stephensackro

My Feedback: (6)

Has anyone tried using an aluminum or soft brass bolt to hold a Walbro carb onto a gas motor. Most of the bolts that come with the engines are extremely hard socket head cap screws. I ruined an Q42 engine that had a side mounted carb when it had a sudden impact with the ground (ouch!). The bolts are so hard that they tend to breakoff the flange on the engine that the carb bolts to. After all you really don't need a very strong bolt to hold the carb on with. Would an aluminum bolt fatigue and prematurely break? How about using a soft brass bolt with part of the center drilled out? Any other ideas??

Antique

My Feedback: (4)

Don't crash
3w engines use aluminum studs to hold the carbs on to the bakelite insulator block, they pull out in a crash.......
Since US engines bolt all the way through to the case it's not likely a softer bolt will help....[]
Any bolt will be harder than the soft aluminum casting under the carb..

RysiuM

My Feedback: (1)

Rubber bands - Just kidding

RysiuM

Nogyro

My Feedback: (10)

They're aluminum on the DA50...........

stephensackro

My Feedback: (6)

Do the aluminum carb bolts go all the way threw the carb and screw into the head of the DA 50 ?? Or are the bolts just imbedded into the heat spacer block like the 3W engines as RCIGN1 says??

Nogyro

My Feedback: (10)

They go through the carb, reed valve assembly, then into the crankcase. It's a rear mounted carb.

stephensackro

My Feedback: (6)

Thanks for you info. Nice clean looking installation. The DA 50 is such a awesum looking motor !!!!

Nogyro

My Feedback: (10)

It runs pretty good too.

davewallace

My Feedback: (29)

Hi,
Why don't you make a new manifold out of G10 epoxy board. It is strong and can be tapped for carb bolts. While you are at it you can rotate the carb for a straight shot linkage. The manifold will bolt to the Quadra and it would be tapped for carb bolts at the top and botton. Don't forget to provide for the pulse port to the carb.

Dave

stephensackro

My Feedback: (6)

Sounds like a good idea. What thickness G10 board do you use?

davewallace

My Feedback: (29)

1/2" works well. You can get different thicknesses. Some guys have used Red Oak with good results, available at Home Depot. The threads must go deep and be course thread like 10-24.

Dave

RysiuM

My Feedback: (1)

Any other material I can use? I don't see G10 around (this stuff is expensive BTW - costs on the internet more than I paid for the engine).

RysiuM

Antique

My Feedback: (4)

Depends on how much you buy...About $23 a square foot in 3/8 thickness, bought 4 square feet at a time..I get more than 30 blocks from a square foot....

RysiuM

My Feedback: (1)

Yah, but I don't do engines for living 4 sq ft even $23 per foot will cost me 4 times more than I paid for the engine[]

RysiuM

rctrax

I would think that one of those plastic cutting boards from Wal-mart wou;d make good materal for this. It is tough and hard to cut and also I don't know what the cost might be but I doubt you would be talking 23$ a foot. We have two of these in our kitchen and they are tough,

RysiuM

My Feedback: (1)

It is mado of HPDE (HIGH DENSITY POLYETHYLENE ). This is good material used in SPAD planes for engine mounts. However I don't think it can handle the temperature of the gas engine without deforming. The deflection temperature is way below 200F.

RysiuM

famousdave

My Feedback: (61)

Rear mounted carbs don't really need breakaway bolts. Bottom line- if you pound it bad enough to have a rear carb separate chances are pretty good the engine will be toast.

Hey NoGyro - I was looking at your picture and there are 3 red flags when it comes to your wiring.. . not trying to be critical, just hoping to see you avoid a mishap.

1> Where your main (thick red) ignition harness rubs the large hole in the firewall - that laser cut hole is very sharp and that edge will chafe through your harness in no time... wrap the harness in some nylon spiral wrap.

2> You have some wires going through a small slot in the lower fuselage. It looks like it pentrates the balsa sheeting - open that slot up and install a split grommet (CA in place) .. that too will abrade your wiring without better protection!

3> The last and worst ... you have a tie wrap (zip tie) holding the ignition module in place. That hard nylon the ty-wrap is made from will couple all the vibration from the motor box DIRECTLY to your ignition module, the foam basically is doing nothing at this point. It would be much better if you were to open up the hole where the ty-wrap is to a slot and install velcro tape instead... much better for vibration isolation.. and much more secure. If that ty-wrap were to pop (where it wears against the wood) bye-bye module...

The rest looks good!

DP