ChrisAttebery

My Feedback: (15)

Hey guys,

I'm looking for a good 45 or 46 FI/SE engine for warbird racing. Jett, Nelson, and other racing specific motors are not allowed. I'm looking for a solid motor that can be ready to race with a little timing and compression work. I'd also like to stick to motors that are currently available. I'll be using an Ultrathrust or JettStream muffler. So far I heard good things about the Tower 46 and the Rossi 45.

Also, can any of you tell me if the Rossi 45 or 46 is a better motor? I emailed Rossi Engines USA and got a generic response.

Thanks for your help,


Chris

Flyboy Dave

My Feedback: (21)

....I don't think any of the sport 45/46's will stay with the Rossi. They weigh a tad
more than the others, but the extra weight might come in handy.

I say....Rossi....[sm=thumbup.gif][sm=thumbup.gif]

FBD.

freakingfast

My Feedback: (3)

YS 45 SE, they pop up all the time new in box, here or on flea bay. But the stock muffler robs a lot high rpm power, must you use the stock muffler?

ChrisAttebery

My Feedback: (15)

No, I can use any exhaust system I want.

My only fear with the YS is that it's not available anymore.

Thanks guys,


Chris

airraptor

My Feedback: (66)

If using the jett muffler any of the 45 size engine will do just fine. Our engine guy in the club has done every engine out there and and they all come very close to the same numbers. Some will last longer than others though, he seems to have great results with the super tiger engines.

Do you have a size limit to go by so i help pick the best engine?

bob27s

My Feedback: (19)

If you can use the jett or ultra-thrust muffler.... just about any of the engines out there are fair game.

The OS46AX loves the tuned muffler. And it has some bit of torque - 9x8, 9x9 - if need by 10x6, 10x7 or 11x6 is not out of the question.

TT46pro my personal favorite teamed with the jett muffler. A bit more rpm and a little less torque than the 46AX. 9x7, 9x8, 10x6

The Tower 46 runs almost the same as the TT46pro - but an example I have seen indicated it was not happy turning the rpm over time.

Rossi is always a good choice.

ST GS-45 is actually a very good engine too - needs the tuned exhaust to really perform. (Could use a slightly larger carb - that is the limiting factor). Figure on a 9x7 on this.

Bob

ChrisAttebery

My Feedback: (15)

I'm leaning towards the Rossi 46 RAL. I just got an email back from the factory. The 46 RAL is a 45 with a bigger bore and 5 ports instead of three. They said it's setup to turn more RPM.

I've reset the timing and compression on quite a few Italian marine motors. They all handled the increased power pretty well.

I'm not too impressed with the compression on my AX. It runs fine, but I have the feeling that once I started upping the power that it would come unglued in short order. Not to mention that parts are pretty pricey for what it is.

Thanks again,


Chris

jaka

Hi!
The Rossi has two problems ...is't heavy and it has a lousy pipe that brakes easily!
It's 50g heavier than all other .40-.46 engines.
Over here in Sweden were we race Q-500 pylon and use .40 engines, standard sport engines without any tuned pipes and use 10x6 plastic props and 80/20 fuel.
The Webra.40 GT is king...and has been for decades. Recently the ASP .40 has arrived and rivals the Webra. The ASP (or Kyosho GX as it also is called) turns a 10x6 RAM prop at 14600rpm and it also is capable of handling a big 12x6 with ease. Perhaps the ASP .46 could be a contender?? Especially on some nitro

Flyboy Dave

My Feedback: (21)

....yep, go for it....

http://shop.vendio.com/RossiEnginesU...679/index.html

....it looks like a winner....it should crank 17K or more easy....

airraptor

My Feedback: (66)

The OS will handle the extra power. we up the compression, retime intake exhaust and the crank, and open up the carb some. I want to say the ST GS 45 turns the 9x7 over 18,000 could be more though cant remember.

the webra's are good too but I wouldnt mess with the 55 though its so thin that we dont think it would stay together long at all. the 40 and 45 are good though. the webra 36 "tuned" with the jett gold muffler out turns many stock 40-45 with jett muffler and its lighter.


If you want to stay with the 40 size block and be under 200 bucks I would use the 55AX with a little work and the red jett muffler with a APC 11x7 is a very strong setup. it's in the 14,500 range.

ChrisAttebery

My Feedback: (15)

This class is limited to .46 cu/in. Period.

I've got two of the 46 AX. One has already lost it's pinch. I hate ABN motors. If it was up to me we'd use the TT 46 PRO, but it's not. I have to say though that it turns a 9.5x6 APC at 17k. Not bad for a motor that isn't supposed to turn.

MJD

My Feedback: (1)

Maybe if you shim the sleeve you'll gain another 2000 rpm... [sm=lol.gif][sm=lol.gif][sm=lol.gif]

bob27s

My Feedback: (19)

Im all out of .125" sleeve shims

As for the sleeve pinch.... dont worry too greatly about it unless its turning over like there is no compression at all. Its the hot seal that is important. If the hotseal is shot, you will see a big drop in top end rpm. My favorite SJ-46 engine (8 years old) feels like and old K&B .40 when you turn it over cold.... but runs great.

Some of Dubs engines (aac in particular) do not have the serious pinch the 10 year-ago ABC engines had. The metals used get to the right shape and size while running.

bbagle1

Sorry for my ignorance but how do you go about raising the timing and or compression? Where did you learn how to do it? Are there any good books that describe what you are talking about? I am very interested in this so any info you can give me would be great.

