Heymow - Lawnmower Racing Forum

Engine Help => Briggs Flathead => Topic started by: HotRodBriggs on November 09, 2018, 01:33:36 am

Title: 22 Ci 10 hp questions.
Post by: HotRodBriggs on November 09, 2018, 01:33:36 am
I recently blew up my 25 ci 10 hp, and I have a 22 ci 10 hp laying around here.
Are there any billet parts (rod, flywheel..) that I could put into the 22ci?

If not then what's the highest I can rev it ungoverned?

Any help is appreciated.
Title: Re: 22 Ci 10 hp questions.
Post by: rotten ron on November 09, 2018, 03:58:14 am
The engine is probably set to go maximum 3650 RPM ,any more than  that you need an aluminum flywheel  I had a stock flywheel on a small block Chev that got to about 8000 RPM before it exploded and ruined the engine and lots of other things If the flywheel explodes it could kill you or someone else
Title: Re: 22 Ci 10 hp questions.
Post by: HotRodBriggs on November 09, 2018, 02:55:32 pm
Thank you, I'm wondering what parts are available. I know OEM parts are available. I don't know what to buy in terms of billet parts.

So in a way I'm wondering what to buy and where. All my searches have ended up with a whole lot of nothing lol.

My budget is $1200 for this engine.

I want to see what 22ci can really do.
Title: Re: 22 Ci 10 hp questions.
Post by: PJG56 on November 09, 2018, 08:35:22 pm
Better off to find a 28 all kinds of parts for them..
Title: Re: 22 Ci 10 hp questions.
Post by: HotRodBriggs on November 09, 2018, 10:26:55 pm
I get the 28 is better, but I can't find one around here, and my local class has a 22ci maximum displacement.
Title: Re: 22 Ci 10 hp questions.
Post by: Leon_Johansson_ on November 10, 2018, 12:03:12 pm
If you just run it ungoverned it could rev up to about 5000-5500 rpms until you upgrade the valve springs. It could probably handle just running ungoverned for a long time depending on how you drive and how much you rev it up.
If it is Synchro Balanced I wouldn’t ungovern it at all because it’s a really weak point in the engine if you dont get the billet dogbone.

The flywheel isn’t as dangerous as some people make it seem, if you haven’t bashed on it with a hammer or it doesn’t have any cracks it will probably be good until you upgrade the valve springs, then it becomes dangerous.

My suggestion is to wait and see if you could find a 28 or at least a 25 to build or see of your blown engine is good enough, maybe some honing and polishing the crankshaft could be enough.
Title: Re: 22 Ci 10 hp questions.
Post by: HotRodBriggs on November 10, 2018, 01:11:02 pm
Thank you, I'll run this 22ci stock for a while then, I'll keep my eyes open for a bigger engine.

Thank you Leon_Johansson_

I think I've seen you on youtube before, I'm probably subscribed.
Title: Re: 22 Ci 10 hp questions.
Post by: cycloneracer on November 10, 2018, 02:40:19 pm
If you just run it ungoverned it could rev up to about 5000-5500 rpms until you upgrade the valve springs. It could probably handle just running ungoverned for a long time depending on how you drive and how much you rev it up.
If it is Synchro Balanced I wouldn’t ungovern it at all because it’s a really weak point in the engine if you dont get the billet dogbone.

The flywheel isn’t as dangerous as some people make it seem, if you haven’t bashed on it with a hammer or it doesn’t have any cracks it will probably be good until you upgrade the valve springs, then it becomes dangerous.

My suggestion is to wait and see if you could find a 28 or at least a 25 to build or see of your blown engine is good enough, maybe some honing and polishing the crankshaft could be enough.


You are 100% wrong about the flywheel.   Do not over speed a stock flywheel.  It is designed to run at stock speed.  When it explodes bad things will happen. 

There are pics out there of one that exploded.   The one pic has jeans stuck to the broken piece of flywheel.   And a chunk of leg.......

Don’t do it.  Don’t risk it.   

I think there is a flywheel out there for the 22.
Title: Re: 22 Ci 10 hp questions.
Post by: Leon_Johansson_ on November 10, 2018, 03:04:49 pm
The whole engine is designed to be able to run well over 3600 rpm for a good well lasting engine. The only reason it only revs to 3600 rpms is because that’s what every small equipment engine is set to run. If it wasn’t designed to be able to rev higher there would be a much higher risk of blowing them even at govorned speeds.
And when we get to the flywheel, the last thing Briggs & Stratton wants is a lawsuit because the flywheel was weak and hurt somebody, that’s why they design it to rev much higher.

Now dont get me wrong i would suggest using a billet flywheel if you got the money or atleast make a scatter shield. But you’re probably going to blow the stock rod before the flywheel.
Title: Re: 22 Ci 10 hp questions.
Post by: Leon_Johansson_ on November 10, 2018, 03:11:24 pm
Thanks hotrodbriggs, yea we talked on some video.
I’ve got another channel with my friend Called F&L garage on youtube where im going to to upload a video of my 28 very soon.

