VALVE GUIDE REPLACEMENT BRIGGS FLATHEAD

small engine shop cleans carbs, changes oil, sharpens mower blades and from what i can tell is all they do. $30 engine... not going to spend $100 on $30 engine... or MORE on $30 engine. bit will self align going thru the stock hole close enough. but we will see.
 
at this point your mind is made up and only thing that will change it is by learning from your mistakes
but you may go through more than the cost of valve guide replacement after the block is destroyed beyond repair
 
CarlsonMotorsports said:
I thought you said that the guide was "wasted?"
So then you tapped a 1/4" valve bore with a 5/16" tap to try to knurl it?
Now you are trying to drill to fit a .310" guide in a .305" or .307" hole?
And you'll finish ream the guide with what size drill bit?
All without centering the guide in the seat?

When you get done with your experiment, install the new valve and shine a light in the port and let us know if you see light around the face of the valve and seat.

You're right, this is not an F1 engine or million mile diesel engine.
I'm all for the DIY'er, but you sir, are in way over your head and capabilities.
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if you see light or how much light you see?
 
A SIMPLE PLAN said:
small engine shop cleans carbs, changes oil, sharpens mower blades and from what i can tell is all they do. $30 engine... not going to spend $100 on $30 engine... or MORE on $30 engine. bit will self align going thru the stock hole close enough. but we will see.
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get some sleep and rethink it in the morning.
 
they did studies on that in schools... college on ppl taking multiple guess tests and over thinking the problem/answer. they found tht much of the time their first instinct ws the correct answer. 7.75mm drill bit... slightly reamed for tight fit of .3096? appx valve guide OD... and a little persuasion went into the guide. for what it is going on, something was better than nothing. wont last forever... neither will i. if ppl changed oil more than 2x in its life it will last a long enuf time. if they cant check/change oil... every <20 hrs. ... we know what will happen to little engine.
 
A SIMPLE PLAN said:
they did studies on that in schools... college on ppl taking multiple guess tests and over thinking the problem/answer. they found tht much of the time their first instinct ws the correct answer. 7.75mm drill bit... slightly reamed for tight fit of .3096? appx valve guide OD... and a little persuasion went into the guide. for what it is going on, something was better than nothing. wont last forever... neither will i. if ppl changed oil more than 2x in its life it will last a long enuf time. if they cant check/change oil... every <20 hrs. ... we know what will happen to little engine.
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Well on the engines we run. Changing the oil every 20 hours is an absolute sin. We change oil more like every 20 laps or 20 mins whichever comes first. First instinct tells me it's no wonder why there were so many mid to back of the packers running in each class if the majority of the masses went by oem oil intervals and probably other oem specs.
 
did that... oil on top of valve... no wicked leakage. yes wont last forever, but... no one does that type of work here now that machine shop is closed and small engine place rebuilds carbs . oh well, will see how long it lasts, not hard to do it again. 8 head bolts and 2 valve spring cover screws.
 
Very interesting reading. Smart bet is he will ruin the block. He could get lucky and get it close enough to lap in. A small maybe. An experiment on an old unimportant engine maybe.
 
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