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#1191994 - 27/03/2011 19:18 atmo cams timing
Sasha Offline
Discoverer

Registered: 18/10/2008
Posts: 36
Loc: Croatia
please some advice of how to adjust timing of atmo cams on 16vt engine rolleyes

thanks, Sasa

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#1192283 - 28/03/2011 11:07 Re: atmo cams timing [Re: Sasha]
Begbie Offline
Ex El Presidente
I AM a Coop

Registered: 16/12/2005
Posts: 12104
Loc: Sandhurst
Vernier pullies
_________________________
Originally Posted By Jonny - After being taken out at Spa
Your car is Usain Bolt with wellies

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#1192381 - 28/03/2011 14:04 Re: atmo cams timing [Re: Sasha]
Julien Offline
On a journey

Registered: 18/03/2008
Posts: 111
Loc: France (Marseille)
You should have a look at this thread :

http://www.fccuk.org/forum/ubbthreads.php?ubb=showflat&Number=1155631#Post1155631

I'm actually mesuring differents fiat cam diagrams to define what are the cam timing you should set up to have 1.6mm of lift at inlet and 0.5mm of lift at exhaust at TDC.

The data will be available in a few weeks (tipo cam : 10.15mm max lift, fiat 16v cam : 9.57mm max lift, stock turbo intake cam 8.5 mm max lift and exhaust turbo cam 7.5 mm max lift)


Edited by Julien (28/03/2011 14:06)

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#1192416 - 28/03/2011 15:02 Re: atmo cams timing [Re: Sasha]
kj16v Offline
My life on the forum

Registered: 12/02/2008
Posts: 1704
Loc: London
Depends very much on when and where in the revs you want to make power and torque. The only way to really tell that is to spend time on the dyno trying different settings, which is what I've been doing recently.

Also, bear in mind that it all also depends on what cams you have; Coupe 16V n/A, Tipo 16V, Coupe 16VT and Delta cams are all different to each other.

I'll post up more about it in the near future, but I can say there's as much 20 bhp and 20 lbs ft difference to be had - and you can't have both!

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#1192485 - 28/03/2011 16:59 Re: atmo cams timing [Re: Julien]
group5lancia
Unregistered


Originally Posted By: Julien
You should have a look at this thread :

http://www.fccuk.org/forum/ubbthreads.php?ubb=showflat&Number=1155631#Post1155631

I'm actually mesuring differents fiat cam diagrams to define what are the cam timing you should set up to have 1.6mm of lift at inlet and 0.5mm of lift at exhaust at TDC.

The data will be available in a few weeks (tipo cam : 10.15mm max lift, fiat 16v cam : 9.57mm max lift, stock turbo intake cam 8.5 mm max lift and exhaust turbo cam 7.5 mm max lift)


I will be very interested to see your results when you publish them.

All the dimension and timing information I have collated is from the internet, so might not be reliable. The most common N/A cam must be the Fiat 7727838 part with 9.57mm lift. From what I have found, standard timing for that in a normally aspirated engine is 1/45 at 0.8mm clearance. In a turbo engine something like 11/35 should give just under 1.3mm lift at TDC - and you could get to 1.6mm lift at TDC by advancing the cam further but I'm pretty sure that the results would not be good. Standard 16VT timing is 8/35 I believe.

With the Fiat 7977190 cam the lift is 10.15mm and the timing is 3/51 at 0.8mm clearance in a normally aspirated engine. For turbo use, advancing the cam to 15/39 would give around 1.6mm lift at TDC I by my rough calculations.

The exhaust valve needs to be more or less on it's seat (0.5mm or less) at TDC, which is what the standard exhaust cam delivers with standard lift and timing. Stock inlet cam gives about 1mm lift at TDC by my calcs.

As I said, it will be good to compare what I have deduced with your own results.


