HangarRash

Hey Jeffie, which bird will you mount the G60 on after you get the work done on it?

hsukaria

That would be bad news if Tower dropped ST engines.

toddj5

My Feedback: (16)

Hello,
I have a question about a NIB Italian GS45 I just bought here on RCU. It is the old style case with the short muffler screws threading into the engine. Has anyone tried drilling out the screw holes in the engine, so that longer screws with 2 nuts could be used to mount the muffler? This engine is going into a cowled plane, would be difficult to tell if the muffler is coming loose without removing the cowl.
I did several searches here, but no one seems to have tried this. Anyone have some input?

rebranger

It shouldn't hurt anything if you drill straight. I have done it with no trouble.

spaceworm

I say don't drill it out. This is an Italian ST and there will be no more made there, only in China. It will be a classic soon, so use another approach to keep the muffler on the engine, like safety wires or equal. Also, the cowl should keep you from losing the muffler, as will the pressure tap line to the tank. JMHO, though, it is your engine.

toddj5

My Feedback: (16)

I would only drill it as a last resort. I'd much rather keep this little beauty as is.

1QwkSport2.5r

I used some really small (maybe #4) lock washers and blue locktite on my S90K with bolt on muffler. Hasn't come loose yet.

toddj5

My Feedback: (16)

Thanks for the input, guys!

radfordc

My Feedback: (14)

Early in this thread there was some discussion about the poor transition from idle to full power with stock ST carbs. I've been running my new G-90 and found that I just could not get the engine to rev up from idle without bogging down in the mid-range. My fix was to install an ASP 108 carb that I got from Hobby King for about $15.

http://www.hobbyking.com/hobbyking/s...carb_assy.html

I put on the carb today and the engine runs so much better now. It will go from idle to full power almost instantly with no hesitation or bogging.

jeffie8696

HangarRash
Dont know why Iput down G60, it is actually an Italian GS40, Imay have been thinking of the V60 I am working on.

Tarasdad

A few weeks back I acquired a looks-like-new ST 3250. It's been run but from what I can tell not a great deal. The engine came with a Bisson Pitts muffler and was on a GP nylon adjustable mount. I don't currently have a home for it but hope that can be changed soon(ish).

One thing I'm considering is converting it to gas, mainly to reduce the costs associated with feeding it massive quantities of glow fuel. I've been reading a lot of contradictory info on the process regarding what should be/needs to be done, mostly regarding needle bearings on the con rod. If all it's for is to reduce the oil used then that's something I can do without.

Does anyone have current info on what needs to be done or where I can get the parts I need? Many of the sources I've seen listed are no longer valid.

AmishWarlord

My Feedback: (5)

Um, I'm just not seeing the "super charger" in the photos.

I wonder if some one confusing an Iron Bay fuel regulator with a super charger?

http://www.ebay.com/itm/Super-Tigre-...item3cc6a19dee

fujiman

My Feedback: (133)

the eng. there is certainly NOT super charged in any sense!!!!! what they mite be referring to is that it has a pressurized fuel system and there fore has a tap into the crank case charging or pressurizing the regulator ensuring a pressurized fuel charge to the carb. the only eng. that i know of was truly a super charger was an OS max eng. (can't remember which model) it had a mini roots type blower. YS eng. had a power box box, thereby boosting performance. i have installed walbro wt-499 ''alky'' pumper type carbs. on my big tigers, but you still have to tap into the case to pulse charge the carb. pump.

fujiman

My Feedback: (133)

i have some OS 108 7D carbs that work great on the big tigers. they are no longer avia. and were expensive!!!!!! once in while 1 can be found in ebay and here in rcu.

hsukaria

I only know from what I have read in these forums. My understanding is that you will still need the higher oil content since this engine does not have needle bearings in them. But, the large ST engines require less oil, like only 12% approximately instead of 18% and you would get by with lower or no nitro. So, conceivably, your fuel will be much cheaper per gallon than regular glow fuel, especially if you mix it yourself.

I have also read in the Saito forum about adding spark ignition but still running glow fuel. That helped reduce fuel consumption and/or increase power. You wouldn't have to put a pumper carb like a Walbro, just keep the original glow carb. I've seen some cheap ignition systems sold in Hobby City, but I can't tell you of their quality (no personal experience).

1QwkSport2.5r

Does anyone know what the differences between the G90 piston and the S90/S90K piston is? I ordered some spare rings for a few engines of mine and the S90K was one I wanted a spare for. Frank Bowman asked me if it had a Chinese piston in it because the Chinese pistons are a little different.. I'm guessing he was referring to a G90 piston?

