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ANGELOS airboats
- Thread starter ANGELO
- Start date
WaterH
Well-known member
Looks like fun. How does it do on dry ground? I just got back from the Haines city area. Are you around there?
I just saw your location, duh.
I just saw your location, duh.
ANGELO
Red Numb Skull
It doesn't do dry ground, unless I had momentum and even then we got stuck. It's a pretty low HP engine with a small prop. I still have to get the mags timed together, I'm having a hard time with that, and tweek the rigging and prop then maybe I can get it run dry.
That was from peace River in Arcadia.
ANGELO
Red Numb Skull
I pulled the old front main out today. It had a one piece split seal.
Is it normal for there to be set screws on both sides of the case? It looking like the screws where putting pressure on the seals, because there was a flat spot worn where the screws where on both sides.
The glue what was used also didn't appear to hold up
Is it normal for there to be set screws on both sides of the case? It looking like the screws where putting pressure on the seals, because there was a flat spot worn where the screws where on both sides.
The glue what was used also didn't appear to hold up
WaterH
Well-known member
Not seen that, but I’m not very “up” on the 235. I’ve worked on the 320’s and 360’s. Does yours have a lot of blow by? Even though the vent is as big as your thumb, they can blow oil out the main seal. Have you done a compression test?
ANGELO
Red Numb Skull
120 all 4.
The seal is pretty shot, it's flat on both sides where the set screws are.
It definitely has some blow by but I'm not sure what's normal for these
ANGELO
Red Numb Skull
There is a flat spot where the screws are
WaterH
Well-known member
I’ve never done a auto compression test on a lycoming. Not saying that’s a bad thing to do, just don’t know what the numbers should be. Obviously, those screws are supposed to be there because of the cast boss. I think they maybe for a “keeper” to hold the seal in.
I will mention, I like the non split seals. I know it looks like you could never stretch a seal over the end, but it does and it goes back to size.
I will mention, I like the non split seals. I know it looks like you could never stretch a seal over the end, but it does and it goes back to size.
ANGELO
Red Numb Skull
Couple aircraft shops have told me to leave those screws out. They also said that engine calls for a one piece split seal. I wanted the non slip one, but I guess I'll try the split one.
ANGELO
Red Numb Skull
I glued a new one piece split seal in, and got rid of those screws. they were self tappers. so far looks like no leaks. I ran it for 10 min, got it up to temp and had it at 2k rpms. let it cool then did it again. looks dry so we will see this weekend. I have 80 PSI warm at 2k rpms, but at idle it drops to like 10. Doing some reading it looks like im missing a restrictor plate for my idle oil pressure.
That new style dodge starter works so much better.
That new style dodge starter works so much better.
ANGELO
Red Numb Skull
There was a concert on a island today that's only accessable by airboat that we went to today. Still have no leaks.
I need a double seat in the rear.
I want to try to pitch the back of the motor up, I feel it's running on it's nose.
And it was running hot with 3 people so I think it needs a bigger/new oil cooler
I need a double seat in the rear.
I want to try to pitch the back of the motor up, I feel it's running on it's nose.
And it was running hot with 3 people so I think it needs a bigger/new oil cooler
ANGELO
Red Numb Skull
You can kinda see the oil cooler here. It's about 12"x6x 3"
It's old and all the fins are all crusty. I think I'm going to go just slightly bigger on a new one, but would I benefit from a thinner core, so it's easier for the air to be pulled through since it's probably a foot always from the prop and no shroud?
It's old and all the fins are all crusty. I think I'm going to go just slightly bigger on a new one, but would I benefit from a thinner core, so it's easier for the air to be pulled through since it's probably a foot always from the prop and no shroud?
ANGELO
Red Numb Skull
I just adjusted my valves. 2 of them were tight. one was perfect and the rest were pretty loose. so that should help it not wanting to idle cold, and hopefully the power some.
SomeGuyFromOlympia
Well-known member
- Joined
- May 31, 2020
- Member Number
- 1706
- Messages
- 857
I need one of these
looks fun
looks fun
ANGELO
Red Numb Skull
Definitely has more power with the valve clearance fixed. I was running dry today. But now I have a oil leak on a cooler fitting
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ANGELO
Red Numb Skull
WaterH
Well-known member
Damb, running real good. There’s a beat up air boat at my local pawn shop. It has a small v6 or v8. Rotted prop. I need to find out the price.
rockmup
El Hefe
You can kinda see the oil cooler here. It's about 12"x6x 3"
It's old and all the fins are all crusty. I think I'm going to go just slightly bigger on a new one, but would I benefit from a thinner core, so it's easier for the air to be pulled through since it's probably a foot always from the prop and no shroud?
You'd benefit from bigger tubes in the cooler, more surface area.
FYI, I'm really jelly of this toy.
WaterH
Well-known member
I just noticed that little trim tab on the back. Does it make much of a difference?
