Engine block to cooling head threads stripped!

Welcome to RCTalk

Come join other RC enthusiasts! You'll be able to discuss, share and private message with other members of our community.

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.

jlobbia

RCTalk Racer
Messages
116
Reaction score
39
Location
South Pasadena, CA
RC Driving Style
  1. Bashing
  2. Flying
I was taking the cooling head off of an OFNA .26 Force engine when all the screws stripped. I used a left hand drill bit and eventually got them out. I used some old screws from my rc toolbox which seemed to be identical to replace them. However they were a bit short, but I used them anyways. Then, when I test ran it, the head came flying off and the threads of the engine block came with the screws (sliver things around the screws) and now I'm debating whether to try to use a longer screw or to just to tap and rethread the whole thing. Any suggestions?
 

Attachments

  • 15924258243004651601372617170894.jpg
    15924258243004651601372617170894.jpg
    285.5 KB · Views: 117
  • 15924258589576641444437755354141.jpg
    15924258589576641444437755354141.jpg
    231 KB · Views: 76
  • 15924258760925042555411099209667.jpg
    15924258760925042555411099209667.jpg
    193.7 KB · Views: 99
  • 15924259074891686964235268223880.jpg
    15924259074891686964235268223880.jpg
    261 KB · Views: 75
Your picture shows 2 different thread pitches on the bolts. You partially stripped it just screwing that bolt in and cross threading them. The block is soft but you should have felt resistance when installing the bolts.

Just my opinion, but I would try getting screws that are correct pitch and a little longer than stock(too long). You can install them until they bottom out with the head button on but not the cooling head. Compare how much too tall they are with the thickness of the cooling head then use a Dremel to shorten them. Idealy, you want them to torque down just short of bottoming in the hole. Many times the hole is deeper than it is tapped too and you can use a bottom tap and extend the tapped depth closer to the bottom of the hole. If that seems like too much work you can tap the next bigger size right from the start possibly drill clearance in the holes in the head and button. All simple stuff for me LOL, i do that type of stuff everyday for a living.
 
Your picture shows 2 different thread pitches on the bolts. You partially stripped it just screwing that bolt in and cross threading them. The block is soft but you should have felt resistance when installing the bolts.

Just my opinion, but I would try getting screws that are correct pitch and a little longer than stock(too long). You can install them until they bottom out with the head button on but not the cooling head. Compare how much too tall they are with the thickness of the cooling head then use a Dremel to shorten them. Idealy, you want them to torque down just short of bottoming in the hole. Many times the hole is deeper than it is tapped too and you can use a bottom tap and extend the tapped depth closer to the bottom of the hole. If that seems like too much work you can tap the next bigger size right from the start possibly drill clearance in the holes in the head and button. All simple stuff for me LOL, i do that type of stuff everyday for a living.


Thanks! I'll see if a longer screw with the correct pitch and see if it works. If it doesn't I'll just drill it out to the next size and thread it. Thanks again!
 
Back
Top