Nobbles In Tu3s Exhaust Ports.

[macaroni 17 1 Cars]

Can anyone tell me what the littles nobbles that can be felt in the exhaust ports of a TU3S head are for?

 

They are also in the exhaust manifold.

 

Reason I ask is that I was told they were put there by Peugeot to limit power as when it was being developed, the TU3S engine was approaching 1.6gti levels of power.

 

This could be absolute rubbish, but it might explain what the nobble is for.

 

If there is an element of truth in it, would there be any benefit in removing it?

[christopher 5 1 Cars]

Can anyone tell me what the littles nobbles that can be felt in the exhaust ports of a TU3S head are for?

 

They are also in the exhaust manifold.

 

Reason I ask is that I was told they were put there by Peugeot to limit power as when it was being developed, the TU3S engine was approaching 1.6gti levels of power.

 

This could be absolute rubbish, but it might explain what the nobble is for.

 

If there is an element of truth in it, would there be any benefit in removing it?

 

 

can you make a picture so we know what these look like

[macaroni 17 1 Cars]

No, as a) my head is away being sorted out it is too far up the port to photo.

 

I could try when my head comes back, but I want to know whether it is worth getting them removed while it is at QEP. Mattsav says not, but I want other opinions too.

 

Where did that smiley come from? Oh I see, b )...Hahaha

Edited February 9, 2006 by macaroni

[christopher 5 1 Cars]

No, as a) my head is away being sorted out it is too far up the port to photo.

 

I could try when my head comes back, but I want to know whether it is worth getting them removed while it is at QEP. Mattsav says not, but I want other opinions too.

 

Where did that smiley come from? Oh I see, b )...Hahaha

 

 

I think Mattsav should know best. He has a flowbench too after all.

 

But I don't remember seeing anything like you describe on TU heads I have seen

Edited February 9, 2006 by christopher

[allanallen 528 2 Cars]

youll have to let us know what your heads like when done, tryin to get some 1st hand thoughts on different tuners

[macaroni 17 1 Cars]

Christopher, have you ever stuck your fingers up the exhaust port of a TU head though?

 

Allanallen, there are few, if any, better tuners of Peugeot engines than Matt at QEP, as I am sure many people on here will testify.

I am not getting any porting done (unless someone confirms the nobbles story), although it does have 3 angles valve seats cut from when Matt had it last. Just testing/skimming and the fitment of a 279 degree cam.

[pacey205 2]

As mentioned I doubt youll find a bad word about QEP, friendly bunch of guys and the workmanship is top notch also.

 

Michael

[christopher 5 1 Cars]

youll have to let us know what your heads like when done, tryin to get some 1st hand thoughts on different tuners

 

 

This is some of Matt's handywork on Sams head

 

http://dcoe.net/gallery/qephead/

 

Christopher, have you ever stuck your fingers up the exhaust port of a TU head though?

 

Well maybe one or twice You talking about these casting marks? This is obviously the inlet ports I didn't want to get my fingers dirty

 

 

 

Edited February 9, 2006 by christopher

[Sam 4]

Those pictures are of the head after it has been used, 4k worth. Its a lovely head, really nice workmanship and certainly performed well.

 

I have noticed these lumps before, they are also present on some of the standard exhaust manifolds also. Seen them on both TU2J2 and TU5 heads.

[macaroni 17 1 Cars]

No mate, nothing like that.

 

In each exhaust port, (you will have to get your fingers dirty!) there is a distinct lump about 2" in. Not just small casting marks but a lump.

 

I wish I had taken a photo before I took the head to QEP, maybe if Matt reads this he can take a photo and post it, or at aeast confirm what the lumps are for.

 

Sam, yes they are in the exhaust manifolds too. I was wondering as I have just fitted a 4 branch manifold if it was worth removing the lumps from the head too. Any thoughts?

Edited February 9, 2006 by macaroni

[christopher 5 1 Cars]

No mate, nothing like that.

 

In each exhaust port, (you will have to get your fingers dirty!) there is a distinct lump about 2" in. Not just small casting marks but a lump.

 

I wish I had taken a photo before I took the head to QEP, maybe if Matt reads this he can take a photo and post it, or at aeast confirm what the lumps are for.

 

Sam, yes they are in the exhaust manifolds too. I was wondering as I have just fitted a 4 branch manifold if it was worth removing the lumps from the head too. Any thoughts?

 

I don't seem to have any on my head...very strange

Edited February 9, 2006 by christopher

[Guest smokinslim]

Fingers crossed my manifold's comin off tomorrow so i'll av a peek at mine. If i av got nobbles too i'll get a couple of pics. Not sure if i've a Tu3s or jus a Tu3 tho, whats the easiest way ta tell?

[Rippthrough 98]

I'll have a look at ours if I get time tommorow.

 

EDIT: Son's checked them for you, yes, ours has them too, about 2mm high?

 

Also does the tu3s usually have different rockers to the tu3? Apparently the Tu3s rockers are all about 15g lighter?

Edited February 9, 2006 by Rippthrough

[macaroni 17 1 Cars]

Yeah I guess about 2mm high.

The TU3S head should have a 3S in raised characters on the front "long" side of the head. No idea about the rockers though.

 

So, having established that these lumps do exist, I still need to know why they are there and do they restrict power at all?

[Rippthrough 98]

Yeah I guess about 2mm high.

The TU3S head should have a 3S in raised characters on the front "long" side of the head. No idea about the rockers though.

 

So, having established that these lumps do exist, I still need to know why they are there and do they restrict power at all?

 

 

Hmm, no stamp, but definately lighter rockers than in the other Tu3 we have.

[stu_woac 1]

I thought they were to direct the exhaust fumes as the manifold had them but as indends on the bottom then on the corner of the tube one again on the top

[jacobs53 0]

racing a tu3s engine this year in incarod, so id like to know if there is any perforance gain aswell... as im not suppose to modify but if the lumps are restrictive there never know about them in the first place

 

cheers lee

[macaroni 17 1 Cars]

Sorry Stu, you lost me there. Can you use a bit of punctuation in that sentence?!

[stu_woac 1]

I thought they were to direct the exhaust fumes, as the standard manifold has them but one is a indend on the bottom at the front, then another one on the corner of the tube in the manifold pointing out on the top of the the manifold inside

 

 

this is from memory tho

 

did that make more sence

 

I'm crap at english by the way

Edited February 10, 2006 by stu_woac

[Rippthrough 98]

They smooth out OK.

[macaroni 17 1 Cars]

It does make more sense Stu and I am sure they smooth out OK Rippthrough, but what I want to know is, if my manifold doesn't have them, would it be better if the head didn't have them too?

[Guest smokinslim]

Not very clear on the head, wasn't enough room to get the camera in really.

They can be seen much more clearly in the manifold (upsidedown); 1, 2.

The ones on the head are much further in the ports than on the manifold.

Is there a noticeable difference whey they're smoothed out?

[macaroni 17 1 Cars]

Nice one smokinslim, but that is exactly what I want to know!

[Guest smokinslim]

3rd port from the left on the head, that was the best of a load of naf pics. Couldn't see the viewfinder on my camera as the rad was in the way

[Ted 0]

another pic :

 

http://public.fotki.com/Ted205/various/picture_021.html

 

 

that in the rollerrocker vtr head