers be used in the 2.0L 16V ZX engine? any benefit

Thanks Jochem

[petert 550]

New pistons with better squish design.

 

 

Are the camshafts mixable from GTi6/Mi16/S16 and what would be the best combination for road use.

 

What's wrong with the standard full floating flat tops? With an 88mm crank you'll have excellent squish and 11.1:1 anyway.

 

GTi6 cams are not interchangeable with Mi16/S16.

[jochem 0]

The 2.0 version of that heads is quite nice. The 1.8 version is a slighty shrunken version (if that makes any sense ).

Edited June 2, 2006 by jochem

[Pug_101 0]

What's wrong with the standard full floating flat tops? With an 88mm crank you'll have excellent squish and 11.1:1 anyway.

 

GTi6 cams are not interchangeable with Mi16/S16.

 

Nothing wrong with standard pistons I guess except. As for mine 100K miles means there probably past there best & I've got a set of these:

86mm bore full floating etc..

also this piston can be got with a protruding roof design I am hoping to get soon to compare. I can get these cheap so main reason for using them.

If you've got a set of 2.0L pistons could you measure the gundeon pin to crown distance for me please?

Thanks

[petert 550]

If you've got a set of 2.0L pistons could you measure the gundeon pin to crown distance for me please?

 

Too cold now. In the morning. Those pistons don't appear to have very deep reliefs. And do they have 23mm pins? Mi16/S16 pistons usually wear very well. Probably thanks to the squirters. 100K is fine.

Edited June 2, 2006 by petert

[24seven 104]

Which Mi16 engine is in the citroes BX19? Assuming the 19 means 1.9? If that's so where was the 2.0 version used?

[Pug_101 0]

Which Mi16 engine is in the citroes BX19? Assuming the 19 means 1.9? If that's so where was the 2.0 version used?

 

As a general rule post 1993 year cars are 2.0L as this is when catalysts were fitted.

I don't know what year the BX stopped production, but the 405 is fitted with both engines, pre 93=1.9L, post 93=2.0L. It should be the same for Citroens. I've got a 94 2.0L ZX and they were available with the 1.9L as well and I think the ZX replaced the BX so all 16V BX's should be 1.9L if original.

Cheers

[Pug_101 0]

Those pistons don't appear to have very deep reliefs. And do they have 23mm pins?

 

 

Yes that's why I want to look at the other design. Will be using custom rods so pin not a problem.

If you get those diamentions done I would appricate it.

Thanks