MGB Using vintage Datsun "Iron Cross" 14" wheels on a CB MGB?

[wkilleffer]

Hello everyone,

My car is a 1974 MGB that's pretty much stock except for the 18GK engine. It's currently equipped with ROSstyle wheels that are probably original. However, they're rather rusty, especially on the inside, and that's causing some slow leak issues. It's time for a new set of tires, so I was looking at taking the steel wheels off the road for awhile until I can get them blasted and painted, but I'm not ready to stop driving the car since I just got it back from having its windshield replaced. So, I thought a set of alloy wheels might work well with it. No one seems to have any minilites for sale, and I can't spend the money to get them new, so I was looking at other options.

Someone has a set of Datsun "Iron Cross" wheels off a 280ZX from the early 80s on the local marketplace. They're 14" wheels with the 4x114.3 bolt pattern that matches up to an MGB's stock bolt pattern. The seller said they would measure width and offset after work today, but most of what I've found so far indicates they're 6" wide with a +10mm offset and 102mm backspace, and center bore between 71-73mm.

I've tried to attach a picture. They need to be cleaned and have the old tires removed.

Has anyone used a wheel like this on their CB MGB? I kind of like the sort of retro, shabby chic, old school look they give, like something you might see on an MGB that came out of California.

It's frustrating that wheels seem so thin on the ground right now. A very few years ago, several people not too far from here had used minilites for sale, but I couldn't do anything about it then. Now that I'm able, none are to be found. I just can't spend the money to buy new ones.

Thank you,
-Bill

 

[YakkoWarner]

I don't know the answers but if you find info let us know - I've been trying to figure out what alternative wheels could be used as well (I have Rostyles also which I don't dislike but after 50+ years I expect they are not exactly straight and true anymore). I don't fully understand what the offset/backspace numbers mean or how they compare to the original wheels. I own a set of 1970's era Appliance alloy wheels which I'd really like to use (was told they were pulled from a MGB-GT), but they require propritary lugnuts that are now unobtanium.

If I ever get the car drivable I'll run the Rostyles as-is (they don't seem to have any problems holding air but I won't know if they are straight and true until I can drive it) but I'd like to have options or at least know options are available.

 

[wkilleffer]

I don't know the answers but if you find info let us know - I've been trying to figure out what alternative wheels could be used as well (I have Rostyles also which I don't dislike but after 50+ years I expect they are not exactly straight and true anymore). I don't fully understand what the offset/backspace numbers mean or how they compare to the original wheels. I own a set of 1970's era Appliance alloy wheels which I'd really like to use (was told they were pulled from a MGB-GT), but they require propritary lugnuts that are now unobtanium.

If I ever get the car drivable I'll run the Rostyles as-is (they don't seem to have any problems holding air but I won't know if they are straight and true until I can drive it) but I'd like to have options or at least know options are available.

The way I understand it, width and offset affect how the tire and wheel fit inside the wheel well. The Datsun wheels have less offset, so they would stick out further. I'm not sure if the difference is enough to cause a problem or not. I'm not someone who needs to use 185 or 195 tires, so that might help. I thought this would be easier given that the cars have been around this long. It's hard to believe no one else has asked about this.

 

[YakkoWarner]

The way I understand it, width and offset affect how the tire and wheel fit inside the wheel well. The Datsun wheels have less offset, so they would stick out further. I'm not sure if the difference is enough to cause a problem or not. I'm not someone who needs to use 185 or 195 tires, so that might help. I thought this would be easier given that the cars have been around this long. It's hard to believe no one else has asked about this.

Same for me - I'd rather run a lower profile 165 on these cars because they were designed with a thinner tire in mind, and a mostly stock car isn't going to have enough power to need the extra traction a 185 or 195 will deliver.

I also wonder (and have zero scientific or engineering credentials to bring to the table with regards to it) if having too grippy a tire would make the car more likely to roll over in a sharp turn as opposed to just getting loose and sliding out.

 

[wkilleffer]

I don't know the answers but if you find info let us know - I've been trying to figure out what alternative wheels could be used as well (I have Rostyles also which I don't dislike but after 50+ years I expect they are not exactly straight and true anymore). I don't fully understand what the offset/backspace numbers mean or how they compare to the original wheels. I own a set of 1970's era Appliance alloy wheels which I'd really like to use (was told they were pulled from a MGB-GT), but they require propritary lugnuts that are now unobtanium.

If I ever get the car drivable I'll run the Rostyles as-is (they don't seem to have any problems holding air but I won't know if they are straight and true until I can drive it) but I'd like to have options or at least know options are available.

There is this list that seems to indicate the wheels I'm looking at would work:

MGB Bolt-On Wheels List : How-To Library : The MG Experience

Library Article: Big list of makes & models that share the same wheel bolt pattern as the MGB and may be candidates for a cheap junkyard-sourced swap....

www.mgexp.com

 

[YakkoWarner]

Another thought - if the Datsun wheels would stick out too far, would it be possible to use a spacer on a wheel that would otherwise sit too far inboard? A lot of smaller front-wheel drive cars use a 4 bolt 14 inch wheel but front wheel drive wheels are designed differently, they would sit way too far inboard on a rear wheel drive car. But with a properly designed spacer could that be made to work?

