60 Minus 2 Pulley for GTV-6

[RexCars]

I'm interested in converting my GTV-6 to GoTech.

The car has sort of become my garage queen, traveling few miles in the last decade. So I will be having the now 10 year old cam belt replaced and the (hydraulic) tensioner overhauled before I start driving the car in the spring.

While I'm doing that, I'd like to have a 60 minus 2 pulley dropped in so I can do the GoTech later in the summer.

Here is my question: can I use a pulley from a 3 L motor out of a 164 on the GTV-6? What I was thinking about doing was having the pulley on the 164 motor I have in the garage machined in advance. Otherwise, the car will have to sit in the shop for a while until the GTV-6 pulley get's shipped out to be machined.

Thanks,
Rex in Albany

[Greg Gordon]

The pulley is an factor in the ballancing of the motor. Technically you really can't put a 164 pulley on unless you are rebuilding the motor and ballance it with that pulley. Now...with that said, you can probably do it. I have switched crank pulleys before with a fair degree of success. The worst I have had happen is a minor vibration within a very small rpm range.
Greg Gordon,
www.hiperformancestore.com

[junglejustice]

These motors are all balanced externally. The crank-pulleys and the flywheels are balanced as a unit - per assembly-line - for each model! (There is no individual balancing per motor from the factory...)

We usually don't worry about it - we use ANY and all pulley and flywheel combinations with ANY of the motors that Dawie builds, (because we get the entire assembly re-balanced as a unit any way as part of the big-bore conversions!)

There does exist some pulley/flywheel combinations that can be mixed between the differing models, but I would hate to be the one to tell you to experiment with the resulting engine balance! (I do know for example that a Milano Verde 3.0 crank-pulley and Verde flywheel work very well together on say a 24 valve 3.0 motor installed in a transaxle car! I also know that a Verde flywheel and a stock 24 valve crank-pulley work just as well together on that same stock 24 valve engine in a GTV6/Milano/75!

Furthermore, Jes (AR4me) was advised to use a 2.5 flywheel (the later model with the spacer), on his 164 3.0 12 valve install in his Roxanne Milano race car in combination with the stock 164 3.0 12 valve crank-pulley that came on the motor! In theory then, that same flywheel and crank-pulley combination can be used on the 2.5 litre engine that the flywheel came from? This confuses me somewhat as I have it on very good authority that all of the 2.5 12 valvers had the same balance factor and the 3.0s were different from that (but the same for the entire line) and that the 24 valvers were different from all of those yest again, (but all the same within the assembly-line...)

On the 12 valvers, the best would be to simply heat that ring-gear from a 164 pulley up a bit, press it off and press it on to the 12 valve pulley. Alternatively, I am in the process of having some ring-gears made that will attach to the front of the stock 12 valve pulleys - either via machine-screws or press-on/tack-welded (2.5 or 3.0...)

[slyalfa]

take a look at this VEMS Install on my verde
I pulled the ring off the 164 and put in on my old pully. but the ring then needed to be thinned so it would not hit the waterpump pully.
so it can be done. but if I had to do over I would have switch to the new style belts and just changed the pullys on the other stuff.

[ToonRboy]

Driveshaft balance is more important. Just think of it, we basically have an engine with a 5' crankshaft! Harmonic balancer on these engines aren't as critical as on a front-trans or FWD motor.

[emBOSSed]

I am looking into the same problem. I have a 2.5 V6 Milano engine and want the 60-2 trigger. It is good to know that moving the trigger wheel might work. Alternativly in upgrading to the serpentine belt here is what I might try to do. Take the 3.0 pulley assembly and mount it to the 2.5 assembly using a rod through the crank hole. then balance the 3.0 to match the 2.5. In theory this should work as long as there is exta metal on the 3.0 pulley that can be drilled away. Or maybe the inside of the hole can be re-keyed to allign the weight where it needs to be.

[junglejustice]

Well, all bets are off on pulley swaps off ALL kinds if you ask me...

