Wrung Out Threads on Intake Manifold (1 Viewer)

[Von Hayek]

The holes for the two short bolts that go through the exhaust manifold into the intake manifold are wrung out. The last person who did this job rethreaded one of the holes to 1.5. The other hole is 1.25 but it stripped when I took it apart.

What is the standard procedure here? Helicoils?

 

[73FJ40]

I used these on my intake manifold carburetor studs.

 

[Spike Strip]

The Time-Sert kit is spendy if you're only going to use it once, but they are superior to the Heli Coil. I think @ToyotaMatt is close to you? He may be able to do the repair...

 

[Von Hayek]

I'm going to attempt this myself as I don't think it is terribly difficult. But what about the differences between the kits? I ordered a pretty cheap one:

Amazon product ASIN B018LMAXFU.

Users seem satisfied with it, and for the frequency with which I would use it, I can't justify the expensive name-brand set if this will get the job done.

 

[matzell]

Drill it all the way through and re-tap it and use longer bolts, that is what I have done in the past.

 

[Braden620]

I just did this repair last week on one of mine. I used the time sert, but be careful of what length insert you use! I wouldn't comment on justifying the cost until you have used one, and put it into service for a length of time. I have yet to see a repair product that is superior, and pulling the manifolds more than once or twice isn't worth the $50 you might save. I also opted to replace the hardware with an OEM equivalent from SOR in hopes of preventing leaks any time soon.

 

[Von Hayek]

Can you please tell me what size you used?

 

[Von Hayek]

And actually, I just had a thought that might save me some time. I'm installing a Specter block of plate -- do the manifolds still need to be bolted together if a block off plate is used?

 

[Braden620]

Can you please tell me what size you used?

I also installed a block off plate, and yes you still need to torque the manifolds together AFTER you torque the cylinder head to manifold hardware.
I used TIME SERT KIT # 1012
Make sure you drill to the bottom of the existing hole and that you run the tap until it bottoms out in this hole. If you do not, the insert will bottom out before becoming flush with the manifold surface.

 

[65swb45]

I didn’t know you were a troll Bart! Your question does not match your sig line.

You’ve got some good information here, especially @Braden620 point about tightening the manifolds to the head first.

 

[Von Hayek]

I didn’t know you were a troll Bart! Your question does not match your sig line.

You’ve got some good information here, especially @Braden620 point about tightening the manifolds to the head first.

Hey Mark This is my father's 40. He is 93 and slowing down, but this is his daily. My brother and I are trying to get him to Fall Crawl so he can drive it in the woods a bit.

Looks like I'll be ordering a Time Sert kit.

 

[Von Hayek]

I also installed a block off plate, and yes you still need to torque the manifolds together AFTER you torque the cylinder head to manifold hardware.
I used TIME SERT KIT # 1012
Make sure you drill to the bottom of the existing hole and that you run the tap until it bottoms out in this hole. If you do not, the insert will bottom out before becoming flush with the manifold surface.

That Time Sert kit is for M10. I thought the bolts were M8? Did you use larger bolts?

 

[Braden620]

That Time Sert kit is for M10. I thought the bolts were M8? Did you use larger bolts?

The OEM fastener is an M10x1.25. To double check you can measure the nominal diameter of the bolt or the hole. You should be right around 10mm on either. For comparison, the t-stat upper housing uses an M8 fastener, or if you don't have any calipers you could see what wrench fits your bolt head and compare to the JIS standards, this will give you bolt diameter. You of course have the freedom to choose your thread pitch, but if I were you I would just keep it the OEM 1.25 pitch so you or the next owner can buy OEM hardware.

 

[Braden620]

Also, the OEM bolt length is 30mm.

 

[Von Hayek]

Glad you made me double check—sure enough M10.

 

[Braden620]

If you order the kit # 1012 you will be good. Don't get a kit that has inserts any longer.

 

[Braden620]

How did your repair turn out?

 

[turdfurguson]

Like others have said above, the bottoms are M10 but the carb studs on top are M8x1.25. Had to perma-coil mine last week. Good repair solution for applications like these. 40+ years of carb maintenance and over tightening finally did mine in.

 

[Braden620]

Don't forget to add some ptfe paste or similar thread sealant to the 2 carb studs that are open to the intake runner.