Big end bearing change procedure (Q4)

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wilco
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Re: Big end bearing change procedure (Q4)

Post by wilco » Sun Sep 23, 2012 8:19 pm

Nice job. any more pics ?
a Q4 always runs a bit rough when cold.
It's the program in the ECU that causes that. Should be better with a squadra chip.
Is it running different when warm ? more power or different then the old engine ?
Henry Ford, 1939: "Every time I see an Alfa Romeo pass by, I lift my hat."
--Alfa Romeo 164 3.0 V6 24V Q4--
--Alfa Romeo 164 3.0 V6 24V--

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Tamariini
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Re: Big end bearing change procedure (Q4)

Post by Tamariini » Mon Sep 24, 2012 6:44 am

wilco wrote:Nice job. any more pics ?
a Q4 always runs a bit rough when cold.
It's the program in the ECU that causes that. Should be better with a squadra chip.
Is it running different when warm ? more power or different then the old engine ?
tons of pics, but nowhere to store those :?

I have squadra chip. Problem is that it runs about 500-600rpm few secs (maybe 5-10s?) before idle stabilizes to about 1000rpm.
--Alfa Romeo Giulia 2.0T 2017--
--Fiat 500 2016--
--Alfa Romeo 75 3.0 V6 Turbo 1988--
--Alfa Romeo 75 3.0 V6 1987--
--Alfa Romeo 75 2.5 V6 24v 1986--
--Alfa Romeo Spider 2.0 TS 1972--
--Alfa Romeo Spider 3.0 12v 1999--
--Maserati 3200 GT 2001--

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Alfan
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Re: Big end bearing change procedure (Q4)

Post by Alfan » Mon Sep 24, 2012 6:10 pm

Tamariini wrote:tons of pics, but nowhere to store those :?

I have squadra chip. Problem is that it runs about 500-600rpm few secs (maybe 5-10s?) before idle stabilizes to about 1000rpm.
https://www.dropbox.com/" onclick="window.open(this.href);return false; works great for me. Could you make a video of the cold start issue? It is not something I have experienced with mine.
1994 Alfa Romeo 164 Q4 Proteo Rosso 550.000km
1989 Lancia Thema 8.32 Verde Indy 270kkm
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Tamariini
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Re: Big end bearing change procedure (Q4)

Post by Tamariini » Sun Sep 30, 2012 4:58 pm

wilco wrote:Nice job. any more pics ?
a Q4 always runs a bit rough when cold.
It's the program in the ECU that causes that. Should be better with a squadra chip.
Is it running different when warm ? more power or different then the old engine ?
It's feels different to the original engine. Not as much power. Feels a bit lazy on complete rev range unfortunately compared to original engine. Or it might just be imagination :P
--Alfa Romeo Giulia 2.0T 2017--
--Fiat 500 2016--
--Alfa Romeo 75 3.0 V6 Turbo 1988--
--Alfa Romeo 75 3.0 V6 1987--
--Alfa Romeo 75 2.5 V6 24v 1986--
--Alfa Romeo Spider 2.0 TS 1972--
--Alfa Romeo Spider 3.0 12v 1999--
--Maserati 3200 GT 2001--

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wilco
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Re: Big end bearing change procedure (Q4)

Post by wilco » Sun Sep 30, 2012 5:41 pm

well.. in a 166 it feels also slower.. atleast the ones i have driven..
Not really and answer on your weird starting problem. leaking injector maybe ?
then it starts bad and runs better after a little while
Henry Ford, 1939: "Every time I see an Alfa Romeo pass by, I lift my hat."
--Alfa Romeo 164 3.0 V6 24V Q4--
--Alfa Romeo 164 3.0 V6 24V--

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Re: Big end bearing change procedure (Q4)

Post by Tamariini » Sun Sep 30, 2012 6:14 pm

wilco wrote:well.. in a 166 it feels also slower.. atleast the ones i have driven..
Not really and answer on your weird starting problem. leaking injector maybe ?
then it starts bad and runs better after a little while
Could be leaky injector. But it's not.

