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Discussion Starter #1 (Edited)
Can somebody please help me positively differentiate between the numbers on a 3.0 Milano/75 Verde/Americano or even an SZ Zagato 3.0 12 valve flywheel, versus those stamped on a 2.5 12 valve Milano/75/GTV6 flywheel? (I don't currently have one of each to compare right here, right now...)
 

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Well, I could give you the part numbers if that could help. Cannot tell if they are using the part numbers or some other coding. Did not notice last time I had one in my hands..
 

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Well, I could give you the part numbers if that could help. Cannot tell if they are using the part numbers or some other coding. Did not notice last time I had one in my hands..

Verde 3.0 flywheel part number starts with 195 on flywheel and is thicker than 2.5L I had numbers of both somewhere in my notes as I have sold all my spares.
 

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Well, both the 2.5 and 3.0 start with 195 so if these numbers can be seen on the flywheel I could list it up here:

75 3.0L 19546 02040 00 00
75 2.5L 19555 02040 00 00
GTV6 2.5 11668 02040 02
75SZ 3.0 60534816 (new part no. system)

Would be interesting to hear if these numbers can be found on the wheels!
 

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It just happens that I am doing a 3 litre conversion to my GTV6 Racecar and I am looking for a 3 litre flywheel.
The difference for a start is the size. The 2.5 litre flywheel is smaller.

Anybody in Sydney have a spare 3 litre flywheel off a 75? The 164 one is different again.
 

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It just happens that I am doing a 3 litre conversion to my GTV6 Racecar and I am looking for a 3 litre flywheel.
The difference for a start is the size. The 2.5 litre flywheel is smaller.

Anybody in Sydney have a spare 3 litre flywheel off a 75? The 164 one is different again.
By smaller your mean thinner and lighter which is a good thing so you can have a spacer made I understand to move 2.5L flywheel back to align correctly for starter and use longer bolts.
 

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Discussion Starter #8 (Edited)
There are a few misconceptions here regarding 12 valve flywheels... In addition, you guys should also try to consider the 3 main issues with regards to these flywheels - separately;

1) There is a balance-factor unique to each motor that should be taken in to account! Regardless of the thickness of the actual wheel, or spacer/no spacer on the back, regardless of how far it sticks out, or whether the starter is going to engage or not - the balance-factor in principal is different between a 2.5 flywheel and a 3.0 flywheel. In addition to that basic difference in the actual casting, there are also individual balancing-drillings unique from one flywheel to the next (even within the same "type" of flywheel!)

2) The 3.0 flywheels have a 4mm thicker spacer in the casting on the rear to clear the back of the block! They are easily recognizable because of the thicker spacer (where the flywheel mates to the crank) however, some 2.5 flywheels from the later cars are suspected to HAVE THAT SAME SPACER and can easily be mistaken for a 3.0 flywheel! This is why I asked the original question! Just because it has the spacer in the casting DOES NOT make it a 3.0 flywheel!

3) A 2.5 flywheel CAN be spaced out with an individual spacer-plate between the crank and the flywheel - just like a 3.0 flywheel and it'll work just fine however, now we're back to talking about point number 1 above - the balance-factor. If you were to rebuild an engine (for ultimate conversion in to a TA car), you could just use ANY flywheel and have it balanced with the crank, pistons, rods and the crank-pulley. Just use a spaced-out flywheel (or an individual spacer to a non-spaced flywheel) if you are running a 3.0 block to clear the block and you're good to go!

Any way, I know that Jes simply took a 2.5 flywheel - one WITH the spacer - and bolted that to the rear of his "S" 3.0 engine to make the conversion work in his "Roxanne" Milano track-car (without having the motor rebalanced.) It works and yet at the same time, the cleanest way would be to rebuild and rebalance the motor with whichever flywheel and crank-pulley you are about to use.

In the case of the 24 valve conversion (without opening it up), you HAVE to use a 3.0 flywheel specifically - not for the spacer, but for the balance-factor, OR you have to have the internals rebalanced with the flywheel and the crank-pulley.

