414-8 muffler

[Mustang67ford 234]

My 414-8 has the kohler k321 motor with muffer #110661.  The flang is not touching the head in a couple spots, small gap.  I vaguely  recall that this can cause motor damage, maybe creating a hot spot on the piston?  Anybody know if this is true, could be wrong.  I am hesitant to remove because I can see busting the cap bolts when I try to remove this I'll have big issues.  If it won't cause engine damage, then I might not touch as the noise isn't bad.  Or maybe smear high temp sealer in the crack.

 

Edited February 25, 2022 by Mustang67ford

[gwest_ca-(File Mod) 11,472]

Looks like socket head cap screw. Good chance it is made of Grade 8 material.

[Handy Don 14,054]

3 minutes ago, gwest_ca said:

Looks like socket head cap screw. Good chance it is made of Grade 8 material.

Start giving those cap screws a dose of penetrant every couple of days (especially after you shut down the engine). That way you can get a bit of an edge when you go to loosen them.

[Mustang67ford 234]

1 hour ago, Handy Don said:

Start giving those cap screws a dose of penetrant every couple of days (especially after you shut down the engine). That way you can get a bit of an edge when you go to loosen them.

Middle of restoration, not able to run the motor at the moment.

[RED-Z06 2,567]

Flange probably warped from being installed with no gasket, the cap screws will usually come out, cant hurt to give en a little twist and see if they move.  

 

Will it hurt it...it will erode the metal in time and get louder, its also blowing exhaust out near the air intake, its not ideal

[oldlineman 1,537]

A little heat on the block where the bolts go in will expand the block and draw in the penetrating oil. Patients is your friend, a little movement in one direction then the other direction, adding penetrating oil often, then maybe more heat. Bob  

[pacer 3,177]

6 minutes ago, oldlineman said:

A little heat on the block where the bolts go in will expand the block and draw in the penetrating oil. Patients is your friend, a little movement in one direction then the other direction, adding penetrating oil often, then maybe more heat. Bob  

This is an excellent method to go at those -- move the heat around the block avoiding the bolt as much as possible adding more lubricant along and try the slight movement back and forth. As it frees up more and more it should back easily - hey, they may just back out easily anyway!

 

Now as far as doing any 'damage' thats pretty doubtful, but a leak there would drive me nuts and I'd have to fix it! When its off clean/file/grind the 2 surfaces to make as flat as possible and add a gasket - or two! 

 

Another thought -- the block just might be threaded with 1" pipe threads and that may be a better way to go at it.

[Mustang67ford 234]

Got the bolts out surprisingly, was sweating that one.  Old muffler is off.  Looks like the exhaust port is also theaded for a screw in pipe type muffer.  Didn't know that and great to know if the bolts would have broke.  Cleaned the threads up with a tap and ready for new.  Based on the shape of the old muffler and some other dents, it looks like previous owner hit something and bent it.  Should I go with new stock cap screw bolts for the new mufffler or go with hex bolts for easier future removal?  Threads are standard 5/16 x 18.

Edited February 26, 2022 by Mustang67ford

[pacer 3,177]

Personally I'd go with hex screw  - with flange head if ya got em. Those Allen head are good for some things, but they can be a problem and when possible I use hex, and as I mentioned, I've taken a strong liking to the flange heads (no washer needed!)

[Mustang67ford 234]

Would you go with grade 8?  I can see that as being better as less chance of snapping during removel, but harder to drill out if it ever came to that.

[pfrederi 18,644]

Just make sure there is enough clearance to use a hex head.  Some  exhaust flanges are very small and you find you have to use an open end wrench as there is insufficient clearance for a socket...

[Handy Don 14,054]

17 hours ago, pfrederi said:

Just make sure there is enough clearance to use a hex head.  Some  exhaust flanges are very small and you find you have to use an open end wrench as there is insufficient clearance for a socket...

And if you have to use open end, you're only operating on two flats when the bolts get rusted in.

Personally, I'm comfortable with grade 8 socket head cap screws and have had good luck with them, especially in tight quarters, but others do have different opinions.