blw

My Feedback: (3)

Electric starter. Have a new plug handy. Maybe open a new jug of fuel. I had a glow plug go out right after I had partially disassembled an engine for sonic cleaning recently.

hsukaria

Yeah, I got to get my act back together. I've been working on some house remodelling (still got a long way to go). So my planes, tools, and workbench are in disarray right now. I will try running the FA82 with all the equipment handy next time.

AeroFinn

ok guys thanks for the great thread!

I'm starting my first engine rebuild (FA-125a)

I'v got a new cylinder, piston, piston ring, connecting rod, bearings, etc.

I won't be rushing with this project but taking the opportunity to learn and do it right. I will then convert the engine to CDI and run it on glow fuel (thanks SrTele for the help on the CDI matter)

Well, I disassembled the engine and the the exhaust valve needs a good clean up, as can be seen in the picture

What might be the best way to remove the carbon on the valve?

I also couldn't remove the rockers from the old cylinder as the rocker arm bolts are stuck? I wonder if I should place the whole cylinder in the fridge to release them? Any thoughts?

thanks Artto

SrTelemaster150

For the valve: A good long soak in Dawn Power Desolver to soften the carbon followed by a soft wire brush in a dremel. Be extra careful that the mandrel does't contact the seating surface.

For the rocker shafts: I would think heat would be better than cold to get the rocker shafts loosened.

If you can find a socket style screw driver head that fits the screw slot precisely, you could use a 1/4" open end wrench on the bit to assist.

Heat the head in an oven set @ 300 °F The aluminum will expand more than the steel shaft.

I would mount the cylinder on the case for a better hold & screw the case down to some sort of fixture that you could clamp in a vise. Get the head/case/fixture good & warm, take it from the oven, quickly mount the whole thing in the vise & have at the shafts W/a good bit type screw driver W/a 1/4" wrench assist.

FNQFLYER

Old Fart have you seen the f/glass Mew Gulls coming out of Rocky??  $1200 for a wing tail feathers and a f/glass fuse.  When powered by any BIG Saito the scream around the pylons much to the dismay of the purists.  The last production run went straight o/seas to both the US and UK after the Spektrum do at Calvert Field.  It would appear as if the Saito gas engines (with suitable attention ) fitted to min weight models are looking for pylon and there are a number of people revisiting the big Saitos for the same events.  Check out the local mags in the months to come.

Rudolph Hart

Yes i read about them a while back in rcmn.The mew gull i have is too small @ 72" w/s i think the minimum is 80" w/s.Will try a 14/16 pitch prop on the 220 and with some proper tuning and a decent dose of nitro it should really hammer along,above the ground will be my preference.I can also go down to an 20x8/10 and throttle back for some scale aero's which will be good fun too.

AeroFinn

Ok Thanks SrTele

Will try that let's see how I succeed!

_Artto

Quikturn

My Feedback: (12)

Anyone have any experience/comments on a Saito 182T? I was looking at one recently but don't really have anything it can go in right now. I always liked twins though.

Rudolph Hart

Yes i bought one about three years ago,it's the twin carb version and sounds nice in the h9 80" taylorcraft

SrTelemaster150

Weren't all FA182s twin carb?

More like a twingle carb. Twin veturies in a single body/barrel.

Quikturn

My Feedback: (12)

Yes, this has a dual carb. A single carb body (I think), 2 high speed needles, 2 low speed air bleed screws and 2 cool looking forward facing velocity stacks. I be seen some pictures of the engine with mufflers but this one has 2 stacks.

Rudolph Hart

The original 182 was st up the same as the old 300 i think.Nowadays companies take more notice of people who can't tune things and provide them with more things to fiddle with.Gets you way away from what you were trying to do if personal experience is anything to go by.

SrTelemaster150

Actually, I found that the twin carb 300 is easier to tune for "proper" balance than the single. IF you know what you are doing.
I have my 300TTDP idling @ 800 RPM W/CDI.

W/the dual carbs, LSNs is so easy to adjust. Just screw the LSN until the cylinder drops out, then open it until the cylinder picks back up.

