Common rail heads

LOL You are stubborn .. if you look better on bmw-audi-mercedes-psa-duramax etc pumps, sprocket and shaft dont have a slot cut into them to keep them in position like your 2.8 crd pump.
Thats the 1st one i see with slot so you can only mount sprocket in 1 position only.
Tightening is offered by the nut and cone shape..it's enough.

Actually so far on this topic i'm the only one to have posted some photos of an actual ported head, my own. I am actually trying to do something , not just talk talk talk, and trying to share what i do so maybe others can follow.
Not an expert, learning on the way by trial and error.

Some guys have given me great advice on how to proceed..thank you..you know who you are.

Please open a thread abut timing and invite drivebywire , you will both agree i am sure.

diffas said:

Read again. Valve control ... Indeed more boost will fix it

Click to expand...

I do not think valve float is an issue.

Did you see my dyno charts? And Lambda logs? Which no-one else has shared?

You think we are hitting valve float at 250bhp at 3000rpm? Which is where my power flatlines at 255bhp and adding more fuel just makes more smoke which extra boost does not cure?

It is absolutely a LACK OF AIR FLOW. 1.1 Lambda proves this.

That seems to be an issue with core understanding. So I'm out of this discussion.

I will be posting results soon with new hardware.

Since seems like you have everything figured out already no need to continue.

But to others adding more fuel and more boost and your max hp rpm keeps dropping to lower rpm. Max hp should be around 4000-4400. Similar problems are on for example on bmw m57 engines. Marko of NPS has some experience about that last time I visited there and tried to find springs for my engine. And to be honest porting head is never bad thing, but it's not the main problem at this small power levels. I believe he had some dyno chart somewhere before and after springs+headwork. Difference was huge.

You can see one of my daily tune dyno runs and the experimental tune with 2.7 bar and more fuel.
The power line was a direct trace. So we did not find that true at all.

We are already doing well over 100mg IQ on daily tune. At that amount of boost / airflow you have clearly and hitting some flow efficiency problems.

The power would undoubtedly climb if it wasn't for a lack of air to mix with the fuel available! Hence you get that weird black sooty air out of the tail pipe.

Edit to add:
I'm not saying that upgraded valve springs won't work or help, but the head is the key.
The heads are very poor for power and designed for emissions and swirl air rather than flow.
Lambda proves that.

2.7bar is a joke.

2.0 CR camshafts have gentle deceleration (acceleration) profile over nose and they work well with stock boost and RPM with really low stock spring pressures.
Though lobes have odd kink before acceleration ramp starts, that may cause odd behavior at high RPM.


If you do the math, valves start to open with pressure above 2.5bar.
That would of course mean that cylinder pressure would need to be 0bar to make 2.5bar pressure ratio.
But also this means that if there is any pulsing, or cross talk, pressures are more than measured static boost or EMP pressures.

Valvetrain is definitely not happy when seat pressure approaches 0 and can get easily out of control.
Typically issue gets worse with more boost and HP just moves lower in RPM, but does not raise.. and actually usually takes dive after peak.

And something for the topic, sorry about above off topic:
Cylinder head cross section should be good as stock for RPMs seen here, but not much higher if you calculate the air speeds.

Porting actually improves intake valve stability if cylinder head is restrictive as it balances pressure before and after the valve making delta P smaller.
I have "fixed" some spring problems with porting =)

Great explanation. Do you think the CUAA valve springs are much stiffer than cr140/170?

Thanks for the post Marko. It looks like you are getting more interested in the CR engine now. That is nice to see. If everyone feels that the current hp barrier is related to valve float, then there is a good spring option that I have looked at. Ferrea spring on left, vw OEM spring on right. You can use oem retainer. I have tested this spring on the bench and it is good for mild upgrade. I am using custom double spring on my build. I might try a set on my cr canyon. Ferrea is a bit pricey. Test at your own risk of course.

MarkoP said:

2.0 CR camshafts have gentle deceleration (acceleration) profile over nose and they work well with stock boost and RPM with really low stock spring pressures.
Though lobes have odd kink before acceleration ramp starts, that may cause odd behavior at high RPM.

