• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

TR2/3/3A Moss alternator & narrow belt conversion questions

Share this page

GTP1960

GTP1960

Jedi Knight
Offline
After installing the moss alternator, (& not having any recent experience with this exercise)
i discovered three issues:
the woodruff key is loose in the alternator shaft slot ; is this normal?

the narrow belt pulley sleeve/collar may be to long, for proper alignment & or shaft nut tightening:
Should I take the aluminum pully to a machine shop( or do it myself) and have it shaved down or find a new pulley, or what ?

Additional conundrum; the pulley pushes the alternator fan to far back on the shaft, causing it to rub against the housing: is it common to shim the alternator fan? Are there shims for that purpose ?

i assumed the moss conversion kits would meld together nicely on this typical stock TR3A engine, so now I'm thinking " what am I doing wrong?"

any advice appreciated.

GP
 
Guy, a few comments. I'm also in the middle of attempting this conversion, and have run into some similar problems. I recommend that you go to a hardware store and buy a new woodruff key that fits the alternator slot tightly. I have found two problems on the aluminum pulley in relation to the water pump on my TR3A. First is that the slot in the pulley is too small for the woodruff key in my water pump, so I filed the pulley slot wider. The second problem with the new aluminum water pump pulley is that the center shaft hole of the pulley is longer than the shaft hole on original steel water pump pulley. Moss Tech support believes this is due to the shaft on their previous Powertune brand replacement water pumps not being built to spec. They now have a new vendor but they have not told me yet the shaft length on their new replacement water pumps. The shaft on my PowerTune water pump is 31/32 long and the shaft hole in the aluminum water pump pulley is 1-3/32 long, thus making the aluminum pulley stand proud of the water pump 1/8 inch farther than the old steel pulley. This has the effect of not allowing the nylok nut for the water pump pulley from actually reaching the thread of the shaft. I am going to wait until I get the damper pulley installed to see how it aligns with the water pump pulley before I decide whether to have the aluminum water pump pulley machined to the length of my water pump shaft. If it lines up ok without machining, I will use blue loctite on the nut of the water pump shaft. The problem with machining the aluminum pulley to match the shaft on your current water pump is that if you have to replace the water pump, the aluminum pulley may not fit the new water pump shaft correctly.

Since I am using a GM alternator rather than the Lucas supplied by Moss, I am not having that problem however, I don't see any problem with putting a washer behind the alternator fan to move it away from the alternator, as long as the bolt holding the fan and pulley will tighten adequately to hold the fan and pulley tight.

Please let us know the progress on your conversion. Thanks!
Regards,
Bob
 
GTP1960 said:
Additional conundrum; the pulley pushes the alternator fan to far back on the shaft, causing it to rub against the housing: is it common to shim the alternator fan? Are there shims for that purpose ?
Click to expand...
Most alternators have a spacer that goes between the fan and the inner race on the front bearing. The pulley nut clamps through that spacer (and the pulley and fan) to lock the shaft to the bearing race. In some cases, the outside diameter of the spacer also has a seal that rides on it. Sounds like your spacer might be missing or wrong. Unfortunately I don't know of a source for generic spacers, but it might be worth contacting Moss to see if they can supply it. Otherwise it's an easy job for a machine shop to make one.

I would definitely contact Moss before changing the key or modifying the pulley. Before you modify anything, they have an obligation to sell you something that works (implied warranty of fitness), or give you your money back. After any modification, they can just say "sorry".
 
thanks for your insights. Before I did anything else, I contacted Moss & they are trying to resolve my issue. I sent them a # of pics and measurements.
their knee jerk response has been that the alternator & water pump pulleys may be wrong sized.(somewhat like your issue , Bob). The issue I am having with the fan may go away with the correct alternator pulley( apparently the fan is a simple compression fit with no backing shim or spacer).
i put locktite red in the woodruff key slot & it seemed to secure it until I got the pulley in place.
also the dampener pulley sleeve has some rust & dings, inside and out, right out of the pkg.
i'm expecting a call tomorrow on their resolution proposal, (if any).

my motto continues:" pay a lot of money to the experts..........then find a way to correct it yourself".
 
Guy, neither the water pump pulley nor the rusty and dinged spacer issues should be a surprise to Moss Tech Support. I raised both of those issues to them over two weeks ago. They are sending me a new inspected spacer direct from Moss Europe. I have not heard back from them on the water pump pulley issue.
Regards,
Bob
 
TuffTR250 said:
Guy, neither the water pump pulley nor the rusty and dinged spacer issues should be a surprise to Moss Tech Support. I raised both of those issues to them over two weeks ago. They are sending me a new inspected spacer direct from Moss Europe. I have not heard back from them on the water pump pulley issue.
Regards,
Bob
Click to expand...

Here's a couple of pics of my sleeve: Moss hasn't confirmed they will take it back, but I took Randall's advice and left things "as-is" for them to sort out, as best they can.


sleeve 02.JPGsleeve 01.jpg
 
I also installed the narrow belt conversion from Moss. The sleeve was about the same condition as shown in the pictures. I just polished the sleeve with crocus cloth after pressing the sleeve onto the pulley.

The supplied aluminum water pump pulley was within 1/16" of align with the crank pulley.

I installed an alternator from a 95 Toyota Corolla to which I fabricated a mounting and adjustment bracket that utilize the original block and water pump mounting holes. The hard part was the fabrication of the pulley which required help from a machinist friend. I'll post pictures if anyone is interested.

