Chris G 3,274 #1 Posted December 8, 2017 i have 2 K-91T engines. One is on a suburban and the other will be on a Panzer once i get this figured out. The engines both came with a pancake style muffler which slid over the studs and then tightened up with 2 bolts. I would like two tap the exhaust port. Because i have tried two different ways of building a manifold that i can adapt the regular black steel pipe to. And in both case they do no secure down tight enough. One manifold i used the studs to secure it and the other i removed the studs and secured the manifold by using a allen head bolt to screw in to the block. I was not very pleased with both of them. So with that being said i would like to tap the block for a standard pipe thread for 3/4 black steel pipe. so any input on a good tap to use or any tips on the best way to do so would be greatly appreciated. Thanks ahead of time Share this post Link to post Share on other sites
Achto 26,505 #2 Posted December 8, 2017 (edited) Chris, I believe that a 1/2" NPT pipe tap will work on those with out machining the exhaust hole larger. Then you can use a 1/2 to 3/4 bell fitting to go to 3/4" pipe. The smaller 1/2" pipe at the start will not effect the performance of the engine. Edited December 8, 2017 by Achto 4 1 Share this post Link to post Share on other sites
Racinbob 10,269 #3 Posted December 8, 2017 That's what I did to mine. I started with a taper tap (left) and followed up with a bottom tap (right) which may not have been needed. I did it for my Suburban and just ran the correct length 1/2" nipple to a 1/2"x3/4" 90° fitting to turn the pipe forward. Worked great. Make sure you control the shavings. I stuffed an oily rag in the hole first. 4 3 Share this post Link to post Share on other sites
Chris G 3,274 #4 Posted December 8, 2017 Excellent guys. I figured I would have to go 1/2 to 3/4 probably should have mentioned that. But anyways thanks you guys and I will let ya know how I make out. 4 Share this post Link to post Share on other sites
WHX?? 46,703 #5 Posted December 8, 2017 2 hours ago, Racinbob said: control the shavings. I stuffed an oily rag in the hole first. Make sure exhaust valve is shut and a blast of air to clean out. A 1/2" conduit ring can be used to lock down the nipple if required. 3 Share this post Link to post Share on other sites
AMC RULES 36,941 #6 Posted December 8, 2017 The process looks like... see post #387 here. 2 Share this post Link to post Share on other sites
