Gso 480 newbie questions

Aircraft powered airboat discussion.
Post Reply
12ftgso480
Southern Airboat Member
Posts: 6
Joined: Mon Jul 20, 2020 10:18 pm

Gso 480 newbie questions

Post by 12ftgso480 »

Hello airboat community. Out of northern Oklahoma right on Arkansas river. Just bought my first boat that sits on a 13' sled and has gso480. Being brand new thought I could ask some real rookie questions like what my oil temp and oil pressure should run after warm up and idle. It appears we have a 750 double pump feeding it with 1/2". Forgive me for I have not a clue about aircraft engine and am trying to work my way in. Notice a little smoke at start up but performed well. Would take off dry sand bar with half throttle ? Seemed like oil pressure was around 50-60 @2000rpm and oil temp was 200ish? Oil sump was half full on sight? I've tried to read through post and was finding spefic info I was looking for. I've got a manual downloaded hopin it will help with general maintenance, also we only ran it with one mag switch on and thought I read somewhere on here that someone was running both? Can you guys please help me with a check list before I put too many hours on it and break something that could be easily avoided. Posted a couple pics below to help describe my setup. Thanks!! :old_glory:
Attachments
20200719_175746.jpg
Screenshot_20200721-090758_Gallery.jpg

12ftgso480
Southern Airboat Member
Posts: 6
Joined: Mon Jul 20, 2020 10:18 pm

Re: Gso 480 newbie questions

Post by 12ftgso480 »

Ps noticed it would burp ( not quite a back fire but sounded kinda loaded ) when shutting engine off after each run we made.

User avatar
Bonefish
Site Supporter - II
Site Supporter - II
Posts: 62
Joined: Thu May 08, 2014 5:09 pm
Location: Melbourne/Laguna Niguel

Re: Gso 480 newbie questions

Post by Bonefish »

GSO, normal operation is to start on the impluse mag then switch on second running both all the time. With that you will get better performence and I suspect your oil temp will drop some.

User avatar
kwanjangnihm
Site Supporter - IV
Site Supporter - IV
Posts: 2072
Joined: Sat Mar 30, 2013 8:23 pm
Location: Bartow FL

Re: Gso 480 newbie questions

Post by kwanjangnihm »

12ftgso480 welcome to SA!

There are no rookie questions here bro, asking is the only way we all learn. :salute:

Do you know any history about the motor? (hours, builder, etc)

Good luck & slide safe!
He'll cut your throat, baby, stick you in the back, drive off in your Cadillac.
He's more trouble than you think, he'll kill your sugar, leave you in the drink.

12ftgso480
Southern Airboat Member
Posts: 6
Joined: Mon Jul 20, 2020 10:18 pm

Re: Gso 480 newbie questions

Post by 12ftgso480 »

Looks like one of the middle cylinders has been worked or replaced. I'll look at hour meter this evening. All my airboat buddies told me not to go aircraft but was on tight budget and got a good buy at auction. I literally know nothing as far as taking care of it starting or running. I looked for an hour filter for 20 min :shock: I got operation manual printed off. Gonna read through it aswell.

unforgiven11B
Site Supporter - IV
Site Supporter - IV
Posts: 577
Joined: Sat May 26, 2012 9:59 am

Re: Gso 480 newbie questions

Post by unforgiven11B »

I’m sure sliding gator or Kwan will chime in, also hit the search function on the site or just type in your questions in google like “gso480 Running temp southern airboat” “ gso480 oil temp or pressure southern airboat” you’ll get more information than you’ll want to read in one sitting. There’s a link here somewhere on the overhaul manuals that you should read up on. Good looking rig and welcome.

Blownaway540
Site Supporter - IV
Site Supporter - IV
Posts: 175
Joined: Fri Feb 11, 2011 7:16 pm
Location: East Orlando/Hatchineha Estates

Re: Gso 480 newbie questions

Post by Blownaway540 »

Welcome, how many quarts of oil does sump hold, have a good oil cooler, it it in a good position,clean? The supercharged motors have tremendous power but high head temps will kill it, burn pistons. I don't run for miles dry with mine in summer heat. I put a nitrous plate under my 750 carb, fuel only with its own fuel pump. If I'm running dry and see temps rising, hit the button for the nitrous plate (fuel only) fatten it up and can see temps drop. Run only AV gas, (100ll) at 16 pounds boost it kicks your compression to over 15-1. Great motors if you are old and lazy and are tired of getting stuck and having to get off and push/pull like me. Regards, Mark
IGSO 0540 (W/out IG) built by the late, great, Dick Hoffman, 13 ft. Alumitech. Member - CRA, KRVSA

