john flynn

G'day to all, I'm putting together a Super Frontier Senior for a friend and he has purchased a OS 70 Surpass for it (probably a bit of over kill). I have mounted the engine inverted and now the fuel inlet nipple is about 1 inch lower then the center line of the tank. I've had little to no experience with 4 strokers and I'm wondering if we're going to have trouble with this setup (looks to me like it will flood). Can someone help out or point me to a link for setting up fuel systems for 4 strokes. Kind regards, John.

jsn

My Feedback: (8)

with any glow engine install you always want the tank center line as even as possible with the spray bar... an 1/8 inch off either way is close enough for me but 1 inch is not good at all UNLESS your gona put in some sort of pump/ regulator... if your not using some type of pump/regulator then you should move the tank down or the engine is going to flood easy and run rich when the plane is up right and lean when inverted. Most arf makers seem to forget that tank height DOES matter and just slap the tank in how ever it will fit the easiest... I haven't had an arf yet that didn't need the tank moved up or down a bit and in a few cases it had to be replaced all together with a smaller or different shaped tank to get it where it needed to be.

John

john flynn

Thanks for the input John, now I have to figure out how to do the job. The rear tank saddle can be easly lowered by a bit of chopping but the front of the tank is supported by the hole in the firewall. I can't lower that because the engine mount cross member is right where the new hole should be to line up with the spray bar. I was thinking of making a front saddle and moving the tank back about 1 1/2 inchs. Then routing the fuel lines out through the original hole in the firewall and down to the carb. Would this be ok, considering the fuel line will be longer and looping up and over the firewall, then down to the carb and back up to the nipple? One big s bend. Regards, John.

jsn

My Feedback: (8)

That sounds good... the only other thing you might consider is plugging the tank hole and drilling two holes for the lines just under and too the right of that cross member, that would shorten up your lines and eliminate the bends. Are you using a fueler? if you are you could route the lines from the tank so they exit close to it.

John

In case you didn't already think of it... I'd make sure to pad the front of the tank well so it can't slide froward and pinch the lines.

campbec

Hi John,

I'll refrain from comments on the RFDS, Flynn of the Inland and if Cardwell has a greater rainfall than Innisfail. I assume you are located at the QLD Cardwell?

If you are following the excellent advice from jsn I would also humbly suggest that you use longer 1/8" brass from the tank through the firewall so you don't have silicon tubing hidden in the tank compartment. Remember Murphy's Law.

I found out the hardway when it seemed to take a long time to fill the tank on a Dynaflite PT 19. It wasn't until I saw fuel running out of the wing saddle area that I realised the silicon fuel tubing had split.[sm=spinnyeyes.gif]

Good Luck,

Colin

john flynn

Good advice Colin and thanks, I've seen something similar and oil soaked wood is very hard to do repairs on. Yes, I live in Cardwell NQ (God's country) and my handle is taken from the great man himself. You'd be surprised at how little rainfall we get here considering it's only 40 km's from Tully the wetest place in OZ. John, thanks for your advice also, I will make the front saddle so it supports the neck of the tank, that'll stop the blighter from moving forward. No I was'nt going to use a fueler but I'll run the idea past my friend and see if he'll invest in one. Thanks again men. Regards, John.

john flynn

Well I took both your advice and come up with this. Thanks again for the input fellas. John.

campbec

Hi John,

Looks good although you may need a Cline pump or similar to draw all the way from the empenage[sm=bananahead.gif]

Good Luck,

Colin

john flynn

Heh heh, good one Col. nah, That tank's for the pusher engine.