How Flathead Briggs Compression Release Works

[@DIYWilly]

I will be rebuild my Briggs 5hp soon. This is a great tip!! Thanks for sharing!!

[@konstalehtineva5215]

but will the pulse jet carbuerator still work if you shorthen the valve

[@sys2]

love it! been battling a rebuild of an engine today .. and got exactly that and couldnt figure it out .. opened the engine and checked everything and it still did the same .. this explains it a bit better =) Thanks! =)

[@tonystanton9223]

This is the only video i can find anywhere on the net that explains this, i thought something was wrong with the cam lol , iv ground my cam to have the valve close earlier, its upped the compression something wild, hoping the starter will spin it , will find out tomorrow i guess, wish id found this earlier lol

[@777dragonborn]

Old flathead briggs looks is more enjoyable to hot rod than the conventional ohv clones.

[@aSpyIntheHaus]

I'm rebuilding this very same engine right now.

[@fnaguitarplayer9]

I hear ya! The rebuild video of this engine will be up this weekend. Thanks for Watching!!!

[@aSpyIntheHaus]

@@fnaguitarplayer9 nice! I look forward to it

[@konstalehtineva5215]

but will the pulse jet carbuerator still work if you shorthen the valve

[@danteerskine7678]

​@@fnaguitarplayer9flathead small engines are garbage. I have one and it vibrates too much that it will tear itself apart and let's not forget the insane 112 db produced. I'm glad Briggs and Stratton got rid of that design

[@jimcatanzaro7808]

Thank you

[@jeanlawson9133]

I can remember when I always kept at 5 or so Flathead Briggs around even using them as doorstop.....but I have been need one for a project and can't even find one.... AIN'T IT JUST AIN'T IT 😜 lols

[@konstalehtineva5215]

but will the pulse jet carbuerator still work if you shorthen the valve

[@rverro8478]

Good to know.

[@fnaguitarplayer9]

Thanks for Watching!!!

[@dutchvanderlinde658]

Bout that big 🤏

[@lewiemcneely9143]

A-PLUS!

[@fnaguitarplayer9]

Thanks for Watching!!!

[@lewiemcneely9143]

@@fnaguitarplayer9 Thanks for posting!

[@mailbox642]

You know Briggs compression release is not active when running, rpms disengage it. You will gain no compression when running by loosening the valve clearance

[@tonystanton9223]

No compression release in these older engines

[@ihus9950]

👍🏻

[@fnaguitarplayer9]

Thanks for Watching!!!

[@aSpyIntheHaus]

Doesn't that stop doing this once the engine starts?

[@fnaguitarplayer9]

Not really, because there is no mechanical / centrifugal mechanism to stop it once it starts, i don't see any way that it would stop once it starts, because the clearance stays the same. Thanks for Watching!!!

[@cravenmoorehead5636]

Nope it sure doesnt. Its the old easy spin comp release. Unlike the new ohv with thee mechanical comp release these old flatheads just used a raised cam grind to release compression. The engineers decided it was more important for grandma to be able to start her yard equipment instead of it creating max compression and breaking her wrist. These days the ohv engines give you the best of both worlds.

[@aSpyIntheHaus]

@@cravenmoorehead5636 yeah of course this makes sense.

[@konstalehtineva5215]

but will the pulse jet carbuerator still work if you shorthen the valve

[@BlainesGarage]

@@fnaguitarplayer9 Are you saying there is no centrifugal mechanism on the intake lobe of the cam? Interesting. Opening up valve clearance will reduce the duration also, so I don’t think that’s the way to go either. Maybe a different cam would be a better option.

[@NaythanLawson]

I got a 1963 penncraft mini riding tracter or riding mower with a huge but small hp Briggs on it and it has no compression 20 30 sm

[@Puro_100]

Is The valve seat , is allways happening just grind the valve until get flat

[@fnaguitarplayer9]

Thanks for Watching!!!

[@cravenmoorehead5636]

True but most folks have no idea where the easy spin begins and ends one the cam lobe.

[@iRepairElectronics]

well damn, im working on one of these too. i cant get mine to run. it starts with the choke for a few turnes, as soon as i let off the choke it dies. i treid a new carb and it does exact same thing. if anone has any ideas let me know

[@sawyerbennett8227]

Not enough fuel. Maybe its getting too much air from somewhere

[@jeanlawson9133]

Fuel delivery.....

[@tonystanton9223]

Blocked jets in the carbie, if not then test your condenser

[@MattsRageFitGarage]

I found out on accident it does not take more than a few thousands larger valve to tappet clearance than what the max spec is to make a big difference in cranking compression.

[@fnaguitarplayer9]

Yes! It doesn't take much to change how it works. They do tend to kick back more if its opened up more though. Thanks for Watching!!!

[@BlainesGarage]

@@fnaguitarplayer9 Kick back is a symptom of advanced ignition timing from a smeared flywheel key, not compression.

[@bcubed72]

​​@@BlainesGarage No, it's a symptom of magneto ignition, which can't retard and advance timing like a distributor/points system can. With fixed timing, if it's optimized for working RPM, it is "too advanced" for starting by definition. Unless you have a separate setup just for starting.

[@BlainesGarage]

@@bcubed72…and when you hit a tree root with your mower, the crank stops dead, but the flywheel has a tendency to keep going, smearing the woodruff key and effectively advancing the timing, so YES, not NO.

[@bcubed72]

@@BlainesGarage What seems to have sailed RIGHT over your smooth little brain, is that a magneto has FIXED timing. Unlike an auto's distributor, which has had both vacuum and centrifugal timing advance since about the Model A, magneto timing IS FIXED. This means the "correct" timing for running at governed RPM is TOO ADVANCED at startup. And any such machine WILL tend to kickback, at least somewhat. Yes, fancier machines can have a timing delay just for starting, BUT generally OPEs aren't worth the cost of such engineering, and tend to deal with the over-advanced timing at startup with a big flywheel and/or compression release. (Try and start a mower without a blade sometime if you doubt this. Kickback city!) Model Ts had magneto timing. Model Ts also *required* you to fully retard the timing on startup to avoid kickback. When people forgot, they had the crank ripped right OUT of their hands from kickback, and possibly a broken wrist. (Google "Ford fracture" if you doubt this.) Yes, a sheared flywheel makes kickback WORSE, but kickback is an inherent limitation of any magneto system with fixed timing.

[@waymonblevins6939]

Great News.

[@fnaguitarplayer9]

Thanks for Watching!!!