New cams

[jimnielsen]

I have some new toys for the Q4 - A set of higher lift, longer duration camshafts. They also came with a new set of springs (because the OEM ones would bind because of the extra lift) and different retainers..And also a set of adjustable cam pulleys.

I have not decided yet whether to install them in the short term or not yet - depend on how the cars goes over the next little while.


jim.

[Steve Webb]

Looks interesting Jim, what are the figures for the cams like compared to the standard ones, and the 16v Tipo one that is always cropping up?

[1NRO]

When you do run them remember to use some rpm above idle straight away so as not to glaze the lobes.

Pretty smelly eh!:lol:

[jimnielsen]

Thank, Nik, I will.. Steve. The cams are 11.3mm lift on the intake and 9.8 on the exhaust.

.... see the pic in below in this post - I am planning on putting the new cams in my 'spare head' at this stage. I notice that the small channels under the top of the first cam bearing (closest to the pulleys) are filled with silicone? Is this standard practice? I didn't do it on my last head - should I just remove this gunk?


jim..

[jimnielsen]

I have decided to make a start on putting this 'new' head on the Q4 that contains the new cams - So.. off comes the old head yet again..

In the process I am also going to

(1) increase the injector size (again...).

(2) provide multiple connections on the inlet plenum to try to smooth the fluctuations in manifold pressure that the boost controller has to work with.

(3) fix the gasket that is between the base of the exhaust manifold and the turbo casting (again..)

(4) get a more accurate fix on TDC

(5) set up these new cams..

[jimnielsen]

.. now i see why the gasket between the turbo housing and the exhaust manifold had blown... I have lost a bolt from the flange...

valves look in good condition..

[Steve Webb]

Those studs and nuts are a little bit special as I recall. Is there supposed to be a washer is there as well?

[Xti]

Those studs and nuts are a little bit special as I recall. Is there supposed to be a washer is there as well?

As I remember there must be some kind of "straining" washers to prevent the nuts from unscrewing.

[Jan]

better is double nuts or nuts with steel locking special for turbo or hot application

[jimnielsen]

The 'spring washers' that come with this 'ebay manifold' are worthless and lose their spring in just one day at the track. I replaced them all with 'cone nuts' that have a locking mechanism, but the actual stud has come out of the hole in this case - the cone nut is assuredly still attached to the stud somewhere around some racetrack.

The studs provided with this system assist the fitting of the manifold because of the way they are short and have flattened ends - but the thread construction is poor and the fitment in the stud holes is far too loose.

However, the system can still be made to work well if you simply replace the provided nuts and washers with cone nuts..

[Steve Webb]

Do you think the problem with the studs\nuts lies with the material that they are made from?
The original Alfa items are pretty pricey for what they are so no doubt contain a high percentage of 'unobtainium' in them.

Has anyone else noticed the different finishes that some of the bolts on the Q4 have? The standard bolts look, well, pretty normal. The high tensile stuff for the subframes etc have a finish that looks almost like brushed aluminium, whilst if I remember correctly the high temp stuff around the turbo is black in appearance.

[jimnielsen]

.. a bit more progress - put in the new injectors (I am changing from Siemens DEKA IV 107961 to 110324). So that's moving from 60lb/hr to 80lb/hr - 33% more fuel - finally that should be enough...

[SteveNZ]

Hi Jim

Can you use the OE sutds and nuts from the OE manifold? They don't usually come lose.

I would not use a gasket there at all. Make sure the surfaces are flat, use large steel washers to spread the load if you can.

[wrinx]

That's what I did, the ones supplied with the manifold are absolute pants but the originals have a wire in them which tightens on the thread.

wrinx

[jimnielsen]

wrinx - are you sure that the oem studs fit into the tubular manifold that we have? The other end of the stud - the bit where the nut goes on is a different thread, but I have not removed the stud to check if that will fit in the tubular manifold...

SteveNz - the surfaces are just not flat enough to run sans gasket - will recheck though..


...later on..Wrinx - the oem studs do fit.. and steve the surface ARE flat enough so I will not use a gasket at all!

jim..

[jimnielsen]

Made a little more progress today - drilled two additional holes in the inlet plenum and fitted connections for rubber tubing.