ANGELO
Red Numb Skull
It's so much fun, so far I'm liking it way more then taking my truck off-road. Definitely worth it.
Props are expensive, if it's a car motor is should have a Gearbox, because the prop can only spin 3k rpms. After this boat, I'm not sure if buying a less then 5k boat is worth it. Especially with a aircraft engine I think I could have bought a more expensive boat that was ready to go with a better engine for about the same amount.
Im starting to think my cooler size is fine, I just need one that's doesn't have crushes fins.
I'm jealous of the guys that have enough power to run dry loaded up hills, and do 100mph
Yes. Its crazy how much it pushs the bow down. Most boats will porpoise at wot without a tab to make it run dry better
ANGELO
Red Numb Skull
I feel it's running bow down. So I put 2 washer under the rear motor mount we will see this weekend if it's better. When I remounted the rigging, I moved it forward. Not sure yet but I might move it back. I positioned it with a 4x4 under the boat to balance it 2/3 the length. So the boat is balanced like 4 ft of the back. But that puts the prop about 12" from the back. The other way to set the rigging is "have the prop one beer can away from the transom and one can deep into the hull" I definitely could benefit from lowering the engine, but I'm not cutting the rigging for that. But I feel it might benefit from having the weight further back.
It burns a decent amount of oil, but I believe that's fairly normal for these. Burns more fuel then I expected, but probably also normal since I have to keep the rpms up there with the small engine. I have to fine torque specs, I want to retorqe the jugs and case, they don't leak but are slightly wet at the seems
It burns a decent amount of oil, but I believe that's fairly normal for these. Burns more fuel then I expected, but probably also normal since I have to keep the rpms up there with the small engine. I have to fine torque specs, I want to retorqe the jugs and case, they don't leak but are slightly wet at the seems
Bacho
Yellow Skull
Very cool project. Remember that engine is very old tech. They like to leak.
On the airplane, baffling around the cylinders is quite important to keep the temps down. Does anyone do that on the boats?
ANGELO
Red Numb Skull
For some reason it's not common.
The cooler seems to be working correctly with a laser thermometer, but the hot side was only at like 150 and cold side was 100, while my gauge said the oil was 200. Could the thermostat be sticky?
WaterH
Well-known member
Oil temp of 200 is not hot. On helicopters, 190 is perfect, 210 is high and 245 is redline. Do you have cylinder temp gauge? I would be more worried about that. If you don’t want all four, there is probably one that runs the hottest. (It’s common to just gauge that one) I also would think there would be shrouding.
Edit, oh, yes, lycomings leak. (And burn oil, and burn fuel)
Edit, oh, yes, lycomings leak. (And burn oil, and burn fuel)
ANGELO
Red Numb Skull
When I was running with 3 people, it was up to 240-250. Cruising it stays about 220. I was checking it in my yard, just reved up on the trailer it'll only get to 200. I just have the oil temp gauge on top of the oil strainer adapter.
WaterH
Well-known member
Yea, 240-250 is not good. Your oil cooler looks big enough to me. I can’t see how close it is to the prop. Maybe you need to move it closer or make a small shroud that gets closer so it sucks air through it better. I do feel like your back cylinders might be getting hot. That’s usually the problem on planes and they have a lot more air going through them.
ANGELO
Red Numb Skull
It was struggling hard with 3 people I think that was part of it getting warm. Since the cooler was only 150 while the gauge said 200, could the thermostat not be opening completely or at the right temp? Not sure entirely how it works on these. It also takes a very long time for the oil to heat up. It sat since 2009 minimum before I got it.
I'm not sure I really trust these gauges, I was going to bring the laser thermometer next time. What should the cylinders be if I point the thermometer at them?
I definitely see why the the shrouds are important, most of these boats don't run them though, I have no idea why.
ANGELO
Red Numb Skull
Looks easy enough to make
Bacho
Yellow Skull
Looks easy enough to make
See if you can use a torch and put your sensor bulb into some boiling water and see what it says to calibrate it. I would do that before you take the IR thermometer as gospel. The exterior the hoses will not always match the temperature of what’s inside.
On cylinder head temperatures you do not want to ever exceed 525°. Ideally, you’re high side is 100° less than that..
Oh, on my airplane, I run to climb, full rich that extra gas helps. Keep it a little bit cooler. Do you have adjustable mixture on your controls? Thinking about it some more I’m not sure there be a reason to have one on a boat?
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ANGELO
Red Numb Skull
is there somewhere specific to check the cylinder temp, or just on the fins
These are the top plugs i'm running a bit rich, I don't see any mix adjustments other then the idle mix. I'll take some pictures of the carb later. I don't think I can set up the mix cable, but some of the bigger ac powered boats use it, I guess they will lean it out after extended idling to clean the plugs, and lean it out before shut down.