Performance Boats Forum banner

1 - 12 of 12 Posts

·
Premium Member
Joined
·
1,016 Posts
Discussion Starter #1
I always wanted to know the answer to this. Why is it that most all engine rail mounting is done with the rails bolted to the side of the stringers where all the load is placed on the bolts going through holes in the stringers???

Seems like to me the best way would be to just lay the rails on top of the stringers and then through bolt them through the stringers and then most of the load is taken away from the bolts and the holes going through the stringers??? Also should stop the wearing out of the holes in the wood stringers!!!!!!!!

Whats the deal with this???!!!!!!!!
 

·
Registered
Joined
·
1,617 Posts
Ideally, there should be no load on the bolt holes in the stringers...especially when you put a plate on the outside of the stringer instead of just stringer washers. The bolts are loaded in tension and should simply clamp the rails to the stringers. The clamping force should take all the load...and would if the stringers were not made of wood and were compressable. Most of the wear you see is most likely due to a decrease in the bolt tension over time due to the stringer compressing....need to check and retighten the rail bolts more often or add a plate to distribute the clamping force better over the entire stringer.
 

·
Boat Nut
Joined
·
5,131 Posts
If the wood stays dry, and the glass does not delam, there is little issue. Seems somewhat common for the flat bottoms to have their rails over the stringer, just not done on jets for what ever.
 

·
Registered
Joined
·
1,278 Posts
I always wanted to know the answer to this. Why is it that most all engine rail mounting is done with the rails bolted to the side of the stringers where all the load is placed on the bolts going through holes in the stringers???

Seems like to me the best way would be to just lay the rails on top of the stringers and then through bolt them through the stringers and then most of the load is taken away from the bolts and the holes going through the stringers??? Also should stop the wearing out of the holes in the wood stringers!!!!!!!!

Whats the deal with this???!!!!!!!!
this is exactly the way my rail set-up is on the boat i'm slowly/surely building...they set on top of the stringers & a flat plate on the other side...the front & rear motor mount plates set on top of the rails with feet to the rails...i was lucky & found plates that would allow me to do this :)...sometimes, if you cant find the right width plates, you have to opt for a different route to take...i think it is alot stronger set-up :)

FastRat
 

·
Registered
Joined
·
1,617 Posts
I ordered my rail kit new from JBP and as you can see it has stringer plates for the outside of the stringer. Even with 1" stringers it is plenty strong!
What diameter bolts does that setup use to hold the plates to the blocks?
 

·
Living in a cage of fear
Joined
·
16,464 Posts
I have wanted to put rails in the Miller for a while now, but the stringers are very narrow.
I think they would have to go over the stringers, or bolt to the outside?
Otherwise it looks like top mount starter and a bunch more expense?
 

·
Impeachment!
Joined
·
3,728 Posts
I have wanted to put rails in the Miller for a while now, but the stringers are very narrow.
I think they would have to go over the stringers, or bolt to the outside?
Otherwise it looks like top mount starter and a bunch more expense?
The stringers themselves are narrow? Or the two stringers are close together?

Here's how Jack setup my old Miller. No top mount starter, but I did use a Powermaster mini.
The new (to me) boat's stringers are farther apart, necessitating new front and rear engine plates. Still have the ones from the Miller though.
 

·
Registered
Joined
·
7,464 Posts
I have wanted to put rails in the Miller for a while now, but the stringers are very narrow.
I think they would have to go over the stringers, or bolt to the outside?
Otherwise it looks like top mount starter and a bunch more expense?
Tommy the plates can be "knotched" and let to run wild over the tops of the stringers (1rst pic) or the motor plates can be custom cut (and edges polished)for specific stringer width's The rails simply need to be relieved for low mount starters Tom
heres a few various recent installs including a Miller similar to yours


 

·
Living in a cage of fear
Joined
·
16,464 Posts
Thanks TX and Tom.

Tom, I'll probably want to have You and Josh do something this winter along these lines!:)devil
 
1 - 12 of 12 Posts
Top