Edited by group5lancia (28/03/2011 17:05)

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#1192507 - 28/03/2011 17:40 Re: atmo cams timing [Re: ]
Sasha Offline
Discoverer

Registered: 18/10/2008
Posts: 36
Loc: Croatia
thanks , we will try and result will be published smile

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#1194629 - 31/03/2011 21:26 Re: atmo cams timing [Re: Sasha]
ragz85 Offline
On a journey

Registered: 22/12/2005
Posts: 148
Loc: Tallinn, Estonia
I will be looking forward to this. Put both the inlet and exhaust cams in my new engine. Have not started the engine yet a couple of days of more work to be done on the car.
_________________________
ex 16VT 12.716s 1/4mile 342hp/466nm GT28RS
ex 16V 2.0 N/A
ex 16v 1.8 N/A
Brera Q4 with SuperSprint

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#1195080 - 01/04/2011 15:10 Re: atmo cams timing [Re: ]
Julien Offline
On a journey

Registered: 18/03/2008
Posts: 111
Loc: France (Marseille)
Originally Posted By: group5lancia
Originally Posted By: Julien
You should have a look at this thread :

http://www.fccuk.org/forum/ubbthreads.php?ubb=showflat&Number=1155631#Post1155631

I'm actually mesuring differents fiat cam diagrams to define what are the cam timing you should set up to have 1.6mm of lift at inlet and 0.5mm of lift at exhaust at TDC.

The data will be available in a few weeks (tipo cam : 10.15mm max lift, fiat 16v cam : 9.57mm max lift, stock turbo intake cam 8.5 mm max lift and exhaust turbo cam 7.5 mm max lift)


I will be very interested to see your results when you publish them.

All the dimension and timing information I have collated is from the internet, so might not be reliable. The most common N/A cam must be the Fiat 7727838 part with 9.57mm lift. From what I have found, standard timing for that in a normally aspirated engine is 1/45 at 0.8mm clearance. In a turbo engine something like 11/35 should give just under 1.3mm lift at TDC - and you could get to 1.6mm lift at TDC by advancing the cam further but I'm pretty sure that the results would not be good. Standard 16VT timing is 8/35 I believe.

With the Fiat 7977190 cam the lift is 10.15mm and the timing is 3/51 at 0.8mm clearance in a normally aspirated engine. For turbo use, advancing the cam to 15/39 would give around 1.6mm lift at TDC I by my rough calculations.

The exhaust valve needs to be more or less on it's seat (0.5mm or less) at TDC, which is what the standard exhaust cam delivers with standard lift and timing. Stock inlet cam gives about 1mm lift at TDC by my calcs.

As I said, it will be good to compare what I have deduced with your own results.


So, I have begun to make some mesurements on the tipo 16v cam.
I'm not sure that we speak about the same think so I want to give some precisions :

the cam diagram at 0.8mm doesn't take into account the fiat valve clearance :
so if you take 0.4mm valve clearance at inlet, you will only see 0.4mm of valve opening at TDC

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#1195099 - 01/04/2011 16:40 Re: atmo cams timing [Re: Julien]
group5lancia
Unregistered


Originally Posted By: Julien
Originally Posted By: group5lancia
Originally Posted By: Julien
You should have a look at this thread :

http://www.fccuk.org/forum/ubbthreads.php?ubb=showflat&Number=1155631#Post1155631

I'm actually mesuring differents fiat cam diagrams to define what are the cam timing you should set up to have 1.6mm of lift at inlet and 0.5mm of lift at exhaust at TDC.

The data will be available in a few weeks (tipo cam : 10.15mm max lift, fiat 16v cam : 9.57mm max lift, stock turbo intake cam 8.5 mm max lift and exhaust turbo cam 7.5 mm max lift)


I will be very interested to see your results when you publish them.

All the dimension and timing information I have collated is from the internet, so might not be reliable. The most common N/A cam must be the Fiat 7727838 part with 9.57mm lift. From what I have found, standard timing for that in a normally aspirated engine is 1/45 at 0.8mm clearance. In a turbo engine something like 11/35 should give just under 1.3mm lift at TDC - and you could get to 1.6mm lift at TDC by advancing the cam further but I'm pretty sure that the results would not be good. Standard 16VT timing is 8/35 I believe.

With the Fiat 7977190 cam the lift is 10.15mm and the timing is 3/51 at 0.8mm clearance in a normally aspirated engine. For turbo use, advancing the cam to 15/39 would give around 1.6mm lift at TDC I by my rough calculations.

The exhaust valve needs to be more or less on it's seat (0.5mm or less) at TDC, which is what the standard exhaust cam delivers with standard lift and timing. Stock inlet cam gives about 1mm lift at TDC by my calcs.

