130LikesO.S Engines thread
09-26-2022, 03:12 AM
#2821
Tech Rookie
I am interested in getting an O.S. for my Mugen MBX8. Today I run Reds 721 Corsa and I think it's a bit unruly, lively and hard to control. And also off throttle is very hard to tune.
Most of those I race with use O.S and these engines seem to be more drivable and easier to tune. Like comparing japanese motorbikes to italian. So thats why I'm looking at O.S.
So what I am looking for is a smoother engine, not too aggressive on initial throttle (to not spin out) and then linear with good acceleration throughout and good top speed. I'm looking for best quality/suitability rather than affordable.
I've read the forum threads I have found and searched the web a lot. But still I can't really find a good comprehensive comparison of all the supposedly top-end O.S engines: B2103, B2104, Ongaro (B2104), AD2 and AD3.
Example: In regards to technical differences as I understand AD3 (compared to B2104) is shorter stroke and bigger bore, lower profile, other backplate, some "boost bypass" thing?? and few other differences. What does that mean for performance, driveability and durability?
Also as I put in an earlier post I am a bit confused of what engine the AD really is based on, visually it seems the budget O.S. Max?? (by the marking)
Most of those I race with use O.S and these engines seem to be more drivable and easier to tune. Like comparing japanese motorbikes to italian. So thats why I'm looking at O.S.
So what I am looking for is a smoother engine, not too aggressive on initial throttle (to not spin out) and then linear with good acceleration throughout and good top speed. I'm looking for best quality/suitability rather than affordable.
I've read the forum threads I have found and searched the web a lot. But still I can't really find a good comprehensive comparison of all the supposedly top-end O.S engines: B2103, B2104, Ongaro (B2104), AD2 and AD3.
Example: In regards to technical differences as I understand AD3 (compared to B2104) is shorter stroke and bigger bore, lower profile, other backplate, some "boost bypass" thing?? and few other differences. What does that mean for performance, driveability and durability?
Also as I put in an earlier post I am a bit confused of what engine the AD really is based on, visually it seems the budget O.S. Max?? (by the marking)
Last edited by Hadez; 09-26-2022 at 02:45 PM.
09-27-2022, 01:17 AM
#2822
Tech Regular
Originally Posted by Hadez
I am interested in getting an O.S. for my Mugen MBX8. Today I run Reds 721 Corsa and I think it's a bit unruly, lively and hard to control. And also off throttle is very hard to tune.
Most of those I race with use O.S and these engines seem to be more drivable and easier to tune. Like comparing japanese motorbikes to italian. So thats why I'm looking at O.S.
So what I am looking for is a smoother engine, not too aggressive on initial throttle (to not spin out) and then linear with good acceleration throughout and good top speed. I'm looking for best quality/suitability rather than affordable.
I've read the forum threads I have found and searched the web a lot. But still I can't really find a good comprehensive comparison of all the supposedly top-end O.S engines: B2103, B2104, Ongaro (B2104), AD2 and AD3.
Example: In regards to technical differences as I understand AD3 (compared to B2104) is shorter stroke and bigger bore, lower profile, other backplate, some "boost bypass" thing?? and few other differences. What does that mean for performance, driveability and durability?
Also as I put in an earlier post I am a bit confused of what engine the AD really is based on, visually it seems the budget O.S. Max?? (by the marking)
Most of those I race with use O.S and these engines seem to be more drivable and easier to tune. Like comparing japanese motorbikes to italian. So thats why I'm looking at O.S.
So what I am looking for is a smoother engine, not too aggressive on initial throttle (to not spin out) and then linear with good acceleration throughout and good top speed. I'm looking for best quality/suitability rather than affordable.
I've read the forum threads I have found and searched the web a lot. But still I can't really find a good comprehensive comparison of all the supposedly top-end O.S engines: B2103, B2104, Ongaro (B2104), AD2 and AD3.
Example: In regards to technical differences as I understand AD3 (compared to B2104) is shorter stroke and bigger bore, lower profile, other backplate, some "boost bypass" thing?? and few other differences. What does that mean for performance, driveability and durability?
Also as I put in an earlier post I am a bit confused of what engine the AD really is based on, visually it seems the budget O.S. Max?? (by the marking)
09-27-2022, 09:01 AM
#2823
Tech Rookie
Originally Posted by Tigergutt
The Ad 1-2-3 is based on the B2101
I still think its weird it says "O.S Max" on it. The B2101 I've seen does not.