I am now finishing wiring the alternator, pulse width modulator, electric fan and headlight relay harness. I'm hoping to have it road worthy this summer!
 
HAWAIICJ said:
I am now finishing wiring the alternator, pulse width modulator, electric fan and headlight relay harness. I'm hoping to have it road worthy this summer!
Click to expand...
I'd like hearing more about the PWM (which I assume is for the cooling fan). What circuit you used, how it worked out, etc.
 
Yes, the PWM is for controlling the electric fan.

I'll start a new topic with the mods I've done in detail with pictures this weekend.
 
Dave,
id like to see your mods as well, ( an electric fan is on my list.)
what does the PMW do?
also your headlight relay harness makes sense.

was the shaft size from the 95 Corolla different? Is that why you had to modify a pulley?

thx
 
HAWAIICJ said:
I also installed the narrow belt conversion from Moss.

The supplied aluminum water pump pulley was within 1/16" of align with the crank pulley.

Dave,

Is 1/16" alignment close enough? Any way to bring the water pump in to closer alignment?

GP
Click to expand...
 
GTP1960 said:
Is 1/16" alignment close enough? Any way to bring the water pump in to closer alignment?

GP
Click to expand...

If Chevrolet can get away with it's belt alignment on the Corvair, I would think that 1/16" off would be just fine.

motor_finished.jpg
 
Hey guys, The belt alignment is (in my opinion) within an acceptable range. You could shim the water pump pulley if it is too far to the rear, but the pump shaft stud is short so you would have to take that into account.

IMG_1271.jpg,IMG_1292.jpg

The alternator shaft is 15mm which required a different pulley, the serpentine belt pulley has a deep shoulder to contact the front bearing so a v-belt pulley was machined. With the pulley installed I manufactured the spacers to line up the alt pulley with the pump and crank pulleys. I don't have pictures but I have a picture of the drawing.

IMG_0997.jpg

The dimension missing is 0.500" for the outer diameter of the stepped shoulder. The mount was made from a new generator bracket cut, modified and welded with a stiffener to support the spacer. The rear spacer is welded and the front is not so the alt can be remove and the original generator and mounting can be reinstalled. The adjuster bracket is also a modified generator part shortened, straightened and the slot lengthened. The wiring has been started but the holidays and cold temps get in the way.

IMG_1290.jpg

The unfinished mounting bracket can be seen in the above picture.

The reason I installed the kit was the running hot and overheating in traffic I wanted to install an electric fan. The fan is mounted to the radiator and controlled by a PWM device to adjust the fan speed from 50-100% duty cycle depending on temperature. The controller also has a jumper that can be changed from 10sec to 1 min key off cool down. There is a sensor that contacts or is installed in the lower tank or hose to sense radiator output temp, there is also a provision for a failsafe switch.

IMG_3514.jpgIMG_1400.jpg

This box will be mounted down out of view. Currently the wiring has been started but needs to be terminated at the new fuse box I'm adding in the passenger compartment behind the hood release.

Note: The switch in the radiator top tank was from before I chose to use a PWM fan controller.

Overall I am very pleased with the Moss narrow belt kit although I have gone a bit beyond the design supplied kit.
 
Last edited:
GTP1960 said:
Wow.....that's a piece of work.
is that the water pump under the air filter housing?
looks kinda like a string -pull top from back in the day
thx!

guy
Click to expand...

Corvairs are air-cooled flat sixes.
 
GTP1960 said:
is that the water pump under the air filter housing?
Click to expand...
Cooling fan. The fan sits on top of the flat 6, which is why the belt goes "around the corner" from the crankshaft. But note that it meets each pulley squarely, in spite of the twist, so there is minimum rubbing on the side. Not the same as having one pulley misaligned.
 
"The alternator shaft is 15mm which required a different pulley, the serpentine belt pulley has a deep shoulder to contact the front bearing so a v-belt pulley was machined. With the pulley installed I manufactured the spacers to line up the alt pulley with the pump and crank pulleys. I don't have pictures but I have a picture of the drawing."

Dave,

I see you have no alternator fan, on your mod., if I remove mine I believe I will have ample room to align my pulleys
( as the alt. Pulley is a bit proud).

so my question is : Do I really need the alt. fan? It 's a Lucas alternator supplied by Moss.

guy
 
GTP1960 said:
"The alternator shaft is 15mm which required a different pulley, the serpentine belt pulley has a deep shoulder to contact the front bearing so a v-belt pulley was machined. With the pulley installed I manufactured the spacers to line up the alt pulley with the pump and crank pulleys. I don't have pictures but I have a picture of the drawing."

Dave,

I see you have no alternator fan, on your mod., if I remove mine I believe I will have ample room to align my pulleys
( as the alt. Pulley is a bit proud).

so my question is : Do I really need the alt. fan? It 's a Lucas alternator supplied by Moss.

guy
Click to expand...

The ND alternator has the fan internally, one of the advantages as well as being compact (2/3 the size of the Lucas) and still puts out 50+ Amps. The Lucas alt like a GM has the fan under the pulley, yes you do need to use the fan.
 
Guy,

I would leave the fan installed on the alternator as assembled and if the pulley is out of align (parallel but too far forward) you could trim the front of the mounting carefully to realign.

McMaster-Carr has shims if you would need to bring the alt forward into alignment.
 
Back
Top