Info on a .25 BRAT engine?
07-26-2006, 06:43 PM
#1
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Info on a .25 BRAT engine?
A good friend gave me this engine it runs GREAT!!!!!!!!! It looks brand new. All it says on it is .25 BRAT. On the front of the carb says N.S. Any info would be great type of props, r.p.m range, age, ect... Thanks for your time
07-26-2006, 07:15 PM
#2
RE: Info on a .25 BRAT engine?
it was made for world engines after john maloney sold the import rights for os and super tiger engines to great planes.this was about the mid eightes.should have the smae rpm range of the os 25 fp.he also imported a bluebird engine and the beginning of the asp line before his death.
07-26-2006, 08:31 PM
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RE: Info on a .25 BRAT engine?
Thanks for the info. I have never built anything small enough for a .25 not sure what to put it in? Something VERY SMALL AND VERY VERY FAST maybe a nice delta?
07-25-2016, 02:18 PM
#5
Brat .25
Warning: Major and to-bump!!
I was recently given this engine - no idea of when it was made, though I know they weren't made for very long. I did a little research on the Brat/Blue Bird engines that World engines sold and later Indy R/C. This one is a .25, and like most Brat/Blue Birds is AAC. This one wasn't run much - if it even ran... Probably hard to when the wristpin started to eject itself out of the piston enough to ding a transfer port. Apparently the circlip either never was installed or it got lost in the mail..
. Anyway, I didn't pay anything for the engine and as such have nothing to lose, so I robbed a circlip from a junk engine and installed it, and then for good measure, packed the wristpin and edge of the piston with JB Weld. This method has worked wonders on other junk engines, so I see no harm in it. Parts are impossible to get for these guys. The piston/liner fit is pretty snug, so when I can give it a run, I'll break it in and if it survives that, I'll put a diesel head on it. They're supposed to be "rough" copies of the OS FSR engines, so I'll put my Davis Diesel head on it and see if she'll diesel worth a crap. My .25 FSR isn't in that great of shape for running on diesel, so why not.
Mine has the big carb that some have said can be problematic - I can see why on a few things... The choke diameter is 7mm - pretty big for running on suction I think... The other thing I noticed is the barrel is slightly misaligned due to a possible too-small barrel guide screw or maybe the barrel guide too wide. Easily repaired, but I'll deal with that if it survives a few rich fast runs. The ports are cut decent - not as rough as some have said their examples were...
I didn't see that this wasn't originally posted in the Engines section. If a Moderator reads this, could the thread be moved to Glow Engines?
I was recently given this engine - no idea of when it was made, though I know they weren't made for very long. I did a little research on the Brat/Blue Bird engines that World engines sold and later Indy R/C. This one is a .25, and like most Brat/Blue Birds is AAC. This one wasn't run much - if it even ran... Probably hard to when the wristpin started to eject itself out of the piston enough to ding a transfer port. Apparently the circlip either never was installed or it got lost in the mail..
. Anyway, I didn't pay anything for the engine and as such have nothing to lose, so I robbed a circlip from a junk engine and installed it, and then for good measure, packed the wristpin and edge of the piston with JB Weld. This method has worked wonders on other junk engines, so I see no harm in it. Parts are impossible to get for these guys. The piston/liner fit is pretty snug, so when I can give it a run, I'll break it in and if it survives that, I'll put a diesel head on it. They're supposed to be "rough" copies of the OS FSR engines, so I'll put my Davis Diesel head on it and see if she'll diesel worth a crap. My .25 FSR isn't in that great of shape for running on diesel, so why not. Mine has the big carb that some have said can be problematic - I can see why on a few things... The choke diameter is 7mm - pretty big for running on suction I think... The other thing I noticed is the barrel is slightly misaligned due to a possible too-small barrel guide screw or maybe the barrel guide too wide. Easily repaired, but I'll deal with that if it survives a few rich fast runs. The ports are cut decent - not as rough as some have said their examples were...
I didn't see that this wasn't originally posted in the Engines section. If a Moderator reads this, could the thread be moved to Glow Engines?
Last edited by 1QwkSport2.5r; 07-25-2016 at 02:36 PM.
07-26-2016, 03:22 PM
#7
Yeah, the carb is huge for a .25!! I don't think some of my .46s even have carb's that big. I will run the engine in hopefully in the next couple days. For being a 30yr old Taiwanese, it seems to be a better made example... We'll see.
07-27-2016, 07:43 AM
#8
As I mentioned in another forum? My .25 had a G clip failure and it scored the piston cyl. I guess that is a problem with them. I got it for $15 at a swap meet thinking I could use it for parts on another Brat that I bought new likely in the mid 1980s. I believe it was about $50 at the time which was quite reasonable for a schnuerle BB motor which was the new thing. Nothing fit between the two. I still have not run either one. The .21 has a heat sink head and a pull start, and looks quite well made. I just never bothered to make a backplate for it yet. Maybe in another 30 years. It did come with a slick little primer bulb. From my little diesel experience, I think they are happier with small carbs. They normally don't rev as high, so it is not needed, plus it gives better suction and reliability.
Last edited by aspeed; 07-27-2016 at 07:52 AM.
07-27-2016, 09:06 AM
#9
As I mentioned in another forum? My .25 had a G clip failure and it scored the piston cyl. I guess that is a problem with them. I got it for $15 at a swap meet thinking I could use it for parts on another Brat that I bought new likely in the mid 1980s. I believe it was about $50 at the time which was quite reasonable for a schnuerle BB motor which was the new thing. Nothing fit between the two. I still have not run either one. The .21 has a heat sink head and a pull start, and looks quite well made. I just never bothered to make a backplate for it yet. Maybe in another 30 years. It did come with a slick little primer bulb. From my little diesel experience, I think they are happier with small carbs. They normally don't rev as high, so it is not needed, plus it gives better suction and reliability.
This engine is more of an experiment than anything - rumors say they wear out quickly and blow rods... I'll be getting a new P/L for the FSR, so this thing will likely end up on the drawer after I beat it up a bit. It was a freebie anyway.