Injectors are from same 166 from which the engine is. There was no such problem on 166 chassis.
--Alfa Romeo Giulia 2.0T 2017--
--Fiat 500 2016--
--Alfa Romeo 75 3.0 V6 Turbo 1988--
--Alfa Romeo 75 3.0 V6 1987--
--Alfa Romeo 75 2.5 V6 24v 1986--
--Alfa Romeo Spider 2.0 TS 1972--
--Alfa Romeo Spider 3.0 12v 1999--
--Maserati 3200 GT 2001--

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wilco
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Re: Big end bearing change procedure (Q4)

Post by wilco » Sun Sep 30, 2012 7:42 pm

Tamariini wrote:
wilco wrote:well.. in a 166 it feels also slower.. atleast the ones i have driven..
Not really and answer on your weird starting problem. leaking injector maybe ?
then it starts bad and runs better after a little while
Could be leaky injector. But it's not.

Injectors are from same 166 from which the engine is. There was no such problem on 166 chassis.
fuelpressure?
Henry Ford, 1939: "Every time I see an Alfa Romeo pass by, I lift my hat."
--Alfa Romeo 164 3.0 V6 24V Q4--
--Alfa Romeo 164 3.0 V6 24V--

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Re: Big end bearing change procedure (Q4)

Post by Tamariini » Mon Oct 01, 2012 4:17 am

wilco wrote:
Tamariini wrote:
wilco wrote:well.. in a 166 it feels also slower.. atleast the ones i have driven..
Not really and answer on your weird starting problem. leaking injector maybe ?
then it starts bad and runs better after a little while
Could be leaky injector. But it's not.

Injectors are from same 166 from which the engine is. There was no such problem on 166 chassis.
fuelpressure?
fuelpressure is also ok. 3bars without vacuum.
--Alfa Romeo Giulia 2.0T 2017--
--Fiat 500 2016--
--Alfa Romeo 75 3.0 V6 Turbo 1988--
--Alfa Romeo 75 3.0 V6 1987--
--Alfa Romeo 75 2.5 V6 24v 1986--
--Alfa Romeo Spider 2.0 TS 1972--
--Alfa Romeo Spider 3.0 12v 1999--
--Maserati 3200 GT 2001--

g84
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Re: Big end bearing change procedure (Q4)

Post by g84 » Mon Oct 01, 2012 6:19 am

[/quote]

It's feels different to the original engine. Not as much power. Feels a bit lazy on complete rev range unfortunately compared to original engine. Or it might just be imagination :P[/quote]

Well you are down 12-13 hp from Q4 engine and every thing was optimised on Q4 engine for quick response to compensate extra weight.
JK
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146 Ti -97

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Re: Big end bearing change procedure (Q4)

Post by Tamariini » Mon Oct 01, 2012 6:31 am

g84 wrote:

It feels different to the original engine. Not as much power. Feels a bit lazy on complete rev range unfortunately compared to original engine. Or it might just be imagination :P
Well you are down 12-13 hp from Q4 engine and every thing was optimised on Q4 engine for quick response to compensate extra weight.
But where does extra 12-13hp come on a Q4 engine? I have thought it's all about strickter emission class on 166 engine. Engine internals are the same on main parts which affect on hp figures (cams: lift, duration + intake valves/pipes + volume + compression ratio)
--Alfa Romeo Giulia 2.0T 2017--
--Fiat 500 2016--
--Alfa Romeo 75 3.0 V6 Turbo 1988--
--Alfa Romeo 75 3.0 V6 1987--
--Alfa Romeo 75 2.5 V6 24v 1986--
--Alfa Romeo Spider 2.0 TS 1972--
--Alfa Romeo Spider 3.0 12v 1999--
--Maserati 3200 GT 2001--

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Re: Big end bearing change procedure (Q4)

Post by g84 » Mon Oct 01, 2012 6:46 am

Tamariini wrote:
g84 wrote:

It feels different to the original engine. Not as much power. Feels a bit lazy on complete rev range unfortunately compared to original engine. Or it might just be imagination :P
Well you are down 12-13 hp from Q4 engine and every thing was optimised on Q4 engine for quick response to compensate extra weight.
But where does extra 12-13hp come on a Q4 engine? I have thought it's all about strickter emission class on 166 engine. Engine internals are the same on main parts which affect on hp figures (cams: lift, duration + intake valves/pipes + volume + compression ratio)
Are you using the 45 mm intakes from Q4? Exhaust cam is different from normal 3,0 24v 164.
JK
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Re: Big end bearing change procedure (Q4)

Post by Tamariini » Mon Oct 01, 2012 7:38 am

g84 wrote: Are you using the 45 mm intakes from Q4? Exhaust cam is different from normal 3,0 24v 164.
No, 166 has also 45mm runners and i'm using them.