The key is getting both crabs @ the same opening @ the low end. I use a drill bit as a gauge & adjust the linkages so tha I get the same "drag" on the guage @ a NEAR idle throttle position. WOT opening is not as critical as the idle opening.

When I was thinking about the purchase way back in '97 I found that most single carb 300s that I ran across @ IMAA meets would not balance well @ idle.

Having experience W/"Limey" bikes from the '60s, dual carbs didn't intimidate me.

Granted, something like the twin barrel single body 182 carb might have been better, but given the choice of a single carb W/O idle adjustments for each cylinder & the duals. I would rather have the duals. Plus, the dual carbs sticking out of both sides of my 1/3 Spacewalker cowl looks gnarly.

Hobbsy

My Feedback: (102)

There is a practical reason for the two carbs, the current 1.82 is a single crankpin uneven firing twin which means that when the no.1 cylinder in on the intake stroke the fuel mixture enters the carb and makes a 90 degree right turn, (looking from the front). Then when the right cylinder begins to intake, the fuel mixture has to stop abruptly and reverse directions, the air can make this change faster than the fuel can and leaves lean air for part of the right cylinders intake stroke. Each cylinder having its own carb cures this.

SrTelemaster150

Probably the very reason the XR750s have dual carbs while the standard firing order Harley "V" twins can run reasonably well on a single carb.

Hobbsy

My Feedback: (102)

In case you forgot, we're talking about Saitos here.

SrTelemaster150

Hence the reference to the similarly but different (close) firing order during a less than single crank revolution of the XR750. I made that reference in an attempt to support your reference of the need for dual crabs on the SAITO 182 W/a different, but also odd firing order.

Here we go again. The (inaccurate) assumpsion that any of my posts are some sort of a personal attack.

SrTelemaster150

It just dawned on me that you are not going to be re-using the cylinder from which you will be removing the rockers.

That being the case, just heat the cylinder in the 300°F oven, then clamp it tightly by the base flange in a vise so that the torque from loosening the rocker shfts will be acting perpendicular to the vise jaws.

Since the cylinder is scrap anyway, no need to concern yourself W/disorting it.

Too bad you aren't local, I have a hand (hammer) applied impact drive from my "Limey Bike" days. that would make short work of getting the rocker safts loose.



If you end up using one of these, clamp your cylinder base so that the impact is working perpendicular to the jaws.

Quikturn

My Feedback: (12)

Hobbsy, that was gonna be my next question but you answered it. That is if the cylinders fired at the same time or not. Saito claims vibration free operation. It's also interesting to me that there are dual glow plugs per cylinder.

hsukaria

How does one go about starting a multi-plug engine? Do you have a remote glow connection to all the glowplugs simultaneously?

Quikturn

My Feedback: (12)

To my knowledge, you have remote glow drivers to the front or rear plugs on each cylinder (your choice), start the engine and the dual plug will start to glow on its own from the operation of the engine.

I read somewhere that they preferred to put the glow drivers on the forward plugs. That way if a cylinder went dead they could put a glow driver on the dead cylinder to get it back.

SrTelemaster150

The firing order for the FA182 does not fire both cylinders @ once. That would not be possible W/a single pin crank flat twin.

The firing order is 0°-180°, then 1 1/2 revolutions (540°) before the cycle repeats. That is the only possible firing order for that engine as the pistons are never @ TDC simultaniously.

A "boxer twin" that has 2 crank throws can fire both cylinders @ once, but most fire @ an even 0°-360° sequence.

A 45° single crank throw "V" twin can either fire @ 0°-315°-385° (front-rear-front) like the conventional Harley "V" twin or 0°-45°-675° (rear-front-rear) like the XR750 flat track version.




As for the dual plugs? Yes it is only neccessary to have 1 plug per cylinder "hot" as the other plug lights off when the engine is running.

hsukaria

So what is the benefit of having dual plugs? More dependable combustion?

Quikturn

My Feedback: (12)

As with most things in aviation, redundancy=reliability.

My question is: wouldn't a boxer configuration be smoother?

SrTelemaster150

Not sure about that one. For more dependable combustion I usually replace 1 W/a spark plug & drill the element out of the other if I don't have a burned out specimen on hand.