Rigging experts, I have a question
 

I am redoing all my engine mounting. Whoever rigged my boat years ago, was an azz. The aluminum angle brackets were drilled like a hot chick on prom night. They used front and rear engine plates.

What I would like to do, is use the original mounting of the ears of the transmissions, to the inner transom plates, along with the front and rear offshore plates. As of right now, the engines are about 3/4'' too far forward, as the stock merc ears wont align with the inner transom plates. I know it might be overkill, but I do boat in some nasty water, and really want everything tight back there. Fountain didn't exactly overbuild the stringers back in 1990. They are dry, but still.

So, I am gonna buy all new aluminum L brackets, and start from scratch. My thought was to get the engines in place, and install the bolts for the rear ears on the transom plates. Then using the alignment bar, raise or lower the front of the engine till its aligned. Then, start drilling the L brackets. This is where any tips would appreciated. Would I clamp the bracket to the stringer, then drill the holes for the raceplate, or clamp the bracket to the raceplate, and drill the holes for the stringer? Which way works better? This is a SSM plug in style setup. Also, how thick should the L brackets and backing plate be on the opposite side of the stringer? 3/8, 7/16, 1/2?

I'm no expert but I just installed a single offshore mount.

I located the bellhousing on the inner transom plate and then placed the engine with an alignment tool. I played with it for quite some time and got the tool to drop in with almost no resistance.

Next, I drilled the mounting holes in the angle on a drill press and then mocked up the vertical aluminum angle (1/2 inch by 3 by 2) and used a c-clamp to hold the angle tight to the offshore bracket and stringer.

Next, I drilled the stringers using the angle as a template.

Once both stringers had the vertical angle in place I drilled the offshore mount, again, using the angle as a guide.

I should add that I continuously kept checking the alignment.

Some pics:
http://i205.photobucket.com/albums/b...ps29635bf6.jpg
http://i205.photobucket.com/albums/b...ps6a95014d.jpg
http://i205.photobucket.com/albums/b...pse9e491ba.jpg

Hope this helps,
Rob

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You can see our engine mount system on the thread on water pick-ups. We rigged it this way about 10 years ago when we removed the engines frequently when racing. The advantage of this method is the time to get the engines in and out is about 1/3 the traditional method. As you can see, the support "feet" stay bolted to the motor mounts. We use a 1/2" drive 3' extension....one guy holds the nut and the other just spins out the 2 vertical bolts per mount. It is really fast and easy way to get the engines in and out. We set up all the wiring to the engines with multiple Weather Pack connectors. The only other items to remove are the water inlet line from the sea strainer and the tail pipes.

I bolted the ears to the transom plates, hung the motor by a chain off the water pump bolt holes so it was even and got it set so the bar slid in and the plate was flush all the way around the bell housing. No humble bearing on the so you line up a flat plate to the drive bell. Once that was set I used a bunch of c clamps to hold the 1/2" angle to the stringer and motor plate, and started drilling. I used all 1/2" hardware and even drilling with a 1/2" bit it all moves around a little bit until tightened down.

I do have that disc for the alignment bar that goes into the bellhousing.

All great ideas guys, keep it coming. And happy easter.

I will never use 7/16 stainless bolts again just do to the lack of availability. Every store In my area is depleting their supply due to lack of demand. I ran into that nightmare on the rig job I just finished. 1/2 from here on out and the added strength of the 1/2 wont hurt either

personally I don't like the use of the transom mount and the front and rear block mount. that makes six points and boats move and twist in spite of what some think. either use the front and rear mount or the front and transom mount. too many points will tend to break things like bellhousings or transmissions when something decides to move.

I would think it would tie everything together, the more support the better.

My cousin's 93 Top Gun used a front plate, rear engine plate and the ears on the transmission to the transom plate all secured. I didn't have to drill new mounts but had to r/r an engine twice in it, I did the same thing that was mentioned above by lil red to check the alignment during the reinstall. I liked the three points of contact for each engine/transmission even tho it was a pain in the ass to get everything mounted.

I also tossed all the galled up stainless bolts that came out of the mounts and switched to grade 5 bolts. 1) Because I couldn't find stainless bolts local and 2) you don't really need stainless bolts in freshwater, the coated grade 5/grade 8 are fine as far as I'm concerned for corrosion resistance and stronger than stainless.

