Autodelta V6 information

[AlfaTipo]

Just browsing this topic and I shall put the cat amongst the pigeons here....

If you can't rotate the engine backwards without it skipping then you have not installed the tensioner properly. I always counter rotate to make sure it stays in place. Hydraulic and mechanical.

This is Alfa mythology. Almost as bad as 'final balancing' of the prop shaft with matched bolts and nuts. I have had a totally different (pitch and tensile rating) bolt and nut combination used on on Alfetta that caused no vibration issues. Changing back to all correct bolts did not incur any vibration. Nice stories, but cast out the demons...

Read Greg's view on prop shaft balance as well. Much more logical than throwing newts at L-Jets ;-)

Gotta go flay a child.......

[Gabor K.]

Well its a question of following basic work routine or not. I am sure there is little chance of damage with standard engines, however with tuned engines with very small tolerances there is a chance of contact turning the wrong way. Also you must turn the right way to check marks etc. I have no problems to make complete turns around all the right way checking all the valves, so what is the problem? Little time?
Now I wonder what standards you are using when torquing the engine and adjusting exhaust valves? Do you torque in hot condition, and measure the gap at the exhaust valve for instance?

[ToonRboy]

I think here is where the misunderstanding is. And you may even have the device installed/set-up incorrectly at your favorite Alfa shop (depending on which mechanic was tasked)! Be that as it may, My Verde and current GTV6 both have the oil fed unit. My Gold Model had the mechanical unit. Guess which one skipped? - That's right, the "superior" mechanical one. Luckily jut a tooth.

The De-tensioner is supposed to do just that (relax tension as the heads expand apart). That means to install it properly, the engine has to be cold and the tensioner must be held in the detensioned position using the factory tool (see prev post). With the belt installed (cams marks aligned and distributor rotor pointing #1) the tensioner is now tightened so the belt is tight as a drum. Then the plate nut is tightened and factory tool removed. Now the belt cannot slip or jump even if the tensioner goes fully detensioned. The biggest issue would then be the oil leaks. But why not? everything else leaks! On the other hand, we don't want oil sloshing about the timing belt now do we?

As for manually cranking the engine backwards, I only mentioned the mechanical de-tensioner because so many have switched over to it and the "dialing-in the cams" instructions could be relevant. On almost every other type of tensioner, this shouldn't be a problem (esp chain driven cams), providing you have the cams properly aligned with the crank. But this is in context of finding true TDC (esp. after milling heads, or installing aftermarket cams) in the process of dialing-in the cams. Not cranking backwards to to make sure it stays in place! I'm pretty sure the consensus is, you bed the timing belt by cranking clockwise - you know, the direction the motor normally runs!

Bad experiences tend to skew the judgement of folks. I can understand that. You think the mechanic that adjusted the mechanical unit is gonna fess-up to passing the mark & then backing-up to it rather than starting all over? Doubtful. I've seen uni-directional tires mounted backwards on many a pimped-out vehicle. - 'Wonder what their "wet-weather rating" of that tire would look like.

[slyalfa]

I have to say I have moved mine backwards and never had a skip. but I do recheck the marks as I go so if it did skip I would catch it. I have the oil type with the oil hole pluged. as for which type skip the oil type or the thermo type. a simple search will show the newer thermo type skips all the time. and you will be hard pressed to find a post where the oil type failed with normal use and belt changes)

[Colin]

The mechanical tensioner appeared on the new style V6 12v ( Alfa 155
916 gtv and spider, late 164 ). These engines have a different cambelt
with high half-round teeth and matching sprockets. The mechanical unit
shouldn't be retro-fitted to an old style V6 12v which cambelt has smaller
square teeth and therefore needs a higher belt tension then the mechanical
unit can deliver. Fitted with a mechanical unit the belt is prone to slip,
esspecially when then engine is turned backward which causes de tensioner
to fully detension. The hydraulical tensioner gives extra tension during
cranking to prevent cambelt slip, when the engine runs it returns to the
detensioned position which you adjusted during the cambelt change. If every
time you change the belt you also rebuild the tensioner with new seals,
it will never leak so much that the belt gets really oily !

@AlfaTipo : I have seen 75's that had there driveshafts final-balanced
with aditional half-nuts straight out of the factory !

[Jim K.]

