Technical Mickey Thompson breather mount bolt size?

I have had a pair of valve covers set up for M/T breathers but have no hardware to attach them. I had been looking for a second breather for a while and recently I found another breather up for sale here and it cleaned up nice.

Figured it would be easy to come up with the hardware but not so much. It is larger than 8-24 smaller than 1/4, but 10-24 only threads in 3 turns and stops. Seems like there is more thread there than 3 turns and I'd hate to tap it for the wrong thread just cause I didn't use the right size to start with.

I'm open to ideas.

Also, any idea of time frame these were made?

Thanks

Mike

 

Try a 10-32 screw. Standard # 8 sizes are 8-32 and 8-36. If you actually have an "8-24" screw it's a real bastard, probably made for a special application. In 50 years of running screw machines, I never heard of an 8-24.

 

Yeah. I fat fingered the 8-24, should have read 8-32.

A 10-32 does not thread in. 10-24 is the closest.

 

Run a 10-24 bottoming tap in there and dont worry about it, your fine

 

I started to tap one of the holes for 10-24 but stopped as it didn't feel right. A 10-24 screw starts loose, goes down 3 full turns and stops, almost as if the hole threads taper down.

A 1/4 size screw or tap don't even start to be close.

 

Wondering if they used self-tapping screws

 

This is the last thing I thought I would have a hard time finding hardware for. I have not considered self tapping. Sees it would be the wrong use for them. I'll check it out tonight.

 

Self tapping screws are a possibility. They were used on applications like this way back in the "old days".

 

When all else fails, put some 8-32 helicoils in them. That will leave plenty of metal around the inserts and you will know what you have.
Make sure to lock tite the screws when you put them in also, don't want that small of a screw getting lost in the motor.

 

Good advice right there.

 

I went and tried self tapping screws. No luck there either. Tried helicoils but no one in town caries smaller than 1/4. I'll order some and go that route unless I can think up another fix.

 

JB weld studs in there?

 

I might run a tap drill #29 in them for an 8-32 and then tap them to the bottom. Might be better than drilling and tapping for a STI.

 

I'm no genius, but I can't believe it's 10 days now, and this 10 minute fix still isn't???? Run the first tap in the holes that gets 50% thread, or more, and mount the damn things.

 

It's been 10 days as I'm in no hurry to make a permanent fix where not needed if it can be avoided. I've got other parts in work and give this breather a thought between other work.

I'll most likely end up going with a 8-32 helicoil if I can't match it.

I just saw today a 12-18 and 12-24 thread on a chart. I've never used a screw in that size before or heard of it. Think it could be it though as a 10-24 will thread in but is too loose and a 1/4 too big.

 

I drove over to fastenal to check if they had anything in 12-24. They did and it fit perfect. Wrong head but was able to have them order the right ones and should be in Friday.

I had never come across a #12 anything before. All my taps/dies skip right over it.

 

Well, that was easy.