Is there a spec on tolerance or is this just an adjust to feel? I align motor machine setups and we strive for less than 2 thou but you would need a horizontal plate in front to shim and adjust side to side. It's amazing how much movement you get just by torqing the bolts down

If you do use stainless dont use nylock nuts unless you have anti seize on the threads. When stainless locks up its a ***** snapping 1/2 or 9/16 bolts off down close to the bottom of the boat.

[QUOTE=BOATMAN302;4111176]If you do use stainless dont use nylock nuts unless you have anti seize on the threads. When stainless locks up its a ***** snapping 1/2 or 9/16 bolts off down close to the bottom of the boat.


I agree, the standard Grade SS bolts from 3/8-1/2" will last indefinitely with Nyloc nuts as long as you use a good lube each time on clean hardware. We have never had a failure with a lubed standard grade SS bolt with a ny-lok nut. Mercury sells a great anti-siege lubricant.
(Deleted grade 5-8)

Standard stainless bolts are about the same as grade 2 steel, only steel bolts are available in grades 2,5 and 8 that I'm aware of. Low carbon content of stainless prevents them from being available as hardened also.

Here is some more info from the Totally Stainless website.

Information on Stainless Steel
Stainless is a series of alloy steels which contain at least 12% chromium. Such steels will not rust when exposed to weather. The most common stainless steel is 304 which is an 18-8 alloy containing at least 18% chromium and 8% nickel. 304 is a non magnetic steel. The metric designation for 304 is A-2. Even more corrosion resistant alloys, such as 316, are available for some of our product line and are a good choice for high corrosion environments such as marine use. We carry medium strength hex and socket head cap screws made from strain hardened 316 in metric sizes. These fasteners have a strength designation of 80 and are approximately equivalent to metric 8.8 or a US grade 5. We have an extensive line of high strength stainless as strong as or stronger than US grade 8. The high strength bolts are made from age or precipitation hardened stainless and have a polished finish.

Stainless steel is superior to chrome plating because it won't crack or peel as it isn't a surface coating but the substance from which the fastener is made. Because stainless steel is softer than medium carbon steels (it only seems harder because it work-hardens) it tends to gall. Always use anti-Seize or a similar product on the threads.

That's good info, I'll look at their site. I was going off my local supply house and :
Stainless Steel
Stainless steel is an alloy of low carbon steel and chromium for enhanced corrosion characteristics. Stainless steel is highly corrosion resistant for the price and because the anti-corrosive properties are inherent to the metal, it will not lose this resistance if scratched during installation or use.

It is a common misconception that stainless steel is stronger than regular steel. In fact, due to the low carbon content, stainless steel cannot be hardened. Therefore when compared with regular steel it is slightly stronger than an un-hardened (grade 2) steel fastener but significantly weaker than hardened steel fasteners.

Stainless steel is also much less magnetic than regular steel fasteners though some grades will be slightly magnetic.

18-8 Stainless
18-8 refers to any stainless steel containing approximately 18% chromium and 8% nickel. This is the most common stainless designation for hardware. For information on 18-8 stainless steel material properties see our Material Grade Identification and Properties Chart.

Ive had this happen a few more time that I`d like , especially taking apart the drives, once it locks up forget it.. now I used some kind of lubricant before trying to tighten or loosen any stainless nylon nut.

[QUOTE=MILD THUNDER;4109393]I am redoing all my engine mounting. Whoever rigged my boat years ago, was an azz. The aluminum angle brackets were drilled like a hot chick on prom night. QUOTE]

I know exactly where you are coming from - mine didn't even line up. You should see the abortion they called tailpipes they gave me - if I told you what I paid you'd sh*t. I spent a lot of money unf*cking the mess I was given.

[QUOTE=yschmidt;4111448]That sucks. Mine worked ok for me, but wasnt right, so i wanna make it right. I think the alignment on a bravo setup, is more critical than on a ssm setup that has no gimbal bearing. Not to say it doesnt matter, Its just a little more forgiving. With a bravo if the alignment is off, the gimbal bearing wont last very long

And misalignment is hard on the coupler[QUOTE=MILD THUNDER;4111452]