I have installed my first gasser on a China Model Products FW-190. The plane weighs in at 13.25lbs. The Toro thin cast 25cc is turning a Master Airscrew 16x8 three blade @7100 rpm. Magneto ignition, stock steel muffler with 2 additional 7/16" holes in the bottom. Walbro 11mm carb. The motor flys this plane great. Good speed but limited vertical. Idles @ 1600 rpm with very smooth transition.
I know I am loading the motor down a bit. It ran 8600rpm with a APC 16x8 2 blade no problem. The lower RPM seems to be much quieter. I consider this a most successful journey. Thanks for all you help guys!!
Tp

Tom,
Great job on the engine.

Dave

Hello all of you Toro fans,
Here are some pictures of how I did my 2 bbl Toro. The first group will be stock before photos, and then after mod group. Some before photos are from the forum.

Dave

Hey Guys, I thought I would dig this thread up after reading the whole thing. It took over 40 minutes

I received one of these engines for free. My plan is to throw it into a boat hull. I have stripped only a couple plastic covers off.

The issue I have is I need to find a header to match the exhaust flange on this engine as I plan to use a tuned pipe with it. I know for aero purposes the pitts style muffler is ideal but while running the engine on land at 9000RPM it is a LOUD. Ideal solution is a header matched to a tuned pipe with muffler. The pipe should give me somewhere around 9000-11000 loaded prop RPM. *Remember this is in the water. That will be about 30mph on water.

EDIT - I'll snap an exhaust flange photo in a few days as nearly all the Toro's in this thread have different dimensions/shapes

Thanks for the help
Ryan

The exhaust bolt to bolt dimension is 32mm or 1 1/4"'

Ryan

Ryan,
A Zenoah G23 compatiable header should work fine. At the most you wil have to make a minor adjustment with a small rattail file. I put a Toro muffler on a G23 with only minor filing.

Dave

Thanks Dave
I could not find an exact bolt spacing dimension for a Zenoah header. What I was thinking since you said "make a minor adjustment with a small rattail file" I could use this [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXMMV3&P=K]HEADER[/link] and take out 1.5mm on each far end of the bolt spacing on the header.

Would taking out a total of 3mm ( almost 1/8" ) weaken the header too much? I don't believe there would be any significant forces on the header. Any other problems I dont see?

Thanks
Ryan

Wish I saw this tread before I converted my

Ryan,
A small washer under the bolt head will secure the header and spread the load.

Dave

Tom I see you found a good use for that 4 cycle..after you went to the dark side (conversions) ha ha ha

well here is what my toro is going in! well, I did actually use a pic of my mac 25 instead of the toro,

and ACTUALLY I am using a LESS scale plane..one of the cheap cmp clones ...when I get it done who knows, I have WAY too many projects going.

YEA...one of those CMP clones...Alright!!!

Hello,
Some folks have been looking for this thread, so I thought that I would bring it to the top for them.

Dave

Dave,

Thanks for reviving this one. I just finished reading it in its entirety.

Do you have the porting specs summarized somewhere (intake - open / closed / duration, exhaust - open / closed / duration, transfer - open / closed / duration)?

Thanks

Foamcut I did a single barrel 25 and ports are stock. Sold it to a friend of mine. We think it runs well, actually it screams. Also have a 2 barrel one here if someone is interested.

tim220225: Can you guys post a photo of the 25cc single barrel. Did you have to balance the crank like the Brill-boys do... so it would run smooth? Thanks Capt,n

That brings up yet another good point that was skirted several times in this thread.
How do you balance your rotating assembly? I'm particularly interested in balancing after removing the flywheel (ignition or gas / glow). Surely there's a thread out there somewhere...

Foamcut,
Here are my Toro stock timing measurements.

Dave

The one I did runs as smooth as any other single I have done. I don't get too concerned with balancing these engines. My opinion is that a single can only run so smooth and that is it. Sorry but I don't have a picture of it. One of the few I don't. When I see it again I will try to get one.

I don't worry about balancing all that much myself. It's also impossible to completely balance a single cylinder engine.

Ryan

POCO242 said he ba;anced his with a prop balancer.

How does that work?

I'd like to know too. And what figures he used to include the piston assembly. My prop ballancer won't ballance anything over a significant amount of weight.

Ryan

If Poco (Scott) said he balanced his engine with a prop balancer...it probably was a Hi-point balancer. If his engines run smoother than other engines on the market I would ask him by PM email. Or read all you can about how to do it and go from there. Type in balance in the search feature. There has been a lot on the subject. Capt,n

He may have just been talking about balancing the flywheel. He converted many mag versions of the Toro.

Dave

I'm looking for a glow adapter for my Toro.

I just got mine back from Scott and it looks very well done.

I didn't relize that it took a small spark plug, now I'm scrambling for an adapter.

Any one have one, or know where I can get one.

Thanks