Xu10j4r And Xu10j4rs Heads

[petert 588]

I decided to strip an XU10J4R head that I acquired recently and I can see why Sandy is excited by the whole thing. From my very basic analysis I have concluded the following:

 

34.5 mm inlet

29.5 mm exhaust

6mm valve stems, single groove collets

tapered valve springs

40-41mm inlet port opening

 

This particular head has been ported somewhat by an "expert" so I'm not sure what the inlet ports looked like originally, but I'd have to say there's plenty of potential there. Add the low mass of the valve train and you're well on your way to making a screamer.

 

So my question is, how much do they differ to a GTi6 head? I know the GTi6 head has double springs and there is some variation in valve sizes.

 

Inlet port volume/shape?

Valve sizes?

Chamber volumes?

[Mandic 0]

Chambers are 36cc

[DamirGTI 342]

Valve sizes?

 

Hello Peter !

 

As per OE Peugeot book :

 

 

Xu10j4r (RFV)

inlet valve - 34.7mm (+0 , -0.2)

exhaust valve - 29.7mm (+0 , -0.2)

 

Xu10j4rs (RFS)

inlet valve - 34.2mm (+0 , -0.2)

exhaust valve - 30.8mm (+-0.1)

 

If you need some more info please feel free to ask and i'll make you an copy/scan from this book as theres a lot stuff inside regarding valve sizes , valve spring types/thickness , valve seats , valve guide measurements , camshafts , pistons etc. etc.

 

Regards !

Damir

[Sandy 191]

The thing I particularly like about it compared to the GTi6 (RS) head, is that the ports are a little smaller, which gives scope for more tailoring (no pun intended) of the port sizes/shapes to the spec, than with the GTi6 head, which like the Mi16, is kind of "a bit big already" on the inlet side.

 

I've got both these heads here, I'll try and take some measurements for you later if I get time.

[DrSarty 90 1 Cars]

For the cheap seats please; which vehicle variants are these engines from?

 

1) XU10J4R - ...

 

2) XU10J4RS - is this GTi6?

 

Thanks, Rich

 

EDIT: Found this on AussieFrogs http://www.aussiefrogs.com/forum/showthread.php?t=16651

Edited March 9, 2008 by DrSarty

[Sandy 191]

XU10J4R is regular spec 306/406/Xantia etc 2.0 16v engine. 1997-01 iirc

 

XU10J4RS is GTi6/Xsara VTS engine, 1998-01 iirc

[VisaGTi16v 1]

How does the XU10J4 differ to the XU10J4R? Why is the J4 limited to ~6600 ish in the zx/306/405 mk2 etc when the earlier XU9 Mi16 and the GTi6/VTS lumps both rev to 7200 ish. I have seen a number of rolling road print outs from zx's and they were all climbing at a consistent rate still when they hit the limiter. Do you think a standard engine could have its rev limit upped to 7000 or more or are there components in it that are just a bit to weak compared to the other two engines above and hence the lower standard rev limit? What does the J4R rev to as standard?

 

cheers

[petert 588]

The XU10J4 is basically identical to the XU9J4. Exactly the same architecture and valve train, just a few minor differences like cam sensor and exhaust stud pattern. The cams are slightly smaller, which probably explains the lower rev limit. Yes, it will rev safely to 7500, the same as the XU9J4, if it had enough cam timing.

[VisaGTi16v 1]

Thanks for that info. Staying vaguely on topic, I have read posts on here to do with the XU9J4 oil issues and some mention there is a lot of empty space in the head taking up valuable oil whereas the XU10J4RS does not have this as the area is filled in and it also has another drain hole. Whats the XU10J4® head(s) like in this area? You certainly dont see as many oil related issues on here. Does the J4 use the same cambelt and tensioner setup as the J4RS which can be its weak spot?

 

cheers

[Mandic 0]

-XU10J4 and XU9J4 share similar heads

 

-XU10J4R and XU10J4RS share similar heads

 

Cheers

 

Ziga

[James_m 0]

How does the XU10J4 differ to the XU10J4R? Why is the J4 limited to ~6600 ish in the zx/306/405 mk2 etc when the earlier XU9 Mi16 and the GTi6/VTS lumps both rev to 7200 ish. I have seen a number of rolling road print outs from zx's and they were all climbing at a consistent rate still when they hit the limiter. Do you think a standard engine could have its rev limit upped to 7000 or more or are there components in it that are just a bit to weak compared to the other two engines above and hence the lower standard rev limit? What does the J4R rev to as standard?

 

cheers

 

You sure? Ive seen 306 S16's revving way beyond 7k, iirc, the limiter cuts in at 7200, same as an XU9J4. Though they dont seem to have quite the same fire at the top end as the 1.9's.

