Swapping Alpha One Gen 1 with Alpha One Gen 2 Gimbal Plate...

[vandentr]

Hi Everyone,

Does anyone know if the Mercruiser Gimbal plate (42259-C) with the 4 bolt exhaust mounts can be swapped out with the (43880-C2) plate with the 5 bolt exhaust pattern (see pics)?

If it can, are there any special considerations for doing so?

Thanks for any info!

-TVB

 

[achris]

Yes, complete housings can be swapped out.

Here's the hook though... You need to swap EVERYTHING. That includes inner transom plate, exhaust pipe, trim rams and drive....

Chris.............

 

[vandentr]

I was afraid of that.

My Sea Ray came with a 260 V8 and the Y-Pipe that would use the two top bolts and the two lower bolts for attachment, but was installed with only 3 bolts because the older gimbal plate with the offset pattern was installed on the boat.

I do not understand the logic of this setup?

 

[kenny nunez]

I just did a job like that on my Donzi. I reused the original bellhousing and plugged off the oil transfer port in the Alpha2 gimbal housing and was able to use the original drive. As Chris said I also changed over to the Alpha hydraulics. A good time to replace the trim and trim limit senders.
I also changed the exhaust back through the drive with a “Y” pipe one of my friends gave me.

 

[vandentr]

I just had a possible epiphany.

Why not simply add an ear to the exhaust pipe?

The only concern would be whether or not there'd be enough clearance between it and the back of the pipe for that to work.

 

[Bondo]

Ayuh,...... Or just get the Right y-pipe that fits properly,.......

Y-pipes are Not all the same,....... My guess is, yer's was swapped for the wrong one, at sometime,.....

 

[vandentr]

That's the problem, Bondo.

I'm not sure what the "right" Y pipe is for this application. There are conflicting messages from Mercruiser, and even within the forum as to what's acceptable and what's not.

If I can get the guys at the shop to tack on another ear then I won't have to modify or swap out anything more upstream or spend a ton on a new or used Y pipe and I'll have 4 bolts holding that sucker in as intended.

Right now that makes the most sense to me given the age and amount of use this thing will likely get.

 

[kenny nunez]

You will not be able to use the original power steering, you need the Alpha 2 style, the “Y” pipe has to be for the Alpha 2 so that the power steering will fit. If your exhaust risers are the rear mount type will make connecting the exhaust a real challenge. If you have center rise style risers then you will need a pair of elbows that will connect the risers to the “Y” pipe. That is what I had to do and I already had center style risers.

 

[achris]

vandentr

How about we sort of 'start again'... Please tell us the engine, it's year, serial number and model. And do the same with the drive and the existing transom housing. Then tell us the serial number of the new parts you are trying to use.

At the moment all we have is an Alpha One, an Alpah One Gen II and a non-descript exhaust y-pipe. We're all just guessing in the dark and throwing thoughts out.

BTW, if it's the wrong pipe, even welding a new mounting lug on won't ensure it will seal.

Chris........

 

[djmakko1]

My 87 Chris-Craft has the 4 bolt pattern 1 on the side 1 on top 2 on the bottom, and I installed a 2 on the top 2 on the bottom Y pipe and only use 3 bolts since there is no place for the 4th one, and never had a problem leaking, until I had water in the bilge and rusted the Y pipe from the outside.

 

[vandentr]

achris

I have parts scattered all over the place right now as I'm just getting back into the rebuild process after winter. I will eventually get to the point of being ready to figure everything out definitively, but it'll be a while before I can provide all of those S/N numbers.

I will post up all of that info on this thread when I'm a little farther along.

My hope was that it was a more common problem than it apparently is, which I should've expected given the nature of these projects.

-TVB