Measurements for installing Mercury external hydraulic steering
 

Would any one happen to have the measurements for installing the old style Mercury external power steering on a 1989 Formula 311SR1 with TRS drives.
I understand that the stern mounted brackets have to be mounted parallel to the engine crank centre line and in my case the steering rams will be mounted between the drives since the boat has the usual Formula silent thunder swim platform.
This is the measurement that I need-from the side of the gimble housing to the edge of the steering cylinder bracket.
My email is [email protected]
THANKS IN ADVANCE FOR ANY INFO.

If it is anything like the 272, it depends on what silent thunder deck you have. There were 2 decks. One had really poor clearance and one had "better" but still would bend rams if mounted in center and drives were tilted full up.
If you do have the clearance, the centerline of the drive position transmitters are crankshaft centerline.

Thanks for the reply
Do you happen to know what the measurement is from the gimble bracket to the steering cylinder bracket?

Wow. Sorry been too many years for remembering that close of detail.
It depends on the style of bracket and how it's mounted. I'm not familiar with the old merc system.

If Baby Formula is still on OSO I think he installed the setup you are looking for. He had a 311 with TRS drives.

Call Scott Smith at Formula TAG. Boiler Daddy here, might be able to help.

Dave

Thanks for the info guys and I will try Scott Smith at Formula tomorrow and Baby Formula on OSO if Scott doesn't work out.

Try imco website ..... they have the diagrams... I'm the road fought now but will check in a bit and try to post ....m

Download the PDF file ....info is there ....m
http://imcomarine.com/nvcatalog/imco_catalog.pdf

Thank you for the web site but I was not sure if the Old Style Merc hydraulic rams are the same length as the Imco.
Ron

[ATTACH=CONFIG]517367[/ATTACH]
:whistle:
Stick steering here
:angry-smiley-038:
Catch up with ya this summer Ron

Do you have the "Old Merc" rams available to measure?
If so, measure them.
Then calculate the IMCO setup utizing the DELTA shaped center ram mount that has the hydraulic thru hulls at the apex of the delta. Figure the length of the IMCO rams required to make that work.
Then you can figure out utilizing independent ram mount brackets that are not connected together like the "delta" mounting plate. You will measure for 3 days trying to get it figured out and essentially will come up with rams the same length within an inch no matter what system you end up with. Remember, you have 34" between drives center to center. So you only have so much room to work with. If your rams are too long, you reduce your travel by not being able to shorten the stroke. If your rams are too short you will not be able to extend the ram far enough. The difference is going to be an inch either way. The available rams are not that exact.
From my experience....
Once you put full hydraulic on the boat you will almost never turn the wheel to the extreme of its travel anyway.

Thanks OPIE272 for that info. I expect to pick up the Old Merc rams in two weeks and will take measurements like you said.
Scott Smith of Formula emailed me back but was unable to give me the gimbal to bracket measurements that I was looking for.
I am going to try Mercury Marine when I can some info on a good Tech person there to contact. I have asked Scott Smith if he could supply me with a name and numer.
Appreciate everyone's help and I am sure we will eventually get things figured out like you mentioned OPIE272