Moving sterndrives

[Peterjfinch]

Hi All,

I am a little concerned that the new engines will be wider than the existing Mercruiser engines. If they are too wide, to line up with the existing drive holes, in the transom., what is the best way to resolve this?

Thanks in advance

Pete

[slomo]

have you any room to move engines forward ?

[DAREDEVIL]

extension boxes and driveshafts then u can run the shafts thru the boxes in an angle !!!!!!! DID IT BEFORE, WORKS FINE !!!!!!!!!!!

Or move the engines forward (like said) and then use driveshafts..but thatway u will change your CG !!! most likeley to the better tho !

[Peterjfinch]

Thanks for the replies. There shouldn´t be much room to move these forwards. As they have the velvet box´s on, they are looking like getting quite close to the fuel tanks, in front of the engines. Am I right to guess, the box´s you mention have UJ´s on the drive shafts?

Thanks

Pete

[Peterjfinch]

PS, I´ll post the exact measuremants later today. Here is an overall view of the setup.

Thanks

Pete

[Tony Davis]

Originally Posted by DAREDEVIL

extension boxes and driveshafts then u can run the shafts thru the boxes in an angle !!!!!!!

That's an expensive solution. Far cheaper to glass the holes in the transom, then cut new ones at the correct centres. How about the engine beds, will they work with the new motors?

[Peterjfinch]

Hi Tony, long time.

The engine bed is a sliid (RSJ style) steal beam, bolted through both sides and lightly glassed over. I will add photos of this later, also.

Pete

[Peterjfinch]

Ok, exact measurements no here. Space between engines, at risers, 8cm. Lower down Exhaust Y piece, 6cm. Engines are 75.5cm wide, at risers. Free space on outside of both engines is 29cm. Drive centers are 84.3cm, measured from greace nipples on top of drives. Photos below.

Pete

[Peterjfinch]

2 more photos

[Tony Davis]

Those drives look far enough apart for diesels, what's the centres?



Drive centers are 84.3cm

[Peterjfinch]

The centres on the boat these were fitted in, is 35" (as per owner´s measurements). My centres are 33 1\2". Are the TRS drives the same size / cut-out, as the Alpha 1? If yes, I will have to wait till I get the engines here, and check the centres when the engines are nearly touching. Is there a standard distance, that there should be, between a twin engine setup?

Thanks

Pete

[Peterjfinch]

Hi All, The engines are now here. Unloaded and covered for now but after a couple of quick measurements, looks like they will be quite high in the boat. Might have to raise the sides of the engine cover, to allow for the extra height. WOuld there be any advantage of lowering the engines? If I need to glass the transom and cut new holes, would there be any advantage to lowering the engines and drive hieght. I remember hearing about "short" housings (I guess for shortening drive length) and "adapter plates" (I guess for making drive longer)??

Any ideas for this would be great.

Thanks in advance.

Pete

[Peterjfinch]

Back to this problem.... The original Alpha 1 drive centre´s were about 33". I have taken many measurements from the new engines and the centres should be about 37 3/4", allowing 4" between the engines. The TRS transom plates are bigger than the Alpha 1 plates but mostly vertically, the width is not much different. So, I need to move the drive holes about 2 1/2" outboard. Does this mean that I must replace the entire transom or can I build up the inner edge of the existing holes and open out the outer edge of the existing holes?

Either way, what´s the best way to do the job.

Pete

[biffer]

i would offer the engines in to see what they look like in the bay, doesn't really matter how close they are except for servicing, starter, filter etc, you could remotely mount all the movable items away from the centre line, you're going to open up a can of worms by moving the drives which will mean altering the engine beds as well

[Peterjfinch]

Its a little difficult to offer the engines into place. I was just concerned that the engines could hit, if not spaced enough. I have heard that it would help with solid plate mountings, instead of rubber mountings but not sure of the "for and against" for these. The front engine mountings will be new and fitted to take the weight so it´s only the transom holes that could be a problem. I plan to move the engines this week, side by side, and get a better idea of the space between each and the consequential centre measurement. I´ll post the results.

Thanks for your info.

Pete

[Tony Davis]

Unfortunately I'm not that clued up on TRS's, but assuming the cutouts are larger than Alpha's, then I don't think it'll be too difficult.

If you use the inner edge of the existing cutouts for the new ones, you will effectively be moving the centres further apart. It looks like your original installation used a cradle type front mount, so that should allow for slightly bigger spacings.

[Peterjfinch]

Hi Tony. Yes, the cutouts are larger but not much wider, this is my concern. I plan to get the engines side by side, this week, and post more photos and measurements.

Thanks

Pete

[Tony Davis]

How much wider are they?

[Peterjfinch]

The engines are about 33 3/4", exhaust riser to exhaust riser. The Turbo on one engine will overlap the next engine but there is room for this, as all 4 turbos face the same way. At the moment, the engines are against a wall and hard to get exact measurements, so I plan to pull them out and get them side by side, then measure better.

The centers of the existing drives are 33" apart.

Pete

[Tony Davis]

Originally Posted by Tony Davis

How much wider are they?

the cutouts