TheSamba.com :: View topic - My generator to alternator conversion

Mon Feb 09, 2009 5:02 pm

I have the type 3 from Mountain Home running a 55 amp for 4 years and am upgrading to a 75 amp next month. (when it warms abit)If you got the alt at Bowwow they should have the pictures from when I did it. If you are part of the Bus pilots look for shakey. The alt needed a big hole on the bottom for cooling along with a block off plate. The cooling tin was removed and a small patch put in NOT BEAT WITH A HAMMER to the tin that sits about 3/8th of an inch at the lowest spot. the only otherwas a small dremel relief in the side of the alt for the distributer clearance. Just a quick reply I will get on later for questions if needed and will take pictures on the garage night in march for the Bus pilots

Mon Feb 09, 2009 7:27 pm

Ok it has been over four years since I converted this. To the best of my knowledge (and memory) I put a cover over the belt driven end of the alternator and drilled a hole in the bottom of the case to route the cooling air as it was on the gen. I had to dremel a little bump on the housing and clearanced the side of the alt case for the distributer cap. For the cooling tin-I cut the tin out rounded it down and had a friend weld in a patch plate. As for airflow I'm not an engineer but it is in the same area as the gen bump and goes down at that point maybe forcing more air into the fins. The ddb kit has a great ease of installation but the advantage I can see using stock over the over the ddb kit is the kit has no provisions to adjust the belt tension and it loses cooling air by not sealing the area. All the naysayers point out the cooling air issue using stock VW parts but no one says anything about the aftermarket. Future plans are to remove the stock oil cooler (increasing air flow in the cylinder area) and adding an adapter, external cooler with fan, and filter. This car is a daily driver it has been drove in weather from -30 to 120 degrees.

Mon Feb 09, 2009 8:46 pm

has anyone here ever gotten thier hands on a alt. from a sp2 or tc? and would it fit the same as a stock gen? or did these cars have a special fan housing designed for the alt? sure looks the same. no mods needed.

Tue Feb 10, 2009 8:18 pm

garrisonme wrote: ...The ddb kit has a great ease of installation but the advantage I can see using stock over the over the ddb kit is the kit has no provisions to adjust the belt tension
Because it's not NECESSARY for the five billionth time! :roll:

garrisonme wrote: and it loses cooling air by not sealing the area...
That's a good point, I think the area below the alternator isn't "capped" off so air could escape. Engine cooling air is used to cool the generator so the same goes for the alternator except, in this case, it comes from the shroud and not from below.

Tue Feb 10, 2009 9:58 pm

JeFIzM wrote: has anyone here ever gotten thier hands on a alt. from a sp2 or tc? and would it fit the same as a stock gen? or did these cars have a special fan housing designed for the alt? sure looks the same. no mods needed.

That alt actually looks like a really clean install. Whose is it? Specs?

Tue Feb 10, 2009 10:15 pm

jimmynotch wrote: That alt actually looks like a really clean install. Whose is it? Specs?
No idea on the specs, but that setup is a Volkswagen do Brasil product. Tag on the alternator looks like Bosch...

Tue Feb 10, 2009 10:18 pm

[[/quote]
Because it's not NECESSARY for the five billionth time! :roll:

I can't help but wonder why belt tension is not important.

garrisonme wrote: and it loses cooling air by not sealing the area...
That's a good point, I think the area below the alternator isn't "capped" off so air could escape. Engine cooling air is used to cool the generator so the same goes for the alternator except, in this case, it comes from the shroud and not from below.[/quote]

The area under the generator would be capped by the alternator so if the cooling air would come from the shroud it will make the installation easier. The other conversation about the flange getting ground off to save as much clearancing of the cooling tin is also a good idea to look into.

Tue Feb 10, 2009 10:53 pm

jimmynotch wrote:
That alt actually looks like a really clean install. Whose is it? Specs?

hey jimmynotch, that is a stock alternator in a sp2. i asked martin today about them and he said that they only put out 40amps and the only difference is the cover on the pully housing. it sticks up a little more, but other than that its all the same.

Wed Feb 11, 2009 1:16 am

garrisonme wrote:

I can't help but wonder why belt tension is not important.

there are two reasons: firstly, the belt provided (commonly available as well) is under the correct tension by design-- when you cinch the alternator down, its already pulled to the correct taughtness-- this is entirely different from the stock set up, which is dependent on several different variables.

furthermore, if the belt stretched to the point that it NEEDED to be tightened (and it shouldn't-- at this point I would replace it-- its 5 dollars :roll: ) then you can rotate the alternator body a few degrees to tighten it, because it isn't perfectly round.

there's the why. its been covered a million times, but perhaps you havn't been here to see the explanations. I understand Toby's frustration about the search feature but I'm less archaic. usually.

Wed Feb 11, 2009 12:59 pm

JeFIzM wrote: jimmynotch wrote:
That alt actually looks like a really clean install. Whose is it? Specs?

hey jimmynotch, that is a stock alternator in a sp2. i asked martin today about them and he said that they only put out 40amps and the only difference is the cover on the pully housing. it sticks up a little more, but other than that its all the same.

