w8ye

My Feedback: (16)

he could open up the valves on that cylinder to .004" and it may help

frets24

My Feedback: (15)

You guys nailed it....Lower left. I've used all the 4c plugs and find that the H9 seems to be hotter and not as pricey as the OS.

I think I've finally got things tweaked and I can get it to run at 3000 W/O heat for 2-3 minutes and throttle up from there without any problems. It will now idle at 2100 for a minute or 1/2 minute without probs and throttle up from there. It's kind of weird though...W/O heat on the 2100 to high speed throttle up sometimes it's a clean but slow rise and then it hits a new stonger 'exhaust note" as one of the cyls seems to spontaneously relight and then it really picks up. One big help was to whip up a 12 D cell alkiline glow pack and seperate my harness leads so I was'nt suffering such a voltage loss while preheating the plugs. Having the harness seperated allows me also to hot just one plug with full mah if it does die instead of having to stop the motor and restart all over again. Having all that power seems to be able to fire up a seeemingly completely immersed plug

Makes such a difference to getting it tuned if you can keep it running for a few minutes!

I'm using the stock exhaust tubes on the bench and am awaiting the arrival of a Keleo ring exh. Do these seem to run better with the collector's inherent contant, even backpressure?

OLd fart....I've been running 3 Saito 62's and a 56, as well as 2 OS 70's inverted and the only thing I can tell you is my experience has been great....well one OS spews crudy castor from the rod tubes and make, the cessna look just like the real thing underneath, but thats just seals....

on the first run of the day, after hand turning to ensure no hydro lock, I spin em up W/O fuel and WOT for a second to blow any afterrun and other deposits out. fuel up, plug the exh with finger and flip the prop a few turns, light the plug and let it sit 20-40 seconds to burn off whatever, touch it with the starter @ 1/3 throttleand they all pop right off. They smoke a bit, one's like an old chevy in bad need of a valve job, but that goes in 10-20 sec @3/4 throttle. remove the glow heat and tinker for 30secs or so and put it in the air..

if the motor has been sitting for any longer than 30 min at the field I'll preheat the plug for a while as well. I've found with mine that if I skip the preheat/burnoff or get impatient with it all of them respond by being a complete *%^!*@^%*$^% to start or run for a little while.

Thanks for all the good words, Lee

Rudolph Hart

Would you expand on that please.

Rudolph Hart

Yes good start-up method lee.Don't have any radial or keleo exhaust ring experience but would like to see a pix when it is fitted.I think it's on "sounds of saito",there's a 90 in a h9? camel i think.Sounds like it's idling at about 1800rpm,good luck.

I'mm hunting around for a cline regulator here in aus,not much luck so far can anyone help?

mistermnkim

My Feedback: (153)

i have a fa90ts going on a 80" spacewalker, need a prop recommendation. prefer wood prop. thanks

GaGeeBees

My Feedback: (23)

Here's a short video of a .90 with a Keleo collector ring.

http://www.youtube.com/watch?v=deGoMmFOM

EDIT: Sorry folks... For some reason when I post, the address gets altered and loses the two dashes between Mm and FOM.... weird. Go to YouTube and search Saito .90 radial for an assortment of videos. Or you can copy and paste the address into your browser and add the two dashes.

mistermnkim

My Feedback: (153)

video would not play?

GaGeeBees

My Feedback: (23)

Lee,

McDaniel/SonicTronics makes a great onboard glow unit for radials. It uses a four-cell NiCd pack (gotta be NiCd... don't try NiMH) and works extremely well. Enjoy your radial!

Paul

sodbuster 1

Is there a reason not to use NiMH?
I use a single sub-c 4500 ma on Sullivan onboards for my singles and haven't had a problem.I get around 3-4 10-14 minute flights and the cell takes about 1600-2000ma when I charge a week later

w8ye

My Feedback: (16)

I use Nmh batteries with my C-H ignition units and they work fine

Ken6PPC

Try this link for the video:
http://tinyurl.com/8j256w

GaGeeBees

My Feedback: (23)

Off topic question.... how did you do that?

GaGeeBees

My Feedback: (23)

According to McDaniel NiMH packs can't supply the sustained current draw needed for their units. I tried it and they're not kidding. Might work on a single but it surely does not work on their multi-cylinder drivers.

w8ye

My Feedback: (16)

that is true NiMh have a higher internal resistance and do not have the instantaneous current draw potential of NiCd batteries of the same size

Ken6PPC

I went to this web site,
http://tinyurl.com/
and entered the correct web address. It made the tiny URL out of the long one. Then I posted the tiny URL. Sometimes, that is about the only way you can email or post long URL's.

LMProd

Saito 90T / Skybolt Question

I just purchased a Saito 90T, First twin, have lots of single Saitos.

Plan to put it on a GP Skybolt. The plan requires nose weight so I thought a twin would be fun. Suggested engines for this plane are OS 70 or .91. I noticed they have a higher HP and the Saito 90 is lower only 1HP but pulls a 14x6 prop at a respectable RMP. Is this because of the second cylinder ?

Would this be a good combination ?

Thanks
Gary

w8ye

My Feedback: (16)

Multiple cylinder engines have the drag of the other cylinders. The smaller they are the worse this parasitic drag is

frets24

My Feedback: (15)

Hey again,
It just so happens that with the trade in which I got the 90r3 I also received a brand new, unopened McDaniel multi cyl onboard driver. I just wasn't going through the hassel of setting it and a RX pack up just to bench run this motor. I also did'nt have a battery for it yet either. I was wondering about the instructions about NiCd only...thanks for clearing that up. I'll pass it along to the bat tech at batteries plus 'cause when I told him the specs for a driver pack I'm having them work up and that the mfr said no Ni metal Hyd...he said the instructions were nuts. I insisted on NiCd anyway, thankfully.