SuprchgedPalmBeach
Southern Airboat Member
Posts: 54
Joined: Fri Apr 27, 2018 4:13 pm

Re: Gso 480 newbie questions

Post by SuprchgedPalmBeach »

25 psi at idle, 60-80 psi running with engine at temp. I typically see nothing greater than 180 oil temp but I run a 4 gallon oil sump with de-foaming baffles and a big cooling shroud. If you get foam in your oil it will also kill it over time and lower oil pressure. Keep cylinder temps low and this engine will perform as it should. The gso480 is a bulldozer but only if its set up correctly.
15' 6" Palm Beach Hull, GSO-480, 82" 3-Blade JX Series

12ftgso480
Southern Airboat Member
Posts: 6
Joined: Mon Jul 20, 2020 10:18 pm

Re: Gso 480 newbie questions

Post by 12ftgso480 »

So dad and I got on it tonight and installed a new set of gauges, all except tach. After all talk about running rich we pulled few plugs and noticed couple were oily while the other half looked healthy. We ran the boat with only one mag switch on the whole day, hoping that will cure oily plug issue. As for my oil cooler I didnt measure but guessing reservoir or sump what ever that thing is :lol: looks like it has to be 2 gallons or more. Took a peak inside with it half full I don't see baffles. Kinda curious at this point if we should run it full ? Half full on the site? It sat on half when we bought. Hr meter reads 80hrs for what that's worth. It has a new cylinder that was put on right before we bought. Also dad doesnt know what to think about our hood/cooler. Ours Is made of stainless do guys recommend aluminum? Gonna see this weekend how were looking after new guages and both mags running. Sorry for long post, I'm open for criticism or helpful info if you guys notice anything way off in our pictures. Thanks guys :old_glory:
Attachments
20200723_215734.jpg
20200723_215750.jpg
20200723_215745.jpg

User avatar
kwanjangnihm
Site Supporter - IV
Site Supporter - IV
Posts: 2072
Joined: Sat Mar 30, 2013 8:23 pm
Location: Bartow FL

Re: Gso 480 newbie questions

Post by kwanjangnihm »

12ftgso480 wrote:
Wed Jul 22, 2020 2:24 pm
Looks like one of the middle cylinders has been worked or replaced.
If the cylinder was replaced, there is a break in period and typically lycomings run Aeroshell 100 Mineral oil until the rings set.
He'll cut your throat, baby, stick you in the back, drive off in your Cadillac.
He's more trouble than you think, he'll kill your sugar, leave you in the drink.

lariat
Southern Airboat Member
Posts: 357
Joined: Sun Mar 27, 2011 8:27 pm

Re: Gso 480 newbie questions

Post by lariat »

It is best to shut it down with fuel cut-off rather than with mags.

Gary S
Site Supporter - I
Site Supporter - I
Posts: 1675
Joined: Wed Mar 03, 2010 3:30 pm
Location: Redlands

Re: Gso 480 newbie questions

Post by Gary S »

All aero shell 100 is mineral. Break in is straight mineral without ashless dispersants.

12ftgso480
Southern Airboat Member
Posts: 6
Joined: Mon Jul 20, 2020 10:18 pm

Re: Gso 480 newbie questions

Post by 12ftgso480 »

Was out today. Noticed after warm up at idle oil pressure was around 25,, at 2000 rpm I was around 55 and closer to 60 at 2300. Its around 85° here now. Engine got up to 190 after 2 to 3 miles of running on average around 2000 rpm in water no dry. Noticed my oil sump was a little low when we got back. Do you guys run yours completely full or half ? When I added some after warm I also noticed a little foam at top or oil. Not much.

Blownaway540
Site Supporter - IV
Site Supporter - IV
Posts: 175
Joined: Fri Feb 11, 2011 7:16 pm
Location: East Orlando/Hatchineha Estates

Re: Gso 480 newbie questions

Post by Blownaway540 »

My sump holds about 3 gallons, I put 2 1/2 gallons in (10 qts).
IGSO 0540 (W/out IG) built by the late, great, Dick Hoffman, 13 ft. Alumitech. Member - CRA, KRVSA

Post Reply

Return to “Aircraft Power Only”