520 Continental rebuild

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John Fenner
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Re: 520 Continental rebuild

Postby John Fenner » Wed Feb 06, 2019 11:57 am

Virtually the same CFM, just has 2 venturies vs 1 big one, so the efficiency is so much better, I like to drill out the pilot circuits on them as well, not so much for a fatter idle but for a smoother transfer off idle to midrange or cruise with the #28 squirter.
I never finish anyth,,,.

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kwanjangnihm
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Re: 520 Continental rebuild

Postby kwanjangnihm » Wed Feb 06, 2019 3:15 pm

there are quite a few threads on SA about the love-hate relationship of the 6AA carb - going the holley route may not be a bad idea!!
" I don't care who you are back in the world, you give away our position one more time, I'll bleed ya, real quiet. Leave ya here. Got that? "

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Slidin Gator
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Re: 520 Continental rebuild

Postby Slidin Gator » Wed Feb 06, 2019 4:28 pm

I've been having the same issues as Rowdy with a lean, hot running O-540, straight valve. I have been running the MA4-5 with the biggest jet and have considered drilling out the jet. I got my hands on a 6AA and found it runs fine but has not helped the lean condition. It looks like I'm going to be diving into the bowl to tweak the Aneroid until she smokes like a diesel, then back a couple hairs.

I keep running out of carb cleaner from spraying it down looking for air leaks.
I grew up thinking I-10 was the Mason Dixon line.
1986 Airboat Engineering Inc., 14' Marsh Master. Refreshed narrow deck, SV O-540, 72” NGQ. A Bob Stossel original.

rowdy1
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Re: 520 Continental rebuild

Postby rowdy1 » Thu Feb 07, 2019 11:53 am

I too have used many cans of carb clean looking for intake leaks. I had to power coat the tubes to keep the paint on them! I have been talking with Justin Ficken, I am most likely going to fuel injection. If so I'll have a very nice MA4-5 for sale. GMAC just went thru it and it has less than 2 hours on it.

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Slidin Gator
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Re: 520 Continental rebuild

Postby Slidin Gator » Thu Feb 07, 2019 7:42 pm

rowdy1 wrote:I have been talking with Justin Ficken, I am most likely going to fuel injection.

That's what I would do too if it were an easy option for my motor, even though John recommended carb for max power. You can't get better cooling than a direct spray of fuel into the cylinder.
I grew up thinking I-10 was the Mason Dixon line.
1986 Airboat Engineering Inc., 14' Marsh Master. Refreshed narrow deck, SV O-540, 72” NGQ. A Bob Stossel original.

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Re: 520 Continental rebuild

Postby rowdy1 » Mon Feb 18, 2019 7:58 pm

I high jacked slidin gators thread talking about my motor! It runs great, has 70 pounds of oil pressure at start up, 40 psi when 180-190. The old motor would turn a 72" NGQ set on 2.5 about 2750. This motor will sling that same prop, set on 3 @ 2950 if you just stomp it. The problem is it still runs hot. 15 minutes from dead cold to 190 deg. Its the same as before I rebuilt it! I have completely changed the oil cooling. I went to a oil filter adapter in the oil pump and forced all of the oil thru the cooler. Everything in the motor is new, different cylinders, cam, pistons, everything. According to the AFR the motor is not running lean! (13.6 - 11.2 average) I am beginning to wonder if there is something wrong with the block. If the fuel injection doesn't fix the oil temp problem Im gonna through it in the bushes and get a LS and a gear box!

Gary S
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Re: 520 Continental rebuild

Postby Gary S » Tue Feb 19, 2019 7:07 am

I got some bushes in my back yard if you need to use them.