If you do the math, valves start to open with pressure above 2.5bar.
That would of course mean that cylinder pressure would need to be 0bar to make 2.5bar pressure ratio.
But also this means that if there is any pulsing, or cross talk, pressures are more than measured static boost or EMP pressures.

Valvetrain is definitely not happy when seat pressure approaches 0 and can get easily out of control.
Typically issue gets worse with more boost and HP just moves lower in RPM, but does not raise.. and actually usually takes dive after peak.

And something for the topic, sorry about above off topic:
Cylinder head cross section should be good as stock for RPMs seen here, but not much higher if you calculate the air speeds.

Porting actually improves intake valve stability if cylinder head is restrictive as it balances pressure before and after the valve making delta P smaller.
I have "fixed" some spring problems with porting =)

Click to expand...

I didnt do any calculations, but ive run over 3 bar boost at 5k4 rpm and measured over 1400 kg/h airflow with stock springs.. and yes I am talking 2 l displacement.

3.0 v6 biturbo runs also same springs as cr140, and runs 2.4 bar boost stock till over 5000 rpm. Now u say this engine has 0 safety margin on valve float?

Rub87 said:

I didnt do any calculations, but ive run over 3 bar boost at 5k4 rpm and measured over 1400 kg/h airflow with stock springs.. and yes I am talking 2 l displacement.
3.0 v6 biturbo runs also same springs as cr140, and runs 2.4 bar boost stock till over 5000 rpm. Now u say this engine has 0 safety margin on valve float?

Click to expand...

Not arguing with you about valve float but part of your nice flow is because you have different valves. Not playing fair Rubin.

CCWA handles 2.7bar pretty well also
Stock springs - in fact stock engine no porting.
059109633J

Rub87 said:

I didnt do any calculations, but ive run over 3 bar boost at 5k4 rpm and measured over 1400 kg/h airflow with stock springs.. and yes I am talking 2 l displacement.

3.0 v6 biturbo runs also same springs as cr140, and runs 2.4 bar boost stock till over 5000 rpm. Now u say this engine has 0 safety margin on valve float?

Click to expand...

I'm quite sure some people ..read above, have made some nice power on the 2.0 CR but keeping quiet , Ruben for example and his "friend" VVT, i have no doubt. Seen VVT 270hp dyno and 300hp on the same dyno ..telling you for months it can be done without issues.


Ferrea springs are quite expensive, would be nice to have something better than stock ones to work with camshafts.


Darkside has the BKD springs 20% more than stock for 9mm lift they say.
Bobby: our CR have the same 059109633J springs inside

TDIsyncro said:

Thanks for the post Marko. It looks like you are getting more interested in the CR engine now. That is nice to see. If everyone feels that the current hp barrier is related to valve float, then there is a good spring option that I have looked at. Ferrea spring on left, vw OEM spring on right. You can use oem retainer. I have tested this spring on the bench and it is good for mild upgrade. I am using custom double spring on my build. I might try a set on my cr canyon. Ferrea is a bit pricey. Test at your own risk of course.

Click to expand...

Hello Louis,

Have you been on drugs when you chose these ferrea spring?

I would advise you and others to first measure the installed height on the
Cr head before ordering 300 US worth of springs that wont fit

I found some springs with correct length and allow 10mm lift 35kg seat press and 50 kg at 9mm lift. Which is in my optinion much betterfind than the darkside springs which only allow 8.5mm and have way too much pressure at max lift....

Hope somebody will put somehing on the market that will allow more lift because right now there is no alternative to oem springs for more lift.
Or maybe Ruben wants to share his secret finding helping those 10 brave around the world to mount camshafts on the CR head.

Rub87 said:

Hello Louis,
Have you been on drugs when you chose these ferrea spring?
I would advise you and others to first measure the installed height on the
Cr head before ordering 300 US worth of springs that wont fit
I found some springs with correct length and allow 10mm lift 35kg seat press and 50 kg at 9mm lift. Which is in my optinion much betterfind than the darkside springs which only allow 8.5mm and have way too much pressure at max lift....