I'm was running a 90T on the H9 Sop Camel that the 90r3 is going into and it was great. It's (90T) going into a Flyboy Models 55'' Fokker DR-1 now...can't have Snoopy without the Red Baron! The motor has been great even if it's a bit excessive in vibration due to the odd fire design. (0 deg-fire 180-fire then 540 deg to start over again)

W8ye is absolutely correct, even though you would expect (mistakenly,) that each cyl would behave as a single and carry it's own burden. The parasitic drag is worse on odd fire because they have to turn 540 deg on the crank by inertia only before the next power stroke...that's 1 piston up, down, and up again, and the other down and up again before the next power stroke all while swinging a loaded prop! Even so, my 90T swings a 14x6 wood Master Airscrew all day long @ 8100. Just be sure to check nuts, bolts, screws and any other vibration suceptible stuff regularly.

The new FA 90Ts is an even fire so the drag coefficient is a bit less and the vibration is less than a single. Both should handle a 13x6 or 8, 14x5 or 6 wood just fine at the 7200-8100 range


Old Fart
was that for me? If so, forgive my density, What would you like expanded upon?

As far as Pix..in my profile/my hangar there's a pic of the Camel, w/ Snoopy and the 90r3, but not yet with the ring.

Rudolph Hart

Good link ken and did'nt it sound good.Never heard it idle real slow tho.What do you think?

Rudolph Hart

Oh heaps no it was the mod.

sodbuster 1

I know this is not a battery forum but I thought you all might be interested in reading this as I think it's very applicable. battery technology has changed TREMENDOUSLY in the last few years and what was true even 2 years ago is not today.
I use exclusively Nimh cells and would never go back to the high maintenance NiCd technology (memory effect and cycling )when there are now NiMH cells that offer just as low impedence as the lowest NiCD's.
This is a direct quote from No BS batteries web site. A very insightful question and answer dissertation on todays NiCD VS. NiMh batteries that would benefit everyone in proper battery use, maintenance and choice.
I got back into this hobby after a 12 year absence and the one thing that I was extremely pleased to find was that I wouldn't have as much plane failures due to batteries going bad on me because so much study has gone into the subject while I was away.

Read and learn.....

Q: The ‘Old Salts’ all say I should stay away from NiMH, that they aren’t dependable. There has to be a reason why. What’s wrong with NiMH?

*


A: Actually, the question really should be “What WAS wrong with NiMH?” Initially, NiMH claims commonly made were ‘More capacity and less weight than Nicad’. That was true then.. but the dependability suffered because the cell insulator materials were relatively fragile and the cell plates were pretty thin in order to keep the cells light. It turned out that ‘lighter’ wasn’t better, and when the cells were used in fast-charged commercial tooling applications significant shortfalls in duty cycle lifetimes and rapid capacity deterioration compared to Nicads became apparent. Luckily for us modelers, yet again, following the same development cycle as Nicads two decades ago, the demands of the portable power tool market has lead to the development of far more robust NiMH cells. The current genre of fast charge NiMH cells now sport thicker plates, better insulators and all welded internal assembly, features that reduced impedance and dramatically improved durability and duty cycle lifetimes in high load and fast charge applications. Today’s fast charge safe NiMH cells are no longer lighter than Nicads in the same physical dimensions but they do continue to offer significantly higher capacities when compared to Nicads of the same dimensions.

*


Q: How about Impedance? Can NiMH cells handle the loads from digital servos in big planes??

*


A: High impedance isn't native to NiMH cells.. there are more than a few Nicad cells with impedance just as high as a comparable NiMH cell. Most folks react to the 'capacity' number as being the big part of their decision in selecting a pack for their big aggressive birds. This can lead to big trouble on board the aircraft. This is why you'll find we won't sell some AA NiMH cell types for receiver & servo applications that we do provide for Tx applications. Our new 4/5 'A' 1950FAUP NiMH Sanyo Rx pack has the same impedance as a 1700 Sub C Nicad, so impedance by itself in NiMH doesn't mean you can't use them, it just means you need to be sure the cell type is appropriate for the job you expect it to do. Smaller aircraft do just fine on AA sized NiMH packs, big birds should use 'A' sized or larger Nicad or NiMH cells (and in some cases parallel setups or 5 cell packs rather than 4 cell packs) to stay ahead of the voltage drops under load associated with higher impedance cells.

GaGeeBees

My Feedback: (23)

Thanks for the info. I'm well aware of the characteristics and developments in NiMH batteries but they do not work in this specific application. The manufacturer says so, I doubted them and tried it anyway and learned the hard way. Try it yourself if you want. If you get it to work, congratulations. I couldn't. As the saying goes... these are my results, your mileage may vary. Here are the McDaniel instructions if anyone wants a copy.

Sorry all for the off topic tangent. And now, back to all things Saito

mike early

Anyone know where I can find a prop nut for my Saito .91 that goes into a Corsair?

sodbuster 1

ditto.was just trying to help

Speaking of Saito, got the newest addition to the collection today . A just broken in 150GK.
Think I'll go down in the shop and stroke it a little before bedtime [X(]

.....the engine that is

w8ye

My Feedback: (16)

http://www3.towerhobbies.com/cgi-bin...?&I=LXL751&P=M
http://www3.towerhobbies.com/cgi-bin...?&I=LXL756&P=7