Denso alternator

sandy

Gold forum user
CAT Member
Messages
300
Powermaster now has a 100mm with same deminsions as 93. This is a polished one I got and will install it with Hoghead's Bracket. It puts out 75A. Also had the Bracket Powdercoated black.
I have the smaller size and saw those a few months back. Figured I would get what I have going first and upgrade if needed. Things are getting costly these days.

Also for everyone doing alternator upgrades make sure your main wire from the alternator and related connections (amp meter if used) are capable. I recall the stock stuff from the generator was not of a large enough gauge for much over the stock generator/alternators that were stock. I don't have stock wiring so not going to be a problem, but for those that do good idea to checks gauge and amperage ratings. Likely 8 gauge for 55 amp and 6 gauge for 75 amp being somewhat overkill but safe for shorter runs 5-10 feet. Again not sure what's in the stock harness.
 

Hoghead

Gold forum user
Messages
578
Looks like instead of a specific counter sink, you could just mill the face an 1/8" or so in the that area, looks like plenty of material and might just clear the hose. Also easy enough to get a counter sink too and DIY it for those running the edelbrock pump/heads. I'm running one but not using the heater fittings. Last resort hit up McMaster for low profile allen, or button heads and use a thin washer as the ARP ones are nice and thick. I'm watching this as I may have to use this bracket if mine doesn't work with the valve covers since the alternator in my case is really close to the head and valve cover rail.
Great minds and all that - I was thinking last night that I could counterbore the 3 holes to the head 4-5mm to fit a 3/8 washer, but still drill for a 5/16 stock bolt. The Owner then could easily drill for 3/8 if not a stock head
Plate is 12mm and a SAE washer is 2mm, so only an additional 2-3mm of clearance to be gained, but just might be sufficient for clamp clearance.

I would have to design for a smaller SAE washer rather than USS, so that it would not look too odd having a 5/16 washer in a 3/8 counterbore.

The 12 point ARP bolts are part of the problem
 
Last edited:

Hoghead

Gold forum user
Messages
578
Powermaster now has a 100mm with same deminsions as 93. This is a polished one I got and will install it with Hoghead's Bracket. It puts out 75A. Also had the Bracket Powdercoated black.View attachment 17039View attachment 17040

Please let me know if that 100mm alternator frame fits the bracket, as it is close to the inside curve using a 93mm body. Also the distance from the bottom bolt to the slot must be the same radius to allow tensioning.
There are 93mm bodies to 90A
 

sandy

Gold forum user
CAT Member
Messages
300
I was looking again at the 100mm, and it looks like just a bit bigger, 3.5mm radius. I don't think it would be a problem for me but not sure on your bracket. I have 2 of the 93mm, one for the mustang and one for the tiger. The problem is that at idle the 75 amp is only a 5 amps more at lower speeds ideally where you need it. My little pusher fan is about 15 amps running, and not much else using power, MSD states 1amp per 1k rpm, and a couple for gauges, and finally lights maybe a solid 20. So pretty close. Still 35-75amp of the bigger unit is appealing ;)

I suspected it was you after seeing your nice work on the bracket

Sandy
 

theo_s

Gold forum user
CAT Member
Messages
148
You should not be using an ammeter with the high power alternators. To do so safely, you would first need to find an ammeter that could handle the higher current, and then you need to bump up the wires running to the gauge. 10 gauge is rated for 30 amps; if you had a 75 amp alternator you would need 6 gauge or larger cable, with suitable connections, to the ammeter.
The alternator state is more suitably monitored with a voltmeter or using the alternator’s light output connection, which is easy to rewire to the original red bulb circuit.
 

sandy

Gold forum user
CAT Member
Messages
300
Here is a good calculator that will help, note that most automotive values use 5% voltage drop as OK. I go to 2% as a safer margin which with result in possibly the next larger gauge. And yes, appropriate amp meter would be needed or dump that mess and get a voltage gauge.