In theory it should be more suitable for high rpms than the 1.9 because of the reduced crank throw.

[VisaGTi16v 1]

My ZX 16v was ~6600 but then it was a 93 and for some reason Citroen changed the book figure to 150bhp for a year sometime around then after it initially being 155 so maybe they did something funny to it, emissions problems perhaps but then im sure the 306 S16 was always booked at 155?

 

Hmm this is weird as my ZX red lined at 6500 whereas this S16 at least starts at 7k which would result in a 7200 ish limit as you say so I wonder why the ZX was lower for that year at least. Note how this ebay person thinks its the same engine as the GTi6 sigh..

Edited March 9, 2008 by VisaGTi16v

[petert 588]

Here's a pic of each type of head. You can see why the oil control in the later engines is a lot better - less space for oil to hang around. Mind you, the size/number of return holes is the same.

[chris 417 mi 34 2 Cars]

Very interested in this topic as i have an xu10j4r engine im stripping ready for a rebuild with gti-6 cams & inlet/exhaust manifolds to put into my 405, first question is will the gti-6 cams fit and will i looking at roughtly the same power as a gti-6 engine ?? (got all the bits for roughly £170 including the engine so thought it was worth a try )

Edited March 10, 2008 by chris 417 mi

[Sandy 191]

The GTi6 cams will fit, but you'll need to block the oilway in the end of the exhaust cam.

[VisaGTi16v 1]

Vaguely on topic regarding the ZX 16v, spoken to a friend who has a mechanic contact in Citroen, pre 93, ie 92 ones were 155bhp then in 93 it dropped to 150bhp with the lower rev limit due to some reason with the cat and emissions but very late 93 onwards returned to 155bhp

[guffe 2]

Not quite the topic, but close enough...

 

How can you identify RS inlet and exhaust cams? I have a pair of Xsara VTS cams, but witch is witch? Cams has markings 106 06H16 0016 and 180 09H01 0323.

[Sandy 191]

Measure peak lift (lobe nose height minus base circle), it's about 10mm on both RS cams.

[petert 588]

I think RS inlet and exhaust cams are identical in terms of lift/duration, but physically there is drive on the end of the exhaust cam for the vacuum pump.

[Sandy 191]

Sorry, I thought guffe meant tell them apart from the normal XU7J4 or XU10J4R cams!

 

In a desperate attempt to save face, here's a pic of the cam ends:

 

 

On the left is the inlet cam (plain), on the right is the exhaust cam (drilled end bearing and slotted end). I was using this set in an XU7J4 head previously, so I blanked to servo pump oil feed by tapping it and screwing in the caphead bolt you can see. Driving in a ball bearing would be easier though!

 

A side note from recent experience. There seems to be slight variation in the diameter of the top of the valve guides. I went to use GTi6 stem seals on the XU7J4 head I'm currently building up and they were too small. The non RS heads usually have top hat style stem seals which sit below the spsing, but it seems even these have had a slight diameter change from early to late XU7J4 heads (L3 and L4 types). I had to find a solution because I'm using double springs, so I split some earlier seals out of the top hats and had to heat them slightly to get them over the guides, but it all seems to have worked ok.

[guffe 2]

Thanks for the answers, but still didn't quite hit the spot.

 

I was asking about the RS cams, which is inlet and which is exhaust, BUT I have the Citroën Xsara VTS-ones that do not have the vacuum pump slots at the exhaust end. So can someone tell me from the numbers or other means of identification?

 

But if they are identical so it doesn't really matter which is which, I can fit them either way.

 

ps. sorry about my english, it's been a while since I've been writing and some words doesn't come out straight

[welshpug 1,661]

not sure if it applies to the later camshafts but I remember that Mi16/S16 cams have the woodruff slot inline with the first pair of cam lobes on the inlet and offset by 120 odd degrees on the exhaust.

[Anthony 1,003]

I was asking about the RS cams, which is inlet and which is exhaust, BUT I have the Citroën Xsara VTS-ones that do not have the vacuum pump slots at the exhaust end. So can someone tell me from the numbers or other means of identification?

The Xsara VTS engine that I've got does have a vacuum pump on the exhaust cam, identical to a 306 GTi-6.

 

Indeed, I might be wrong, but as far as I know the engines are 100% identical (except for the badge on the inlet) between a Xsara and 306 of the same age, and only minor differences between engines of different years (cam pulleys etc)

[jonnie205 1]

yes xsara and 306 engines are identical. The loom is different as is the routing of the loom but engines are identical

[guffe 2]

Is it me or don't you just get it?

 

I was asking about the CAMSHAFTS, which is inlet CAMSHAFT and which is exhaust CAMSHAFT. Not the difference about Citroën and Peugeot engines or wiring.

 

I'm starting to regret that I even asked...