Xu10j2 Head

[Anthony 1,003]

Sorry, but 150bhp would IMO be a very poor result!

Ported XU9 head, pt36 cam, standard induction, kn-filter. Nothing else will net you 155 bhp and 150hp with cat. I had that for several years. The pt36 is just as bad/good as the standard OEM GTI cam.

Can't help but think that was an optimistic dyno, or a *very* good ported head to gain 30hp odd on standard with no other mods of note.

 

Certainly I'd say that suggesting that most people will achieve that with those mods would be very misleading....

[Saveit 0]

I refered to XU9 top on XU9 block.

As mentioned some people get disapointed with the XU10J2 head on the 83mm block.

Anyway more lift help equal flow loss by valve shrouding so your pt27 will help.

Good luck with the tuning/rolling - remember to post your result here. That will be quite interesting

 

Did some slight head work to try to eliminate the valve shrouding. Also made a custom pulley with slight advance to overcome the problems with retarded valve timing when skimming the head as much as you need to when doing this conversion. Skimmed my head by 1.8 mm.

 

Ill post the results here yes.

[Saveit 0]

Can't help but think that was an optimistic dyno, or a *very* good ported head to gain 30hp odd on standard with no other mods of note.

 

Certainly I'd say that suggesting that most people will achieve that with those mods would be very misleading....

 

My thoughts exactly...

[Jakob 1]

Can't help but think that was an optimistic dyno, or a *very* good ported head to gain 30hp odd on standard with no other mods of note.

 

Certainly I'd say that suggesting that most people will achieve that with those mods would be very misleading....

 

 

This was and still is the output of the 1,9 rally / CTI engine with a well ported xu9 GTI head with the PT36 cam with a head from that person. And yes the head was well ported, but other companies should be able to deliver the same job. Before fitting, flow cfm was infomed, expected output AND at what RPM it would hit. Why could it be informed before fitting?, because it has been done multiple times before. And yes on dyno: 150 hp at 6200 rpm precize. It will net you 150hp at all time 155 without cat on proberly running engine.

The small difference here is that you will have a slightly higher CR compared to GTI due to other pistons (rally/CTI). To compensate for detonation you turn the distributer som small degrees to retard ignition. That is all. No funny tricks or holiwood dyno.

 

I would now at all times fit a pt27 cam and a larger one-size throttle >70mm (however I run turbo now), then you will have peak output (hp) at >7000 rpm and a lot more flow. Maybe already from heron go up a size above 2' in exhaust. If you go the step further with throttle bodies and engine management, you are in a hole other class.

 

With the XU10 head: I am just saying that I see people getting less and disapointed with that head on 83mm block. I have today not seen anyone achiving above 155hp without cat with the same specs as above. Maybe I havent read of heart of them. But how will you compensate or change valve shrouding in the block?? You simply cant, then you would need to have the valve going in different angled than vertical. And we all know peugeot only do these angles on 16v heads unlike i.e fiat 8v heads with one cam for each valve. However the XU10 head surely have better flow to start with over the xu9, due to design and 43mm inlet valve, but this is only achieved on 86mm block IMO.

 

At some time I hope to have flow bench XU10 standard, XU10 3 angle ported, XU 9 standard, XU9 ported ALL on 83mm attrap setup. Only then we know for sure about the valve shrouding. Untill that it will only be guessing and some theori regarding valve shrouding which include my own assumptions here!

[wardy18 33 1 Cars]

so there is no way of possibly flaring the top inner lip of each liner to remove the 83mm bore edge and making it open up to 86mm

[Saveit 0]

Sure there is. Just dont go lower than the top piston ring. Will it work? - try :glare:

Edited July 27, 2009 by Saveit

[Tom Fenton 1,542]

Doesn't sound a good idea to me, will promote burning down the side of the piston- not good for piston life IMO. Not to mention significant loss of static compression, plus a very poor squish band.

Edited July 27, 2009 by Tom Fenton

[Saveit 0]

You are right Tom. But if Wardy feels like it i think he should try. We wont know until it has been tried. Practice beats theory :glare:

[DrSarty 90 1 Cars]

Doesn't sound a good idea to me, will promote burning down the side of the piston- not good for piston life IMO. Not to mention significant loss of static compression, plus a very poor squish band.

 

Now Tom's answer is text book, and I would be inclined to agree. BUT - and here's the funny thing - if you're prepared for the potential failure and associated costs, then there's nothing stopping you try it is there?

 

Even if you try it and it goes wrong, I doubt very much that anyone will give you a hard time about it as they now know the reasoning and that it's a brave experiment. In fact I would respect you for trying it as I'm a big fan of thinking outside the box.

 

Personally, I think you have a Dane on here (Jakob) who seems to know a lot (from experience if the figures are to be believed) about tuning the XU9JA (1.9 8v) engine. I was of the impression early on that this XU10 head swap seemed cool and snazzy, but the money was better spent on actually getting more power by clever use of the standard items with tried and tested mods like certain cams.

 

This is one reason I'm doing my 16v tandem build the way I am, because PeterT's tried and tested the route to 180BHP many times. With my changes to push the envelope a bit, we may not get more BHP but we may get a better overall performing engine.

 

Good luck with whatever you choose.

[Tom Fenton 1,542]

I'm all for trying something different- 1600 8v XU turbo- I don't believe anyone else has one.

 

However with things such as this there is a reasonable expectation that they COULD work, how well is not known until tried, but the basic formulae is no different to other tried and tested engines by OEM's and third parties.