https://www.gtsparkplugs.com/WireSizeCalc.html
 

Hoghead

Gold forum user
Messages
578
You should not be using an ammeter with the high power alternators. To do so safely, you would first need to find an ammeter that could handle the higher current, and then you need to bump up the wires running to the gauge. 10 gauge is rated for 30 amps; if you had a 75 amp alternator you would need 6 gauge or larger cable, with suitable connections, to the ammeter.
The alternator state is more suitably monitored with a voltmeter or using the alternator’s light output connection, which is easy to rewire to the original red bulb circuit.
Jim Gislason has a nice, modern, Smiths voltmeter to take the place of the 30A Smiths ammeter or fill the blank hole where it should be
 

CLIFF_MK1

Gold forum user
CAT Member
Messages
212
Please let me know if that 100mm alternator frame fits the bracket, as it is close to the inside curve using a 93mm body. Also the distance from the bottom bolt to the slot must be the same radius to allow tensioning.
There are 93mm bodies to 90A
Robert, the alternator pictured above PowerMaster 28163 is 100mm, slightly bigger than the 93mm. The body fits the bracket for the most part but loses about 25% of the adjustment because some body protrusions hit the bracket when the body is turned in to loosen the belt. This is on this particular alternator. Without any changes, this means less ability to tension the belt. This may be OK if the choice of belt lenght is choosen carefully (I haven't tried it yet). Also it's possible to gain some additional travel by grinding the bracket where the alternator body hit the bracket (2 places).

Based on what I could find available, Denso 93mm alternators are limited to 55A. Powermaster has one 93mm listed at 75A, but it's for circle track and only puts out 7A at idle. There are lots of Denso style alternators available higer than 55A, but they are 100mm or the size isn't listed (probably not 93mm). Based on what I've been able to find, if you need more that 55A, it's necessary to go with the 100mm size. I need more than the 55A because at idle and lower speeds the alternator is putting out much less than 55A. I am running 2 8in puller fans, electric water pump, electric fuel pump, ignition plus any accessories not counting lights. So, I really want to keep the 75A 100mm alternator. And I really like you're bracket. I've tried 3 other brackets and I've had fanbelts flip off due to the flex in the brackets. You're design appears mch better because the bracket and adjusting slot are all one piece. Maybe you could consider a small design change and enlarge the opening in the bracket to fully accept the 100mm body? Cliff
 

Hoghead

Gold forum user
Messages
578
Robert, the alternator pictured above PowerMaster 28163 is 100mm, slightly bigger than the 93mm. The body fits the bracket for the most part but loses about 25% of the adjustment because some body protrusions hit the bracket when the body is turned in to loosen the belt. This is on this particular alternator. Without any changes, this means less ability to tension the belt. This may be OK if the choice of belt lenght is choosen carefully (I haven't tried it yet). Also it's possible to gain some additional travel by grinding the bracket where the alternator body hit the bracket (2 places).

Based on what I could find available, Denso 93mm alternators are limited to 55A. Powermaster has one 93mm listed at 75A, but it's for circle track and only puts out 7A at idle. There are lots of Denso style alternators available higer than 55A, but they are 100mm or the size isn't listed (probably not 93mm). Based on what I've been able to find, if you need more that 55A, it's necessary to go with the 100mm size. I need more than the 55A because at idle and lower speeds the alternator is putting out much less than 55A. I am running 2 8in puller fans, electric water pump, electric fuel pump, ignition plus any accessories not counting lights. So, I really want to keep the 75A 100mm alternator. And I really like you're bracket. I've tried 3 other brackets and I've had fanbelts flip off due to the flex in the brackets. You're design appears mch better because the bracket and adjusting slot are all one piece. Maybe you could consider a small design change and enlarge the opening in the bracket to fully accept the 100mm body? Cliff
No problem and happy to make the change.

The 93mm frame also has "bumps" on the body and the current bracket version is radiused to clear the bumps - an earlier version had scallops to clear the bumps.
It would be easy enough to incorporate either approach to fit a 100mm frame, but I am at my Thai home until June so not so simple to just buy a Powermaster unit. Sourcing items here is not easy, and importing an alternator to measure is just too expensive. Let me see if I can get a 100mm frame alternator with that Desno mount to measure.
 