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kwanjangnihm
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Re: 520 Continental rebuild

Postby kwanjangnihm » Tue Feb 19, 2019 8:30 am

rowdy1 what was your oil temp going in and coming out of your oil cooler? what size oil cooler are you using?
" I don't care who you are back in the world, you give away our position one more time, I'll bleed ya, real quiet. Leave ya here. Got that? "

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kwanjangnihm
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Re: 520 Continental rebuild

Postby kwanjangnihm » Tue Feb 19, 2019 11:26 am

went and read your old thread and see you have a hayden 1260 oil cooler - a bunch of us use them and have no cooling issues

also read a few older threads on 520 high temp oil issues - here are a few quotes for thoughts

ssinor wrote: I have a new 520 with a MA4-5 and have two oil coolers. I was getting temps of 230 to 240 after about 15 min of run time. I tried 3 different gauges to make sure that wasn't the problem. I did read one of the manuals on the 520 that said to expect high temps to be in the 210 range. In the end after about 100 + hours of short runs the motor finally broke in and now It will max out a 210 maybe 215 but that’s it. Not much help but thought I would throw it out there.


twister69z wrote: Had a situation where a customer has a O-470 on his airboat. After a few hours the crankshaft broke right at the crankcase face. After surveying the engine installation it was discovered that the original builder installed oil filter in the oil cooler line. For those of you unfamiliar with a sandcast crankcase the oil cooler is either remote or bolted to the crankcase, in this instance the cooler is remote and on the side of the crankcase is two ports one out to the cooler and one in to the crankcase to oil the left side of the crankcase. There is a vernatherm ( thermostat) that regulates the temp by forcing all the engine oil through the cooler as the temperature increases. Oil HAS to return to the crankcase or the engine will starve for oil. When this was built the remote filter put in the oil cooler line was plumbed incorrectly so the oil out of the engine was trying to go in the out of the filter housing . The oil won't travel backward through a oil filter it starves the left side of the engine and makes bearings fail. Also ,the oil pressure sender was plumbed directly out of the oil pump, not out of the oil galley on the engine. If the oil sender would have been plumbed correctly a drop in oil pressure would have been observed as the vernatherm closed off the bypass.
Long winded way of saying pay attention to the engine and the flow of oil through the engine .
Twister69z
" I don't care who you are back in the world, you give away our position one more time, I'll bleed ya, real quiet. Leave ya here. Got that? "

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John Fenner
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Re: 520 Continental rebuild

Postby John Fenner » Tue Feb 19, 2019 12:13 pm

Keep in mind, she still has to break in
I never finish anyth,,,.

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Re: 520 Continental rebuild

Postby rowdy1 » Tue Feb 19, 2019 2:41 pm

Ill try to post a few pics. I have an oil filter adapter that takes the place of the oil screen in the oil pump housing. This is off of an aircraft, and runs an Oberg style filter. ( very fine screen and large surface area). On the aircraft it was plumbed with -8 fittings. I changed them to -10 fittings and hose. The lines run out of the oil pump housing, into the filter, then to an oil thermostat, then into the oil cooler and back to the oil pump housing. The thermostat directs 80% of the oil back to the motor and 20% thru the cooler until oil temp reaches 160 deg. At 160 the thermostat begins to open, and at 180 deg. 100% goes thru the cooler. I'm running a Mishimoto oil cooler, 19 row, double pass. Its built like a small aluminum radiator. With the vernatherm, only excess oil pressure is directed thru the cooler and then back to the cam bearings on the lower left side. My system forces all of the oil thru the cooler. You would think having all of the oil go thru the cooler would make a huge difference, NOT. Before anyone asks, yes I did check all of my ins and outs. It's actually pretty simple and everything is labeled in and out. Yes I bled the entire system as I installed it, including the cooler to get all of the air out. I had this identical problem with the old motor. 0 to 230deg in 15 minutes on the old one, 0 to 200 in 15 minutes after rebuild. The only system I have not changed is the carb, although I did have GMAC rebuild it. My next step while I wait for the fuel injection is to find my heat gun and shoot temps in and out of the oil pump, and in and out of the cooler.

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Slidin Gator
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Re: 520 Continental rebuild

Postby Slidin Gator » Tue Feb 19, 2019 5:07 pm

rowdy1 wrote:My next step while I wait for the fuel injection is to find my heat gun and shoot temps in and out of the oil pump, and in and out of the cooler.

Monitor cylinder temps with the IR too.
I grew up thinking I-10 was the Mason Dixon line.
1986 Airboat Engineering Inc., 14' Marsh Master. Refreshed narrow deck, SV O-540, 72” NGQ. A Bob Stossel original.