I am going to use these three connection labeled A, B and C for the ECU map sensor to try and smooth out the manifold pressure. I have made the additional connections A & C - but what is the connection "B" used for on the standard unmodified Q4?

Also used a more accurate means of determining crankshaft TDC. I was about a degree out in my earlier "guess"...

[Steve Webb]

Its not where the fuel pressure regulator connects into is it? Strange place to put a connector as its totally inaccessible with everything back together.

[SteveNZ]

SteveNz - the surfaces are just not flat enough to run sans gasket - will recheck though...

Thats your problem in a nutshell then. You will always have problems with gaskets blowing and studs breaking if the surfaces are not flat.

[jimnielsen]

More progress - i have put the head back on and torqued up the bolts. Everything has gone to plan so far - tomorrow I have to do the part I am less familiar with...

using a couple of guide bolts really helps the process of putting the head on when you are doing it by yourself. I also helps to measure the angle of the motor and configure the head at the same angle so that it slide down the bolts easily...

[Jan]

connection B is original map sensor!

What kind a app is that??

[jimnielsen]

just a 'bubble level' app... there are millions of em...

[jimnielsen]

Set the new cams up today. Its actually more straight forward than I'd imagined - you just set the crank at TDC, then position the cams in the required places and pop the belt on. The correct places for the cams are measured off the shim face with a dial gauge. Its very simple to put the belt on than because the teeth on the cam wheel move independently of the cams so its simple to mesh the belt teeth in..

[jimnielsen]

connected up the rest of the system this morning and the car fired up right away. running a bit lumpy at present with the new injectors - will be taking the car to the dyno in a week or so to fine tune...

jim..

[Steve Webb]

Jim, with those new injectors, and running E85(?) fuel do you have enough resolution with the fuel system at low revs to control the fuelling properly?
Just wondering if you would run into problems with bore wash at low rpm, not of course that you ever really use low rpm with it being a track car.

[SteveNZ]

I would hope an Autronic would have enough resolution.

[Steve Webb]

I was questioning more if the injectors could deliver the necessary resolution rather than the ECU.

[jimnielsen]

These injectors are really only suited to racecars (in my opinion) - but they are a modern high performance injector with low latency and very low recovery time. I am more worried about cold starting and idle stability really. I did a cold test start this morning and the car started no problems at 4 degrees centigrade, so I am pleased with that!!

Perhaps I should have opted for the Injector dynamics ID1000 injectors - they have even better resolution, but are not so easy to obtain here...

just a note - I am using these injectors @ 50 PSI (3.5 bar) static where they yield 900cc/min.

Anyway that is it for this car except that I need to make it all work properly....but I am planning no more changes to it (assuming that these new cams actually do what they are supposed to do.......)

[Steve Webb]

Regarding cold starts, I was at the Goodwood festival of speed back in 2000 and the first step in the start up procedure for the 155 v6 ti was to get a large gas fired space heater and blow hot air over the engine.

4c would be considered a hot start back in the UK given the state of their summers.

[jimnielsen]

One of the consequences of using these new cams (other than more power) is more exhaust gas..because of this the internal wastegate just does not function properly any more. Base boost is set at 1.1 bar, and that works ok, but after 5000RPM once the wastegate opens it does not flow enough gas to control the boost properly. So we have used a dual chamber BOV to bleed off some air on the inlet side - the bov is actually controlled by the boost controller - the spring in the wastegate sets the minimum boost...

The injectors I am using can deliver 900cc/min - but I am now using 95% of their flow capacity to produce 330 wheel hp - E85 uses a lot more volume of fuel and produces more exhaust gas..

[Steve Webb]

Blimey, by my calculations thats 3.4litres/min at full power. Or to put it another way, it'll empty the tank in less than 20 mins if you ran flat out!

How much does it use out on track l/min?

[jimnielsen]

The Autronic can log fuel use, i will log a bit for you when I take the car to the track in a few weeks!


cheers, jim..

[Steve Webb]

How long do you usually spend out on track at a time? I was just wondering if you needed to drag a whole load of jerry cans to the track with you.

[jimnielsen]

I normally take 80l of fuel with me for a day at the track! But in the past it has not been reliable enough to use that much!!