As I said, it will be good to compare what I have deduced with your own results.


So, I have begun to make some mesurements on the tipo 16v cam.
I'm not sure that we speak about the same think so I want to give some precisions :

the cam diagram at 0.8mm doesn't take into account the fiat valve clearance :
so if you take 0.4mm valve clearance at inlet, you will only see 0.4mm of valve opening at TDC


I agree that with 9.75mm lift cam and the original timing of 1/45 the lift at TDC will be 0.47mm with clearance set at 0.4mm rather than 0.8mm. But if you advance the cam to 11/35 - i.e. 10 crank degrees or 5 cam degrees - lift at TDC will be 1.2mm-1.3mm by my rekoning.

However, unlike you I don't have the cam diagrams/graphs, so my figures might be different which is why I am interested to know what you find so I can correlate the two sets of results.


Edited by group5lancia (01/04/2011 17:00)

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#1198353 - 08/04/2011 01:36 Re: atmo cams timing [Re: ]
Julien Offline
On a journey

Registered: 18/03/2008
Posts: 111
Loc: France (Marseille)
So,

I will try to explain with my little english what I have found. I'm missing the fiat turbo inlet cam diagram but it should be done soon.

Before the mesurements, I have checked all the cam max lift and compared to what is given from fiat /lancia.
On this point everything is ok so I guess the cam I have are not too much used...

Fiat tipo 16v (10.15mm) cam :
The lift at 0.8mm is about 232° (
fiat gives 236°) so not much difference here.

This cam is one of the most aggressive fiat/lancia cam for the 16vt engine (see picture below, it's the red curve). We see that the opening of the valve is sooner than all others cams.
I need the results from fiat inlet cam diagram to give you the stock cam timing for this cam used with the turbo inlet cam pulley on (I think it should be the same as what is given by fiat but I have some doubts.)

To have an idea of how these cams or set between each others, I have put them on the same pulley to see what are the results... so the picture below gives the cam diagram when the camshafts are simply "exchanged" between each others without any vernier pulley modification.



Fiat 16v NA (9.57mm) cam : the lift at 0.8mm is only 198° (fiat gives 226°). I have checked many cams from the camshaft (only 2000km) and it gives the same results...

So for me the lift at TDC with this cam on the inlet is 0.58 (0.3mm of gap +0.28mm valve lift)

and to go from 0.58mm of lift to 1.2mm, I have to put 12° of advance at the cam pulley (or 24° to crankshaft).




Then the last one is the fiat 16vt ewhaust cam (7.5mm) : the lift at 0.8mm is 190° (fiat gives 210°)

So for me the lift at TDC is 0mm which should be ok.

Here is the link for the cam curves :

http://img19.imageshack.us/i/camdiagrams.png/

Sorry for my bad English! rolleyes


Edited by Julien (08/04/2011 01:38)

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#1198713 - 08/04/2011 15:14 Re: atmo cams timing [Re: Julien]
group5lancia
Unregistered


Well done Julien - very interesting information. It is very curious that in two cases the durations given by Fiat don't agree with the actual cams. Maybe they changed from measuring at 0.8mm lift to something lower at some point.

Is there anyway you can post/share the data, maybe as a spreadsheet, giving lift value for each degree of these camshafts? Plus the standard cam when you have plotted it.


Edited by group5lancia (08/04/2011 15:16)

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#1198916 - 08/04/2011 19:54 Re: atmo cams timing [Re: Sasha]
sediciRich Offline
we dont need no stinking turbos
My life on the forum

Registered: 19/12/2005
Posts: 1600
Loc: glasgow
be sure to note there are 2 types of tipo 16v cam profiles.
_________________________

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#1198925 - 08/04/2011 20:13 Re: atmo cams timing [Re: sediciRich]
group5lancia
Unregistered


Originally Posted By: sediciRich
be sure to note there are 2 types of tipo 16v cam profiles.


Absolutely - the 10.15mm lift (5 door) cam is Fiat part no. 7697190 and the 9.57mm lift (3 door) cam is Fiat part no. 7727838. I can't find any other cams from Fiat for the 16 valve engine that have the same lifts as these two, so I think that Julien is measuring up the correct cams.

There is a cam used in early N/A Lancia Themas - part no. 7625939 - but that has less lift (only 9.1mm) and slightly longer (published) duration of 239 degrees.

