valve adjustment schedule

[MikeB.330]

Don,

What would you use as a general rule of thumb for when it's time to check the valve clearances? I have about 250 hours on my(2 yr old) MMI A4 and have started to hear a little ticking on at least one lifter.
The engine runs like a top and is only burning around .72 gal / hour cruising at 1900 rpm. So far this season I've put about 60 hours on the engine so those should be good numbers. Should I wait until the fuel consumption starts to rise.


thanks
Mike
1965 Pearson Vanguard #244

[Don Moyer]

Mike,

If you have reasonable access to the valve cover and can check clearances
without undue hardship, it would be good to check valve clearances after a
rebuild within say 50 to 100 hours.

That being said, knowing that most of our customers will have no reasonable
opportunity to check their valve clearances after a rebuild, let alone
adjust them, we make a major effort to err on the high side of valve
clearances in the belief that a little ticking sound as the engine settles
in is far better than valve seat erosion caused by a clearance ending up
being too tight.

Don

[castinemarine]

Valve ticking

My recently purchased MMI A4 rebuild has that ticking on at least one lifter. The engine has about 1.5 hours under no load and about an 0.75 hours under light (< 1200 rpm) load. Is this ticking normal? I am hoping this goes away as I go through the MMI break-in schedule ( 8-10 Ounces MMO added per 10 gal of fuel @ 1800 rpm for the first 50 hours of operation).

Someone said I should squirt a little Marvel Mystery Oil into each spark plug hole and see if that makes the ticking go away. My old engine made the same type of ticking sound but it was much less pronounced. The new rebuild has run well, so far (I have less than 3 hours of run time ).

I hope to run the engine under load dockside for as long as I can get away with this weekend I let you know if the ticking sounds gets better or worse next week! Any insight anyone cares to share would be greatly appreciated!

I hope I am just being overly conservative, I feel like a brand new father left alone with a little bundle of joy for the first time....

Don,

With regard to your reply:

If you have reasonable access to the valve cover and can check clearances without undue hardship, it would be good to check valve clearances after a rebuild within say 50 to 100 hours.

That being said, knowing that most of our customers will have no reasonable opportunity to check their valve clearances after a rebuild, let alone adjust them, we make a major effort to err on the high side of valve
clearances in the belief that a little ticking sound as the engine settles
in is far better than valve seat erosion caused by a clearance ending up
being too tight.

Do you have a procedure for checking the valve clearances should that become necessary? I am hoping your last statement proves to be the case and my worries are unfounded. I believe MMI did a great job with this rebuild and I am looking forward to years of future enjoyment of this fine powerplant. My first a4 only lasted 35 years until I decided to give her a rest, I am confident that my new MMI rebuild with FWC will go at least that long!

Fair Winds, Chris

[Don Moyer]

It's always difficult to relate to a sound via email but my guess is that the ticking sound is a benign valve sound. The Atomic 4 has mechanical lifters which make a sound that is sometimes referred to as a "sewing machine" sound. I think I'd give the engine more of a chance to wear in. If the ticking sound is a benign valve tick, it should largely disappear at higher power settings under load.

Don

[castinemarine]

Don,

Thanks for the informed reply, this concerned father of a brand new adopted MMI rebuilt A4 only hopes that he can keep this little gem purring along as long as its older brother which will start it's 36 yaer overhaul this fall. Thank you again for your insight and inspiration and please give my best regards to the fellows at Spring Garden I wish my schedule allowed me to participate in the seminar you had last month! Maybe next time.

Cheers, Chris