Click to expand...

lol. nice choice of words.

ok. I made a mistake about retainer. Its has been 5 years since I have looked at the spring. I refreshed my memory in my notes now. Let me clarify.. it does not fit installment with factory retainer. It requires a retainer with 1mm offset. The valve pockets also need to be cut 1mm deeper. Perhaps OEM retainer could be used if head is cut 2 mm deep but I do not have a sliced up head to know if that depth is ok. This gives coil bind+2mm for max compressed height with OEM lift cam. (and there is only one exhaust valve/cyl with this lift, the other three valve lifts are less in varying amounts) I agree it does not work with aftermarket cam lift. Now...we are all working on experimental engine modifications here. If anyone rushes out and buys 16 springs without buying one for testing first, then they are probably not equipped to be doing this type of work.
I am surprised you found a single coil spring solution that fits the OEM space All the materials we ran simulations on did not look possible. You have some special wire material property or square wire product or you went larger O.D.? Are you going to share your spring or....your leaving us hanging... At least repackage it and sell it.

Since i'm trying actually to do something and not just waste everybody's time, maybe some advice-indications will arrive from the more knowing guys out here.
I would pay for better springs to use with dbilas camshafts 9.9mm lift.
On exhaust side with 9.4mm lift, OEM springs have 0.5mm coil distance at maximum lift, just measured mine.

In photo the intake spring at max lift with 1mm distance, pass.
Exhaust has 0.5mm

The CUAA valve springs are part # 03N 109 633. They are $7 each. I have no idea if they fit cr140/170 engines, but might be worth looking into.

turbobrick240 said:

The CUAA valve springs are part # 03N 109 633. They are $7 each. I have no idea if they fit cr140/170 engines, but might be worth looking into.

Click to expand...

worth looking at for sure. Thank you for the post. I will order one and check it out unless someone has already. (?)

I will order one tomorrow to see how it goes. If the head is much better its not 100% certainty that spri gs are also better.

OEM springs are 43mm height and 21.35mm diameter

Whats the install height?

close to 31mm

Let me see the measurements i took
install height of intake is 37.8mm average with retainer
exhaust is 34mm with retainer

something tells me that is very unlikely that there is almost 4mm different install height between in and ex. and that vw uses same spring.. 0.4mm I can believe

you know yourself coil bind of vw spring is 21mm, now you say installed height is 34mm and you say 8.5mm is max stock lift possible..

there is a difference in spring location pocket, exhaust sits at 102.6mm from head surface

intake sits at 106.1 mm from surface
surface to retainer mounted is pretty consistent 68.31 highest one
106.1-68.31=37.79mm height of spring with retainer mounted intake

102.6-68.6=34mm height of spring with retainer , exhaust side

I measured inlet this evening 33.5 with retainer (2.6) so you have approx 31

We must be having different heads Bobby because my Intake spring mounted with retainer is at 37.79mm
Intake and exhaust springs have different compression on my head.Spring pockets have different depths

What head part number you have?

03L103373E V280 the one ported and ready to be put on the car.
Measured on another head now, V260 , exhaust pocket is 3.5mm higher than intake. I'm pretty sure its identical on your head
Retainer is 2.5mm

The head I have is 03L103373 v260 - Engine code CBBB

Macradiators.com said:

We must be having different heads Bobby because my Intake spring mounted with retainer is at 37.79mm
Intake and exhaust springs have different compression on my head.Spring pockets have different depths

Click to expand...

May be you guys have different valves with different valve stem length? And what about how valve sits on valve seat? Both of those affect your install height too. I measured 33.4 mm and moved it a bit with custom springs but tip of valve needs to remain the same with factory base circle cam. If you cam is a regrind your tip can extend up more to take up the reduced base circle. Top of retainer can also be moved up a bit before it interferes with the cam follower. Make sure tip of valve is in the right place.