ToonR, going Motronic is actually very easy. You'll need: ECU, harness, afm, 60-2 crank pulley with sensor and that's it! You can use the L-Jet TPS (its a switch not a pot). This afm is the same size as the big BMW one. Plus, a very convenient added perk, is the facility for the idle control motor which is standard with this system on the 164. Don't worry about the distributor, you can leave the L-Jet one in place, no problem. It will still distribute the spark which is all you want. So where's the difficulty, besides locating all the above parts? I understand the particular 164 (donor) model was also sold in NA. For the curious, the ecu p/n is 0261200130 and the afm 0280203035. As far as I'm concerned, the most difficult part is resizing the wiring harness to fit a gtv or 75 and the necessity to rebalance the rotating assy (although I've seen too many people get away without doing this).
Jim K.

[ToonRboy]

Well that's encouraging. I know the L-Jet has a standalone spark box, just not sure if there are any other dependancies from the ECU (tach feed?). I know they're all on the same wiring harness. Do you know of anyone who has performed this swap Jim?

I dunno, but the way I see it, without the "S" cams and more compression (as in the "S" engine), we're ultimately right back to academics of the BMW AFM swap.

[75evo]

JimK,

Are SZ and Potenziata AFMs the same size as the 164Q? They look smaller, like non QV 164s.

[Jim K.]

From L-Jet to Motronic? I've done it in my 75. Straight as I described. First I built the engine with the new pulley and front timing cover, installed a blanking plate over the 7th injector hole (airbox) and welded up the 7th injector fuel supply hole on the fuel rail (unless you want to use the fitting for a fuel pressure gauge!). The rpm sensor can also be mounted on older 3liter timing covers which have the bosses in place and only require drilling and tapping (two bolts securing the sensor)
Then, remove the entire L-Jet harness and install the Motronic one. You'd be advised to have an electrical diagram handy for the connections (no problems with the tach at all). I really think its that simple! If the harness comes from a 75, you're lucky as it has the proper lengths. From a 164, you'll have to adjust (generally shorten) most wires and this can get involved, unless you're ok with bundling up the extra length and cleverly hiding it someplace.
75 Evo, the 75Pot/SZ afm is 0280202205 and ecu 0261200141. This afm is the 'normal'size. The 164S has large afm 02080203035 same size as the BMW one and ecu 0261200130. I'm not familiar with the Q model unless its the 164 Quadrifoglio (Europe) which is the one with the big afm mentioned above. To clarify, its best to go by engine numbers as the model designations (S, Q, QV etc) were thrown around by the marketing clowns: the big afm and -130 ecu were only used in the 164 engine no. 64301, both in Europe and NA.
Jim K.

[Gabor K.]

We went a little bit further and did away with Bosch all together. No distributor and 60-2 wheel etc. Autronic 3 point trigger at crank and one trigger at right camshaft. Big runners, 11 CR. 3L 164 engine. Works very well!

[Jim K.]

The point of going Motronic is that you can find the parts in the junkyard; probably costs a lot less than any aftermarket system. For what its worth, I believe reliability is much better also as you can't possibly compare the environmental testing Bosch has conducted to qualify their systems to any aftermarket specialist.
Jim K.

[Gabor K.]

I really dont see other than environmental advantage of the Motronic over the L-jet. That was that reason it was introduced. A junkyard Motronic more reliable than the Autronic - don´t think so. When the Motronic was introduced the power of the 3L dropped by 3Hp, so no extra there. Ok, you can buy an expensive tuning chip for$$ or do dyno runs for additional $$. For much less you can manipulate the orignal L-jet to give sufficient more fuel. As an old tuner guru said, getting more fuel into the engine is never a problem. The problem is getting more air into it!

[75evo]

Gabor,

Do you have pics of the camshaft sensor pickup?

[Gabor K.]

Yes I have that. The sensor is fixed to the right head inside the V. The trigger must have a certain size to be able to trigger the sensor. Best is a bolt head. Distance must be no more than 1mm.

[raff_gta]

Quote:

Originally Posted by Gabor K. We went a little bit further and did away with Bosch all together. No distributor and 60-2 wheel etc. Autronic 3 point trigger at crank and one trigger at right camshaft. Big runners, 11 CR. 3L 164 engine. Works very well!