Which side iz tha rite side????

[Trident]

Don't have pix.

Anyone?

Externally, they don't look much different... just a 2.4 or whatever, with an aluminum plate in place of the Stb. cyl. head to save weight and hold the water in, and only one switchbox.

Other changes are internal. PVC sleeve plugs, dummy reedcages plugged with Devcon in 1,3,5. One side of each duplex carb plugged with a soldered inlet needle seat.

Pretty heavy for a three cylinder 1.2 or 1.25, but they make good power and run well.

Strongest one I've seen is Mike's 1/2 2.5 for Formula 100. That one has special sleeves and porting, etc. and made his Mod 50 Burgess way too small. Same boat ran really well with the SST 70 2.4 version.

[tunnelvision07]

so you use the 2.4 midsection and lower unit?

[Trident]

Most do use the 12" racing tower, any one of several versions, as the powerhead, V-6 cowls and SSM 6 gearcase bolt right up.

I have seen a few with the earlier die cast gearcase, not sure of the model number. Usually painted black, slightly smaller...

Hot setup for short course racing was 13 / 16 gears. Need a pretty small prop with 14 / 15 although that works, too. Maybe Ron can whip up some 15's?

Now, all the ones I've seen were for racing on true racing tunnels. I have no idea what else would work. Is there a short service tower for a 2.4? 20" would be shortest? Yes?

Anyone?

[Fastjeff57]

Me too!

What do you do with the other 3 cylinders in regards to balance and other issues (like sealing the block and crankcase)?

Personally, I'd LOVE to build a looper 3 cylinder Merc with removable heads!

Sweet!

Jeff

PS: My homemade triple with external reeds really worked out great. With the same setup, the external reeds motor made nearly 1,000 more rpms at WOT and planed the boat off much easier (superior mid-range torque). Apparently, that stock Merc reed cage setup is a serious flow restriction.

[Trident]

Surprisingly, to me at least, is you do nothing to balance except remove three rod / piston assys. They run nicely on the remaining three. No nasty vibration.

As for sealing, that's what the PVC sleeve plugs and dunmmy reedcages do. Those PVC sleeves get a blind or closed end glued in, which goes in toward the crank. Sleeves are flush with block deck dimension. The sleeves are lightly pressed and glued in. Butter 'em up, push 'em in. Wipe off any drool.

The aluminum head plate holds the sleeve from shifting out and holds water in. You can use a head on that side, but most remove it for weight savings.

The reedcages bolt up like normal next to the working ones, on the same gasket surface and allow nothing to pass through to the 'dead' cylinders. Carb venturis ahead of those dummy cages have no fuel, as inlet seats are plugged. Adjacent venturis on the duplex carbs are fully functional to feed 2, 4, and 6.

Hope this helps.

[Fastjeff57]

..."Hope this helps. "

It sure does! I'm very interested in giving this a try--my next winter project.

A few more questions:

1. Do V-6 Mercs (that I nothing about--yet) use the same driveshaft as the in-line 6s?

2. On the V-6s that use two switch boxes (similar to those used on triples): can one simply omit one box and get the three cylinders firing in the right order? I assume that is how it's done with all 6 cylinders.

Thanks again!

Jeff

[Trident]

No idea on driveshafts for inlines.

Anyone?

Everything I ran, SST 90, SST 120, SST 140 was on the SSM6. The 90 used a stub M/F spline adapter. The 1 / 2 six was a 2.4, same spline as the race V-6's

That ignition with two swtchboxes is, in effect, two 3 cyl. ignitions. I use one of that same switchbox on my 650XS FE Mod motor. The trigger tells which box to fire what cylinder.

[Fastjeff57]

Gotcha! Thanks for the info.

Fascinating project!

Jeff

[T-REX]

OK, Investigate'in haz begun...lol.......

I have a 2.5 block that I am use'in to exsperiment wit, but I will be use'in a 2.4 BP block for tha project...Instead ov PVC, tha unused rod slots will be welded up...Also, I will try and run NO water in tha unused side ov tha mota.....I will be use'in tha starb. side for exsperiment'in purposes(I kan oil tha bottom and top bearin's off any cyl used)....Exhaust will be directed out the back(sorta a horn setup)...Az for tha front, I will run a spacer(1") between the front half and manifold, with only the cyls used cut out!!...A 14 peddle front, and a XRI 14 peddle manifold will allow the use ov both venturi on the carb for each cyl(small venturi 135 carbs will be tha carb ta start)...Tha 2 venturi setup per cyl may be too much, but if I kan git it jett'd, it will allow good air flo....I'm kinna excited about this lil project.....I kinna like da odd stuff(maybe dats why I talk to Ron once in a while...)

Tha main reason I wanna do this iz wher I live iz a bote club that allow's any type 2 or 3 cyl to play....and, if this works out, I kan swap fron tha 3cyl back to tha Outlaw V-6....My lil bote iz a Comp(Kevlar) 16' laser, 260#s, It's gitt'in to tha dangerous point wit tha pump'd V-6's, and if this 3 cyl iz fun, I will feel a lil safer......I have a 2.7 stroker, "Z" port to hang on tha lil bote, but ain't made up my mind if I wanna pull tha trigger or not...

Thankz for all ya'llz input on this....Sho help'd me git goin on this!!!!

Oh yea, juss fer info purposes, I run a 15" mid, wit a big geercase...2:33 geerz...Tha big geercase iz quicker for 1/8th mile stuff....

[Ron Hill]

Thanks, T-Rex for includinging in your list of "Crazy People".....Could you make a four cylinder this way?? Or are there no timing things for a four banger???