Large Frame alternator in M25XP
- Thread starter Hayden Watson
- Start date
The belt kit came in and it looks beautiful.
And even prettier when installed. 
Did you get the belt buddy too? I found the standard arm could not cope with the increased load from the larger alternator.
Did you get the belt buddy too? I found the standard arm could not cope with the increased load from the larger alternator.
I picked up the new alternator this afternoon complete with the test report. It looks very nice.
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Well, I started the install today and it defiantly fits. The large frame is only a bit bigger than my old Ample Power 100A that it is replacing. I will need to create a new adjuster arm because the old one is too short.
I found a remote oil kit that works with my XP which will be a nice addition.
Size comparison between new and old. The new sure has a lot more cooling ventilation and the 12-diode rectifier with large heat sink should work cooler than the old 6-diode configuration in the Ample.
Front view. I will need to lift the engine about 3" to install the crank pulley. I did the motor mounts a couple of years ago so that will not be a challenge.
Top view. Lots of room for new alternator.
I am hoping to install an Hiem adjuster as was suggested by Rod Collins but not sure what I could attached to down here. One though is to make an angle bracket that bolts to the top side of both port side engine mounts and use the motor mount bolt to hold it in place. The end would then cantilever out past the front mount to provide an anchor for the Hiem.
I am installing a forced cool air duct which will bring cool bilge air through the foam insulated firewall and blow it directly into the rear ports into the rectifier heat sink.
This picture shows the fan mount coming through the foam.
This is the model of remote oil filter I found. The inner O-ring has an OD of 2.5" and fits the filter flange on the M25XP perfectly.
I found a remote oil kit that works with my XP which will be a nice addition.
Size comparison between new and old. The new sure has a lot more cooling ventilation and the 12-diode rectifier with large heat sink should work cooler than the old 6-diode configuration in the Ample.
Front view. I will need to lift the engine about 3" to install the crank pulley. I did the motor mounts a couple of years ago so that will not be a challenge.
Top view. Lots of room for new alternator.
I am hoping to install an Hiem adjuster as was suggested by Rod Collins but not sure what I could attached to down here. One though is to make an angle bracket that bolts to the top side of both port side engine mounts and use the motor mount bolt to hold it in place. The end would then cantilever out past the front mount to provide an anchor for the Hiem.
I am installing a forced cool air duct which will bring cool bilge air through the foam insulated firewall and blow it directly into the rear ports into the rectifier heat sink.
This picture shows the fan mount coming through the foam.
This is the model of remote oil filter I found. The inner O-ring has an OD of 2.5" and fits the filter flange on the M25XP perfectly.
Well, my installation was going swimmingly right up to the point where I tried to install the Balmer drive pulley from my serpentine belt kit. It is 64-thousants less than the original pulley and no amount of lube will get that to fit.
Phe pulley is intended to mount over the top of the factory drive pulley and be clamped to it by using the three holes in the pulley intended to be used with a puller in removing the pulley. It should be a close fit with a couple of thou clearance. I haven't heard from Balmar because I did not discover it until 6:00pm on Friday. They are based out of Marysville which is only about 55-miles from me but still frustrating.
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I ended up needing to pull the front balancer pulley from the engine and take it to a machine shop that cut the edges of the V-bely pulley down to fit the drive wheel. The end result was a perfect fit although I could have done without the $137 in tools and machinist fees.
I have the alternator installed and needed to fabricate a new adjuster arm because the new large frame is about 1/2" larger diameter and the new belt causes the alternator to rotate farther away from the exhaust manifold which is a good thing. I really did not like the old adjuster given that there was about 150º at the pivot bolt from the adjuster anchor at the mount and the alternator. This creates a lot extra load into the mount which is not needed. I fabricated an angle that bolts to the top of the motor mount flanges and supports a hiem link that has much better geometry and completely removes all loads in the adjuster from the alternator mounting bracket. I used a light perforated angle that I could nibble away at until I was happy with the fit and then had a welder make up the final. Completely thrilled with the final results.
Here is a Flir shot of the first test run. The alternator had been putting out 100A for about 15-minutes and was at 135ºF with none of the external cooling fans running. once I get everything set up, I plan to increase the output in steps and take Flix photos of the alternator from every angle and also check all wires and connections back to and including the battery. That way I can identify any issues before they become problems.
I have the alternator installed and needed to fabricate a new adjuster arm because the new large frame is about 1/2" larger diameter and the new belt causes the alternator to rotate farther away from the exhaust manifold which is a good thing. I really did not like the old adjuster given that there was about 150º at the pivot bolt from the adjuster anchor at the mount and the alternator. This creates a lot extra load into the mount which is not needed. I fabricated an angle that bolts to the top of the motor mount flanges and supports a hiem link that has much better geometry and completely removes all loads in the adjuster from the alternator mounting bracket. I used a light perforated angle that I could nibble away at until I was happy with the fit and then had a welder make up the final. Completely thrilled with the final results.
Here is a Flir shot of the first test run. The alternator had been putting out 100A for about 15-minutes and was at 135ºF with none of the external cooling fans running. once I get everything set up, I plan to increase the output in steps and take Flix photos of the alternator from every angle and also check all wires and connections back to and including the battery. That way I can identify any issues before they become problems.
Now I get why you wrote DEFIANTLY. Sometimes you just have to beat it into submission!!!!!