is it ok to use a thin layer of high temp sealant on the head gasket. i've tightend the bolts to the point where if i go any further i fear striping the incredibly cheap threaded rods. my super rat is still oozing. not much but enough to see a fresh sheen of burnt oil. trying to work out all of the possible air leaks this build likes to cut out when the choke is wide open. went through tightend every thing i could. checked all gaskets. put sealant on them tweaked the carb down (cns carb). also has anybody drill and tapped the intake manifold on the super rat. its got that weird flat round part on it. it seems like it could be done. i'd like to put my boost bottle on it. haven't seen any premade parts for it yet.
head gasket and silicone sealant
- Thread starter kyl 46&2
- Start date
No to the silicone on the head gasket....!
The acorn nuts may be bottoming out on the studs because the studs are known to be too long on many of these engines, i put a washer under all the acorn nuts on my engines, just to make sure they are bottoming in the nut before they actually get the head pulled down tight.
Also, if the nuts are actually tightening like they should and you are still getting a leak, that is a good sign of a warped head which is another thing that isnt uncommon on these engines......this can be corrected with a flat piece of glass and some 150 grit sand paper taped to it so it will be nice and flat & tight on the surface of the glass, then lay head on the sand paper( gasket surface down ) and with light to medium pressure use a circular movement as you maintain the downward pressure in the center of the head by holding it firm against the glass with your fingers, use this circular motion for about 20-30 seconds and then turn the head over and look and see if there is any area where the gasket should seal that doesn't show signs of being against the sand paper, and if there are spots that aren't touching the paper this is the area and reason for the gasket leak, place head back down on the sand paper and continue the sanding proccess until the gasket surface on the head is showing signs of the surfacing proccess evenly on the entire gasket sealing area of the head, I would also either make or purchase a new gasket and if you use any kind of seal agent I would either use a product that can normally be found at you r local auto parts shop called ( Permatex "Coppercoat") and get it in the spray can, much easier to use, or if you have a can of silver high heat engine paint you can spray the NEW gasket with it and let it dry and then but it back together and torque the head back down in a criss cross pattern and I think it should torque at around 17 ftlbs, the silver paint works because what actually makes it silver is aluminum powder, I sealed many head gaskets on lawn mowers all the way up to 455 olds engines in a jet boat with the silver high heat engine paint, works great.
Go to one of the venders here like Pirate cycles or That Dax and order a new head gasket or two and then do what I have said here and this should fix you up on the leaky head gasket issue.
BE SURE TO GET A GASKET FOR 8MM STUDS and NOT 6mm or you will have to enlarge the 4 holes for the head studs
Never had the super rat engine or ran the "problem-ed" CNS carb. so cant comment on those.
Good luck hope you get it fix soon.
Peace
The acorn nuts may be bottoming out on the studs because the studs are known to be too long on many of these engines, i put a washer under all the acorn nuts on my engines, just to make sure they are bottoming in the nut before they actually get the head pulled down tight.
Also, if the nuts are actually tightening like they should and you are still getting a leak, that is a good sign of a warped head which is another thing that isnt uncommon on these engines......this can be corrected with a flat piece of glass and some 150 grit sand paper taped to it so it will be nice and flat & tight on the surface of the glass, then lay head on the sand paper( gasket surface down ) and with light to medium pressure use a circular movement as you maintain the downward pressure in the center of the head by holding it firm against the glass with your fingers, use this circular motion for about 20-30 seconds and then turn the head over and look and see if there is any area where the gasket should seal that doesn't show signs of being against the sand paper, and if there are spots that aren't touching the paper this is the area and reason for the gasket leak, place head back down on the sand paper and continue the sanding proccess until the gasket surface on the head is showing signs of the surfacing proccess evenly on the entire gasket sealing area of the head, I would also either make or purchase a new gasket and if you use any kind of seal agent I would either use a product that can normally be found at you r local auto parts shop called ( Permatex "Coppercoat") and get it in the spray can, much easier to use, or if you have a can of silver high heat engine paint you can spray the NEW gasket with it and let it dry and then but it back together and torque the head back down in a criss cross pattern and I think it should torque at around 17 ftlbs, the silver paint works because what actually makes it silver is aluminum powder, I sealed many head gaskets on lawn mowers all the way up to 455 olds engines in a jet boat with the silver high heat engine paint, works great.
Go to one of the venders here like Pirate cycles or That Dax and order a new head gasket or two and then do what I have said here and this should fix you up on the leaky head gasket issue.
BE SURE TO GET A GASKET FOR 8MM STUDS and NOT 6mm or you will have to enlarge the 4 holes for the head studs
Never had the super rat engine or ran the "problem-ed" CNS carb. so cant comment on those.
Good luck hope you get it fix soon.
Peace
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I'm going to add:get a 3/8ths inch torque wrench and use it. Just reefing down the bolts is not enough, the chances of uneven torque are much too great for that. Do not just run the nuts to torque, either. Torque them all in stages with a crossing pattern like an "X" or "Z". I like the "Z" type pattern. Go up in like 2 1/2 pound increments for a 66 and 2 pound for a 6mm on a 49.
After you run it, oh, a tank of fuel or so re-torque the nuts. Do this cold. Unless a set of instructions say to do it hot don't. Things are expanded and you have aluminum and steel that expand at different rates.
After you run it, oh, a tank of fuel or so re-torque the nuts. Do this cold. Unless a set of instructions say to do it hot don't. Things are expanded and you have aluminum and steel that expand at different rates.
Excellent points here DaveC,
You covered a couple things here I didn't, sometimes I just take for granted someone knows certain things and fail to mention them, plus my mind moves much faster than my fingers and sometimes in the proccess of pecking the words out I lose my chain of thought and forget stuff..........
Great points sir!
Peace
You covered a couple things here I didn't, sometimes I just take for granted someone knows certain things and fail to mention them, plus my mind moves much faster than my fingers and sometimes in the proccess of pecking the words out I lose my chain of thought and forget stuff..........
Great points sir!
Peace
