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Discussion Starter · #1 ·
Hi.
Curious if I buy more modern lotus wheels not meant to fit my front end of my 89 lotus esprit non se, such as the S4 wheel. I realize it must be bored out to 60mm.
What is the hubs actual size? What sort of clearance has to be achieved?
Do you just bore it out to 60mm and the wheels fit fine?
:facepalm
 

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You get the front wheel spigot diameter bored to 60mm. the hub spigot is slightly smaller to account for tolerances. The hole has to be concentric, since the wheels are hub-centric, they rely on the fit to that hub spigot to hold the wheels concentric to the hub. You will need a machinist who can do that part correctly on a CNC mill. Not a hole saw!
 

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Discussion Starter · #3 ·
You get the front wheel spigot diameter bored to 60mm. the hub spigot is slightly smaller to account for tolerances. The hole has to be concentric, since the wheels are hub-centric, they rely on the fit to that hub spigot to hold the wheels concentric to the hub. You will need a machinist who can do that part correctly on a CNC mill. Not a hole saw!
Hi. Thanks for responding.
I was wondering if the spigot or the wheel made had the minus or positive tolerance.
I have never read that!
I am a Machinist. Manual all the way.
And.....what size is the Spigot?

No need for a CNC whatsoever.
Mike
 

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Discussion Starter · #4 ·
After I buy my wheels, Im going to Home Depot to buy a Hole saw!
It musst fit! ! ! ! ,
 

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I swapped my 60mm hubs for 58mm hubs to maintain the wheel integrity.

If you're going to remove metal, would it be easier to machine the hub from 60mm to 58mm? Or does it remove metal from a more critical area than the wheel being bored?

Lastly, someone mentioned that he had spacers installed that allowed an inside spacer hole of 60mm with an outer spacer surface with a 58mm hub centric ridge. No mod to hub or wheel.

If you're going to put spacers to line up with your fender lips, that may be a less drastic mod.

Eddie
 

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I swapped my 60mm hubs for 58mm hubs to maintain the wheel integrity.

If you're going to remove metal, would it be easier to machine the hub from 60mm to 58mm? Or does it remove metal from a more critical area than the wheel being bored?

Lastly, someone mentioned that he had spacers installed that allowed an inside spacer hole of 60mm with an outer spacer surface with a 58mm hub centric ridge. No mod to hub or wheel.

If you're going to put spacers to line up with your fender lips, that may be a less drastic mod.

Eddie
The hub spigot is thin already, taking 2mm out of it could seriously weaken it. However taking 2mm out of the wheel does nothing to the strength.

Out of curiosity I just measured my hub and wheels.

My hub spigot is 59.97mm at the largest point, and my V8 front wheel bore is 60.20 as machined to fit my hub spigots (measured with inside bore telescoping gauges). They fit without any issue. You do need a generous chamfer on the wheel bore to fit though. The root of the hub spigot has a fillet.
 

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Discussion Starter · #7 ·
The hub spigot is thin already, taking 2mm out of it could seriously weaken it. However taking 2mm out of the wheel does nothing to the strength.

Out of curiosity I just measured my hub and wheels.

My hub spigot is 59.97mm at the largest point, and my V8 front wheel bore is 60.20 as machined to fit my hub spigots (measured with inside bore telescoping gauges). They fit without any issue. You do need a generous chamfer on the wheel bore to fit though. The root of the hub spigot has a fillet.
Hi.
So if I put a. 250 chamfer on the the back of the wheel it will seat properly?
Yes?
 

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The hub spigot is thin already, taking 2mm out of it could seriously weaken it.
That is exactly what Lotus did when they introduced the S4, so I seriously doubt there is an issue. And it's only 1 mm removed from the spigot.
 

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Hit up Quadcam for his spacer specs. You won't be sorry. Fits well and flush too. S4 wheels in my opinion are too sucked in anyways. Get the spaces and no boring required.
 

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You get the front wheel spigot diameter bored to 60mm. the hub spigot is slightly smaller to account for tolerances. The hole has to be concentric, since the wheels are hub-centric, they rely on the fit to that hub spigot to hold the wheels concentric to the hub. You will need a machinist who can do that part correctly on a CNC mill. Not a hole saw!
would be a lot easier to put the wheel in a manual lathe and open the bore radius .040." should be a simple job.... assuming you can fit the wheel to the lathe.
 

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Discussion Starter · #16 ·
I haven't seen many lathes that can handle an 18" wheel, and hold it without denting it.

There are many ways to do it, I was just mentioning the way that I did it.
Thanks for All the info.
VulcanGrey. Its not a problem whatsoever to machine and hold the wheels.
Best thing to do to aviod warping or denting the wheel is to use aluminum or brass shims on the teeth.
You really do not need much holding pressure for small cuts like what is required. You have to keep your rpms low so the wheel doesnt fly off.
Ive machined my 928 wheels without any drama.

Btw my Lathe at work, has a 6.5 foot swing.
And no, I wont be using it to machine the wheels.
Mike E.
 

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Discussion Starter · #17 ·
Hit up Quadcam for his spacer specs. You won't be sorry. Fits well and flush too. S4 wheels in my opinion are too sucked in anyways. Get the spaces and no boring required.
Hi.
I just cant afford the deal.
Imgoing through an awful custody battle.
ThankYou though.
Mike.
 

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would be a lot easier to put the wheel in a manual lathe and open the bore radius .040." should be a simple job.... assuming you can fit the wheel to the lathe.
That would have to be a large lathe, around a 20-22 inch gate or so, larger than most shop lathes. A typical shop milling machine with an adjustable offset boring bar would do it well provided it was properly centered first.

As was mentioned earlier, it's got to be perfectly centric otherwise you'll feel it going down the road....
 

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That would have to be a large lathe, around a 20-22 inch gate or so, larger than most shop lathes. A typical shop milling machine with an adjustable offset boring bar would do it well provided it was properly centered first.

As was mentioned earlier, it's got to be perfectly centric otherwise you'll feel it going down the road....
I'm not a machinist, but we've got a lathe at work that will turn the fan disk for a GE CF6-80C2 turbine engine. That disk is about 4' in diameter, the lathe has a wooden platform that gets you up to it that is 8' off the floor rotfl
 
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