Flyboy Dave

My Feedback: (21)

.....it's an old engine modification trick. Instead of grinding and raising the exhaust
and transfer ports....you raise up the liner. Then you lower the head to get the
compression back up, and you have a modified engine that usually gives a great
gain in performance.

It doesn't work well on high performance engines that are alredy in a high state of tune.
It works really well on "sport" engines.

The best thing about it is, you don't change the shape or direction of flow in the transfer
ports, which is very important.

FBD.

ChrisAttebery

My Feedback: (15)

Yeah, what Dave said.

Basically, you measure the port timing. Then you shim the sleeve up until you have your exhaust timing. Hopefully, the transfers are in the right range at that point. If not you set the transfers and recut the exhaust to get the correct blowdown ( I think that's the correct term) ie the difference between the exhaust and trnasfers. Once you have your sleeve timing set you measure your head clearance and recut the top of the sleeve so that the head can get into the correct range. Then you shim the head to get the correct clearance. Now you go run it. If it isn't blowing plugs after every run you can either cut the sqishband down on a lathe and reset the clearance or you make up a bunch of head buttons with different sized bowls and keep going down until you start popping plugs all the time, then you back off just a bit.

Just so you have an idea, the boat motors I usd to race had timing numbers in the range of 180 ex, 128 trans, 210 crank.


Chris

MJD

My Feedback: (1)

I was only teasing Bob because of his recent involvement in an enlightening technical debate on the subject of shims. Now look what I've started.. a real tangent. Sorry.

MJD

rmenke

My Feedback: (13)

Chris:

Key here is the Ultrathrust or Jettstream pipes. Works wonders on OS, TT, ST engines. If you can get away with the Webra 55 and UT of JS pipes, thats a combo that will run close to a Jett 60LX. You gotta break them in with care, two gallons on the bench, minimum of one and lots of ritch runs in the air, and yes truly a apc 10 X 10. Have run that thing for 2 seasons, am still lapping the OS, TT, ST and Rossies bad. Still running on top after two seasons of racing, it is not a poof engine. Nothing better in life than lapping the gang. He he he. ENJOY

ChrisAttebery

My Feedback: (15)

So, I went to the field to fly today and a couple guys are hovering over a trainer. One of them says "ask Chris he probably knows". I wondered over and this guy had a Midwest Aerostar trainer with a YS 45 SE and Macs muffled tuned pipe on it. [sm=what_smile.gif]

He bought the plane as is used from a guy that passed away in the club. It was turning a 11x6 APC at 13,200 on the ground, but the pipe didn't seem to be tuned correctly. The motor would wind up to 13k at half throttle and then would not advance any further. The pipe was 14" from the plug to the wide point of the pipe. I helped him get it running fairly consistantly. He took off and almost planted it as it lept off the ground. I got him to calm down and slow down. He flew a couple laps and "landed" breaking the prop. Afterward I helped him set up dual rates on his radio and told him he needed a prop with less pitch. I recommended the 12.25x3.75, but I think at 12x4 might be a better choice. It'll probably let the motor wind up a into the correct range and he can cut the pipe to the proper length. I offered to buy it off him or trade him another motor. I have a feeling it will be mine before too long.


Chris

freakingfast

My Feedback: (3)

The YS 45 want's to wind up to make power. Good props to start out with are 11X5, 11X4 10X6 and 9X9 APC. With a correctly tuned pipe or TUNED muffler those props should put the RPM around 16K on the ground and leaves room to unload in the air using 15% and a OS#8 plug. With the right sized pipe the length should be around 11 5/8" from glow plug to pipe's apex (start at 3/4" longer for your setup and shorten by 1/4" increments).

He may have been a tad long on the header and the prop was bit much if he wanted more rpm. The 45 is glow plug sensitive and will like crud if the heat range is too far from an OS #8. Once the engine is running good, try some 30%.... yahoo!

Chris, if you don’t tell him this, maybe he’ll get frustrated and you’ll be right about the engines ownership.

ChrisAttebery

My Feedback: (15)

He was pretty close to being sick of it when I showed up. I shoulda kept my mouth shut and let him fight it. I told him it's not really the kind of motor you put in a trainer and told him I'd trade an OS 46AX for it. He mentioned he wanted a 60. I can't see why the trainer is a 40. His other planes are 40 trainers and park fliers.

After he almost totaled it on takeoff he said "well, you almost got the engine for free right there." I think I'll just wait and see.

Thanks for the info on the setup.


Chris

still4given

My YS 45 turns an APC 10x6 at about 16,400 on the ground with an ultra thrust muffler. It unloads quite a bit in the air. It is hard on plugs though, especially if I go over 15%.

By the way, though the engine is not produced anymore, you can still get all the parts at yspartsandservice.com

ChrisAttebery

My Feedback: (15)

I got some test stand time on my Rossi yesterday. This is after doing the timing mods, stock compression ratio, 15% fuel and using the Rossi Mini-pipe.

I wasn't very impressed with the mini pipe. I feel like it is the limiting factor right now. I'm trying to get a Jett muffler here next week.

Bolly 9.5x7 - 16400 rpm
APC 10x6 - 15300 rpm
APC 10x7 - 14200 rpm

With this pipe the motor seemed to be happier with the heavier load of the 10x7. Adding nitro or compression did very little for the Bolly, but the 10x7 gained a fair amount.

Once I get the new muffler I plan on testing the same 3 props with 3 different compression ratios and 5 percentage levels of nitro.

Chris

SpeedBoy

Hi Chris .

Wich Rossi is this ???

ChrisAttebery

My Feedback: (15)

It's a blackhead 45.