Hoghead

Gold forum user
Messages
578
I was looking again at the 100mm, and it looks like just a bit bigger, 3.5mm radius. I don't think it would be a problem for me but not sure on your bracket. I have 2 of the 93mm, one for the mustang and one for the tiger. The problem is that at idle the 75 amp is only a 5 amps more at lower speeds ideally where you need it. My little pusher fan is about 15 amps running, and not much else using power, MSD states 1amp per 1k rpm, and a couple for gauges, and finally lights maybe a solid 20. So pretty close. Still 35-75amp of the bigger unit is appealing ;)

I suspected it was you after seeing your nice work on the bracket

Sandy
Is the 100mm frame just a fatter 93mm with the 2 bumps 3.5mm greater in radius, and in the same location? If so then it is simple for me to modify the bracket to fit both 93 and 100mm frame alternators.
Maybe not, as Cliff MKI above indicates that this 3.5mm loses 25% belt adjustment, leading me to believe that the bumps are either larger and/or in a different location?

If I could only find a drawing of those bumps.................
 
Last edited:

Hoghead

Gold forum user
Messages
578
img-42-f.png


Looks like Powermaster make a 93mm frame with 30A idle and 55A max.
The race version of the 93mm has only 7A at idle and 75 max
One must use the 100mm frame to get 35 idle / 75A max

All have the same mount, and the only bracket question is clearance for the bumps on the 100 mm frame

http://www.powermastermotorsports.com/catalog.html
 
Last edited:

Hoghead

Gold forum user
Messages
578
I have now re-designed the bracket to fit both the 93mm and 100mm Powermaster alternators shown above. Why they measure 98 and 104mm + the case screws at 10mm is beyond me
Other changes as a result from CAT members, and thanks to all for the suggestions:
One mounting bolt to the head is counterbored 4mm to gain additional hose clamp clearance at the water pump
The "S" logo version is relief milled 4mm rather than milled through
Will post a pic when the machine work is complete, but this is the idea:
1678260237270.png
 
Last edited:

Hoghead

Gold forum user
Messages
578
I have now re-machined the Sunbeam Tiger Denso alternator bracket to fit both the 93 and 100mm Powermaster alternators. While at it I counterbored one hole to give a bit more clearance on the hose clamp at the water pump heater outlet.
Fits:
93mm Powermaster (30A idle x 55A max speed) models 8162 /8172 /28162
100mm Powermaster (35A idle x 75A max speed models 8163 / 8173 / 28163

Why they are called that while measuring 98 or 104mm + another 14mm for the case screw bumps is beyond me

I have had it with Ebay, their fees, forcing me to pay their VAT obligations to the Thai govt, and general business practices. If you want one these can be found cheaper here or PM me as a CAT member
https://rstech.my-online.store/product/sunbeam-tiger-alternator-bracket

_DSC7670 - Resize 65%.JPG


View attachment _DSC7635.JPG
 
Last edited:

66TigerMK1A

Gold forum user
Messages
1,130
Jim Gislason has a nice, modern, Smiths voltmeter to take the place of the 30A Smiths ammeter or fill the blank hole where it should be
Yep... I still sell those and I would highly recommend one over an Amp gauge as it's a much better indicator of what's really going on in the system and eliminates the high current connections behind the dash

As far as using the higher amp alternators... my local auto electric 'guru' told me a long time ago to add an 'extra' wire (of a bigger gauge) and run it direct to the battery terminal on the solenoid from the alt output so if you ever have a very week battery and fire the car up, that alt will be pushing a LOT of amps and this wire takes some of the load directly without taxing the stock harness!!


Voltmeters.JPG
 

Hoghead

Gold forum user
Messages
578
Revised the Sunbeam "S" logo version to a 4mm relief cut as suggested rather than cut through. The counterbore for hose clamp clearance is also 4mm
Will post on my store when the cut through logo versions are gone https://rstech.my-online.store/
In the interim you can PM me if you want the relief cut version

_DSC7914 - resize 65%.JPG


_DSC7917 - resize 65%.JPG
 
Top