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Rail Pressure is Low__seeking confirmation of the Intake Cam's Tri-lobe measurement:

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
I am not in need of this at the moment, but I thought it might be helpful to others. This may be something to remember, or recommend to others, to do whenever you've removed the chain cover for servicing the chain & tensioner and VVT service.

I found the pic below and cleaned up the specs to be more legible. Hoping for confirmation on the dimensions. I will leave it posted for future use when others are struggling to find why the rail pressure is suffering.

This pic is supposedly of the std-K03/BPY (and the like) cam on the EA113 engine. Remember, or know, what is important to produce rail pressure is the cam lift...in other words; the travel/stroke of the piston inside the HPFP.

As we know, the K04 equipped cars have intake cams with a bit more cam lift on the tri-lobe.

So anyway, take a look and if you can confirm the specs in the pic, just comment below please.

Thanks to all who help to help others in the future.
tri-lobe stock measurement.png
 
Last edited:

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
I think this is definitely something worth attempting to avoid having to remove the chain cover. Some calipers may make the reach while some may not, but....so long as cam lift measuring is achieved; 8.75mm - 3.50mm = 5.25mm



tri-lobe measure 1.png


One more way: you can remove the HPFP and use a depth caliper over the HPFP opening. Measure the peak, then rotate the engine and measure again where it is supposed to be 3.5mm to find the cam lift. This way has you guessing where the 3.5mm spot is, but with any luck???
 
Last edited:

Cadbury

Ready to race!
Location
Winnipeg
Car(s)
GTI MKV
Mine was pressed off, and was also damaged by a failed cam follower. I think the majority of the damage was in the center, not near the edges. Calipers show a 0.1mm ish difference between the center and the sides.

All measurements on each lobe/side matched the others.

42.05, 7.84, 3.54


-Cad
 

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ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
Thank you for the addition.

I am more so seeking numbers for when new, when the tri-lobe is mounted onto the cam.
Only so I know if there's a need to edit those numbers in the two pics.
It's difficult knowing the overall measurement when the lobe is not mounted. Given the tri-lobe, when pressed on, fits over the cylinder on the end of the cam. I know it doesn't change much, but.....?

Did you swap lobes because of the follower failure?
What you've shown has me questioning the 42.5mm in the pic I found with dimensions on it (first pic). Because looking at this; 7.84mm-3.54=4.3mm. So if cam lift is indeed 5.25mm, then it would seem reasonable to do; 5.25mm-4.3mm=0.95mm. And so then; 42.05mm+0.95mm=43mm, right? But then how much additional growth takes place once the lobe is pressed onto the cylinder? Maybe 42.5mm is really 43mm+ '.x' ... Or maybe the first pic (the one I found) is truly 42.5mm before the lobe is pressed onto the cylinder. But when removed it doesn't shrink down as much.

Either way, I am hoping for the measurements of a new lobe while on a cam. So folks have a reference for when they go out and check this on their own, while all is mounted. And what may be most important is having the two dimension needed to calculate the cam lift...8.75mm and 3.5mm.
 
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