Also, I noticed a weird phenomenon with my S.29 lately. I haven't ran it lean, in fact each time I run it I peak it and richen 500rpm as its still breaking in. The issue is it seems the compression is getting soft already. This engine has about 1 gallon through it, maybe 1.5 gallons since new. Its been run on 20% oil, all castor and 5% nitro the whole time. I tried 2 tanks of 50/50 blended oil cas/syn at 20% content but that was just an experiment. It seems to run well, though the transition isnt "instant" like it was the last time I ran it. Wondering if the stock ST ring is maybe crapping out? The last few times I ran it I had a 9x4 APC on it, but it was broke in on a 9x5 APC.

Any thoughts?

p.s. I have a Bowman ring for the S29 on-hand, and I have another coming as a backup spare. The S90K does not have this problem - compression is very very good on that engine. The S29 is 10 years or less in age, the S90K is suspected to be made sometime in the mid-80's. Both have stock ST rings in them.

hsukaria

Not sure if anybody is paying attention to this forum anymore, but I need some help with my ST 40 high speed needle. I would like to install a remote needle valve and remove the stock one because it sticks out the bottom of the plane and I don't want it to get damaged if I nose over the plane in a landing. The engine will be installed sideways to the right with the exhaust going up.

Why such a crazy setup you ask? Well, since you asked, I'll tell you. I have it on a Viper 500 (Quickee) and the Macs one-piece muffler going out the bottom drags on the grass on take-off and landing. It also is not good if I land hard or nose-over with the muffler dragging on the ground.

So, what do I replace the HSN with to prevent potential impact with ground?

Alternatively, can the carburator be turned around? If so, the fuel inlet nipple will be facing forward and I have to rotate that 180 degrees also. Thanks.

jeffie8696

Perhaps a different carb would bolt on and give you the remote needle you are looking for? Perhaps one from an OS 46FX?

1QwkSport2.5r

I agree, Jeffie8696 - A different carb is going to be the answer. On ST carbs, turning the carb 180* would put the fuel inlet nipple towards the prop. Rotating the spraybar 180* in the carb would have the discharge nozzle pointing up which will not work. Depending on which needle assembly the engine has, one might be able to fabricate something but the timely thing to do would be to use a different carb IMHO.

fujiman

My Feedback: (133)

replace with a perry carb. if the rules allow it run a pump carb and pressure pump, 1000 rpm gain. go to perry/conley web site and pick out a large trot carb for racing, if i doubt call dave and he'll give you the rite combo.

1QwkSport2.5r

I am in the process or re-ringing my Super Tigre S29. The factory ring doesnt seem to be doing its job very well anymore. I checked the ring gap in three locations of the stock ring, top, middle, and bottom of its (the ring's) travel and I have found the gap to be .005" at the top, .008" at the middle of the stroke and .007" at the bottom of its travel. The Bowman ring gap is less than .002" at the top (I dont have a .001" feeler gauge on-hand), .004" middle, and .005" at the bottom. Does anyone know if there is a spec for the ring gap on these?

The tension of the bowman ring is probably twice that of the stock ring.. Quite noticeable.

1QwkSport2.5r

I reassembled my s29 with the Bowman ring and I'm already impressed. The compression has easily doubled without even running the engine. I lightly honed the cylinder with 400 grit wet/dry paper and used some castor oil as assembly lube. This engine should actually run quite a bit better than it did before I think. If I get time this coming weekend I'll break the new ring in. This engine was well mannered before - it still ran pretty good but I couldn't get consistent tach readings. Each time I ran it, top rpm would be lower by 300-500rpm. I figured I would have gotten more than 2 gallons from the stock ring. Oh well. It should be good for awhile now.

AmishWarlord

My Feedback: (5)

Ok so let me get this strait.

"New in box" means that the used engine has been newly placed back in it's box.

Silly me, I thought "New In Box" meant that someone had bought something but
never used it so it's in a un-used condition in it's original box as if it where new.

http://www.rcuniverse.com/market/item.cfm?itemId=853901

Next, "never flown or anything."

"Anything" dose not include taking it out of the box,
opening the small item packets, bolting on the muffler, glow plug and carburetor.
Mounting the engine to a test stand and then running it. Loseing parts off the engine
and haveing to replace them.

earlwb

New in Box seems to mean different things to different people. I was amazed at the gall of someone who put a rusty, well worn engine covered in castor oil varnish stains in a box and was selling it as "New in Box".

1QwkSport2.5r

Some folks have a different idea if what NIB means... Then again, some sell engines they know nothing about. The last engine I bought was listed as used good condition, like new compression. Turns out my Enya 60-4C never ran but came without a box, tools, or paperwork. That like new compression meant the ring was stuck in castor varnish from assembly. After cleaning the compression was near zero but once ran, cleaned up nicely.

A picture truly is worth a thousand words. If its being sold as NIB, it should have nary a scratch on it and come with a box and if lucky, paperwork. It's a blessing if you get the decals with it.

I'm saving my vintage SuperTigre and Enya decals for my custom field box I'm building. No sense sticking the decals on a plane since I'll be one to swap engines on a regular-enough basis.

My S29 is on the test stand ready for a re-break-in with a Bowman ring. Looking forward to what it *should* run like.