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OMC 800 Ford 351 - stringers to hull dimensions

Z

ZipperAu

New member
Hi All,

Need some help down under please. I have an OMC 800 with Ford 351 (hydraulic engine tilt).

I am replacing the stringers and engine bearers in my boat (Sidewinder Ski boat).

I noticed that the engine bearers have been modified previously (height and Center line) and the engine mounts are now offset to the centreline of the hull (approx. 40mm). The boat was definitely originally manufactured with this outdrive and engine combination.

Can anyone please provide an installation diagram showing centreline and height of engine bearers for OMC 800 Ford.

Any help most appreciated.

Bob
Australia
 
Great opportunity to do it right. Ideally you will not use any wood when building up the stringers. Best is to use blue foam house insulation panels 1.5 inches thick and then wrap them with several layers of roving and mat.
I just use a string line from the drive to a point somewhere forward. It takes some bit of setting up to get it all perfectly lined up but once you have the crank center line established you can take measurements from the engine and transfer them to the boat.
 
Hi o2batsea,

Many thanks for your reply.

My whole intention was to replace it all with foam however I have been talked out of this by a boat builder. His reasoning has all to do with flexing and original design etc. He has identified the timber as Oregon and I have sourced some here imported from Canada...wow.

The big issue now is that I don't trust the engine / drive installation position. To the best of my knowledge and research the engine / drive mounts are symmetrical to the centerline of the prop. I can therefore not understand why it would have been mounted offset to the centerline of the boat. The only thing I can come up with is that the stringers were modified (widened) by the boat manufacturer to allow for a wider engine mount spacing than the jetdrives which were usually installed in this model. IE he was lazy and only widened one bearer so the lag bolts made it into the timber. I haven't ben able to get a single dimension anywhere on the net.

Height has also been modified on both stringers from manufacture so I am just chasing some dimensions from top of stringer to bottom of hull to get it right.


BTW I love this boat for its design which is timeless and still looks great today. I am in the middle of a total rebuild including a roller cam Ford 351W. She was upside down for a long time but I finally managed to get time to grind back all the cracks etc and give here a nice coat of 2pack. It was only when we put her back upright that all the rot was discovered.

Now that she is stripped bare maybe I should have listened to my Dad and started from scratch building a plug to copy her and build a new hull with todays technology.

Thanks again,
Bob
 
Ayuh,..... I gutted that driveline from an Old Town Atlantis hull, 'n am goin' back in with a SBC/ Bravo,.....

That stringer drive was also off-set a few inches to port from center in this hull,.... from the OEM,....

I've done a couple Highliner 222s,.... their stringer drives were centered,...
 
Hi Bondo,

Thanks for your reply.

I wonder if it is really noticeable in how the boat steers, mine is offset to starboard. Being a fairly shallow V hull it is probably more noticeable than an offset on a deep V.

I still think it is lazyness on the manufacturers account, same as there was no treatment done to the underside of the floor. Anyhow at this stage unless I find out different I will set it up on the centerline, would be nice to confirm the height however.

Bob
 
ZipperAu said:
1.... BTW I love this boat for its design which is timeless and still looks great today.
2.... I am in the middle of a total rebuild including a roller cam Ford 351W.
3.... It was only when we put her back upright that all the rot was discovered.
4.... Now that she is stripped bare maybe I should have listened to my Dad and started from scratch building a plug to copy her and build a new hull with todays technology.
Click to expand...

Bob, notes 1 through 4.
If you love the boat, and since you are going to this much work and effort....., why not ditch the stringer drive, and go with a later Stern Drive system????

You would not regret it!!!!!




.
 
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Hi Rick,

Yep...........you are asking the question I was expecting.....



I have owned her for nearly 10 years and had all intentions to install a Berkeley Jet or equivalent, very hard to obtain in Australia as all here are Hamilton Jets which are off the planet pricewise. Like the jet for safety and simplicity. I tried 3 times to get a used unit from USA but all fell through because of various reasons.

I do however now have 3x OMC 800 legs with 2 different ratios and 4 different props as well as the 351W roller block. So for the moment with this hull I am pretty much committed (and well aware of the OMC pitfalls), it is a time issue as well, kids want it in the water by this summer...sigh.


My long term plan is to copy the bottom hull which I already have converted partly to CAD (work in progress). The deck design needs some alterations to get it modernised without upsetting the sleek lines. I have access to CNC to make a plug.

So for this time it is a decision based on dollars, time and convenience.....but you are right....it is far from ideal.

Best regards
Bob
 
The wood inside the stringers does nothing. The strength comes from the fiberglass. Anyone who tells you different doesn't know what they're talking about. That's why when you see these old boats from the 1970's with the wood stringers barely tabbed to the hull you run away!

PS if you want to make a deal I have two complete AT 309 drives with all the goodies sitting in my barn in Maryland collecting spiders. freight will hurt but they are cheap!
 
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Hi o2batsea,

I am definitely interested in a drive as I can still change the setup. Freight may indeed kill it, I will send you a PM.

Thanks
Bob
 
PS they have b cut impellers, rudders, hydraulic trim and transom adapters. new bearings and seals from american turbine. have u joint connections for pto and two chevy pto adapters. They are literally ready to drop in. I built them all up for another project that died.
 
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