Any mechanical engineers out there?

I am starting the process of replacing the fuel tanks in my boat. In order to do that I need to lift my engines. I need to know what size and type of I or H beam I need to support 1350 pounds on an 8’ span. There is a company here that sells steel but they say they don’t have any idea what size I need. I don’t know enough about steel to even ask intelligent questions. Also on one end I have only 2” for the vertical support so I am thinking of 2” round or square tubing. What would I ask for to support that end? On the other end I have a lot of room so I am going to use a 6x6 as the vertical support. Can anyone help me out?

I used 2, pressure treated 4X8s spanning my salon to lift 3208 Cats one at a time.


They weigh over 2000 with tranny attached.


Used long eye bolts through them cained to the engines. greased washers and used a long box end wrench and ONE finger on the wrench to lift the engines off their mounts.


Cheap enough, easy to drill a hole through and used in landscaping when done.

In steel, probably the smallest I beam that you can buy will work, maybe a 2" flange and a 6" web. That will easily support 1,350 lbs over 8'. Or as psneeld recommends a couple of 2x8 yellow pine joists will hold that load easily and will be lighter to move around and cheaper.



Use 1-1/2" pipe with a couple of floor flanges top and bottom for the support on the tight end. A 4x4" yellow pine post will hold the other end. Brace the beam so it won't slip sideways.


David

I want to use an I beam so that I can use a trolley to roll the engine sideways.

Do you have the trolley?


If not just buy the entire rig and sell it afterwards....or rent one if possible.


But the trolley is going to have to match the I beam so you are in the chicken or egg circle....as just about any beam a trolley will run on will be strong enough. The trolley will have a rating to be sure.


If you only have to move the engines a little...you can still use beams and have them on rollers....a little sketchy...but not all that bad.

Comodave said:

I want to use an I beam so that I can use a trolley to roll the engine sideways.

Click to expand...

Then the I beam and pipe on both ends will work fine. What flange width does the trolley require? That will determine your I beam size.


David

There are many beam calculators on the internet. I looked at the smallest steel I-beam W4x13 with an 8' span loaded to 1500 lbs at center. It would deflect only 0.1 inches at your load. This would certainly work. The beam would weigh 104 lbs.

I don’t have room on one side for any prefab hoist system. I have to make that side out of angle iron. I have not bought the materials yet but I cannot roll the engine on the deck with an engine dolly. The deck beams will not support the weight. I appreciate the feedback. I will go with the 6x6 I beam, I just wanted someone knowledgeable to look up on a calculator like gsholz did.

6” beam