Do you know how is 166 cams compared to Q4? I've been told they are the same :?
--Alfa Romeo Giulia 2.0T 2017--
--Fiat 500 2016--
--Alfa Romeo 75 3.0 V6 Turbo 1988--
--Alfa Romeo 75 3.0 V6 1987--
--Alfa Romeo 75 2.5 V6 24v 1986--
--Alfa Romeo Spider 2.0 TS 1972--
--Alfa Romeo Spider 3.0 12v 1999--
--Maserati 3200 GT 2001--

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wilco
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Re: Big end bearing change procedure (Q4)

Post by wilco » Mon Oct 01, 2012 10:06 am

the cam sensor on a 24V is an inductive. on the Q4 they changed that to a hall sensor, together with a different intake camshaft.
I assume the 166 uses the same .. but not sure
Last edited by wilco on Mon Oct 01, 2012 2:06 pm, edited 1 time in total.
Henry Ford, 1939: "Every time I see an Alfa Romeo pass by, I lift my hat."
--Alfa Romeo 164 3.0 V6 24V Q4--
--Alfa Romeo 164 3.0 V6 24V--

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Re: Big end bearing change procedure (Q4)

Post by g84 » Mon Oct 01, 2012 11:31 am

Tamariini wrote:
g84 wrote: Are you using the 45 mm intakes from Q4? Exhaust cam is different from normal 3,0 24v 164.
No, 166 has also 45mm runners and i'm using them.

Do you know how is 166 cams compared to Q4? I've been told they are the same :?
Sorry dont know if cams is different on 166. Cant really see why you are lacking power if using Q4 engine management system.
JK
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Re: Big end bearing change procedure (Q4)

Post by Maffia_Alfista » Wed Nov 21, 2012 8:39 pm

Same sound? http://alfaromeo164register.com/viewtop ... 6796#p6796" onclick="window.open(this.href);return false;
Daniel Jansson
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Re: Big end bearing change procedure (Q4)

Post by Tamariini » Thu Nov 22, 2012 4:50 pm

Maffia_Alfista wrote:Same sound? http://alfaromeo164register.com/viewtop ... 6796#p6796" onclick="window.open(this.href);return false;
exactly same sound... Big end shells gone bad :?
--Alfa Romeo Giulia 2.0T 2017--
--Fiat 500 2016--
--Alfa Romeo 75 3.0 V6 Turbo 1988--
--Alfa Romeo 75 3.0 V6 1987--
--Alfa Romeo 75 2.5 V6 24v 1986--
--Alfa Romeo Spider 2.0 TS 1972--
--Alfa Romeo Spider 3.0 12v 1999--
--Maserati 3200 GT 2001--

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Re: Big end bearing change procedure (Q4)

Post by sportston » Thu Nov 22, 2012 11:02 pm

g84 wrote:Do you know how is 166 cams compared to Q4? I've been told they are the same :?
Just because they have the same duration and lift doesn't mean they have the same overlap. They may start to open earlier or later?
But, that may not be the problem. Lumpy idle and lack of power are common symptoms of incorrect valve timing due to slipping a tooth on the timing belt or accidental incorrect installation.

Come to think of it....
Didn't you have a problem with the oilpump drive pulley slipping on this one? Could it have wobbled enough for the belt to jump a tooth on one of the cams? Might be worth checking that.

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Re: Big end bearing change procedure (Q4)

Post by sportston » Thu Nov 22, 2012 11:09 pm

Wait a minute! I've had another thought.
I seem to remember reading somewhere, maybe on this forum, about the timing belt idler wheel/pulley being different on 166 24v than the 164 24v engine.
I don't know for sure as I have never had them to compare. But if they are different, then is it a difference in diameter? If that is the case then rebuilding the engine with the wrong idler wheel would actually alter your valve timing slightly, not enough to make it run like a dog, but just enough to lose you a few horses and make the engine a little sluggish.

