Gti6 Cylinder Head

[PumaRacing 1]

Does anyone have a Gti6 head stripped down at the moment? I'm designing some new cam profiles for it but don't have one here at the moment to measure what lift the std springs will take before going coilbound.

 

Catcams ought to know if they've ever measured one but we're waiting to find out if they have.

 

Ideally I need to know the fitted length of the spring as std to a high degree of accuracy and the coilbound length of one compressed in a vice.

 

cheers

 

Dave

[chunkymonkey 0]

Does anyone have a Gti6 head stripped down at the moment? I'm designing some new cam profiles for it but don't have one here at the moment to measure what lift the std springs will take before going coilbound.

 

Catcams ought to know if they've ever measured one but we're waiting to find out if they have.

 

Ideally I need to know the fitted length of the spring as std to a high degree of accuracy and the coilbound length of one compressed in a vice.

 

cheers

 

Dave

dave you have a pm

cheers gaz

[16v205 9]

Hi

 

From memory they go coil bound at 10.9mm. I have a set in my garage id lend if you wanted to measure them.

The other thing I found when fitting Catcams 4903108 Camshafts was the oil spray bar gets in the way.

 

 

Rich

[PumaRacing 1]

Hi

 

From memory they go coil bound at 10.9mm. I have a set in my garage id lend if you wanted to measure them.

The other thing I found when fitting Catcams 4903108 Camshafts was the oil spray bar gets in the way.

Rich

 

Oh dear, that's a PITA. Kind of tricky to run them without spraybars too. So how did you solve that or haven't you yet?

 

Looks like Catcams are going to have to come up with a fix or grind the lobes on a smaller base circle diameter. That then has knock on effects on the hydraulic lifter but they usually have plenty of travel so it shouldn't be a problem.

 

I think the coil bind position must be larger than 10.9mm as the 11.2mm lift cams are meant to be fine on the standard springs but maybe that's not right either. If you were closer I'd come by and measure things. I'll see what Matt comes up with first though.

[TB_205GTI 1]

No one mentioned it, but the XU10J4RS uses double springs - at least according to peugeot parts programme

[James_R 3]

I've got a flow graph of a 6 head, and max flow is at a little over 12.5mm lift, I'll scan you a copy if you want Dave.

 

I've also got a RS head with thew valves back in but not built up. if you want anything measured.

[16v205 9]

Got a pic of the springs. The 2 on the left are the inner/outer double springs from the gti-6 engine. The single spring on the right is the replacement item from Catcams with a Catcam retainer. If you want to measure a set yourself I can pop them in the post as ill not be using them.

 

 

As for the oil spray bars, when we first discovered the issue we contacted Matt @ QEP who put a call into Catcams.

In the meantime my dad and I drew up a little engineering drawing to make some 'top hat' style spacers. It would also involve removing material from the underside of the rocker cover and removing the rocker cover baffle.

We visited QEP with the engine and cam fitted so Matt could see the issue, and again after speaking to Catcams they decided to block the oil passage to the cam spray bars and remove the feed completely.

Apparently because its still using hydraulic tappets there wouldnt be an issue as there will be a puddle of oil sitting on the tappet the cam can splash through.

 

QEP have offered me a replacement cam if it wears at a fast rate. Once I rebuild the engine after losing a piston in the summer ill see how fast it wears as apart from mapping ive only done 100 miles with it

 

Rich

[Sandy 189]

The XU7J4 and normal XU10J4 have the same head and cam arrangement without spray bars. Obviously they don't have the same lift and duration as the XU10JRS, but I've had several high mileage ones with no sign of abnormal cam wear.

[PumaRacing 1]

I've got a flow graph of a 6 head, and max flow is at a little over 12.5mm lift, I'll scan you a copy if you want Dave.

 

I've also got a RS head with thew valves back in but not built up. if you want anything measured.

 

Hi James. I'd be interested to see the graph. Looks like you aren't too far away. Maybe I can come and measure sometime if you haven't fitted it. However unless Catcams alter the base circle size it might be all rather academic so I'll wait and see how Matt gets on with them.

[PumaRacing 1]

Got a pic of the springs. The 2 on the left are the inner/outer double springs from the gti-6 engine. The single spring on the right is the replacement item from Catcams with a Catcam retainer.

 

That retainer looks like it's aluminium. I'm very dubious of those. I've seen them pull through the collets. It does at least look pretty chunky though and no doubt it'll be properly hard anodised.

 

 

If you want to measure a set yourself I can pop them in the post as ill not be using them.

 

Thanks for the offer. I'll see what feedback I get from Catcams and take it from there.

 

 

As for the oil spray bars, when we first discovered the issue we contacted Matt @ QEP who put a call into Catcams.

