motor position

[1949huey]

Hi, i am restoring a wooden twin cockpit boat and at present about to refit the motor but the previous owner has replaced the engine bearers so i'm not sure of the engine position.
i have hung the hull off the garage ceiling to find the balance point.so does the engine go over that point or further forward or back. any information would be appreciated.
the motor is a ford y block.
regards stuart

[glennr]

hi mate is this the original engine out of that hull? im no expert but if you have all of the engine mounts then i would say if you line it up with the prop shaft in its running position it will be very close? im probably wrong but that would be my thoughts, Glenn

[bauchy]

yep keep it simple. stick ya prop shaft up the hole. set your engine up with mounts and slip it in untill the whole shebang lines up. try and keep it as low as you can for centre of gravity. personally i have not played with moving engines allot but if its mid mount i dont think you will have to much dramas

bauchy

[Sunbeam11]

I dont want to overcomplicate this engine alignment stuff, but going on to the next step, its suggested a .002 feeler gauge (paper thickness) gap is about the tolerance you allow when aligning up engine and prop shaft coupling, rotating prop shaft 360 deg and stopping every 90 deg and checking gap. Make sure the prop shaft is blocked/wedged into position either at the shaft hole or at the shaft log position. With the self aligning (rubber sleeve) shaft logs, there is flexing, but should be adjusted in such a way that it will turn freely and not bind at the bearing.
This will limit engine/shaft vibration etc. too absolute minimum, and thats hoping prop shaft etc is not bent, or coupling has been put on square to shaft etc.

Bloody tedious job, but a matter of trial and error until each point is bought into correct alignment although adjustable engine mounts will certainly help, otherwise its shimming with correct size packing etc. to get it right.

Gees dont ya just love the way I have a great way of making things more complicated than what they seem lol….

Hey….dont any of you blokes start asking me stuff at Nerrandera…... I wont have my book with me..…... for what its worth….

[DaveD]

Hi,
I would also agree not to complicate it too much. By all means align as best as you can but remember these are wooden boats and they flex and move by nature.
As an example, when I had my prop balanced and installed a new prop shaft, the guy who tweeked the prop said I should allow 1/4" between the back of the prop and the skeg to allow for movement, whereas if it was a Glass hull only 1/8". This is from a guy who also races boats, as did his father before.
If you get a chance, go for a ride/drive in a Skiff and watch the motor move in front of you!
Dave

[1949huey]

Hi guys ,thanks for all the replies. the problem is as far as i know this particular motor hasn't been fitted to the boat before. the previous owner started restoration on the hull had the y block rebuilt then lost interest. there is a prop shaft but i don't think it is original.

regards Stuart

[bauchy]

it be right mate ! shove the shaft up the hole. have your mounts mounted on the engine then get the engine as low as you can in the boat. bolt it in where you want it to sit. If you have a look at most old boats they have a few holes in the bearers where people have ahd different engines in there. my clinker use to be a mid mount and had so many holes drilled it was like a piece of cheese. i have no idea where the original engine was mounted and im sure all the other owners had no idea either.

personally if i was you just put it in. line it up the best you can by turning the prop to make sure it spins freely when you have it where u want and away you guy. get it centred and you shouldnt have any drama.

if you have problems when its running and on the water you will be able to sort it out then but i bet its fine

[1949huey]

thanks for that..does the motor sit over the centre of balance(don't know the correct term) or towards the stern a bit

[bauchy]

lol yeh im not up with the lingo either. stick it in the middle of your bearers and you will be fine

[antique-boatique]

It has to be astern of midway especially if its a twin cockpit boat - allow for the foredeck and the space for the dash and front seat and then you can have it as close as practicable to the back of that seat so in reality its about a third of the way from the stern