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#1198983 - 08/04/2011 21:35 Re: atmo cams timing [Re: ]
Julien Offline
On a journey

Registered: 18/03/2008
Posts: 111
Loc: France (Marseille)
Originally Posted By: group5lancia
Well done Julien - very interesting information. It is very curious that in two cases the durations given by Fiat don't agree with the actual cams. Maybe they changed from measuring at 0.8mm lift to something lower at some point.

Is there anyway you can post/share the data, maybe as a spreadsheet, giving lift value for each degree of these camshafts? Plus the standard cam when you have plotted it.


Yes I wonder How did they do to give the cam durations. The corresponding lift to fiat cam data would be more around 0.6-0.65mm but not 0.8mm.

I will give you the excel sheet with all the data but at the moment I have only mesured the cam lift every 3° (I didn't have the tools to make better mesurements).

So It would means that the fiat coupe 16v NA camshafts are the same as some version of tipo?

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#1198991 - 08/04/2011 21:45 Re: atmo cams timing [Re: Julien]
group5lancia
Unregistered


Originally Posted By: Julien
So It would means that the fiat coupe 16v NA camshafts are the same as some version of tipo?


My research (again Internet only but cross-checked on multiple sites/references) suggests that the 3 door Tipo cam and the Coupe N/A cam are identical. The same cam appears to have been used in the Fiat Croma IE/Lancia Delta IE/Lancia Dedra IE/and Lancia Thema S3.

This is the 9.57mm lift part no. 7727838

I had hoped that the cam profile you haven't yet plotted is the standard 16VT inlet cam? As that is the one that people will want to replace with the 'best option' and so a comparison would be very useful.


Edited by group5lancia (08/04/2011 21:49)

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#1201651 - 14/04/2011 11:26 Re: atmo cams timing [Re: ]
Julien Offline
On a journey

Registered: 18/03/2008
Posts: 111
Loc: France (Marseille)
There it is (i will translate later from french fiat coupe forum):

So,I have taken out the fiat 16vt inlet cam to take some data :

With 0.8mm of gap i have only 210° of duration; I have to set up the gap at 0.6mm to obtain the fiat value (223°) which confirm my previous ideas concerning the others camshafts (16vt exhaust and 16v NA).

I have corrected the curves as my first try was not very accurate : if we compare the tipo and the 16vt inlet cam, it seems that the tipo cam opens generally later than standard 16vt inlet...and there is more than 20° of difference at the max lift of the cams !!. I wonder if the air doesn't escape a little from the cylinder to the inlet plenum as the intake valve closure is about 60° after BDC


And for those who want to put the fiat 16vt inlet cam to the exhaust, we can still gain some power because the inlet cam opens before the OEM exhaust cam (about 10-12°).

So for me, with the tipo cam at inlet and the 16vt intake cam at exhaust, I think I should try in a first time to advance tipo cam by 8-10°(at camshaft) and to delay the exhaust cam about 4-5°(at camshaft)



This is the curves, I have corrected the tipo one (I had done a mistake in my mesurements)

[img]http://img830.imageshack.us/img830/1713/aack.jpg[/img]

Uploaded with ImageShack.us


Edited by Julien (14/04/2011 14:05)

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#1202089 - 15/04/2011 01:08 Re: atmo cams timing [Re: Sasha]
kj16v Offline
My life on the forum

Registered: 12/02/2008
Posts: 1704
Loc: London
Nice work Julien smile

I take it echappement and admi mean exhaust and inlet?

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#1202141 - 15/04/2011 08:02 Re: atmo cams timing [Re: kj16v]
Julien Offline
On a journey

Registered: 18/03/2008
Posts: 111
Loc: France (Marseille)
Originally Posted By: kj16v
Nice work Julien smile

I take it echappement and admi mean exhaust and inlet?


Yes you are right wink

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#1202213 - 15/04/2011 11:45 Re: atmo cams timing [Re: Julien]
group5lancia
Unregistered


Originally Posted By: Julien
it seems that the tipo cam opens generally later than standard 16vt inlet...and there is more than 20° of difference at the max lift of the cams !!. I wonder if the air doesn't escape a little from the cylinder to the inlet plenum as the intake valve closure is about 60° after BDC


I think it is highly probable that the Tipo has a different cam wheel and that when the cam is fitted to it the inlet opens earlier than the VT and closes later too - but not as much as 60 degrees ABDC.