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Re: Big end bearing change procedure (Q4)

Post by sportston » Thu Nov 22, 2012 11:25 pm

Tamariini wrote:Engine has still some hesitatation when starting from cold. it runs rough for a first few seconds, almost everything has been changed now on the engine bay + ecu. Engine/injectors/coil packs/wiring loom worked good on a donor 166 and this car had same problem before engine swap
Have you used the 166 idle speed control valve and throttle assembly or did you re-use the 164 ones?
Possible causes of poor idle:-
1.TPS giving incorrect value
2.Base idle incorrectly adjusted
3.Clogged air filter or intake system.
4. AFM faulty
5. Inlet air leak (check rubber joiners, brake servo and related pipework, inlet manifold, stainless inlet pipes, vaccuum pipe perished or leaking, clogged oil breather system, perished or split inlet trunking).
6. Wiring to TPS or AFM faulty.
7. Fuel pressure regulator leaking into vaccuum take-off.
8. Low fuel pressure.
9. Valve timing incorrect.

You may well have already checked most of these, but I put them all down, even the obvious, for the sake of being thorough.

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Re: Big end bearing change procedure (Q4)

Post by Tamariini » Fri Nov 23, 2012 3:02 pm

sportston wrote:
g84 wrote:Do you know how is 166 cams compared to Q4? I've been told they are the same :?
Just because they have the same duration and lift doesn't mean they have the same overlap. They may start to open earlier or later?
No, overlap is not the case. I used same locking tools on both engines so the timing is most likely same.
sportston wrote:Come to think of it....
Didn't you have a problem with the oilpump drive pulley slipping on this one? Could it have wobbled enough for the belt to jump a tooth on one of the cams? Might be worth checking that.
Yes i did. But i believe strongly that it's not the case either. There is so tight fit between the crank axle and pulley so it cannot wobble.
sportston wrote: I seem to remember reading somewhere, maybe on this forum, about the timing belt idler wheel/pulley being different on 166 24v than the 164 24v engine.
Yes, idlers are totally different but it should not affect on timing when using locking tools
sportston wrote: Have you used the 166 idle speed control valve and throttle assembly or did you re-use the 164 ones?
Possible causes of poor idle:-
1.TPS giving incorrect value
2.Base idle incorrectly adjusted
3.Clogged air filter or intake system.
4. AFM faulty
5. Inlet air leak (check rubber joiners, brake servo and related pipework, inlet manifold, stainless inlet pipes, vaccuum pipe perished or leaking, clogged oil breather system, perished or split inlet trunking).
6. Wiring to TPS or AFM faulty.
7. Fuel pressure regulator leaking into vaccuum take-off.
8. Low fuel pressure.
9. Valve timing incorrect.
I reused the 164 ones.
1. TPS values are reasonable, seems not to be the fault
2. I have no idea how to adjust this and how much should it be? Idle actuator disconnected or connected?
3. That's not the case here
4. Checked the values, seems ok.
5 fixed these ones.
6. these are ok
7. this is ok.
8. pressure is good (3bars with no vacuum)
9. I'm beginning to think my locking tools are not ok. Friend of mine had similar problem with his 156 GTA and we sorted this problem out by original GTA locking tools.. I might try these ones also even GTA intake cam is slightly different to other V6's..
--Alfa Romeo Giulia 2.0T 2017--
--Fiat 500 2016--
--Alfa Romeo 75 3.0 V6 Turbo 1988--
--Alfa Romeo 75 3.0 V6 1987--
--Alfa Romeo 75 2.5 V6 24v 1986--
--Alfa Romeo Spider 2.0 TS 1972--
--Alfa Romeo Spider 3.0 12v 1999--
--Maserati 3200 GT 2001--

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wilco
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Re: Big end bearing change procedure (Q4)

Post by wilco » Fri Nov 23, 2012 3:21 pm

how i adjusted the base idle on the 24V. i disconnected the idle actuator and made it run just a little above the minimum.
If it's the right way, i don't know, but it worked for me on my 24V.
On the Q4 it was allright, so no adjusting.

