So I finally decided to pull the cam cover for inspection, gasket replacement, heli-coil, & crank case/oil pump drilling modification (after I've nearly finished building the bike - judge me later).

I'm concerned about this gouging I found in my breather gear bore, though the bike ran mint before the tear down and there's not much I can do to fix this anyway, I'd just like to hear some thoughts on it.


Scoring in the breather gear bore.


Rough casting? Google Images seems to show me a lot of the same finishing of the breather cavity.


Missing material? culprit of the grooving?


Breather Gear
I notice two defects of my breather gear. There is a minor burr and it appears as the screen got bent in just a wee bit. It looks like it can be used again with some work of a file and sandpaper, again, would love some opinions. I'm in a few arms and a couple legs into this bike, running low on the uncle sam notes.

 

we have a tool that lets us re bore the breather hole out to .030 over size - and then install the S&S breather that uses a longer timing hole for better vacuum - that will never work as intended with the damage in the engines breather hole - and the engine vent will spit oil out all the time - a reed breather is an option but it may also bypass oil as a correct seal / to create vacuum can no longer be achieved

its a fix it the right way of live with the outcome

 

What would you recommend for a proper fix? maybe I'll just ride it out one season since I'm a few body parts into this build and send it somewhere next winter?

what kind of damage are we currently looking at? is it just the bore? is the half-ring in the back normal?

what causes this? could it be a result of improper shimming?

and lastly, what are the risks I face running my engine in this condition?

 

So I've done a little reading and learned that the S&S Reed Breathers made for the evos will work on shovelheads just fine?

Here's a link,
https://www.jpcycles.com/product/433...iABEgIMgvD_BwE

Seems like a pretty cheap alternative to a fix. There's a very snug fit and doesn't appear to be grooving in the first 1/2" of the bore, which is good.

 

John answered your question, but I don't know if it can be done on the bike.

 

S&S REED VALVE CRANKCASE BREATHER FOR EVOLUTION BIG TWIN

this not the answer I have one I don't use it catches everything in the engine and eventually bend the small covers inside
when that happens not worth repairing, then a whistling noise occur because air escaping, may work on Evo's but not shovelheads

 

^^^ And yet... there are more than a few Shovelhead owners who are using the reed Successfully...
Curious... Seems quite divided there... for as easy as it is to replace... I think I will try one... for my own edification, and education..

 

I have used the reed in all of the engines pan shovel from 1948 to 1999

NOW I will say this it does NOT - I said it does not work for some reason on every one BUT most and even with the oil recirculation system in place 1965 to 1984

to add to that its is well worth a try - one of the shop bikes just came back from a cross the USA trip taking rt 66 and all country roads on a 12 over springer hard tail 1948 pan engine 2 up with a reed valve - and he said it never spit any oil out the entire trip = the engine was stripped to the screws to confirm the build and its new still inside will picture up the pistons tomorrow if I remember

 

^^^ And yet... in many circles... it is Despised for pre-1993 Big Twins...
I will try it just because...
The Above is at the very least "Encouraging".... Thanks john!

 

I have what can be considered a loaner its a 1985 FLHTC now I restored the bike mechanically then tweaked the engine

new flat top pistons But 030 head gaskets and 010 base gaskets both cometic set the wall at 003 balanced it at 60 percent 015 rods side to side - its a stock 80 inch evo engine

heads we used hi tulip black coated valves - 3 angle valve job and blue rubber seals cast iron guides 002 intake 003 exhaust - and comp cams b hive spring kit for 600 lift cams -

we then used a an Andrews cam everyone will say does not work with a 800 pound dresser - the evo 45 - switch the carb out to a CV and the kinsler kit jetted as per instructions

ignition is a ultima and its dual fire - 32 amp charging system - stock exhaust except super trap mufflers with a double defuse disc package and the open off road end cap

from a light I look for 1200 sportys to harass - as by 3rd gear I am 6 to 8 bikes out on them - forget twinkies its way too boring its likie I am just making believe they did not even try

----- it has a reed breather in it and spits oil out every time I run it from cold it stops once warm but it does it every time --- its mine so that's my cross to bear for making it fast - putting an S&S breather in it this winter -