 

BUT this idea will not work well IN MY OPINION, even if you ignore the squish and the burning down the sides of the pistons, the compression needed for a race derived engine will be hard or difficult to achieve, so what are you left with- an engine that does not have the neccessary compression for the desired cam profile to work to start with, plus a whole load of other compromises as mentioned, plus the likelihood of needing severly reduced ignition timing, leading to an expensive to build engine, that is probably no better than the same engine with the XU9 head on it.

 

Going back to my initial point; I am certainly not against trying things. But I wouldn't want to see someone throw good money after bad.

[wardy18 33 1 Cars]

im just goin on the fact that i have spoken with Matt at QEP and he is more than happy with this head converted onto the XU9 block, hasnt mentioned any of these issues ie valve shrouding and cr.

 

he said he normally skims them enough to get 11:1 CR which to my ears is pretty good if he can get that even without decking the liners/block

 

i mean anything would be better than a sharp edge to the bore for the flow to get around so even just removing the worst of the edge would be acceptable!!

 

also gotta think about the headgasket being in there too, Matt said to run the normal 83mm gasket but surely that would simply add to the issue, maybe using a 84 or 85mm would be better?!

 

thanx for everyones input by the way, much appreciated and good to read all opinions

[Anthony 1,003]

Standard 83mm XU9 headgasket was fine on mine, and 22k miles later when I removed the head, the fire rings were in good condition, not burnt to a crisp as I feared they might be since they're partly exposed in the combustion chamber. I know others have used the XU10 86mm headgasket, but I wasn't happy with the sealing on the liners with that option, and also there wasn't much sealing area for the main oilway to the head as they are slightly different shapes between XU9 and XU10 - no problems using an XU9 gasket though.

 

The only thing I would say with XU9 head gaskets is try and look at it before buying - there seems to be slight variations in the size of the fire rings between different manufacturers, some of which are narrow enough that there would be very little sealing against the larger 86mm bore of the XU10 head. I've just put a Payen gasket back on as that had the largest fire rings that I found.

[wardy18 33 1 Cars]

so did u find this head better over the XU9 even with the valve shrouding?!

 

is it worth it would you say!?

 

what was ur engine spec

[Anthony 1,003]

As I said earlier in the thread....

 

The head was done by Mattsav at QEP. It was skimmed for approximately 10.2:1 compression, 3 angle valve seats, flowed/tidied valve throats, and the port shape matched to the XU9 manifold. It's running a mild Kent PT36 cam and vernier, and is otherwise standard.

 

No idea on power and torque I'm afraid as I've not rolling roaded it - it feels good and is noticeably quicker than other fresh 1.9 8v's that I've driven, so that's good enough for me. Others that have driven the car agree that it feels quick for an 8v.

For what I wanted from the engine and the costs involved, I would say that it was worthwhile yes - the engine feels eager, revving round to the limiter strongly and yet still happy lugging along in 5th at 1500rpm, and the power delivery suits the character of the car. Would a properly ported 1.9 8v head have made more power? Possibly, at a cost of course.

[wardy18 33 1 Cars]

i didnt wanna spend the 800 to 900 for the proper XU9 BV head

 

this way i can spend £300 and get kinda close to the results but a darn site better than standard head

 

my spec will then be:

 

XU10 Head

11.1 CR

Rally Catcam

Vernier Pulley

Double Valve Springs

3 Angle Valve Seats

Flowed Throats

Twin 45 Webbers

Matched Ports for Carbs mani

H&H Dizzy

 

Standard XU9 Refurbed Block

Helix Ally Flywheel

4:4 CWP in 1900 Box

4 Branch Mani

S/Steel System

 

Think thats everything

 

ive been told with the XU9 head and Webbers im looking 165bhp so with the XU10 hea id like maybe 180BHP, whats anyones thoughts on that!?

[DrSarty 90 1 Cars]

so did u find this head better over the XU9 even with the valve shrouding?!

 

is it worth it would you say!?

 

what was ur engine spec

 

No text speak please. It's gay! It's also in the rules.

[wardy18 33 1 Cars]

sorry boss, force of habit!!

[petert 588]

Doesn't sound a good idea to me, will promote burning down the side of the piston- not good for piston life IMO. Not to mention significant loss of static compression, plus a very poor squish band.

 

It's called "eye browing" and it's quite common. You need to use a copper head gasket however, which also gets relieved, and of course find the CR you've lost in the process.

[wardy18 33 1 Cars]

now thats the reply i like to read......"its quite common"

 

so how deep down the bore would you start the 'eye browing'

 

i assume then a 86mm copper gasket would be needed!?

[petert 588]

With an 83mm bore you'd use an 83.50mm gasket diameter, and remove metal as required. The depth would be just above the mark left by the top ring. It's one of the secrets in making 36.50mm inlet valves work in Mi16 heads on 83mm bores. The lost CR is recovered by using a thinner gasket.

[wardy18 33 1 Cars]

ah ok so from that i assume you cant get an 86mm copper gasket?! do you have to start with the 83.5mm gasket and bore that to 86mm too?!

[petert 588]

Find a picture of an XU10J2 chamber and I'll show you what I mean.

[wardy18 33 1 Cars]

here's an ok pic in its raw condition

[petert 588]

You can see from the pic that the gasket doesn't need to be 86.00mm all the way around. It can be 83.50mm on the squish areas, then taper out to maximum width of the chamber. The liner needs to be eye browed in the area between the green lines. Other people will have their own ideas, but that's what I'd do if building a hot 1.9L with a 2L head.

Edited July 28, 2009 by petert

[wardy18 33 1 Cars]

ah ok i understand what you mean now, thanx

 

so with the eye browing between these lines, would you leave an edge either side of your eye browing or would you smooth either side off?!

 

please see quick pic