You can check the timing. there are markings om the cam axles on the oposite side of the timingbelt. they should lie up on the horizontal metal part.
I never use those locking tools and always running smooth.
So to check if the locking tools are ok, you can put them on and check if the lines are correct.
Henry Ford, 1939: "Every time I see an Alfa Romeo pass by, I lift my hat."
--Alfa Romeo 164 3.0 V6 24V Q4--
--Alfa Romeo 164 3.0 V6 24V--

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Re: Big end bearing change procedure (Q4)

Post by sportston » Fri Nov 23, 2012 7:03 pm

sportston wrote:Just because they have the same duration and lift doesn't mean they have the same overlap. They may start to open earlier or later?
Tamariini wrote:No, overlap is not the case. I used same locking tools on both engines so the timing is most likely same.
That is possibly an incorrect assumption. Have you checked using the timing marks on the pulleys?
I'm not sure what parts you used from the 166 that may effect the valve timing. Which pulleys,idlers and tensioners did you use?
Tamariini wrote:Yes, idlers are totally different but it should not affect on timing when using locking tools
This is also a possible incorrect assumption. Think about it this way. If you use the locking tools off a 164 and IF they are different than the locking tools off a 166 you could end up with incorrect timing.

Also, in theory, if you used the 164 idler (labelled "G" in illustrations below) in the 166 engine and IF it has a different diameter, even with the locking tools, you may find that the belt between the cylinder heads is of an incorrect tension, leading to valve timing being incorrect once you remove the locking tools.
this is the 24v 164 timing belt arrangement
Image


this is the 24v 166 timing belt arrangement
Image
Tamariini wrote:9. I'm beginning to think my locking tools are not ok. Friend of mine had similar problem with his 156 GTA and we sorted this problem out by original GTA locking tools.. I might try these ones also even GTA intake cam is slightly different to other V6's.
Hmmm food for thought!
Tamariini wrote:2. I have no idea how to adjust this and how much should it be? Idle actuator disconnected or connected?
I have no exact data of what the base idle rpm should be on a 24v. You'll have to do it by trial and error. But the procedure is done like this:-
Below is the procedure for a 3.0 V6 24v. I used to do this for a living and it isn't that hard if you're handy with a screw driver and willing to learn.

1. First you make sure that you have no air leaks in or around your inlet manifold, intake tubes, throttle body, brake servo, plenum chamber, injectors, airflow meter etc. You do this by warming the engine up fully then unplugging the ISCV (Idle Speed Control Valve) and then with the engine running (it will be idling faster than normal) spraying with a can of "cold start" or "start it" in the area of any possible leak sites. If the spraying causes the engine revs to increase or decrease you have found the site of a leak. If the engine revs stay the same while you are spraying then you do not have a leak. You may now put the plug on the ISCV back in.
2. If you have a leak, fix it before doing anything else!
3. If you have the facilities to do so, check the mixture using a gas analyser. If you do not have this facility then you can skip it, but if there is a problem with your mixture control it will effect your idle control. On an engine with a catalytic converter, if your CO% is 0-0.2% then you can move on to the next step. If the CO% is higher than 0.2 you have a problem. If so check the O2 sensor is switching. You should find that the signal wire shows the voltage fluctuating, up, then down, up again then down etc. (if not, replace it).
You might think this is a hell of a rigmarole just to adjust the idle, but it should be pointed out that the idle speed should control itself, therefore if your idle is incorrect then you have a fault somewhere. or someone has already been fiddling with it and messed the settings up.
4. Now unplug the throttle position sensor (TPS) on the side of the throttle body. Loosen the screws that hold the throttle position sensor so that it may pivot freely.
5. Remove the black plastic cover that goes over the cable side of the throttle mechanism. You should now see a small throttle stop screw on the top of the throttle body. Squirt some WD40 or similar onto the screw to help make sure it will move freely (it may be tight due to never having been adjusted before).
6. With the engine running, you may now set the idle speed using the throttle stop screw to approximately 975-1050rpm (make sure you use a GOOD screwdriver for this as it is very easy to mess the head of the screw up). You may find your 24v engine works better at a different setting so you will have to use trial and error here. PLEASE NOTE THAT THIS SETTING OF 975-1050RPM IS AN EDUCATED GUESS (I don't have the exact figures in any of my data files).
7. Turn the engine off.
8. With the engine still turned off but with the ignition on, set/twist the TPS so that in the throttle closed position the voltage from the signal wire is 0.5v. Tighten the screws holding the TPS in this position. Make sure that you haven't used too much force whilst twisting the TPS or you might find that the throttle doesn't return all the way to the throttle stop screw! Now recheck the same wire with the throttle fully open and make sure it is as close as possible to 4.4v.
9. Make sure you haven't dislodged the throttle cable from the cam that it goes around (often happens when you're operating the throttle manually from under the bonnet). If you forget this step you may find that your engine will rev its balls off when you restart the engine!
10. Restart the engine. Check the idle is still between 975 and 1050rpm or at the same setting as it was before you adjusted the TPS.
11. You may now plug the TPS back in. The engine revs should now decrease to about 650-800rpm (if the revs are too hi or low start the whole procedure again and set the base idle at a different level).
Thats it, you should by now have successfully reset your "base idle speed".
If you still have problems, then you might suspect ISCV but it is probably best to call in a diagnostic specialist/engine tuner at this point. He would then test the ignition system, wiring and other things on an oscilloscope before replacing parts willy-nilly.