What do you think of AD2 or AD3 compared to B2104, for 1/8 buggy?
09-27-2022, 09:54 AM
#2824
oops
Last edited by token; 09-28-2022 at 08:48 AM.
09-27-2022, 11:27 AM
#2825
Tech Rookie
Originally Posted by token
The AD3 is based on the 2104, not the AD2. The 2104 came out not to long ago. AD2 is based off the Max speed 2103.
Originally Posted by token
I to came from Reds, and find the AD series alot smoother to drive. Im currently running the AD2 in buggy and 2104 in truck. They dont product the same kind of power the Reds do, and in truck, I miss it. But in Buggy, Im WAY faster since switching to the AD. And yes, tuning is a lot easier than the Reds.
09-27-2022, 03:47 PM
#2826
Tech Regular
Originally Posted by token
The AD3 is based on the 2104, not the AD2. The 2104 came out not to long ago. AD2 is based off the Max speed 2103. I to came from Reds, and find the AD series alot smoother to drive. Im currently running the AD2 in buggy and 2104 in truck. They dont product the same kind of power the Reds do, and in truck, I miss it. But in Buggy, Im WAY faster since switching to the AD. And yes, tuning is a lot easier than the Reds.
Crankshaft, conrod, piston and sleeve is the same on all engines. Crankcase is the same on AD 1 and 2, different on AD3. Backplate is new on AD3
all 3 use the same carburettor.
B2104 is a longstroke engine 16.27-16.8
All AD engines are medium/square stroke 16.4-16.55
The B2103 is also a longstroke engine
09-27-2022, 08:08 PM
#2827
AD3 is still based off the AD2 which is a hybrid of the 2101 using a semi-long stroke 3 port. Only thing different is the lowered cooling head and crank case that features porting for smoother exhaust pressure flow making the engine responsive. it is not based off the 2104.
09-28-2022, 08:48 AM
#2828
So my bad....
10-23-2022, 06:04 AM
#2831
Went through my first quart with an OS. Picked up a lightly used b2101, I think ty2 edition. Weather was in the low 60’s in the shade and the motor was ripping!
I did notice, more so than my other engines that the engine did not like running below 200, if it would sit at idle for a bit the temp would drop and get very rich. Is this normal for an OS? Just to get it started I had to lean out the bottom and top a few hours or so. Would return right back to a good tune after a half a lap. Maybe a tad rich on the bottom? Didn’t want to lean out the bottom with the cold air temps and risk overheating.
I did notice, more so than my other engines that the engine did not like running below 200, if it would sit at idle for a bit the temp would drop and get very rich. Is this normal for an OS? Just to get it started I had to lean out the bottom and top a few hours or so. Would return right back to a good tune after a half a lap. Maybe a tad rich on the bottom? Didn’t want to lean out the bottom with the cold air temps and risk overheating.
10-24-2022, 07:06 AM
#2832
Originally Posted by wely324
Went through my first quart with an OS. Picked up a lightly used b2101, I think ty2 edition. Weather was in the low 60’s in the shade and the motor was ripping!
I did notice, more so than my other engines that the engine did not like running below 200, if it would sit at idle for a bit the temp would drop and get very rich. Is this normal for an OS? Just to get it started I had to lean out the bottom and top a few hours or so. Would return right back to a good tune after a half a lap. Maybe a tad rich on the bottom? Didn’t want to lean out the bottom with the cold air temps and risk overheating.
I did notice, more so than my other engines that the engine did not like running below 200, if it would sit at idle for a bit the temp would drop and get very rich. Is this normal for an OS? Just to get it started I had to lean out the bottom and top a few hours or so. Would return right back to a good tune after a half a lap. Maybe a tad rich on the bottom? Didn’t want to lean out the bottom with the cold air temps and risk overheating.
10-24-2022, 12:18 PM
#2833
Originally Posted by Blaster1
If your just playing around the yard it may load up, if your on track, your not going to get very good results in that low of temp range, also running rich to long can also start pushing fuel through the front bearing. get your HSN set so its good and clean, then start bumping in the LSN. should be able to sit 15-20 seconds and clear out real good afterwords.
