mcbrat Posted October 17, 2004 Share Posted October 17, 2004 I'm going to be installing a ea81 from '83 that only has 1 of the 3 holes tapped for the PS pump mounts. anyone have a motor out that can check the depth of the holes this motor only has 86k on it, so I don't want to mess it up Quote Link to comment Share on other sites More sharing options...
TomRhere Posted October 18, 2004 Share Posted October 18, 2004 Could just put drill bit into the one tapped hole, and wrap tape around it to mark depth. Then drill out other 2 holes, stopping at the tape. Quote Link to comment Share on other sites More sharing options...
WJM Posted October 18, 2004 Share Posted October 18, 2004 I think this EA81 block i have had PS...i will check it out and measure tomorrow morn. Quote Link to comment Share on other sites More sharing options...
mcbrat Posted November 8, 2004 Author Share Posted November 8, 2004 I think this EA81 block i have had PS...i will check it out and measure tomorrow morn. I got the holes drilled, and tapped, but because of the space of the tip of the tap, the threads don't go all the way back in.... I drilled the holes to the depth the bolt would need. nervous to go any further. the one hole I already had there was a through hole, so I couldn't measure it. need to find a tap with less "non threading tip" on it I probably have about a 1/2" of threads to work with..... Quote Link to comment Share on other sites More sharing options...
92LoyaleSW Posted November 8, 2004 Share Posted November 8, 2004 You can grind the tip of your tap down and then use a thread file to fix the first thread. I have had good luck doing that in the past. What you need is called a blind tap (at least that's what we call them). Quote Link to comment Share on other sites More sharing options...
mcbrat Posted November 8, 2004 Author Share Posted November 8, 2004 You can grind the tip of your tap down and then use a thread file to fix the first thread. I have had good luck doing that in the past. What you need is called a blind tap (at least that's what we call them). I thought about grinding the tip down, but will go find a spare for that operation or look for a blind tap..... thanks. Quote Link to comment Share on other sites More sharing options...
NorthWet Posted November 9, 2004 Share Posted November 9, 2004 I thought about grinding the tip down, but will go find a spare for that operation or look for a blind tap..... thanks. I believe that the name that I have heard it called is a "bottoming tap". Might try that if tool man looks at you funny. :-\ Grinding a high-quality tap can be a PITA. Probably ruin the hardness. Another option is to use a regular bolt and run it down the hole and let its threads "cut" the last bit. Works better on a bolt that has had its threads cut rather than rolled. Maybe make your own bottoming tap from a bolt that has had some waste slots cut into them. Just be sure to have a couple extra bolts in case you waste a couple. Quote Link to comment Share on other sites More sharing options...
mcbrat Posted November 9, 2004 Author Share Posted November 9, 2004 I believe that the name that I have heard it called is a "bottoming tap". Might try that if tool man looks at you funny. :-\ Grinding a high-quality tap can be a PITA. Probably ruin the hardness. Another option is to use a regular bolt and run it down the hole and let its threads "cut" the last bit. Works better on a bolt that has had its threads cut rather than rolled. Maybe make your own bottoming tap from a bolt that has had some waste slots cut into them. Just be sure to have a couple extra bolts in case you waste a couple. I bought a spare tap, and ground it down with the bench grinder. piece of cake. didn't even have to clean up the cutters afterward. had to use the coarse wheel though. the fine wheel was too soft as it started to peel on the tap... tapped the hole all the way to the bottom, and bracket snugged up great... as a side note... wow. that head aluminum is soft!!!! Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.