Hope this is of some use to you. If you have further questions I can be reached at motamenda@homecall.co.uk
Best of Luck
Tom

this is the legal bit;- if you choose to undertake this procedure you do so at your own risk and I cannot be held liable for any subsequent harm or damage that results from your attempts at DIY mechanics.

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Re: Big end bearing change procedure (Q4)

Post by sportston » Fri Nov 23, 2012 7:10 pm

One more thing!
Might the crankshaft pulley and flywheel on the 166 engine be differently weighted than the 164?
Heavier ones will lead the the engine not revving up quite as quickly as lighter ones (being a bit lazy as you called it).
If they are different weights and you use the pulley from one and the flywheel from the other, they will be imbalanced and this may lose you a few horses or lead to it running a bit lumpy.

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Tamariini
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Re: Big end bearing change procedure (Q4)

Post by Tamariini » Wed Dec 12, 2012 8:01 am

sportston wrote: 9. Valve timing incorrect.
Tamariini wrote: 9. I'm beginning to think my locking tools are not ok. Friend of mine had similar problem with his 156 GTA and we sorted this problem out by original GTA locking tools.. I might try these ones also even GTA intake cam is slightly different to other V6's..
I think this was the cause of a shaky idle problem. Problem seems to be indeed on my locking tools which are marked falsely (n1 cyl locks crossed) so apparently i have timed my bank 1 exhaust cam with inlet cam lock and inlet cam with exhaust lock... I compared my locking tools to these GTA ones i borrowed from fiend of mine.

I retimed my belt last night but did not have time to properly test the car but so far seems that idle problems are gone :)
--Alfa Romeo Giulia 2.0T 2017--
--Fiat 500 2016--
--Alfa Romeo 75 3.0 V6 Turbo 1988--
--Alfa Romeo 75 3.0 V6 1987--
--Alfa Romeo 75 2.5 V6 24v 1986--
--Alfa Romeo Spider 2.0 TS 1972--
--Alfa Romeo Spider 3.0 12v 1999--
--Maserati 3200 GT 2001--

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Re: Big end bearing change procedure (Q4)

Post by sportston » Wed Dec 12, 2012 11:21 am

Tamariini wrote: Problem seems to be indeed on my locking tools which are marked falsely (n1 cyl locks crossed) so apparently i have timed my bank 1 exhaust cam with inlet cam lock and inlet cam with exhaust lock... I compared my locking tools to these GTA ones i borrowed from fiend of mine.

I retimed my belt last night but did not have time to properly test the car but so far seems that idle problems are gone :)
Great stuff. You'll know not to use your own set in future. That is strange that they should be incorrect like that though. Hope that has solved your problem ok.
I have come accross that once before when a set of incorrect tools were used. I would be guessing you have got a set of locking tools intended for a different engine perhaps?

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