Engine leveling

Lonewolf9029

Lonewolf9029

Well-known member
A question on engine setup: On this picture, the stringers of the boat are level and the camera held as level as possible. Is this engine and prop angle way wrong or is it just my thinking. Also prop just barely swings in boat.
DSC01416.jpg

from what I have been studying on this site, prop should be perpendicular (90 degrees) to level stringers. Then for an adjustment--up and or down maybe a 1/4-1/2" for issues such as porposing, etc. this was the way it was when I bought it, but that doesn't mean it right.Thanks in advance>>Don

Picture from other side
DSC01417.jpg
 
Don it could be that there is something optical going on with the picture, but if not I sure would want to check that out. I have never seen one that was jacked up that high in the rear.

If it has to be that high to make the boat run right, Id be checking whats going on with the hull.

Just looks strange to me from the picture.

Scotty
 
whitebear: the boat is level in all points checked. Stringers and transom is even 90 degrees. I noticed this when I bought it. Now that I'm have pushing problems I am looking and maybe who I bought it from was not to knowledgeable about airboats either. I mentioned this about 5 months ago in a post about engine height that she was up approx 3" in the rear and someone said they used to make them like that. With this angle no wonder it won't push. It's just pining the boat down-reckon? Don
 
Thats one way not to need a trim tab :shock: From the pics that motor needs to come down in the rear the motor's crankshaft should be level with the stringer , if not a tick nose heavy , but not like that JMO
 
I agree with Whitebear. I've played around with engine angle on my boat to solve porpose problems. I jack the back of my engine around 7/16" above level and cleared most of my porpose problems but it wouldn't push dry worth a crap. I've found around 1/4"- 3/8" with the back of the engine lower of level, help me push dry a lot better but then I had the porposing problem back. I rather push dry and propose in deep water. Mind ya I've played with my jack plates and a piece of aluminum between the hull and poly and that helped out some, just didn't want to worry with a trim tab and forgetting I had it down when I hit dry or want to play and do 360's. :lol:

I hope it helped and made sense to ya.

All the best.
 
thanks Ford and Instigator: I've backed it under the lift, going to hook up the torch and drop it to level (up 7/16"), weld it so I can test it. Thought something was way off. Maybe thats why he sold it :mrgreen: . Don
 
I ALWAYS START OUT WITH MY MOTOR LEVEL AND GO UP A 1/4 BUBBLE OR DOWN THE SAME.THAT IS WAY TO HIGH IF YOU ASK ME. I HAVE HEIRD OF GOING UP 3/4" OR 1" IN THE REAR ON BAD A$$ GEAR BOX BOATS BUT NEVER NEVER THAT HIGH ON A DD BOAT. I WOULD MAKE IT SO WHERE YOU CAN AJUST THE MOTOR UP OR DOWN A LITTLE . BUT START WITH THE MOTOR LEVEL. IF YOU NEED IT THAT HIGH IN THE REAR TO GET IT FROM PLOWING ON THE NOSE. THEIR IS SOMETHING WRONG WITH YOUR HULL!! :shock: :shock: :shock: :shock:
 
You're Very welcome. I agree with C.C. Just an idea and thought. Why don't ya weld your back support about 3/8" below level, Then you can always use washers and a longer bolt to adjust your engine pitch, that's what I did to mine. Bets the heck out of welding and cutting it all the time. Plus this will allow you to find your "sweet spot" a hell of a lot easier!!!! You can have up to an inch to play with, if that doesn't work then I'd be looking into the hull for problems or rigging set up.

Hope it helps and makes sense.

All the Best.
 
Meant to add Lonewolf, using stainless fender washers allows you to do 1/8th inch adjustments for fine tuning. If your cage is strong enough you can use a ratchet strap to raise n lower your engine in the rear to add or take away washers while you're out playing and testing your boat instead of cussing all day and waiting till you get home to do any adjustments.

Just a thought, I hope it helps and makes sense.

