View Full Version : Cam and springs
Very tempted by THIS (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=170221574672&ssPageName=STRK:MEWA:IT&ih=007), is it worth the money though?
wrinx
Ooh they would be nice.
Would you have to price in a re-map too?
Looks good, if it had been available a few weeks ago I might have been tempted too.
I suppose it depends how far you want to go with the mods, once you start you get it to non-standard cams, remaps, modified turbos, Intercoolers etc, etc, etc,
Got tempted going this route but at the end of the day I will settle for a mildly tweaked road car.
Think I want to know the bhp increase before taking the plunge...
wrinx
Might be worth a call to Guy Croft:
01522 705222
guy.croft[<@>]btconnect.com
Looks like something that will seriously give more BHP, (up to 20% or so) on low turbo pressures.If you do the rest of the mods, 450hp should be achievable (GT28R, big intercooler, 4" exhaust, forged pistons etc.)
you will need a custom remap since this is a major change in volumetric efficiency.
UKP 225 looks like a steal, to be honest, you don't want anything more hot in a turbo engine anyway, unless you'll go drag-racing with it.
Well...the deed is done! Deliberated as I think it's expensive, but the possible gains you've mentioned have sold it for me :D SWiMBO won't be impressed :O
Just got to work out how to fit the damn thing now :lol:
wrinx
cuore_sportivo_155
23-05-08, 12:26
looks like a decent price for what you get...
The seller posts a lot on FCCUK :)
looks like a decent price for what you get...
So do I now, I read some prices on the Fiat forum of ?850 for a pair of cams and I think it was ?250 for the springs!
So I'm happy now :D
wrinx
As the seller writes "could be ideal for turbo aplications when the std exhuast camshft is retained" it sure improves the volumetric efficiency and works as long as you don't increase duration of exhasut cam (= have exhaust valves considerably open when inlet valves open).
Price is ok. It is about what it costs if you buy it directly from C&B and here you got the springs as well. A good affair I would say.
However, more ideal for a turbocharged engine is to increase duration of exhasut cams and only increase einlet valve lift, not duration. Earlier exhasut valve opening makes miracle with spool up and low end torque and it works as long as an eventual overlap is handled with higher (~2 times) lift on the exhaust cam.
I received the cam today,looks good....but I need to find out how to install it properly!
The Tipo inlet upgrade includes moving the current inlet to the exhaust side, would it be worth doing that with this cam or keeping it standard for the exhaust as the seller suggests?
wrinx
There is no information about this camshaft on the C&B webpage, but given the same figures as for the 276 deg. race min turbo cam you will have:
Exh op / Exh cl / Inl. op / Inl. cl
30 bbdc / 0 atdc / 8 btdc / 35 abdc = Original => 8 deg overlap
35 bbdc / 8 atdc / 30 btdc / 66 abdc = New cam + inl. at exh. => 38 deg overlap
Real opening/closing (zero lift) of original inlet cam is 38/65 which means opening of exhaust valve starts at 65 deg before bottom dead center if you but it on th exhaust side with no modifications. You could go up to 90 degrees for good boost performance, so lets say you advance the "new" exhaust cam by 10-20 degrees, then you will have 18-28 degrees of overlap by definition, but quite early closing ov exhaust valve. I would have tried someting like that.
....eek! This is all getting a bit technical for me :lol:
So, if I put the inlet cam in the exhaust side it would need setting up 90deg beyond TDC marks???
Sorry to be stupid but this is a new area for me...from what you say the "new" cam has to be advanced by 10-20deg beyond the TDC mark...think I have a degree wheel gauge somewhere :D
wrinx
I've emailed Guy Croft who has said it has 10.8mm nominal lift and 276 deg duration.
He needs full information "from top to bottom" before being able to advise any further.
Presume he means bore, stroke, cc, cam angles, other????
Any thoughts?
wrinx
cuore_sportivo_155
29-05-08, 11:46
which turbo, which conrods, which pistons etc... all the things that determine airflow AND compression, especially dynamic compression ratio...
Yes Wrinx, camshaft phasing is a mess to visualise or to understand. I try to sort it out:
bb=before bottom
ab=after bottom
bt=before top
at=after top
dc=dead center=highest/lowest piston position=vertical piston speed is zero
Overlap means that both inlet and exhaust valves are open and it occurs around tdc where exhaust valves are about to close and inlet valves are about to open. Since the fuel is premixed with air in the lnlet manifold runners you do not want inlet "gas" to go straight through the engine into the exhaust system, that wuld lead to high HC emissions (HydroCarbons). On the other hand the boost pressure in the inlet "gas" could push some of the remaining exhaust gas out of the cylinder during overlap - if there is a positive pressure balance over the engine. In some operation conditions the exhaust back presure from the turbine will be higher than the boost pressure and that is bad for the scavegning process, i.e. getting the exhausts out of the cylinder.