If you re-plot all the curves so that the peak lifts coincide I think this will show more clearly what happens. At 0.6mm lift the Tipo timing will be something like opens 7 degrees BTDC and closes 47 degrees ABDC - maximum lift 110 degrees ATDC. I would suggest timing of 15/39 for turbo use - maximum lift 102 degrees ATDC. If you are able to publish the data at some point I will plot it myself and show you what I mean.


Edited by group5lancia (15/04/2011 11:56)

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#1202258 - 15/04/2011 12:49 Re: atmo cams timing [Re: Sasha]
sediciRich Offline
we dont need no stinking turbos
My life on the forum

Registered: 19/12/2005
Posts: 1600
Loc: glasgow
don't know if this is already known, but this is the cam data for the tipo 5dr cam

http://img.photobucket.com/albums/v74/sediciRich/0001000.jpg

click to enlarge


Edited by sediciRich (15/04/2011 12:49)
_________________________

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#1202445 - 15/04/2011 19:55 Re: atmo cams timing [Re: sediciRich]
group5lancia
Unregistered


Interesting sedici. From that data it would look like the duration at 0.8 mm is 240 degrees (60 x 4) - assuming the profile is symetrical of course....


Edited by group5lancia (15/04/2011 19:56)

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#1203295 - 17/04/2011 23:35 Re: atmo cams timing [Re: ]
kj16v Offline
My life on the forum

Registered: 12/02/2008
Posts: 1704
Loc: London
Originally Posted By: group5lancia
...I think it is highly probable that the Tipo has a different cam wheel and that when the cam is fitted to it the inlet opens earlier than the VT and closes later too - but not as much as 60 degrees ABDC...


Yep, that's right. When you put the Tipo and 16VT inlet pulleys side-by-side, the keys are almost 90 deg apart. Got to use the Tipo pulley with the Tipo cam.

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#1234241 - 05/07/2011 09:48 Re: atmo cams timing [Re: Sasha]
Julien Offline
On a journey

Registered: 18/03/2008
Posts: 111
Loc: France (Marseille)
BUMP!

SO I have done a few try (+5° at inlet)....and it seems that Guy was right. the engine was idling badly, and I lost some torque between 1000 and 3500rpm but above, the engine feels more free to rev up (at only 1 bar).

The tipo camshaft is not that much different from the original settings (I'm only speaking about lobe center distance from TDC)

I don't know how I did it, but I made a mistake (sorry...)

I will post the new curves tomorrow and try a new settings : -4° at exhaust and -2° at inlet.

Mr GC, I should be able to give you the data in the week.

Stay tuned.

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#1234651 - 06/07/2011 09:47 Re: atmo cams timing [Re: Sasha]
Julien Offline
On a journey

Registered: 18/03/2008
Posts: 111
Loc: France (Marseille)
There it is :

notice that, I have done the mesurements every degree only for the fiat 16vt inlet, all the others cams have been mesured every "1/2 tooth" (I hope it is the right word...)

the cams on the graph are now how they should be if you just exchange them without changing the timing or the pulley.

http://dl.free.fr/pOCWkbA1c


Edited by Julien (06/07/2011 12:52)

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#1234690 - 06/07/2011 11:35 Re: atmo cams timing [Re: Julien]
group5lancia
Unregistered


That is a bad/infected link I think Julien

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#1234712 - 06/07/2011 12:40 Re: atmo cams timing [Re: ]
Julien Offline
On a journey

Registered: 18/03/2008
Posts: 111
Loc: France (Marseille)
Originally Posted By: group5lancia
That is a bad/infected link I think Julien


Oups, i will try an other site wink

This should work better :

http://dl.free.fr/pOCWkbA1c



Edited by Julien (06/07/2011 12:52)

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#1234789 - 06/07/2011 15:26 Re: atmo cams timing [Re: ]
kj16v Offline
My life on the forum

Registered: 12/02/2008
Posts: 1704
Loc: London
Originally Posted By: group5lancia
That is a bad/infected link I think Julien


It's an Excel download so maybe your anti-virus/web browser is blocking it

Julien: Nice work there!

