racerdonnie13 Posted March 23, 2014 Report Share Posted March 23, 2014 I bought a used 421 cub (whole motor) that was running with no issues. I pulled it apart, just for my own knowledge. Found a junk chinese crank, and only about 3 threads of the head studs were sticking out of the top of the head. Bought a new crank, seals, gaskets, and some extended head studs and put it all back together. The extended studs are for a pro design head so they are actually a little long for mine (chariot head). So i put the copper washers on the bottom plus two lock washers on top so i could get the nuts to tighten down. I had to use regular flange nuts cause the studs are too long for the acorn nuts. When i filled it up with coolant it started oozing out of all the head studs. My question is do the studs go down into a cub cylinder farther? I have a friend that runs a chariot head on a stock cylinder motor and his stock head studs work fine. I tried going back to the stock studs but i cant get enough threads to stick up out the top of the head. Are the chariot heads designed to work with the stock studs? Any help or info is appreciated. Quote Link to comment Share on other sites More sharing options...
Finch Posted March 23, 2014 Report Share Posted March 23, 2014 go back to stock studs and back em out till there long enough they dont need to be bottomed out and cub cyls threaded hole depth isnt consistent Quote Link to comment Share on other sites More sharing options...
racerdonnie13 Posted March 23, 2014 Author Report Share Posted March 23, 2014 I did try that also, but when i go to tighten the nuts down it just twists the stud back in. Quote Link to comment Share on other sites More sharing options...
Finch Posted March 23, 2014 Report Share Posted March 23, 2014 Quote Link to comment Share on other sites More sharing options...
Larry's Shee Posted March 23, 2014 Report Share Posted March 23, 2014 Instead of using a Presidential solution (NR) why not do it right? Either get correct studs or cut those off right amount. You take a chance of pulling studs if they are not threaded in enough. Clean holes and studs and use Loctite on them. Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted March 23, 2014 Report Share Posted March 23, 2014 You mentioned that you used the copper washer and lock washers. The copper washer works like a gasket. It needs to be tightened between the acorn nut and head. That is how it's designed. The lock washers them selves are leaking as well as the open top style nuts you're using. Quote Link to comment Share on other sites More sharing options...
Finch Posted March 23, 2014 Report Share Posted March 23, 2014 Instead of using a Presidential solution (NR) why not do it right? Either get correct studs or cut those off right amount. You take a chance of pulling studs if they are not threaded in enough. Clean holes and studs and use Loctite on them. they'd be threaded in the same as in stock cyls. So how is that a issue? Quote Link to comment Share on other sites More sharing options...
J-Madd Posted March 23, 2014 Report Share Posted March 23, 2014 You can use silicone on the studs and get away with the open flange nuts as long as you're not bottoming out the nut on the unthreaded shank of the stud. Quote Link to comment Share on other sites More sharing options...
Finch Posted March 23, 2014 Report Share Posted March 23, 2014 ive never used accorn nuts. copper washers or any sealer and ive never had a prob with a head leaking unless i forgot a oring Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted March 23, 2014 Report Share Posted March 23, 2014 The pro design head doesn't need them finch, but Noss and chariot heads should. Quote Link to comment Share on other sites More sharing options...
racerdonnie13 Posted March 24, 2014 Author Report Share Posted March 24, 2014 Ok i think im gonna find the right length studs, and get some new acorn nuts and copper washers. Hopefully that will solve my problem. Quote Link to comment Share on other sites More sharing options...
racerdonnie13 Posted March 24, 2014 Author Report Share Posted March 24, 2014 Where is the best place to get new copper washers and acorn nuts from? Im having a hard time finding them. Quote Link to comment Share on other sites More sharing options...
sprinklerman Posted March 24, 2014 Report Share Posted March 24, 2014 Chariot or noss. Sent from a van down by the river Quote Link to comment Share on other sites More sharing options...
Man-O-Steele Posted March 24, 2014 Report Share Posted March 24, 2014 Use red loctite and back out studs to give you enough length. I got my copper washers from rmatv. Quote Link to comment Share on other sites More sharing options...
g_low0885 Posted March 24, 2014 Report Share Posted March 24, 2014 I have a noss head and have the problem of after a few years the stud pokes thru the top of the acorn nut. It has happened a couple of times. I am a machinist so I am going to made some deeper acorn nuts at work so I won't have to worry about it again in a few yrs. But if you need copper washers and regular acorn nuts Fastenal carries both of them. It will take a couple of days to get it to the store but they do have them. If anyone is interested in getting a deeper acorn nut let me know and I will find out how much the material is going to be. I am making mine from 316 S/S if you want to save a bit they can be made out of 304 S/S. Quote Link to comment Share on other sites More sharing options...
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