Racing Alternator

A

Al Seim

Well-known member
A few years ago I installed a "mini-Denso" alternator in my HP Scirocco, identical in appearance to the smaller units at:

http://www.powermastermotorsports.com/d ... ators.html

I'll confess that I purchased elsewhere and maybe that's the problem -

I've gone through three of these in the last 8 or so races, the last one died the first weekend. They seem to literally fall apart internally, it's the stator windings and their attachment to the regulator/diodes that seems to fail.

I'm not spinning it too fast (not that that should kill the stator), I've got underdrive pulleys on both the crank and alternator. Drive is by conventional V belt shared with water pump, much as stock.

These alternators (first was bought online, second was a warranty replacement for the first, third was (probably foolishly) bought locally) all had no manufacturers nameplate and had a sticker saying "Worldparts" or similar. So I'm thinking likely "cheap Chinese copy of a Denso"??

Interestingly, I was visiting a friend's shop and saw an identical (including sticker) alternator on his newly purchased vintage Datsun 2000 roadster - and he told me that the previous owner had had many similar failures. So maybe it's not just me.....? OTOH I worry that maybe my (solid, no rubber) mount has some sort ot resonance at high RPM that is shaking the alternator apart????

To bring a long story to a close, what has worked for you alternator-users out there? Is Powermaster wotrth the extra cost? It sure would be if it did not fail quickly!

Thanks,

Al Seim
HP Scirocco 1.6
 
Don't know how well this translates, but we've been running alternators from AutoZone on our HP Midget for over 10 years; they are "Lifetime Warranty", and we've on our fourth one in that period. The first couple were Lucas, but now they seem to be generic, manufactured who-knows where, and have an ever-decreasing lifespan. This seems to be what we will have to accept in running "stock" components on these older cars-- more and more junk due to a limited market.

James Wiley
#72 HP Midget
 
I run a alternator from a toyota, can't fault the supplier, they are about $20 at the local u-pull-it salvage yard, seems to be a fairly common part on a lot of toyota's.

Shutting the engine off with the kill switch isn't good for the alternator, sometimes they will check the kill switch at annual tech inspection.

I do think vibration also doesn't do it any good, we tend to have the motor mounted diffrent than stock, also the RPM range we use might cause vibration issues. One of the alternator mounts actually cracked, which might have helped to kill one of the alternators, might have had more vibration with the broken mount.
 
On the other hand, what is the downside to running a total loss? I went this way in vintage and probably will do the same in production, because it eliminated one more thing that could break at the track and ruin my weekend investment.
 
The advantage of having a alternator, can then use a cheap lawn tractor battery.

Lawn tractor battery is the lightest, cheapest battery, and can find a replacement anyhwere.

Having a alternator is one more thing that can fail, but then you need a bigger, better battery.
 
Al,
I run that very (50amp) alternator. Have had it in there 5 seasons. No problem at all. However, Vibration is a factor. I have a 1.8 which has a beefier mount on the head, compared to the 1.6 At long tracks like RA, a bad vibration shows up. I've had several configurations of mountings and the latest is working good so far. Mine is mounted solidly and driven off the cam at a slower speed than stock. It uses a 10mm cog belt to drive it. I prefer an alternator as the F.I. and pumps like a constant voltage and it just makes life easier. Plus it enables me to use a smaller battery (oddysey) to compensate for the alternator weight. I could send you pics if you email me.
 
I have been using the same alternator since 2001. I have used it on both the F production 2002 and the 1600 H car. I have had no problems with the unit. I have had problems with corrosion on the battery terminal but that is just a maintenence issue on my part. G
 
So when you guys say you use "that same alternator", do you mean a stock Denso alternator, the Powermaster "tweaked" (I think) Denso, or?

Mine looks like this too but I suspect is Chinese.

Dick - I don't think I have your email address but would appreciate the pics. My email is aseim@race-technology.com

Like Dick I prefer a stable, higher voltage as given by an alternator. Plus you can't forget to charge the thing overnight if it does not need it. OTOH I'll be running total loss this weekend as the friggin' thing is dead and disconnected. I suspect that the CIS does change mixture a bit with voltage variation but have not quantified it, although warmup is much better w/ alternator (CIS has an electrically and engine-heat heated warmup regulator). I HAVE discovered that electronics don't like the very dirty power given off by dying alternators.

Al
 
I run total loss with an Optima yellow top. But my car is carbureted not FI, only runs one fuel pump, Electramotive, and the brake lights. I don't even run a jump battery for starting. I use a Auto meter battery tender I won once at the Spints to keep it charged between race weekends but nothing for the weekend or the Runoffs week. Am considering adding a 6volt Optima to bump the voltage to the Electramotive but have not done anything yet. None of this helps you with an alternator but I think the vibration thing can be a big deal. On the Spec Racer Ford where the engine is rubber mounted we do not seem to see much trouble but on the Formula Enterprise car the motor is solid mounted and we see problems with the OE throttle return springs breaking, have to have them custom made as they are not available as a replacement part, never even had anyone ask about them for the SRF.
 
use a good quality stock alternator and that will be the end of your problems- as long as it has an underdrive pullley I bought a high end Bosch alternator for my EP RX7 which routinely turns 10K- no problems for 6 years

All the "discount" alternators that come from the big box stores are junk-

Al
 
speaking of junk--stay away from ANY of the World Products brand.

We havn't had ANY of their starters or alternators work out of the box !!



Sam Moore
 
sorry, I mispoke. That would be Worldwide Automotive we have had no luck with instead of World Products.


Sam Moore
 
We've gone through 2 Powermaster 8168's.

The first one lasted a lap or two, sent it back, they said the brushes became miss aligned.
I'm not sure how that can happen in this alternator.

The one they sent back, according to the data log, lasted 3/4 of a lap at VIR.

We'll probably send it back, but the last time it took a month....

Les.
 
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