 

[JPSmit]

Not necessarily a deal breaker but 280Z studs are M12 while MGB are 1/2" - So the nuts won't work and the Rostyle nuts might not work either. When I put the cosmics on the Midget I was able to source new nuts as the company is still in business. Not sure how that would work for you.

In terms of Front Wheel Drive cars - they are either 4X100 or 4X110 so slighly smaller PCD. Some people use wobble bolts but that scares me.

 

[wkilleffer]

Another thought - if the Datsun wheels would stick out too far, would it be possible to use a spacer on a wheel that would otherwise sit too far inboard? A lot of smaller front-wheel drive cars use a 4 bolt 14 inch wheel but front wheel drive wheels are designed differently, they would sit way too far inboard on a rear wheel drive car. But with a properly designed spacer could that be made to work?

That's a question someone else would have to answer. Sounds good on paper, but I would wonder how well it would work in practice. As far as these Datsun wheels go, I wish I could find a definite answer about them. Lots of Maybe and Highly Likely to work out there. The sellers aren't asking tons of money, but if the only way to find out for sure is to get a tire mounted to one and put it on the car, only to find it doesn't work, then there's the risk that I could end up stuck with them and never see my money again. I'm a low-budget MGB owner, so there's not much room for silly mistakes.

Not necessarily a deal breaker but 280Z studs are M12 while MGB are 1/2" - So the nuts won't work and the Rostyle nuts might not work either. When I put the cosmics on the Midget I was able to source new nuts as the company is still in business. Not sure how that would work for you.

In terms of Front Wheel Drive cars - they are either 4X100 or 4X110 so slighly smaller PCD. Some people use wobble bolts but that scares me.

I'm not sure the Datsun lug nuts are included in the deal, but what you're saying is that the change in offset might make the current wheel lugs too short to work with the Datsun wheels?

 

[YakkoWarner]

Not necessarily a deal breaker but 280Z studs are M12 while MGB are 1/2" - So the nuts won't work and the Rostyle nuts might not work either. When I put the cosmics on the Midget I was able to source new nuts as the company is still in business. Not sure how that would work for you.

In terms of Front Wheel Drive cars - they are either 4X100 or 4X110 so slighly smaller PCD. Some people use wobble bolts but that scares me.

I wouldn't want to use wobble bolts either. When I said "properly designed spacer" I was thinking more along the lines of spacer/adaptors BORA makes, that bolt onto the original hub using shortened studs in a countersunk hole, and then has a new flush surface with its own studs in whichever pattern is needed for the wheel being used. They don't list anything specific for smaller cars on their site, but once I see if the rest of the car is going to work well enough to make it worthwhile I will probably reach out to them and see if they have the ability to make something that would work.

 

[YakkoWarner]

On a similar note, Classic Industries (which only makes stuff for domestic US muscle car/truck classics) does have a very informative article on exactly what wheel offset and backspacing is, which made it a little more comprehensible to me:

Custom Wheels 101: What are Wheel Backspacing and Offset?

What are wheel backspacing and offset? How about wheel bolt pattern? And why do they matter? We've got the answers to all these questions right here.

news.classicindustries.com

 

[Joe Reed]

I've seen a number of MGBs with those iron cross wheels so I wouldn't think fitment would be much of an issue.

As for FWD wheels....I've also seen those used a lot (Honda wheels, for one). Obviously they would require spacers, but those are common. I'm sure longer wheel studs are also mandatory.

 

[wkilleffer]

I've seen a number of MGBs with those iron cross wheels so I wouldn't think fitment would be much of an issue.

As for FWD wheels....I've also seen those used a lot (Honda wheels, for one). Obviously they would require spacers, but those are common. I'm sure longer wheel studs are also mandatory.

Another concern which has come up is the center hole spacing. MGs seem to have a range for that, where the Datsun wheels are always going to be 73.1mm. Another source told me he tried to run these wheels on his track car and the center hole on the Datsun wheels was too small, and to offset that would cause a problem with the suspension geometry. Guess I should take one of the wheels off my car and take a measurement and see how it compares to these wheels.

 

[wkilleffer]

Another concern which has come up is the center hole spacing. MGs seem to have a range for that, where the Datsun wheels are always going to be 73.1mm. Another source told me he tried to run these wheels on his track car and the center hole on the Datsun wheels was too small, and to offset that would cause a problem with the suspension geometry. Guess I should take one of the wheels off my car and take a measurement and see how it compares to these wheels.

I took some measurements on the front wheel. The center that sticks out from the brake rotor was 50.2mm, the brake rotor at that point was 61.1mm, and hole in the wheel under the center cap was 53.43mm. I read that the center bore on a set of these Datsun wheels is 73.1mm, but not sure how accurate that is.

 

[wkilleffer]

I've seen a number of MGBs with those iron cross wheels so I wouldn't think fitment would be much of an issue.

As for FWD wheels....I've also seen those used a lot (Honda wheels, for one). Obviously they would require spacers, but those are common. I'm sure longer wheel studs are also mandatory.

I just heard from the seller. The wheels are 14x6, +10mm offset, and an 80mm center bore hole. To my mind, the concern is the offset more than anything else, but I have seen a pic of an MGB with these wheels installed:

Pearl has 280ZX wheels! : MGB & GT Forum : The MG Experience

Well, here she is, and other than awful paint, doesn't she look nice. Not bad for an Antique!

www.mgexp.com