So, what I say regardng the camshafts is that the first row of figures is the valve opening/closing angles with 0,8 mm lift as specified from Alfa Romeo with stanard cam configuration. If you just put the new camshaft in the engine and take the standard inlet cam to the exhasut side you will have results by the same 0,8 mm lift as specified in the second row. The ovelap is then a bit large for a turbo engine and probably the best thing to do is to advance (earlier opening) the exhaust cam and by that decrease overlap. 90 degrees was just a rule of thumb and I had to translate the valve/cam angles to zero lift to be able to compare it.
By opening the exhasut valves earlier you transfer energy to the turbocharger - there is then higher pressure/temperature in the cylinder when the exhaust valves opens. By doing the reverse you transfer more energy to the crankshaft by letting the hot gas be expanded against the piston to a larger extent - the work being done by the piston is a function of total decrease in pressure and crank angle. So opening the exhaust valve earlier improves the turbo performance when the turbo is fed with less energy than it needs to build up the requested bosst pressure and flow.
/A
Thanks, interesting :)
So, move the inlet cam to the exhaust, retard it 90deg from TDC and stick the "new" inlet cam in 20deg past TDC?
What about leaving the standard exhaust cam where it is and just installing the "new" inlet?
wrinx
Thanks, interesting :)
So, move the inlet cam to the exhaust, retard it 90deg from TDC and stick the "new" inlet cam in 20deg past TDC?
What about leaving the standard exhaust cam where it is and just installing the "new" inlet?
wrinx
I'd clock it close to the values #84 got off the C&B website just to make sure.
I'm trying to keep up honest....:lol:
....so lets say you advance the "new" exhaust cam by 10-20 degrees, then you will have 18-28 degrees of overlap by definition, but quite early closing ov exhaust valve. I would have tried someting like that.
Ok, so put the standard inlet on the exhaust side and move it clockwise 10-20 degrees from TDC mark...?
Is it worth just keeping the old exhaust cam instead of moving the inlet?
On to the "New" inlet, should it be positioned at the indicated TDC mark...or can I not trust it?
Sorry if the questions are stupid....this is beyond my knowledge :rolleyes:
...beginning to wish I hadn't bought this :tapedshut:
wrinx
Sorry if the questions are stupid....this is beyond my knowledge :rolleyes:
...beginning to wish I hadn't bought this :tapedshut:
Relax, it's not that complicated. The new cams have other timing, you are moving an inlet cam to an outlet position. This means that the TDC markings on the cams are not going to be useful anymore, since you are using them for other purposes than they originally were designed for.
This means that you have 2 ways to determine the position they are to be mounted in the car. 1) use a micrometer clock and a degree-wheel and determine at which degrees they open and close valves. 2) calculate offset from the markings using the specifications of the shafts.
Since I'm no hero at doing the calculation I personally would measure the degrees before/after TDC when they open/close. Maybe someone else can do a step-by-step calculation for you to calculate how many degrees the TDC mark should be off for both inlet and outlet?
Who are you going to get to remap your ECU? I'm just interested in who (in the UK) can do these.
Who are you going to get to remap your ECU? I'm just interested in who (in the UK) can do these.
All the locations of the various maps are known, there's documentation somewhere on the forum here. This makes it easier for someone that hasn't done the specific engine before. The hard part is going to be the 4WD rolling road. Having said all this, you'd want a guy that knows this engine really well to get the max out of it without trashing it to bits.
Not really, a turbo engine is a turbo engine to a good mapper, you need someone with the relevant hardware and software to actually tap into the ECU/Eprom, not many have this although it is relatively easily obtained. A RR is not neccessarily needed as you can map it on the road, although 4wd RRs aren't uncommon.
Not really, a turbo engine is a turbo engine to a good mapper, you need someone with the relevant hardware and software to actually tap into the ECU/Eprom, not many have this although it is relatively easily obtained. A RR is not neccessarily needed as you can map it on the road, although 4wd RRs aren't uncommon.
As I stated, all maps and description on how they work is already publicly available so you can bring those to the tuner. "A turbo engine is a turbo engine" until it breaks because the tuner has no experience how far he can push the particular engine in question. It's not just a matter of getting torque out of the engine, but also keeping it in one piece.
Mapping it on the road is less precise than on a rolling road, it's nice to do for a rough setup but you'll want a rolling road for the final setup. A G-tech is a nice tool, but it's not as precise.
I think you got it right. Ask the seller or C&B what opening/closing angles this cam has, then you know what happens if you just fit it as it is. Then I am pretty sure, but not 100 % sure, that you will have the opposite opening/closing values if you switch a cam from inlet to exhaust; i.e. 8/35 inlet turns to 35/8 exhaust. Anyone who knows for sure?
/A
That sounds familiar, they are like a mirror image I think...but what do I know! :lol:
Thanks for the advice guys...not sure whether to fit this now or wait.
