Small Problem at Sandown Raceway

[RMB-Racing]

They do take longer to warm up this way (at idle..) but on the track, its not a problem. I have used them with an on-off switch before, the problem is that is SO EASY to forget to turn the switch on. Its just simpler to wire it to the ignition and not have to worry about it. Also, you get used to hearing it come on when you turn the ignition switch to the 'on' position.

jimn~

In your opinion, do you think that this is a better solution, than the original waterpump?

And what is the benefit of using a an electrical waterpump?

[jimnielsen]

They (EWP's) are very common here. They provide lower water temp on a circuit racing car. A few more horsepower, less complexity, less belts.

In my giulietta racecar an EWP made a great contribution to reduced temps. Often people fit flow restrictors to control the cooling. In the giulietta, I used a 13mm flow restrictor - that worked very well.

[jimnielsen]

I am going to try to have some better insight into detonation (knocking, pinging.. whatever its called in the various geographies...)

so I have built this thing..


from autospeed.. its a knock listening device. - basically its a hearing aid modified for use for listening to engine knocking. I am going to use it to calibrate the 'generic' knock sensing device from MSD (on the dyno). It has an LED output that you can see in the car.

I have tested both the standard Q4 knock sensor and the MSD one with an oscilloscope, they both look to have similar output (and both appear to be working..)

does anybody know anything about how the standard Q4 knock sensor interfaces with the ECU data tables - would it be possible to control how much the ECU retards advance if it sees knocking?

cheers, jimn~

[arjunior45]

yes, it is possible. I'll send you later an e-mail.
If I remember well , in 101.05 IMMO bin file, the hex address is 004cc up to 0050b.

I think you're going for a state of art set up for your car, congrats.

Do you have any link for this 'knock alert?

Nick

[jimnielsen]

nick.. here is the manual, its pretty simple. Its called an MSD 8964. It uses a GM piezo detector that is sensitive in the 5Khz range. It has a 1/4" BSP thread that I am still not sure how I am going to connect it to the Q4 block.

http://www.jegs.com/InstallationInst...1/121-8964.pdf

cheers, jim.

[arjunior45]

thanks Jim

Nick

[1NRO]

Hi Jim,

The 16v Fiat coupes have the knock sensor fitted to the block rather than the head. I can't find a pic of the location but have a block I can look at tomorrow to see whats what.

Nik

[jimnielsen]

Maybe its this hole here?? This is the hole I am planning on putting the external knock sensor in. It looks to be out of the way of essential things and 'unused' at least on my engine...

cheers - jimn~

[arjunior45]

workshop manual, posted by Steve at tech pages, has the 'Q4 engine' manual and it's easy to see the location of the oem knock sensor in the drawings!!!

Nick

[arjunior45]

@ Jim,

do you have the tech data {output voltage} of the oem knock sensor? It might be helpful for the hex address of the convertion volt to bit.

Nick

[na15575]

Maybe its this hole here?? This is the hole I am planning on putting the external knock sensor in. It looks to be out of the way of essential things and 'unused' at least on my engine...

cheers - jimn~

in that hole is mounted the knock sensor for fiat coupe
our Q4 is in the cylinder head
it is unsed in all the Q4s

[jimnielsen]

Then I will use that hole for my 'after-market' knock-sensor. I will need to have it converted to 1/4 BSP

[mindus]

Then I will use that hole for my 'after-market' knock-sensor. I will need to have it converted to 1/4 BSP

It is exactly the hole my OEM knock sensor was fitted before I bought my car... It seems that previous owner took care of that

[jimnielsen]

Where does this wire go to? I remember cutting it because I could not get access to whatever it joins to when I removed the head from the block - and I remember thinking that I'd remember where it went to, but I cant

[Juan AR155Q4]

A/C pump

[jimnielsen]

Yep! That's it ... I remember now.. Thanks!

[Brul(tm)]

It is exactly the hole my OEM knock sensor was fitted before I bought my car... It seems that previous owner took care of that

That is also the location where the kncok sensor is fitted on the engine from my Q4 and the Q4 I am taking appart...

Greetings,
Marc

[Gery83]

That is also the location where the kncok sensor is fitted on the engine from my Q4 and the Q4 I am taking appart...

Greetings,
Marc

Is it a better solution to mount the sensor on the block, not on the head, where it was mounted by the factory?

[SteveNZ]

In the manual, I can see that there are three thickness of main bearings - a, b and c. presumably so that you can machine the main journals down and use a thicker bearing. BUT... why does the radial clearance specified vary for each thickness of bearing - wouldn't this be setup the same regardless of the thickness of the bearing??

Hi Jim

Class sizes are to make up for the difference in original machined sizes. They offer 3 different size standard bearings so you can pick exactly the right one to get the prefered clearance as close as possible.

[jimnielsen]

Hi Steve, welcome to the forum.. I'd agree with you as it seems logical but as wrinx points out in his reply quoted below there is actually a point where these values all cross over..Anyway to keep it simple I am using standard main bearings and standard conrod bearings. I have already checked the mains - they are 003 thou clearance. The pistons and rods actually arrive tomorrow - so I will check the rod bearing clearances then.

I had to pay GST on the rods and pistons today. Not pleasant...

Especially when, looking at the figures, they could all be set at 0.037 and be within tolerance.

I'm guessing it's something to do with the way the oil flows (less shoulder on the bearing), but haven't got a clue really!

wrinx

[SteveNZ]

Class A, B And C are all "standard size" bearings. That chart is difficult to understand, maybe the measurements are in relation to a measurement made from a control size bearing during assembly. From that measurement, pick the bearing class.

From what I understand, in simple terms, Class A will give more clearance than Class B which which will give more clearance than Class C and so on. So for whatever reason if your journal is slightly on the small side, you'll need to use a Class C bearing. If its slightly on the large side, you'll want to use a Class A.

Fiat do the same thing with pistons. Class A, B, C and D are all standards size pistons for a standard size bore. After you have measured the bores closely you pick the best fit piston to give the closest to optimum clearance. This would not be necessary if all the bores were exactly the same size but they will vary as they come off the production line and as they wear out over time.

In the aftermarket world its usually done in reverse. The pistons come off the production line in set sizes. Measure the piston and rebore the block to give exactly the correct clearance.

As far as the bearings go I too have only ever asked for the "standard" size. (Probably class A supplied) put them in the engine, measured the clearance which has been within spec and all is good. For the majority of engines that is probably alwasy going to be the case.

[jimnielsen]

well, the wait is over!!! My shiny new forged rods and pistons turned up in the mail today! Now at last I can get the damn block bored to size and start the process of putting the Q4 back together! Boy those piston rings look tiny!!

[arjunior45]

well, the wait is over!!! My shiny new forged rods and pistons turned up in the mail today! Now at last I can get the damn block bored to size and start the process of putting the Q4 back together! Boy those piston rings look tiny!!

congrats Jim, they look ok!!!
If I may say so, you could - should - ought 'weigh balance' them all {pistons, rods and as a complete set} at 100mgr {milligrams} - 0,1gr - although 5 grams difference is acceptable by FIAT.
I know 0,1 gr is too much and a pain in the a...ss job but in long terms you won't regrade it. You'll need at least two long weekends {days and nights} but this 'job' can make the difference for your car {engine}.

Sorry for giving you this advice although you did not asked it, but ...
Too many 'buts', but ...

[jimnielsen]

all advice gratefully received, Nick!

[SteveNZ]

What parts did you go for in the end?