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Re: 520 Continental rebuild

Postby rowdy1 » Mon Feb 25, 2019 9:53 pm

Here are a few pics of the motor.
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rowdy1
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Re: 520 Continental rebuild

Postby rowdy1 » Mon Feb 25, 2019 10:01 pm

And the boat. It only took me 3 years to figure out how to post pics!
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lilly-Pad
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Re: 520 Continental rebuild

Postby lilly-Pad » Tue Feb 26, 2019 4:29 am

that's a good looking rig right there
12 ft Don Davis / 0470 conv / 68 NGQ , A.A.O.F member

Best laid plans of mice and men, wont always get you laid.............

Mossy Cypress
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Re: 520 Continental rebuild

Postby Mossy Cypress » Tue Feb 26, 2019 7:59 am

X2 nice looking rig for sure.

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kwanjangnihm
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Re: 520 Continental rebuild

Postby kwanjangnihm » Tue Feb 26, 2019 8:22 am

great looking AC rig rowdy! rudder art is way cool :thumbleft:
" I don't care who you are back in the world, you give away our position one more time, I'll bleed ya, real quiet. Leave ya here. Got that? "

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John Fenner
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Re: 520 Continental rebuild

Postby John Fenner » Tue Feb 26, 2019 8:41 am

Very clean rig!!
I never finish anyth,,,.

One Eyed Gator
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Re: 520 Continental rebuild

Postby One Eyed Gator » Tue Feb 26, 2019 8:53 am

Very Nice

rowdy1
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Re: 520 Continental rebuild

Postby rowdy1 » Tue Feb 26, 2019 9:43 am

I own the tm for the artwork. I have tee shirts and yeti cups. I also own fillet&release.net, but I haven't set up a web site yet.
Its my get rich quick scheme! A buddy of mine here in Williston, FL owns "Farm Life". He is retired @ 44 and hunts and fishes year round. He's got it rough! A FWC officer said I was "begging to be checked" with that logo. I told him to go ahead, I'll sue for profiling!

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Re: 520 Continental rebuild

Postby rowdy1 » Tue Mar 26, 2019 8:35 pm

Motor update: I have almost completed the fuel injection install. I'm missing a couple fittings to complete the return line and I need to fabricate a throttle cable bracket. I plumbed everything with brass AN fittings and push-lock hose. As long as amazon delivers by Friday it will be running this weekend.

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Re: 520 Continental rebuild

Postby rowdy1 » Sun Mar 31, 2019 8:43 pm

I got it all buttoned up on Saturday, went to watermelon pond Sunday and ran it around. The motor runs fantastic, it runs and sounds smoother from idle out to 3100 rpms. Yes I turned it 3100 for just a second, with a 72'' NGQ set on 3. I will adjust the prop this week. The throttle response is amazing! I actually need to change the throw on the pedal to take some of response out of it. Right now it has a hair trigger. The oil temp is also much better although it did eventually get to190. The plugs have plenty of color now. I have not quite figured out a start procedure yet. Right now I have to pump a fuel bulb a few times to get it to pop off. I also need to hook up a cable for the lean out. Overall, I am pleased with it.

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John Fenner
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Re: 520 Continental rebuild

Postby John Fenner » Mon Apr 01, 2019 9:04 am

Get a facet cylindrical pump with 1/4"npt ports, put it post water separator, to pump inlet, switch pump on, once you hear the pump go to a softer tone, fire it up.
I never finish anyth,,,.

rowdy1
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Re: 520 Continental rebuild

Postby rowdy1 » Mon Apr 01, 2019 1:55 pm

I have one on it now, but its before the water separator. It doesn't seam to have enough pressure. If I squeeze the fuel bulb until I hear fuel squirt into the cylinders in will fire right up.

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Slidin Gator
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Re: 520 Continental rebuild

Postby Slidin Gator » Mon Apr 01, 2019 7:48 pm

rowdy1 wrote:I have one on it now, but its before the water separator. It doesn't seam to have enough pressure. If I squeeze the fuel bulb until I hear fuel squirt into the cylinders in will fire right up.

Is that the same pump you had on it with the carb? The spec for fuel pump pressure at idle is 9-11 psi and you would have needed a lower pressure pump for the carb.
I grew up thinking I-10 was the Mason Dixon line.
1986 Airboat Engineering Inc., 14' Marsh Master. Refreshed narrow deck, SV O-540, 72” NGQ. A Bob Stossel original.


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