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#1235153 - 07/07/2011 13:52 Re: atmo cams timing [Re: Julien]
group5lancia
Unregistered


Your plots are great - and interesting in that the Tipo cam does not seem to have the same profile as the one in the spec sheet posted above (post #1202258) by sedicirich.

The profile you have produced seems to be asymetric, opening much slower than the other profiles but closing at a similar speed to the other profiles. Because of this I think the cam timing would be hard to guess right for a turbo and would need to be done on a dyno.

The Fiat 16V Cam, on the other hand, looks like it could be good just by setting peak lift at the same point as peak lift on the 16VT cam it is replacing.


Edited by group5lancia (07/07/2011 13:53)

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#1235175 - 07/07/2011 15:06 Re: atmo cams timing [Re: ]
Julien Offline
On a journey

Registered: 18/03/2008
Posts: 111
Loc: France (Marseille)
Originally Posted By: group5lancia
Your plots are great - and interesting in that the Tipo cam does not seem to have the same profile as the one in the spec sheet posted above (post #1202258) by sedicirich.

The profile you have produced seems to be asymetric, opening much slower than the other profiles but closing at a similar speed to the other profiles. Because of this I think the cam timing would be hard to guess right for a turbo and would need to be done on a dyno.

The Fiat 16V Cam, on the other hand, looks like it could be good just by setting peak lift at the same point as peak lift on the 16VT cam it is replacing.


Yes, i think a few try will be neede to find the right timing, I'm now trying -4° (= retard) at exhaust pulley and -2° at inlet cam. It should improve a little bit at high revs without losing too much torque at low rpm.

I have already tried some advance at inlet cam, (+3°) and the engine had way less torque at low rpm, but was easily revving past 4000rpm.

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#1251657 - 21/08/2011 03:38 Re: atmo cams timing [Re: Julien]
kj16v Offline
My life on the forum

Registered: 12/02/2008
Posts: 1704
Loc: London
Being the sad sort of chap who has an unhealthy obsession with engines and doesn't get out much, I've been experimenting with different cam timing on the dyno with my own car and I thought it would be interesting to share the results with you peeps.

The setup is exactly the same for every run - well, nearly. The final run was with forged pistons, but they are still stock size and compression:

>Tipo 16V 5-door inlet cam and pulley, stock Coupe 16VT cam and pulley
>T34 hybrid turbo, 44-trim comp, 63 a/r hot-side, stock turbine @ 1.3 bar
>3"custom downpipe
>2.5" exhaust system & decat
>tubular manifold
>external wastegate & screamer pipe
>cylinder head knife-edged port dividers, but otherwise stock

Every change of cam timing has been remapped to suit.

I traced all the results on to the same chart for easy comparison.

click to enlarge

The picture seems to have lost some of its colour after being uploaded to Imageshack, but these are basic results:

Both cams stock positions: 280 bhp @ 5100 rpm, 333 lbs-ft @ 4000 rpm.
Nice big wodge of mid-range torque, but drops of quickly and dies a death just over 5000 rpm. Well suited to a fast-spooling T3, but a poor match for a T34, which is capable of flowing well past 5000 rpm.

Both cams retarded 1 tooth: 313 bhp @ 6300 rpm, 279 lbs-ft @ 5200 rpm.
Engine now makes more power and further up the revs, but at the expense of a lot of torque. On the road the car feels like it takes ages for the turbo to spool and is sluggish to accelerate. Not good.


Inlet retarded 1 tooth, exhaust stock: 296 bhp+, 323 lbs-ft @ 4200 rpm.
Great torque at low revs. Still drops off sharply, but much better than the first result. We stopped the run before it reached peak bhp but it looks like it would have made similar power to the previous run.
Only one problem. The idle was irritatingly lumpy, with a loss of performance just off-idle. Although this may have been partly down to the MAP sensor at that time, which turned out to be faulty.


Inlet and exhaust retarded somewhere between result 2 and result 3: 321 bhp @ 6200 rpm, 296 lbs-ft @ 5600 rpm.
The exact timing is, well that's my business! laugh Besides, optimum timing will depend on each individual engine's setup. The engine feels like it picks up at 3500 rpm. Then there's a kick at 4500 when the turbo hits full boost and it keeps pulling right to the rev limit. Perfect match for this particular turbo

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