Alternator Mounting on my Subaru 2.5

CLS447

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Here is where I am..........

I have a lightweight aftermarket crank pulley for my engine. Some like it & some don't. It is smaller in diameter, much lighter & prettier.

The pulley positions are the same as stock. 4 grooves close to the motor & 5 grooves outboard......make sense ? So everything would be the same if I was using the stock 8 lb pulley.

The original Subaru mount is very heavy & puts the alt. closer to the center of the engine with the AC compressor off to the side. I do not need AC.

The original alt uses a 5 groove pulley & belt & also runs the ====== ?

I purchased a mounting plate,& adjuster setup from the Sparrowhawk people. I also got an alt with underdrive pulley (4 groove ) from a friend.

I have been scratching my head trying to figure the proper mounting.

I believe I now have the answer & it will work, but I had other ideas.

I wanted the 4 groove alt pulley & belt to line up with the inner 4 groove portion of the crank pulley.

I took a few steps back & tried to think out of my square that I seem to get stuck in sometimes !
 

CLS447

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Air Command 503 & Air Command SxS /EJ2.5
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Aprox 400 gyro
More to the story......

Here is the pulley I have. I wanted the single 4 groove pulley, but they were out of stock or something.

I actually thought about having the useless 5 groove forward portion machined off.

The Groen Brothers pulley that I have on my alternator is 4 groove.

What do you think I wanted my 4 groove alt pulley to line up with ? The 4 or 5 groove section of my crank pulley ?

I don't like the way the alt did not stradle the rod ends when I line up the 2 four groove pulleys !

Does anyone see where this is going ?
 

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eddie

RAF, turbo subaru 230hp
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I thought that the stock pulley was also a harmonic balancer?



Best regards,
 

CLS447

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Aprox 400 gyro
I thought that the stock pulley was also a harmonic balancer?



Best regards,
Eddie,that has been beat around quite a bit, I am gonna use it. We'll see how it works out for me.

I'll try to post the links on that......
 

CLS447

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Reading, PA
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Air Command 503 & Air Command SxS /EJ2.5
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Aprox 400 gyro
Here are some of the alternators I have.....

This one is a stock 2.5 Sub alternator with 5 groove pulley.........no fan ?

All of them have similar mounting lug spacing & similar front lug to pulley distance.

They do have different shaft & thread sizes.

The SH underdrive pulley can be flipped for different setback measurements (small difference, but not the same).

This pic shows where the alt would be positioned on the rod ends to get the alt pulley to line up with the 4 groove section of my crank pulley.

If I stradle the rod ends by moving the alt forward, I like it much better. One spacer in between & a couple of washers on the outside of the rod ends.

This will put my belt out on the 5 groove portion of the crank pulley ( not where I wanted it or expected it to be ).

Moving it forward also gives me less control rod clearance ( not a big problem, just another change)
 

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CLS447

Platinum Member
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Reading, PA
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Air Command 503 & Air Command SxS /EJ2.5
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Aprox 400 gyro
If I had purchased the single 4 groove pulley from Tech Welding or had the front 5 groove section machined off, I would not have much choice but to keep the alt back.

If you look at this pic of the SH alt mounting plate........There is not enough material there to redrill the rod end holes toward the rear , at either of the 2 locations.

There is enough room to have a new plate made that would allow me to do this.

More time & more money, but get the result I originally wanted......Do you think I am CRAZY ?

Why did Groen bros design the plate to put the belt out there ? I hate to have to redesign things that should have been thought out better. Or did they do it for a reason ?
 

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CLS447

Platinum Member
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Reading, PA
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Air Command 503 & Air Command SxS /EJ2.5
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Aprox 400 gyro
These are the little things that are holdin up the show !

Neil, what is up with that tiny little breather ? I have to make it fit behind my drum.

Today was the last time I am going to look at that little overflow bottle & try to come up with a way to mount it to the bellhousing.....unless you like to just smear some silicone on it & a couple of wire ties !

I snagged my bottle & mount from my EA81 & got it mounted using the same plate I made before.

I like the way the socket head bolts are recessed, But it offers a challenge for mounting things. Luckily I had some washers that fit right in the recess to make a flush surface for mounting.
 

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CLS447

Platinum Member
Joined
Oct 30, 2003
Messages
6,320
Location
Reading, PA
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Air Command 503 & Air Command SxS /EJ2.5
Total Flight Time
Aprox 400 gyro
I removed the little plate that is tapped for the vent fitting, to try to understand it better.
It was made like this for a purpose ?

Rotax gearboxes vent through the fill fitting. Why can't I just use a vented top plug ?

My Souza gearbox vented through the fill.

The catch bottle I used on it worked well....I am going to try it on my Autoflight.

The vent is piped to the top fitting , which allows it to breath through the filter & catch the fluid.

The bottom fitting returns to the full level plug on the side if the valve is open. The clear tube can also act like a sight glass !

So Neil, if you read this, what are my venting options & why such a tricky vent system ?

I would also like to thank you guys for the help with the alternator. I am pretty happy with it, except for the fact that the belt runs on the 5 groove pulley.

I used the shortest belt I could which keeps it down & out of the way.

It is all tightened down & ready to spin. FINALLY ! No fan though ?
 

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