rc34074

My Feedback: (5)

For essentially the same price the Syssa looks like the better engine, especially since it has the rear exhaust system so you don't need to buy an aftermarket muffler for tight installations with the Syssa. Plus its made in the USA

Ed

skillet92

You are right on the initial cost! What I should have said is the back end cost. The OS will most likely out last 2 or 3 dle 30's! So you make it up on the back end! And I am not bad mouthing dle. I have three and love all of them! I have an original dl50 and a dle 30 and 20! All are great motors but not up to par with the MVVS 45 and 35 or Zenoah 20 and 38 that i have. I am willing to bet that none of the dle's will out last a single one of the other engines I have! And the OS should be as good of quality. Now on this time will tell.

But for me buying a better quality engine at close to the price of an economy one is something that I am willing to try if the engine has good initial reviews!

skillet92

Wasp I to have a MVVS 35 that I run on a GP Super chipmunk. Great engine and easy to start! I run a 18X8W APC on mine because of clearance issues. But as for the lower OS rpms though I ran an 18x8 xoar before the wide blade apc and I lost almost 600 rpm using the wide blade but picked up a lot better performance. So I would be interested to know the RPM's of the 20x8w APC on the MVVS?

But in saying that...... Somebody on here a while back made a statement that we RC'ers worry to much about rpm's and HP's instead of how an engine actually performs in the air! I believe it was TOM. And since then I have stopped worrying so much about peak rpm's on mine unless it just does not seem to be opening up at the top. I just worry what the plane performs like in the air.

This is my ESM Corsair that has a 18x8w APC. The plane weights almost 19 and a half pounds and the G-38 engine just pulls it great! Have no Idea what the top RPM's are!

ghoffman

My Feedback: (3)

And chances are, the OS will use an iron liner instead of the plated cylinders most others use. The iron liner is heavier and has less heat transfer into the fins because it is not in intimate contact like plating is.

kochj

skillet92
You are so right.

Everyone should read a book called "CHEAP- The high cost of Discount Culture".... it really exemplifies the american agenda....and our own demise...

TimBle

Not in intimate contact?

A press fit is a very intimate fit between aluminium and steel.
Steel liners allow for better honing marks therefore better oil retention. AL makes a great heat sink so heat transfer is not impeded.


The advantage of Nicasil plating is that is it lighter and expands with the aluminium allowing closer tolerances between bore and piston as well as better heat conductivity and therefore better cooling. Postplating honing is typicaly done so oil retention isexcellent but the honing process needs to be conducted more carefully to prevent cracking of the plating.
However in time the platingcan start to flake if fuels with high sulphur is used I.e. AVGAS 100LL @ 0.1% wt or 1000ppm. Not an issue for pump gasoline.
The O.S GT33 will be more resistant to AVGAS over time than e.g. a DA or DLE.

There is nothing wrong with nicasil plated engines. In fact they are superior to lined engines in terms of specific power output (all else being equal). It is a common process used in many high perormance engines today e.g Porsche 911 Turbo, GT, GT2, GT etc, Audi R8, and TFSi range, BMW N14, N35 (335i),Mercedes and Ferrari F1 engines

The OS GT33 is nothing special and not what I expect from OS. Others will no doubt differ

cuwaert

I don't care about carb position or what mounts it has as long as it fit's my modell and it runs great for a fair price.
To my knowledge it's not the first engine they build so they should know about those things.
I don't know the drive for carb position, is it technical? marketing? I know 3W builds engines with side carb for the US?
don't understand a "sikkepit" what's the purpose of that.
Basically I believe OS know what their doing, but they suffer price pressure and that leads to economic alterations wich
many times turns out ... ( by the way, is it "which" or "wich", one of them is wicked old woman) if not fatal, then quasi fatal.

the Wasp

My Feedback: (1)

""Somebody on here a while back made a statement that we RC'ers worry to much about rpm's and HP's instead of how an engine actually performs in the air! I believe it was TOM""

for the most part I do agree with that statement,, and I have to say I bought my MVVS 35 with knowing very little about it, I just knew it was not a cheap Engine

Jim

MetallicaJunkie

thats four pounds of thrust difference

grimbeaver

Alright so the Tower page states:

FEATURES: Electronic ignition accepts LiFe, LiPo, NiCd and NiMH power and also
offers low voltage warning

REQUIRES: Ignition Battery: 4.8-6.0V NiCd or NiMH, 6.6V LiFe or 7.4V LiPo pack
LiPo battery requires voltage regulator

So I'm confused. If it "accepts" a LiPo why is a voltage regulator required?

gibatta

My Feedback: (1)

you need a voltage regulator because working voltage for the ignition is from 4.8 to 6 Volt max. LiPo batteries will provide 7.4 Volt (if you use LPo 2S without a voltage regulator you will pretty much toast you ignition)...

grimbeaver

I was hoping by some chance OS was leading the way and was going to be the first with a high voltage ignition. The last glow plane I built was all HV with Hitec HS-5495BH servos and a Hitec Optima 6 rx.