So how does the 40amps compare to the stock 12v generator that is in every other T3? Also, how hard would it be to source that specific alt from an SP2 (I assume the cover would be a bit difficult-)? Not that I see anything wrong with DDB's kit.... in fact I am on the fence about it only because it doesn't look OEM. Asside from that, I would plop one in right now.

Wed Feb 11, 2009 1:04 pm

it is my understanding that new belts should be retensioned after their first hour of operation, after the belt seats itself and starts to loosen up from use. What type of tool is being used to determine that this is the correct belt tension? Exceesive tension accelerates the wear on pulleys and bearings.

Wed Feb 11, 2009 1:28 pm

jimmynotch wrote: JeFIzM wrote: jimmynotch wrote:
That alt actually looks like a really clean install. Whose is it? Specs?

hey jimmynotch, that is a stock alternator in a sp2. i asked martin today about them and he said that they only put out 40amps and the only difference is the cover on the pully housing. it sticks up a little more, but other than that its all the same.

So how does the 40amps compare to the stock 12v generator that is in every other T3? Also, how hard would it be to source that specific alt from an SP2 (I assume the cover would be a bit difficult-)? Not that I see anything wrong with DDB's kit.... in fact I am on the fence about it only because it doesn't look OEM. Asside from that, I would plop one in right now.

even though ddb still owes people parts for over a year? based on how others have been treated, I wouldnt buy from him if he was the only supplier left

Wed Feb 11, 2009 1:37 pm

Erik G wrote:
even though ddb still owes people parts for over a year? based on how others have been treated, I wouldnt buy from him if he was the only supplier left

I have never been burned by Martin. He is a good freind of mine and has come through for me in the too many ways to say here.

BAck to the Alt question.... Who can give me some more info on that SP2 alt? Part number? Availability? How to find the cover? Etc?

Wed Feb 11, 2009 1:47 pm

Thanks no one I have talked to has ever said the ddb alt was oval to allow for some adjustment. I was under the impression that when you bolted down the alt case it just pulled all the slack out and you hoped your belt fit.

I can understand you're frustration of explaining things 5M times. I had never looked for a how to on the ddb kit and as far as I was aware when I converted the 'back no one had a alt conversion. After that I had no reason to look into a kit although it is nice and definately simple to install, but since my car is already done it serves me no purpose. I only jumped into this thread when a friend told me that they were talking about my car and offered a alternate method that is not to difficult (I did it with hand tools in my driveway) and in my opinion looks cleaner and not so out of place.

The conversion is not hard but it sure seems to piss alot of people off. :)

Wed Feb 11, 2009 8:51 pm

jimmynotch wrote: ...
So how does the 40amps compare to the stock 12v generator that is in every other T3? ...
My alt. is 40A. With my Compufire IX system drawing 12A I haven't had a single electrical issue, even in worse-case situations (like rainy, night driving while listening to an after-market stereo). Am I at the electrical edge?...I don't know. Don't care as the light doesn't glow 8)

Still running the original belt when I made the conversion, too :wink:

Wed Feb 11, 2009 8:58 pm

JSMskater wrote: garrisonme wrote:

I can't help but wonder why belt tension is not important.

there are two reasons: firstly, the belt provided (commonly available as well) is under the correct tension by design-- when you cinch the alternator down, its already pulled to the correct taughtness-- this is entirely different from the stock set up, which is dependent on several different variables.

furthermore, if the belt stretched to the point that it NEEDED to be tightened (and it shouldn't-- at this point I would replace it-- its 5 dollars :roll: ) then you can rotate the alternator body a few degrees to tighten it, because it isn't perfectly round.

there's the why. its been covered a million times, but perhaps you havn't been here to see the explanations. I understand Toby's frustration about the search feature but I'm less archaic. usually.

Yes and thanks. The belt deflection should be close to a 1/2" (about 1.3cm).

Wed Feb 11, 2009 9:13 pm

Ok.... So how hard would it be to find an SP2 alt and the fan housing? I emailed Bob1 who has one for sale in the classys and he gave me some good info on it with some better pics. I like the way the SP2 alt looks a lot more than the options.

Wed Feb 11, 2009 11:00 pm

I think that SP2 alternator is actually only a 35A. Not much of a gain in output for all the expense and trouble.

Thu Feb 12, 2009 1:24 am

What does a stock 12v genny put out?

Thu Feb 12, 2009 2:40 am

W1K1 wrote: it is my understanding that new belts should be retensioned after their first hour of operation, after the belt seats itself and starts to loosen up from use. What type of tool is being used to determine that this is the correct belt tension? Exceesive tension accelerates the wear on pulleys and bearings.

there is no tool, never has been. You check tension by the deflection or, more commonly, the ability to twist the belt about its axis of travel. As it stands, the DDB kit's belt is tighter than it should be on initial installation, and after the hour or two of stretching is the correct tension-- this was done by trial and error before settling on the correct belt to include in the kit. I had to go through the same process with my home brew kit.