In the meantime my dad and I drew up a little engineering drawing to make some 'top hat' style spacers. It would also involve removing material from the underside of the rocker cover and removing the rocker cover baffle.

We visited QEP with the engine and cam fitted so Matt could see the issue, and again after speaking to Catcams they decided to block the oil passage to the cam spray bars and remove the feed completely.

Apparently because its still using hydraulic tappets there wouldnt be an issue as there will be a puddle of oil sitting on the tappet the cam can splash through.

 

QEP have offered me a replacement cam if it wears at a fast rate. Once I rebuild the engine after losing a piston in the summer ill see how fast it wears as apart from mapping ive only done 100 miles with it

 

Rich

 

It'll be a pretty minimal amount of oil compared to what would be there with the spray bar working but I guess you'll just have to see what happens. Bear in mind it's not just losing the cam and lifters you have to worry about. The swarf can wreak havoc with the rest of the engine if a lobe fails. That's why Ford CVH engines expired so fast. The cam lobes wore at a steady rate as a matter of course so there was always swarf circulating with the oil. With basically the same bottom end under a non-wearing 16v top end in the Zetec engine you see no bore wear or crank bearing wear at all.

[Guest richardjt]

Hi,

 

Interesting to see that you're investigating cam profiles for the gti6 engine. I've been thinking about installing new cams for some time but there doesnt seem to be much that takes my fancy, other than perhaps catcams. Its my mistrust of most performance camshaft profilers/manufacturers that has held me back so far.

 

The gti6 world is crying out for some good cam options, particularly profiles that offer improvements but retain std parts and clear the spray bars etc (seems to be your aim on reading recent posts), inlet only options are more attractive still.

 

Look forward to hearing how you get on.

 

Rick

[TB_205GTI 1]

Any news on the max possible lift on the XU10J4RS?

[PumaRacing 1]

Any news on the max possible lift on the XU10J4RS?

 

Nope. Haven't heard anything yet. Given how busy Catcams are and that this isn't the most common engine in the world I suspect I might not do either. I think this one will have to go on the back-burner for a while. I won't have time to look into it more for a couple of months now.

[TB_205GTI 1]

Nope. Haven't heard anything yet. Given how busy Catcams are and that this isn't the most common engine in the world I suspect I might not do either. I think this one will have to go on the back-burner for a while. I won't have time to look into it more for a couple of months now.

 

Ok

[Sandy 189]

I posted this a while back:

http://forum.205gtidrivers.com/index.php?showtopic=50516

 

I've got two Gti6 heads in bits at the moment and they're both the same. I'll double check my measurements becausee I can't remember if I was applying safety to those figures or not now.

[Sandy 189]

I've measured again and it's 26.4mm compressed stack, and fitted height of 38.2mm, so coilbound is at 11.8mm lift, rather than the 10.9 I posted originally.

 

The spray bar is 29.5mm from the cam centreline and the base circle is just under 38mm, so 10.5mm would appear to be the maximum lift without alterations.

[whizzer71 0]

So what are the lariest pair of cat cams you can get In a J4RS head without mods changing the valve springs and / or losing the spray bars,Wouldnt mind changing the valve springs but losing the spray bars doesnt really appeal to me !.

 

Cheers

 

Tris

 

[PumaRacing 1]

I've measured again and it's 26.4mm compressed stack, and fitted height of 38.2mm, so coilbound is at 11.8mm lift, rather than the 10.9 I posted originally.

 

The spray bar is 29.5mm from the cam centreline and the base circle is just under 38mm, so 10.5mm would appear to be the maximum lift without alterations.

 

That's handy info - cheers. So it looks like the std springs are not a problem and the spray bar issue could be solved if the cams were ground on a smaller base circle. That leaves the matter of whether the lifter has enough free play in the plunger to cope with a base circle say 1mm smaller which would comfortably allow lifts up to the nearly 11mm the springs will cope with.

 

Do you happen to know how much longer the plunger is when fully extended than the fitted position on a std base circle cam?

[PumaRacing 1]

So what are the lariest pair of cat cams you can get In a J4RS head without mods changing the valve springs and / or losing the spray bars,Wouldnt mind changing the valve springs but losing the spray bars doesnt really appeal to me !.

 

Cheers

 

Tris

 

 

The 248 degree 10mm lift ones. Can't access their site at the moment though. That's a lot of duration for a 16v engine and it wouldn't be very tractable. What I'd ideally like is a mid 230s duration with 10.8mm lift for fast road cars and about 244 with the same lift for track day ones. Those are both easily done if the base circle issue can be solved. Matt is going to chase them up again and see what can be done.

[Mattsav 1]

The new mechanical profiles wen on the site this morning and the hydraulics should be there this afternoon.

Unfortunatley the site has died completely at the moment......