Hi All, any ideas for engine mounts, for these engines? Pics of engine bay here http://www.seriousoffshore.com/forum...6&postcount=23

Pete

Since the the diesel setup is going to be heavier, shifting them further forward is a good move. I did a single with a Duramax back in 2004, running into a SSMIII. I had to bolt 50 lb in the nose of the boat to get it to balance correctly, and not porpoise like crazy. I had that motor putting out about 375 hp and I got it to run 55 mph. Boat was a 26' Corsa.

Through hull pickup is no problem, just try not to put them right in front of the props. Best place on a twin is going to be down near centerline. You are most likely going to be running in the 50-60 mph range, so plenty of hull in the water, and exact placement is not critical.

Thanks for the points. Sounds like the Corsa was an interesting boat. I am hoping that with these moving forward slightly (because of Velvet boxīs) I shouldnīt need extra weight forward. There is a domestic water tank forward, so I might have to use that to ballance things out.

I just need to work out the engine mounts now. I am looking at some kind of light weight crossmember, similar to the old one. Maybe mounting on both steps, to add security. Looking below the engines, it looks like the mounting surface could be streight, as the sump and the rest of the underside of the engine, looks like itīs all well above the mountings.

Any ideas welcome.

Thanks again.

Pete

talk to smitty from opa racing wazzup race boat i think his kid races a 26 ft corsa boat papa dukes i might be wrong but he will no what you need look under opa jersyboyz they are out of new jerzy

Hi All, My original Alpha 1 drive centreīs were about 33". I have taken many measurements from the new engines and the centreīs 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, whatīs the best way to do the job.

Pete

Hi All, I got the rough template done today. Itīs not mm perfect but when I transfer it to a stiffer card I will trim exact. I think it will help a lot, having the transom in the lounge (not what the other half said though)

Ok, a couple of questions;

1, Should the transom be exactly symmetrical?
2, If not, where should measurements be taken from?

I have taken a centre measurement, from the outside edges of the boat (close to top of transom), down to the centre of the lowest part of the hull. I think that the original drives were put in Pis*ed, as you can see (here) http://s751.photobucket.com/albums/x...ito/?start=all . I am hoping that this is nothing like the "offset" for some outboard installations.

Next step is to make card template and cut exact, then plan new drive holes, based on cavitation plate (gear box) 1 to 2 inches above hull bottom.

Anyone have any ideas or observations?

Thanks

Pete

Hi All

The centres are not fully decided as yet. Mainly because I am realising that the further outboard the drives are, the higher the engines will be, in the boat. I have also noticed that the TRS, drive shaft to prop shaft, is about 1"1/2 longer, lifting the engine that much higher also. Then, if that wasn't enough, I see that the TRS also stands back from the transom about 5"1/4 more than the Alpha 1. Is there a way to work out how much higher the drive shaft should be because of this setback?

I have found a setup sheet for the Apla / Bravo installation. This includes measurements for a right angle (90 degree tool) here http://www.boatfix.com/merc/Install/gas/86017211.pdf , itīs lined up with the drive centre line and level with the hull, at that point, then the top of the upright is the correct (cav plate level with hull) position for the horizontal centre line. Is there any measurements for this type of tool, for the TRS drives?

Iīm going to spend some time getting the exact measurements but I think I have the general idea. It does look like I might have to raise the engine cover, although it might look a little strange with a 2 story aft end :-)

Pete

Pete - Wonder if you considered that the TRS is not serviced by Mercury any more and that spare parts are not available - how is your salvage yard supply of TRS in Spain?

Reality says beware but gut says go for it. I doubt that there will be anything in Spain, for the TRS but, they are strong?

The problem I have is, I canīt afford new drives and I really like the idea of the smooth gear change, of the velvet drive.

Either way, I must get these engines off the floor, so any ideas are very welcome.

Pete

Hi all. It's time to revive this thread and the job. I've started getting things ready to get this done. The centers of the engines are 86cm and after careful measuring I have marked out there position, allowing 1cm between the engines.

As you can see from the photos Here, the old drives were not symmetric. I don't have much room inside the boat, to rout out the entire drive hole, 2 x 75mm. So my question is: Can I scarf in new wood where it's needed, or must I fill the entire hole. I was thinking of making up two x 3/4 ply, to the shape of the drive cutout and overlapping where new wood needs to go. What are your ideas on this?