Got to replace the belts and water pump in the very near future (like now!) but think I want to wait and get some vernier pulleys to make tweaking the cams much easier...
wrinx
Hi wrinx,
I cant find it just now but C&B has their own website and i seem to remember it gave specs for all of their camshafts ie lift, duration, overlap etc.
i just cant find it anymore??
try a search.
EB spares do C&B stuff too, so they might help you out?
I was quoted 500 and something for a pair for the Q4.
Good luck mate when you go thro with it.
I cant find it just now but C&B has their own website and i seem to remember it gave specs for all of their camshafts ie lift, duration, overlap etc.
The frontpage of Colombo & Bariani (http://www.colombo-bariani.com/risposte.php?lang=eng)
Greetings,
Marc
From their site:
"Colombo & Bariani camshafts can be fitted utilizing exactly the original reference marks.For inlet camshafts with phase variator specific fitting instructions are included in the kit."
That makes it sound easy...just the inlet to exhaust to set up then, or perhaps leave the exhaust as standard :)
wrinx
This cam isn't listed, but thanks for the link, I've emailed them :)
wrinx
Are the prices on the C&B page PER cam or PER pair?????
Per pair I would have thought....or four in the case of 24v engines!
wrinx
cuore_sportivo_155
06-06-08, 12:04
prices are per engine...
For both the EX and IN cams??
cuore_sportivo_155
06-06-08, 14:01
depends if your engine even has an ex cam.... per engine, thus a full set
This cam isn't listed, but thanks for the link, I've emailed them :)
Update, they replied a couple of days ago with the following:
"Dear Sir, you can fit our inlet camshaft with the original exhaust. We don't suggest to move the original in to the ex: we think you can have some problems with the torque to lower rpms.
Use the original exhaust camshaft.
max lift: 10.8
68? / 28?
276 cam degrees
lift @ TDC 1.9
clearence 0.4 lobe
angle 110
Best regards..."
Very helpful I thought :biggrin:
wrinx
they do seem pretty helpful at C&B,
so will only be a five minute job then :D
:D
more seriously tho.
I will be very interested in the "results/improvement" when youve done th swap,
as its something i would still like to change on my engine at some point in the near future.
Its not supposed to be too difficult as once top cover is off its all easily accesible, according to Walkers, but they still wanted a grand or so for the cams and fitting plus VAT !!
where`s the "eek - how much?!?!" smiley...?
Exactly...eek!
I'm waiting on a water pump and will then tackle the belts, pump and cam at the same time...time allowing that is!
wrinx
cuore_sportivo_155
21-06-08, 10:47
on a similar note, are the exhaust valves sodium filled in the Q4/delta engines?
Thought they were all sodium filled???
wrinx
on a similar note, are the exhaust valves sodium filled in the Q4/delta engines?
Yes and cost a lot!!
Inlets are a lot cheaper.
cuore_sportivo_155
21-06-08, 12:47
Thought they were all sodium filled???
wrinx
It's unusual for the intake valves to be sodium filled, but then the whole engine is unusual :)
a word of warning with using higher lift cams and sodium filled valves... even light contact tends to brake the head of a sodium filled valve, so make sure your valve springs are up to the job, as are your conrods. conrods stretch a fair bit (a mm is not uncommon) at high rpm, and coupled with high lift cams might be too much... this wouldn't show when turning the engine by hand, obviously.
maybe it's not an issue with the lower CR of a turbo engine though...
Maybe a thicker head gasket would help in that case.
How on earth do they measure the stretch of a rod at high rpm...:eek:
cuore_sportivo_155
21-06-08, 13:21
my guess, by noticing piston to head impact, but having no clearance issues when testing...
it seems 21m/s mean piston speedseems about as high as you can go with cast rods, or with a 90mm stroke about 7000 RPM.
Finally got a water pump and fetched the cover off to have a look at the cams....and hit the first hurdle! :rolleyes:
There don't appear to be any timing marks on the original cams :doh:
So...I'm a bit stuck with how to fit the camshaft without taking the head off and messing with a dial gauge!:( Or am I missing something?
The C+B cam has been marked for position (presuming it's TDC)...but not in my head of course! So if I line the engine up according to TDC and the timing marks in the picture below...could I then just drop the cam in? There's a small lug on the end to locate in the cam wheel....is there one on the Q4?
http://i7.photobucket.com/albums/y300/GialloEvo94/Lancia%20Delta%20Integrale/Literature/TimingBeltMarks.jpg
wrinx
Finally got a water pump and fetched the cover off to have a look at the cams....and hit the first hurdle! :rolleyes:
There don't appear to be any timing marks on the original cams :doh:
So...I'm a bit stuck with how to fit the camshaft without taking the head off and messing with a dial gauge!:( Or am I missing something?
wrinx
The timing marks are on the pulleys not on the cams (as per your diagram)
Juan AR155Q4
15-07-08, 01:44
And cams have an unique position with the pulleys.
That's what I was wondering. There is a little located "thing" on the end...just hoping there's one on the pulley wheel :lol:
There's always the slot in the other end :D
wrinx
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