Just pulled 4 pulleys (a 2.5 GTV6, a 2.5 Milano, a 3.0 Verde and another 3.0 Verde) - ALL different!

I mean - ALL 4 were different! The two 3.0s seemed to have smaller weights than the two 2.5s - that part was consistent between the two pairs - but that was where the similarities ended!

The individual balancing holes drilled on the back, on the front (on some of them) and on the sides (on some of them), leads me to believe that these were all individually balanced!?

I am sure that some will work here and there with these flywheels and those, but as a whole, how can anyone suggest that flywheel X will always work with pulley Y on installation Z with this much variance!? (ME included...)

I am baffled.

[nizam]

I think they are all cast together, then the counterweights are drilled out to get within a particular specification for the engine they are to be assembled on. If what you say is true (each engine is individually balanced) then it would be impossible to replace crank pulleys that occasionally crack because you'd immediately be out of balance.

The counterweights should be different between the 2.5's and the 3.0's, but they will ALSO be different between the 3.0's installed in FWD cars versus RWD cars.

[junglejustice]

And that is my point...

If each motor was balanced individually this way then, rather than by assembly-line (as previously believed), what is the part number for "my pulley" in the event of the need for replacement...?

It is just weird - sure - not strange to see individually balanced motors, but we never thought of the Alfas this way before and then here is APE and everybody else advocating simply mix-and-matching this pulley and that flywheel to make up an accurate balance-factor on any third-party motor!

How can "...a pulley from "a" 3.0 and a flywheel from "a" 3.0 be the right combo for this or that engine, when there are differences from 3.0 to 3.0 and from 2.5 to 2.5...?

Unless these small balance-holes are just so subtle that the main difference lies between the 2.5 and the 3.0 pulley (like I mentioned - the two 3.0 pulleys above have smaller weights than the two 2.5 units...)

[nizam]

Do you have a crank balance shop nearby? Bring by those crank pulleys and ask 'em what the counterweights are. Then you'll know

[junglejustice]

Yeah-yeah - that's not the problem... We get the Glenwood engines custom-balanced ALL of the time... Having a balance-factor of one particular pulley or flywheel replicated once and engine is zipped up is not the issue either - that part is simple to comprehend.

The question that we are not answering here is the thought process to date that a 3.0 pulley is a 3.0 pulley is a 3.0 pulley...

How can APE for example tell Jes that his 2.5 flywheel of a particular model/year/spacer will work just fine on his S motor in Roxanne, when we have just determined that the balance factor varies FROM ENGINE TO ENGINE within the 2.5 line, WITHIN the 3.0 line etc etc...?

[nizam]

Quote:

Originally Posted by junglejustice The question that we are not answering here is the thought process to date that a 3.0 pulley is a 3.0 pulley is a 3.0 pulley...

[Greg Gordon]

Nizam, I strongly suspect the values of the counter ballancing for each pulley is different. It's a problem and it's why I went with magnets. It seems to me that JJ has the ultimate simple solution, use Gotech standard and forget all this pulley stuff.

[emBOSSed]

I was suggesting that it might not matter what pulley you are using if you can balance the new pulley to the original. find the heaviest point by letting gravity rotate it to the bottom. draw a line at the heaviest point. do this on both pulleys. then mount both pulleys with the lines 180 degrees apart. hopefulle the new pulley is heaver than the original (the set up should rotate so the line on the new pulley drops to the bottom). if the new pulley is heaver then drill balance holes until the set up is neutral. now the new pulley will have the same balance as the one you took off. if the new pulley is lighter then you might be able to fill some original balance holes with melted lead. I might try this and take pictures and post them.

[AR4me]

Quote:

Originally Posted by junglejustice How can APE for example tell Jes that his 2.5 flywheel of a particular model/year/spacer will work just fine on his S motor in Roxanne, when we have just determined that the balance factor varies FROM ENGINE TO ENGINE within the 2.5 line, WITHIN the 3.0 line etc etc...?