So, back to my original question, anybody have the actual numbers stamped on a 3.0 flywheel for me, versus those stamped on a 2.5 flywheel please?
 

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JJ,
As a last resort, get your black verde on a lift, remove the little cover at the flywheel, and I think you should be able to read the numbers - you may need a little dentist's mirror and practice reading mirrored :eek:

If that doesn't work. Isn't it about time to pull that 3.0 12v out of the black car anyway ;) :p :D
Jes
 

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Discussion Starter #10
Good thinking...

Yeah, that poor old ***** - she just still pulls SO strong, that I can't bring myself to do it, but I will soon! Working on the 24 valve right now, but it looks like it's sold now (as part of the deal on the CF hood and trunk-projects...)

Working on the 12 valve 3.0 rebuild, but that has been sold too! Waiting on another 24 valve core headed my way - maybe that one will finally make it in to the Verde!

-Got the GTV6 that will need a motor too and I have yet another 24 valve in the works for that one...
 

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Done some more thinking... ;) Tell you what, send that 24v down here, and I'll pull my 12v and read the numbers off the flywheel for you ;) :p :D
Jes
 

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Discussion Starter #12 (Edited)
Hey mr. funny-man - we're you a stand-up in a previous life...? :) I like my humour funny... :D It's yours if you want it. Dammit! Now I have to find yet another one...
 

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Hmm, that was easy :) Let me try this: Can you add 700cc before sending it down? ;) :cool: :eek: :D
Jes
 

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Discussion Starter #14
Sure - just need the keys to the three-point... :rolleyes:
 

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Haha... :D Now, go to your kitchen window, open the blinds :eek: Keys are under the front seat :eek: Now wouldn't that be something? :p ;) :D
Jes
 

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So let me get something straight.
I have a damaged 3 litre flywheel at the moment which I can not use. How could I adapt my 2.5 litre flywheel to fit my 3 litre 12v engine in my racecar? Obviously I want my starter motor to work too.
 

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This has come up before with a mix of responses. Personally I don't believe every 2.5 has an individual balance factor. It's so impractical to assemble crank, flywheel and front pulley, balance, dissassemble then re-asssemble those same parts into a block another half a dozen steps down the production line. On a Ferrari or Lamborghini no doubt, but I can't see it on a mass production Alfa. As JJ's posted before, balancing holes drilled at the factory looked different between a pair of 2.5 front pulleys photographed. From this it was concluded that every motor had a different balance. Another way of explaining it is differences in the castings. This theory was suggested in the 1st link below.

2.5 and 3.0 should have different balance factors but Jes and others have mixed and matched components with good results.

Here are a few threads on this topic. The 2nd thread is one I started about a jig I used after lightening but could be used to turn a 2.5 flywheel into a 3.0 for your conversion.

ALFAGTV6.COM ~ View topic - Front flywheel balancing

http://www.alfabb.com/bb/forums/milano-75-1987-1989/46463-flywheel-balancing-jig.html

http://www.alfabb.com/bb/forums/engine-management/37332-60-minus-2-pulley-gtv-6-a-2.html
 

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The information in the first link isn't necessarily correct! I think you need to be careful and keep in mind that people often state an experience with a single encounter as a general fact. Some later style Milano 2.5 V6 have a flywheel that does not need the 4 mm spacer, nor is re-drilling the rear holes on that 2.5 V6 Milano sump necessary to line up with the 164 block. Other smaller modifications to the sump/block are necessary, but the parts (starter, flywheel, bellhousing, sump) of such a later style 2.5 V6 are practically bolt-on like parts from a Milano 3.0. Yes, you can discuss flywheel balance, but I have had no problems so far - that is my encounter ;) Although, I know of more cases of the same.

Jes
 

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Thanks for the responses boys.

Just to note the 3.0L is from a Milano and my 2.5L is from my GTV6. I am dropping the 3.0L into my GTV6. I stress, the 3.0L is not from a 164. Should the 2.5L flywheel just bolt straight on??
 
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