All the Best.
 
i found somethang crazy the other day a friend of mine has a airboat the splash at the back of the boat we pulled it up and the boat went crazy you couldn't drive the boat for crap we bent it back down and the boat drove great!!! its the crazest thang that i have ever seen! just a thought check it out and try it on your boat and let me know if yours does the same please
 
Makes sense to me guys! I just cut 2" out of both sides of the back stand supports. Have it hanging from a come-a-long now. I'll grind it up and let it down till a little below level. raise it and weld 2 stainless nuts, upper and lower where I can use a jack bolt to raise or lower. When I get it where I think I want to try it, I'll double nut it into position. Good idea about being able to raise and lower with setting up torch and stuff. why didn't I think of that? :shock: Don
 
Don ;
I'm with Whitebear , that looks very unusual to me too. I have a gearbox but my prop has a very slight lean back totally the other way . I can't really see your hull that well in the photos but if you get a problem with porpoising the lip at the back of the hull can be bent down a touch . Works on my metal hull .
Do a search in pictures for Hull bending tool . I put some photos there that show a tool I made up for doing it .( really easy ).
The way your boat is now does it really lift the nose when you take off?
 
Bob: It definitely kept the nose down with no porpusing what so ever. I have already cut and cleaned up the material for tomorrow, but when I let off the come-a-long nothing came down.I will start early in the moring and I will make two more cuts on the front of the stand and she will sink down in place. weld some adjusting bolts on and go from a hair below level to level and take her out and run it.
Instigator come up with a good idea on jack bolts for it. all along I thought that looked funny but the fellow I bought it from seemed to like it. I dont beleive the way it was angled was doiong anything but pushing down :shock: . Don
 
ID ALSO LIKE TO ADD, IF IT DIDNT COME TO ANYONES MIND---THAT ON A SMALLBLOCK CHEVY THE OIL PUMP IS IN THE BACK OF THE MOTOR! SO WITH IT LEANING FORWARD LIKE THAT ALL THE OIL IS AWAY FROM THE PICKUP!!! IF YOUVE EVER NOTICED, IF YOU LOOK AT A CHEVY V-8 MOTOR IN A CAR, ITS ALWAYS RAISED UP IN THE FRONT.
 
Lonewolf, you were right all along, I reckon.... just as you thought it was way too high at the back/low at the front.... I reckon when you get it level, then adjust it like you are in the process of doing, it will be like a different boat :wink: Having the extra clearance from the transom to the prop will be a real plus too :mrgreen:

Having the motor at that angle would have made it run slow/if at all on the ground? & prolly run on the water with the rake up high? or was it doing both ok?

Cant wait to hear how it goes once you fix it :wink:
 
When you get it leveled it will be a different boat .. no doubt. HOWEVER it still is too big to be a DD if you want to run dry like you eneded up in the other day. The grass closest to the water is usually the stickiest just ask folks about the stuff at the milk bus in Kiss. you don't notice it when coming out cause you are riding a wave of water ... but when you want to get back to the water LOL it is a whole new ball game. your boat may run dry fine up by the tree's but get back down by the water and you better not lift off the throttle if you are marginal powered.
 
Couple of thoughts here.....

Just dawned on me, shouldnt' the ideal be the stringers level while the boat is sitting in the water? Could be different with the weight issues?

Also am I wrong in thinking that the prop self levels itself is the theory, IE if (looking from the side) the top tip of the prop is a bit further forward and the bottom a bit further back, IE motor raised in the back some, than when it starts to bite it'll pick the nose of the boat up some then to correct itself?

Jeff
 
Rost it doesn't matter how it sits in the water it is how it runs in the water. Yep the prop will self level and selfalign to a certain extent based on how much power is applied to it and how much it can lift but there are limitations. When it come to dry running Mr. Combee always told me if the boat don't porpise a little it won't run dry well. I always like for my boats to have a gentle lope to them when running in the water kinda like a good horse. I always think it is about right when a little rudder twitch will take the porpoise out of it or applying full throttle flattens it out. I am not sure I got it figured out but it works for me anyways but others have their own opinions as well and I am sure they work for them. I am gonna keep on workin on it and may change my opinion in the future.
 
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