Hot rod wheel spacers

[dnewps]

I need a little help from the RDP brain trust. I have a 65 vette, trying to fit 78 Z28 wheels. I need to run a 1/2 in spacer so the wheels don’t hit the calipers. I can’t run any wider without rubbing fender. I orig planned to replace the studs with 1/2” longer studs but now I find that it is a huge ordeal to replace the rears so now I’m trying to run the spacer on stock studs. I want to know how much thread engagement I need to be safe?

interweb says minimum thread engagement should be equal to the width of the stud. 7/16”. This is a shank style lug nut and with the wheel mounted the end of the stud is 1/8” BELOW the wheel/lug mounting surface. Thoughts?

 

[dnewps]

 

[Racey]

1.5x the diameter is the rule of thumb for minimum thread engagement.

1/2" stud = 3/4" engagement

In steel, with a nut, you can get away with 1x. so 1/2"

 

[dnewps]

1.5x the diameter is the rule of thumb for minimum thread engagement.

1/2" stud = 3/4" engagement

In steel, with a nut, you can get away with 1x. so 1/2"

It’s 7/16 stud. So 7/16 thread engagement at 20 thread is 4 complete turns. That enough?

 

[monkeyswrench]

Find longer shank lugs for the wheel? That may make up the difference. Do a plunge depth with the tail of a caliper, and see what length would work.

 

[dnewps]

Find longer shank lugs for the wheel? That may make up the difference. Do a plunge depth with the tail of a caliper, and see what length would work.

Yeah, thats what I was thinking. The max depth, rim surface to surface is 9/16. The stud sits 1/8” below. So if I nailed it with the perfect shank length the thread engagement would be 7/16. Or 4 full turns of the lug

 

[v6toy4x]

with shank nuts I like to get 6-8 threads min above the top of the shank so the actual head of the nut is held by the stud threads. when the stud stops short, the head is only as strong as the cross section width of the shank shoulder and the material the nut is made from?? Just MO after popping a few.

 

[gottaminute?]

Yeah, thats what I was thinking. The max depth, rim surface to surface is 9/16. The stud sits 1/8” below. So if I nailed it with the perfect shank length the thread engagement would be 7/16. Or 4 full turns of the lug

I think I would want the stud beyond the face of the wheel (proud) so i wasn't relying on only the shell of that lug nut to "clamp" my wheel. getting out to where the face and hex have threads to pull (or push from, depending how you envision it)

 

[v6toy4x]

I think I would want the stud beyond the face of the wheel (proud) so i wasn't relying on only the shell of that lug nut to "clamp" my wheel. getting out to where the face and hex have threads to pull (or push from, depending how you envision it)

You said that so much better than me with fewer words!!

 

[gottaminute?]

You said that so much better than me with fewer words!!

I've seen WAY too many broken poly locks to ever trust my life pulling on a piece of Chinesium tubing with a machined in thin spot and stress riser. I've NEVER seen a nut split in 1/2. Chromoly tubing and heim joints , It,s done all the time. Just in this case, not comfortable with it.

 

[bonesfab]

Machine the spacer and get longer shanks.. The shank would go into the spacer also at that point. If you are just driving it and not beating on it you should be ok with what you have. Just make sure it is a billet spacer. no castings.

 

[Apex svt]

Find longer shanks. I run a 3/4in spacer on mine to clear the wheels and the shanks are long enough to go through the wheel/spacer and just shy of bottoming out on the axle.

But really for $300 you could get a set of strange axles with longer studs and jam them in. Would only take an afternoon especially if it has drum brakes.

 

[monkeyswrench]

Find longer shanks. I run a 3/4in spacer on mine to clear the wheels and the shanks are long enough to go through the wheel/spacer and just shy of bottoming out on the axle.

But really for $300 you could get a set of strange axles with longer studs and jam them in. Would only take an afternoon especially if it has drum brakes.

I think this is for a Vette, so swapping the studs in the rear hub is kind of a PITA. Doable, but lace with profanity.

 

[SBMech]

I would never use a wheel with a spacer on any sort of performance vehicle. You completely change the ratio and dynamic of the clamping force not only on the studs, but the hub and bearings/ball joints etc.

In todays aftermarket, you could just find a company that would make the wheel with the correct offset in the style you want.

 

[Tooned Up]

I ran wheel spacers on my 2wd dune Jeep with long Moroso studs and aluminum wheels for years both in the dunes and the drags. I can’t stress enough that if you go this route to check the lugs nuts regularly. When I say regularly I mean every time you drive it. I never had an issue running it at the drags, but the dunes was a different story. I can count 5 times off the top of my head losing a wheel. The last of those times being Halloween weekend in the middle of Olds. Luckily when it happened a guy on a quad stopped the 20.000 STU paddle before it killed anyone.

 

[pronstar]

I’m not a fan of spacers, mostly because 99% of the are eBay crapola.

But done right, and torqued regularly, they can be safe. Safe enough that BMW has put them on some performance M variants.

Then again, I’m not convinced that BMW still knows how to build things for reliability or longevity [emoji90]


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[Apex svt]

I think this is for a Vette, so swapping the studs in the rear hub is kind of a PITA. Doable, but lace with profanity.

Good catch. Those cars are a pain to work on.

 

[707dog]

Machine the spacer and get longer shanks.. The shank would go into the spacer also at that point. If you are just driving it and not beating on it you should be ok with what you have. Just make sure it is a billet spacer. no castings.

yes on the billet spacers no more cast crap for me, coming from the lowrider side spacers or grinding calipers is how those wheels fit the car(until recently). full size car with under sized rims/tires playing at me own risk.