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Tue Apr 10, 2012 1:48 am

Forgive me if this has already been covered but has anyone got first hand experience of the RPM required to explode a Type 3 fan?

I have welded the tabs on my Type 1 fans on engines previously but it occured to me that I have not done this to a Type 3 fan (perhaps foolishly).

I have just started up my new 2028cc and already hit more than 6,500 rpm (thats when the shift light comes on).

The fan's on this engine were previously on my 2276c that hit about 7,500 rpm without any incident.

Curious to hear your responses.

Tue Apr 10, 2012 5:24 am

hey look who it is :)

to answer your question, apparently they are only good for 5500rpm and thats welded and balanced.

In my experience I don't ever see a problem as I frequently go into the 5000-6000 range. Nothing has ever blown up on me, well I would be lying, I did explode main pinion bearing and first gear once :P

Tue Apr 10, 2012 7:35 am

Aaron Britcher wrote: Forgive me if this has already been covered but has anyone got first hand experience of the RPM required to explode a Type 3 fan?

I have welded the tabs on my Type 1 fans on engines previously but it occured to me that I have not done this to a Type 3 fan (perhaps foolishly).

I have just started up my new 2028cc and already hit more than 6,500 rpm (thats when the shift light comes on).

The fan's on this engine were previously on my 2276c that hit about 7,500 rpm without any incident.

Curious to hear your responses.

I don't think you'll have a problem with the t-3 fan. However, something to think about; on a t-1, the fan is spining at 3.1:1 to the crank (got my info from a t-1 Bentley). That means that @ 5000 rpm, a T-1 fan is spining at least 15000 rpms. :shock: That's why most people recommend welding and balancing them. Just a thought. :wink:

Tue Apr 10, 2012 7:39 am

Quote: Type 1 fans on engines previously but it occured to me that I have not done this to a Type 3 fan

5500rpm on a type 1 is not 5500rpm at the fan like it is on a T3. I'm not sure of the pulley ratio but if it's 2:1 for the T1 then that fan is turning 11000rpm at 5500rpm VS the T3 turning the fan attachet to the crank at 5500 rpm.

my 1600 was buzzing up to 5500 on a regular basis for the last couple years and the fan still looks new.

Tue Apr 10, 2012 9:10 am

Lauffers blew theirs up around 6500 on a dyno run, IIRC. But, I know they also rang that engine out often.

Tue Apr 10, 2012 8:38 pm

Bobnotch wrote: Aaron Britcher wrote: Forgive me if this has already been covered but has anyone got first hand experience of the RPM required to explode a Type 3 fan?

I have welded the tabs on my Type 1 fans on engines previously but it occured to me that I have not done this to a Type 3 fan (perhaps foolishly).

I have just started up my new 2028cc and already hit more than 6,500 rpm (thats when the shift light comes on).

The fan's on this engine were previously on my 2276c that hit about 7,500 rpm without any incident.

Curious to hear your responses.

I don't think you'll have a problem with the t-3 fan. However, something to think about; on a t-1, the fan is spining at 3.1:1 to the crank (got my info from a t-1 Bentley). That means that @ 5000 rpm, a T-1 fan is spining at least 15000 rpms. :shock: That's why most people recommend welding and balancing them. Just a thought. :wink:

don't forget the type 3 fan is a harmonic balancer. The fan itself will flop all over the place as it counter balances the rest of the rotating mass's harmonic and dynamic vibrations. The fan would be fine for lower rpm, but I bet it would vibrate like hell at 6k and above.

Tue Apr 10, 2012 9:11 pm

vlad01 wrote: Bobnotch wrote: Aaron Britcher wrote: Forgive me if this has already been covered but has anyone got first hand experience of the RPM required to explode a Type 3 fan?

I have welded the tabs on my Type 1 fans on engines previously but it occured to me that I have not done this to a Type 3 fan (perhaps foolishly).

I have just started up my new 2028cc and already hit more than 6,500 rpm (thats when the shift light comes on).

The fan's on this engine were previously on my 2276c that hit about 7,500 rpm without any incident.

Curious to hear your responses.

I don't think you'll have a problem with the t-3 fan. However, something to think about; on a t-1, the fan is spining at 3.1:1 to the crank (got my info from a t-1 Bentley). That means that @ 5000 rpm, a T-1 fan is spining at least 15000 rpms. :shock: That's why most people recommend welding and balancing them. Just a thought. :wink:

don't forget the type 3 fan is a harmonic balancer. The fan itself will flop all over the place as it counter balances the rest of the rotating mass's harmonic and dynamic vibrations. The fan would be fine for lower rpm, but I bet it would vibrate like hell at 6k and above.

You need to re-read that post I made Vlad, I was taking about T-1 fans (getting welded and balanced). :roll: I already know a t-3 fan is a harmonic balancer, but that doesn't mean the blades can't be welded to the fan (where they're spot/tack welded). :wink:

Tue Apr 10, 2012 9:17 pm

Bobnotch wrote: vlad01 wrote: Bobnotch wrote: Aaron Britcher wrote: Forgive me if this has already been covered but has anyone got first hand experience of the RPM required to explode a Type 3 fan?

I have welded the tabs on my Type 1 fans on engines previously but it occured to me that I have not done this to a Type 3 fan (perhaps foolishly).

I have just started up my new 2028cc and already hit more than 6,500 rpm (thats when the shift light comes on).

The fan's on this engine were previously on my 2276c that hit about 7,500 rpm without any incident.

Curious to hear your responses.

I don't think you'll have a problem with the t-3 fan. However, something to think about; on a t-1, the fan is spining at 3.1:1 to the crank (got my info from a t-1 Bentley). That means that @ 5000 rpm, a T-1 fan is spining at least 15000 rpms. :shock: That's why most people recommend welding and balancing them. Just a thought. :wink:

don't forget the type 3 fan is a harmonic balancer. The fan itself will flop all over the place as it counter balances the rest of the rotating mass's harmonic and dynamic vibrations. The fan would be fine for lower rpm, but I bet it would vibrate like hell at 6k and above.

You need to re-read that post I made Vlad, I was taking about T-1 fans (getting welded and balanced). :roll: I already know a t-3 fan is a harmonic balancer, but that doesn't mean the blades can't be welded to the fan (where they're spot/tack welded). :wink:

I wasn't talking about the welding, I was merely pointing out that the reason we can't go as high as the type 1 speed is because its a 2 piece design as it is a balancer despite if its welded and balanced or not.