| MayanArch |
Posted
Thursday, Aug 23rd 1:08am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 1344
Florida, USA
Baur E21 2.7 1982, Baur E30 318i 1985, 323i 1978 |
OK, I have a beautiful set of Hartge 7.5x16 wheels sitting around. However, they are 5 bolt pattern.
It seems to me that the conversion wouldnt be hard. The most expensive thing would be either the time or money in dissasembly and reassembly of the drive shafts.
However, I think it would be rather easy and cheap to get a machine shop to create a plate that is identical to the one with 4 holes....except with 5.
If I am not mistaken, those plates, retain the wheel bearings, and are made out of cast iron.
Would there be any problems machining them out of billet metal?
FRONT:
REAR:
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| MayanArch |
Posted
Thursday, Aug 23rd 6:06pm [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 1347
Florida, USA
Baur E21 2.7 1982, Baur E30 318i 1985, 323i 1978 |
Read through Ray's write up. This is what others have done....but I am concearned about putting steel against cast iron. |
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| M42powered |
Posted
Thursday, Aug 23rd 11:47pm [Edit] [Quote] [IMS] [View car] |
Staff
Post nr. 727
Arizona, USA
1981 BMW 320i |
You might want to explore the option of having 4 hole hubs drilled and tapped to five lug. The big problem is brakes at that point. |
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| MayanArch |
Posted
Friday, Aug 24th 3:38am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 1348
Florida, USA
Baur E21 2.7 1982, Baur E30 318i 1985, 323i 1978 |
I would be fearful of taping cast iron parts. I think they would break....unless someone can tell me different.
What would the brake problem be? Arent the calipers and rotors the same? |
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| KenDanielson |
Posted
Friday, Aug 24th 7:19am [Edit] [Quote] [IMS] [View car] |
Junior Member
Post nr. 192
Petaluma CA
'82 320is, '78 320i |
Many parts are cast iron and drilled and tapped with no issues... engine blocks, transmissions, hubs, differential carriers and a bunch more.
Hubs could be made from aluminum by a good machine shop easily but it won't be cheap.
Don't e3/e9 hubs fit front and rear?? Seems to me I heard that a while ago. There was a Bavaria at the local pic-a-part that I was going to scavenge to check it out but couldn't find any 5 lug wheels I liked at a reasonable price (CHEAP!!) so I'll just stay with 4 lugs.
ken |
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| MayanArch |
Posted
Friday, Aug 24th 2:37pm [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 1349
Florida, USA
Baur E21 2.7 1982, Baur E30 318i 1985, 323i 1978 |
Ken, the issue here is that this isnt a big block of cast iron. It is a 1/4" disk that has other holes in it already, and you would drill holes very near the edge of the cast.
I like CHEAP too. I live for cheap.  But things get expensive when a hub breaks off at 80mph. 
If I remember, that post talked about e12 hubs with some brake and rotor issue that was untested and undefined. I cant see why there would be a problem as the brakes and rotors should stay the same.
Is there a difference....other than in the hole pattern in a 5-lug rotor? |
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| M42powered |
Posted
Friday, Aug 24th 7:21pm [Edit] [Quote] [IMS] [View car] |
Staff
Post nr. 728
Arizona, USA
1981 BMW 320i |
It is impossible to cast threads. The hub is thicker than a 1/4". And many times where people drill and tap a block is MUCH thinner than that. If you drill the right hole for the tap it shouldn't be an issue. But I can't make you feel any better about it. If you worry, then you worry. |
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| MayanArch |
Posted
Saturday, Aug 25th 2:15pm [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 1350
Florida, USA
Baur E21 2.7 1982, Baur E30 318i 1985, 323i 1978 |
OK, ok...good points....
So what are the brake issues everyone refers to? Are there 5-Lug rotors.....from say an E30 that are geometrically the same as an E21? If so, there should be no brake issues. |
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| davethedog |
Posted
Tuesday, Aug 28th 3:08pm [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 180
Northants, England
E21 320 |
I have noticed alot of high performance cars have 5 lug wheels. Where is the performance level where you would go from 4 to 5? |
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| M42powered |
Posted
Wednesday, Aug 29th 2:44am [Edit] [Quote] [IMS] [View car] |
Staff
Post nr. 729
Arizona, USA
1981 BMW 320i |
| MayanArch wrote: | OK, ok...good points....
So what are the brake issues everyone refers to? Are there 5-Lug rotors.....from say an E30 that are geometrically the same as an E21? If so, there should be no brake issues. |
Caliper placement might be different? I really don't know. I don't know anyone with 5 lug hubs and rotors who could comment either. You are in uncharted (or very poorly charted) waters. |
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| sunbeam*** |
Posted
Thursday, Aug 30th 12:07am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 309
wirral UK
1982 323i |
Some very useful infomation on this thread.
http://e21.tricord.be/forum/view.php?view=1303&highlight=5+lug
Just a shame the links to photos are NLA.
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| KenDanielson |
Posted
Friday, Aug 31st 10:07pm [Edit] [Quote] [IMS] [View car] |
Junior Member
Post nr. 192
Petaluma CA
'82 320is, '78 320i |
I pulled the front suspension and brakes out of my '82 (I think it has '77 hubs)... Once the brake disks were off I can see there is no way to re-drill them to 5 lug, the outer dia. is too small to accommodate the 5x120 pattern.
ken |
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| MayanArch |
Posted
Saturday, Sep 1st 2:57pm [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 1360
Florida, USA
Baur E21 2.7 1982, Baur E30 318i 1985, 323i 1978 |
| KenDanielson wrote: | I pulled the front suspension and brakes out of my '82 (I think it has '77 hubs)... Once the brake disks were off I can see there is no way to re-drill them to 5 lug, the outer dia. is too small to accommodate the 5x120 pattern.
ken |
That was my feeling. I think you have to make them from billet.
Ken, can I talk you into getting the critical measurements so we can put it into CAD and look into getting them CNC'd??? |
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