And if you ever find a billet rod that works for whatever engine you’re gonna build make sure it’s the right length because the model 28 uses the model 28 avs piston with the billet rod or some of the model 21 pistons, the piston number is 792307 thanks to pjg56 for helping me find it.
Title: Re: 22 Ci 10 hp questions.
Post by: HotRodBriggs on November 11, 2018, 01:40:21 am

You are 100% wrong about the flywheel.   Do not over speed a stock flywheel.  It is designed to run at stock speed.  When it explodes bad things will happen. 

There are pics out there of one that exploded.   The one pic has jeans stuck to the broken piece of flywheel.   And a chunk of leg.......

Don’t do it.  Don’t risk it.   

I think there is a flywheel out there for the 22.


Thank you, under due consideration I would like to keep my legs, billet flywheel is on my shopping list for a weighty 350 dollars, do they make a rod for this?
Title: Re: 22 Ci 10 hp questions.
Post by: Leon_Johansson_ on November 11, 2018, 11:42:52 am
What’s the complete model number on your engine?
Title: Re: 22 Ci 10 hp questions.
Post by: HotRodBriggs on November 11, 2018, 12:41:55 pm
220707 is the model number, I don't know the type or code.
Title: Re: 22 Ci 10 hp questions.
Post by: Leon_Johansson_ on November 11, 2018, 02:56:02 pm
From what i have heard the 21, 22, 25, 28 are basically the same engine with different strokes, head and sometimes different pistons.

If this is the case then they should all work with the 28 billet flywheel

I know the 28 and 25 shares the same rod and piston except the 28 avs that uses the same piston as the 21 wich is a shorter piston.
If the crank has the same rod journal as the 28/25 and if the stock rod is as long as your 25 rod or the same length as the arc 28 rod you could probably just use the 28 billet rod.
Title: Re: 22 Ci 10 hp questions.
Post by: HotRodBriggs on November 11, 2018, 03:47:55 pm
I'm gonna find a 28, I'll run this until she blows
Title: Re: 22 Ci 10 hp questions.
Post by: Leon_Johansson_ on November 11, 2018, 06:43:59 pm
Sounds like a great plan
Title: Re: 22 Ci 10 hp questions.
Post by: PJG56 on November 12, 2018, 08:42:34 am
From what i have heard the 21, 22, 25, 28 are basically the same engine with different strokes, head and sometimes different pistons.

If this is the case then they should all work with the 28 billet flywheel

I know the 28 and 25 shares the same rod and piston except the 28 avs that uses the same piston as the 21 wich is a shorter piston.
If the crank has the same rod journal as the 28/25 and if the stock rod is as long as your 25 rod or the same length as the arc 28 rod you could probably just use the 28 billet rod.


22 rod is different than 25 and28 rod
Title: Re: 22 Ci 10 hp questions.
Post by: birdman_express on November 13, 2018, 11:55:42 am


The flywheel isn’t as dangerous as some people make it seem, if you haven’t bashed on it with a hammer or it doesn’t have any cracks it will probably be good until you upgrade the valve springs, then it becomes dangerous.


Yes the flywheel is dangerous, if you wish to take on financial responsibility for every flywheel made, you can make that statement.
Please do not make that statement here again.
Title: Re: 22 Ci 10 hp questions.
Post by: Leon_Johansson_ on November 14, 2018, 09:51:37 am
Yes the flywheel is dangerous, if you wish to take on financial responsibility for every flywheel made, you can make that statement.
Please do not make that statement here again.

Yea not saying it’s completely harmless but the flywheel often fails above 5500 rpm where you get valve float or it already is damaged, most often someone has tried getting it of and cracked it in the process. The first thing to fail in a stock ungoverned engine is almost always the “dogbone” (if it has one) or the rod. Not suggesting to get a billet rod and no flywheel, if you have the money spend it. Look at this he explains it great http://www.atltf.com/t2575-governors-flywheels-and-an-internet-full-of-crap
Title: Re: 22 Ci 10 hp questions.
Post by: birdman_express on November 14, 2018, 09:56:34 am
The rule that we go by, if the governor is gone, so is the stock flywheel.
It is not up for debate. Also, nobody will teach anyone to do so from
This site.
Title: Re: 22 Ci 10 hp questions.
Post by: Leon_Johansson_ on November 14, 2018, 10:28:54 am
The rule that we go by, if the governor is gone, so is the stock flywheel.
It is not up for debate. Also, nobody will teach anyone to do so from
This site.
Alright, no need getting angry. Ill tell everyone that they’ll have to invest a ton of money if they want to rev a little higher if that makes you happy.
Title: Re: 22 Ci 10 hp questions.
Post by: HotRodBriggs on November 15, 2018, 01:27:05 pm
Do I need the flywheel, that also includes the bigger starter. That's $400 total for an engine that I can't get a rod for.