PlaneKrazee

My Feedback: (14)

And the mvvs weighed a pound more. Four pounds of thrust for an extra pound of weight? If you want light for a aerobat, maybe the OS, Mintor or DLE would be better, if you can use the extra weight and thrust in a tail heavy plane get a MVVS. It's all what YOU want. There are so many engines, good, bad, cheap, expensive. Buy it, fly it, crash it, sell it. Who cares, lifes too short.
Weight wise the Mvvs 26 is more on par with the OS 33. The 26 is weak by comparison. 17X6@ 8800 on a regular muffler. Apples to apples otherwise we may as well compare the DA 60 to the MVVS 35, right?
The OS looks like a nice engine and I'm sure the fit and finish are as good as any other engine on the market, including a Mintor. It's all a matter of personal choice. What engine fits in the cowl, what engine balances out the plane, what engine makes you happy. If you want the most durable get a Zenoah or other industrial/chainsaw conversion.

The GT-33 Gasoline Engine produces 10% more power than any other engine in its class! An electric ignition system offers fast, easy starting and accepts LiFe, LiPo, NiCd and NiMH power. The E-5030 muffler resists distortion, resulting 5dB less noise than the competition. Includes a Walbro carb and CM-6 spark plug.


Specifications
Displacement: 2.013 in3 (32.98 cc) Bore: 1.417 in (35.99 mm) Stroke: 1.276 in (32.41 mm) rpm Range: 1000-8000 Total Weight: 43.39 oz (1230 g) Engine: 34.57 oz (980 g) Muffler: 4.94 oz (140 g) Ignition: 3.88 oz (110 g)
Requirements: 2-cycle oil, 4.8-6V (4-5 cell) NiCd or NiMH or 7.4V (2S) LiPo or 6.6V (5.5-cell) LiFe battery pack, Voltage regulator (LiPo use only) and 18x8 prop (for break-in); 18x10-12, 19x10 or 20x8-10 (for subsequent use)

MetallicaJunkie

3w has done it... my ignition handles up to 8.5 volts and mvvs/evolution handle the same if im not mistaken

MTK

ZDZ also

MTK

Just picked one up from Tower. Looks nice, is fairly light but not as light as the SAP and DLE 30cc engines, comes with muffler and CDI only, no stand offs. But it also has a single nut prop tie down just like my SAP's do, which is great for my application. Why do some of the engine makers insist on multi bolt prop tie down??

I'll be using a piped set-up for mine. I have a return to center header from Hatori that is being coaxed into service (modifying it to fit). I hope to have the thing flying Sunday, maybe. We'll see how it stacks up against the SAP 180 (one of the best if not the best 2 stroke 30cc gas engine out there for what I do)

The numbers Tower posted certainly caught m y eye, especially the 2 1/2 mm longer stroke comparedto the other 30 cc engines. Should compare more favorably to the YS170 4 stroke...but it's all BS until I actually run the thing. If it does what YS does on a 19x11 at 2/3rds throttle, I'll be happy. If it doesn't, well, I'll have a nearly new OS33GT for sale soon.

TimBle

MVVSand Evolution engines offer High voltage ignitions with their engines.

ameyam

Cool, keep us updated

Ameyam

PlaneKrazee

My Feedback: (14)

2.58 oz more weight than the DLE 30 and 1.29 oz more than the Syssa.

Would like to hear the performance on the stock quiet muffler vs. a tuned pipe. The tuned pipe results should be interesting, performance gains will be dependant on exhaust port timing. The included quiet muffler being 5 db down from the DLE should be very quiet. The O.S. cylinder being located further aft than the Syssa should help with consealing the cylinder in the cowling in scale aircraft (other than radial designs).

k4lm

The Owner's Instruction Manual states the  power source for the ignition module is "4.8 to 7.6 volts (rated)".  Looks like it will take Lipo 2s without regulator.

TimBle

Nope, 2cell Lipo is 8.4V max Voltage.

Looks like ti will take a LiFe without any issues. Life tops out at 7.2V.

MTK

Gary,

The OS has a steel liner. Not really a big deal tho. Engine is a couple ounces heavier than SAP and DLE 30cc mostly due to the liner. The prop drive washer is extended 3/4" which extends the crank that much. That adds to the weight difference too

On the lightness side we have a one piece case with a head. No bolting a cylinder and case together like on other engines which use two piece case/cylinder.... heavier. The wrist pin is removable via a port on the back. We also have the much simpler and much much lighter single nut prop install.

ameyam

And how does it work?

Ameyam

ghoffman

My Feedback: (3)

And that is what I would like to know as well. The EF 78 inch Extra is just a bit big for the existing 30's, so I am looking for some more power.

grimbeaver

I sent an e-mail to Great Planes engine support asking for clarification about the ignition voltage. We'll see if they respond. Hopefully we'll see some review of the engine soon. Someone was doing price comparisons but didn't take the muffler into account. Yes it's more expensive then a DLE but if you need a Pitts muffler your DLE just got closer to the price of the GT33. A DLE30 + J'TEC Pitts - $50 coupon is $350 while a GT33 - $50 coupon is $370. So really only $20 more for the OS is pretty good.