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Fan and generator problems
Adam_C - October 1st, 2003 at 10:03 PM

Hey, so today i change the gen off the 1500 over to the one off of the 1600 which is known to work . . . . its longer than the 1500 genny

will this be ok.... then dont seem to line up but only by a few mm

any help appreciated
cheers
adz


geodon - October 2nd, 2003 at 08:30 AM

When I change gennies, I make a point of putting the fan that came off back on the genny that's going in- they seem to fit better!


Baja Wes - October 2nd, 2003 at 08:40 AM

are you sure the 1600 genny is a beetle one?

The 38amp bus genny is longer than the 30 amp beetle one. They compensate by the beetle having a genny backing plate that bulges out, and the bus genny has a backing plate that bulges into the shroud.


Adam_C - October 2nd, 2003 at 09:14 AM

it is possibly a bus coz i think it has 14V-38a or something printed on it , can it be used? it was used on the 1600 seemingly without problems

Geodon ichanged the fan over aswell . .. .the 1600 fam was bout 2-4mmthicker and rubbed on the back of the shroud where the air is sucked in

so . . .. can i still use the gen?

cheers
adz


geodon - October 2nd, 2003 at 10:25 AM

Yes, I have overcome this prob (on beetles tho) using washers as spacers.
1st the fan itself can be moved forward & back using the those shims that adjust the fan belt tension but putting them "under & over" the big nutt & the spigot that attaches the fan to the back of the genny.
2ndly you can use 6mm flat washers under the fan cover plate that attaches to the front of the fan housing to "pull"it out but bear in mind you still need to seal it!! You can only pick 2-3mm this way.
I suppose if you need to come out more you could use what someone charmingly called black gorilla snot (silastic) to take up the clearance and longer coverplate screws but you may alter the juxtaposition of the fan relative to the crankshaft pulley & start to prematurely wear out fan belts.

[Edited on 2-10-2003 by geodon]


Baja Wes - October 2nd, 2003 at 11:35 AM

The problem is the 38amp bus unit is longer, so shimming it further out doesn't help.

Now you said the 1600 fan was thicker. The early non-doghouse fan is 28mm thick. The later doghouse fan is 34mm thick. You should only put the wide fan in the doghouse shroud. You can fit it in the early shroud, but it takes some modifcation. What shroud do you have?

As I mentioned before, the fan backing plates should look different. They are not completely flat, and have a ridge in them.

When looking at the assembled motor, the bug backing plate is convex (ie bulges out from the shroud).

However the bus backing plate is concave (ie bulges into the shroud / is dished into the shroud).

What does your backing plate look like.


Adam_C - October 2nd, 2003 at 01:39 PM

Wes i have put the 28mm fan onto the longer generator to go into the earlyier fan shroud (1500SP)

will go and check the backing plate and let you know

cheers
adz


vw54 - October 2nd, 2003 at 04:19 PM

Adam

Listen to Wes


Adam_C - October 2nd, 2003 at 10:39 PM

thanks for the input dave lol will look in the mornoin . . . i had to goto work thisarvo and couldnt check and its to dark now!

will post inthe mornin

cheers
adz


Adam_C - October 2nd, 2003 at 10:56 PM

By backing plate you meen the but that bolts to the shroud?

im confused now!!!

cheers
adz


vw54 - October 3rd, 2003 at 08:07 AM

Yep the one that mount into the fan housing with 4 x 6mm screws. there are 2 different types and you must get the correct on for the gen you have

Take a trip to Campsie they can set you on the right path.

The clearance between the fan and backing plate is critical as well. Other wise the fan does not do a 100% job air will escape and not go over the engine


Adam_C - October 5th, 2003 at 01:26 PM

ok the backing plate on the genne is indented into the shroud and the smaller gene is pushed out, soo . . . . what can i do


vw54 - October 5th, 2003 at 02:03 PM

Adam dont know with out looking at it.


68AutoBug - October 5th, 2003 at 03:47 PM

Adam,
Yes You need to replace all the bits off the back of the 1600 doghouse cooler generator and replace them with all the bits off the 1500 generator...
There is a difference between the normal!!
1500 fan shroud and the doghouse cooler fan shroud .
The Generators should be the same length... its all in the bits that bolt onto the rear of the generator... including the large backing plate with 4 screws that are different. The 1600 twin port engines had a wider fan etc....
regards
Lee
Lee


Adam_C - October 5th, 2003 at 06:32 PM

ill go from the start

took the generator off the 1600 with the doghouse cooler with the indented backing plate, and also removed the gene on the 1500 with the backing plate that bulges out of the generator toward the decklid, i left the backing plates on both of the gene and simple changed the circular fan that bolts with the 36mm nut and is shimmed onto the back, it seems like it is slightly out of line by a fewmm (the pulleys ) is this gong to be a prob or do i just see how it goes?

cheers
adz


Baja Wes - October 5th, 2003 at 07:40 PM

it sounds like you have the correct indented backing plate for the longer 38Amp genny.

Now try changing the pulleys on the generators. Some pulleys are different offsets to others. You need to get it right otherwise it will throw belts off.
You can even shim where the whole pulley assembly sits on the keyed generator shaft, to a certain extend anyway.


Grey 57 - October 5th, 2003 at 07:46 PM

You beat me to that one Wes. Any time I have had trouble with gennies not lining up was the rear pulley. There are a few different sizes and offsets floating around.
Adz, if all is OK at the front, fan not scraping either front or back, then you could spacer the rear pulley out or file it down to get it to line up.


68AutoBug - October 6th, 2003 at 12:05 AM

I think You have to change EVERYTHING over Adam... including backing plate...
I have a nice yellow backing plate hanging on the wall that I had to take off to change the standard 1500 generator fan etc to a doghouse cooler generator etc.. Everything is different...
I wouldn't be filing etc...

Lee


Adam_C - October 6th, 2003 at 10:42 AM

Lee, if i change the backing plate over then the generator will stick out even more, thats not my problem i will get it goin and take it to my brother see what he can do bout it otherwise ill have to get one of the smaller generatrs

thanks for your help guys

adz


Baja Wes - October 6th, 2003 at 11:53 AM

Have you played with the generator pulleys yet? As I said, the generator pulleys themselves have models with different offsets. It is the rear / back half of the pulley which sits on the keyed shaft that has different offsets. You can even get shims to shim it, but it sounds like you want to go the other way. The earlier pulley might be what your after.


Adam_C - October 6th, 2003 at 11:56 AM

i will get some pulleys from a wreckers and play around, but untill then this will me ok its only out by a mm or 5 lol i will measure it now that im putting it back together and see what thw difference is


thanks wes
adz


68AutoBug - October 6th, 2003 at 12:13 PM

Adam,
You may be able to grind some metal from the back of the pulley where it is too thick or wide.... as the woodruff key groove goes all the way thru the pulley half.. it won't make any difference to the woodruff Key... on how much you grind off.
Best Wishes
Lee