OPS .21 power on O.S. lower

[JoachimRuess]

Has anybody experience with the last OPS .21 Dac next on the lower part of the O.S. outboard?
I am interested about the torque and power output and if it is a good replacement fot the O.S. motor.
Thanks for any reply
Joachim

 

[Joern Markset]

Yes I have, and it was not what I like. Very lazy on low nitro. At the time I had a lot of different engines available, so I did not do any modifications to it.
Some years ago I rebuilt some OS Speed engines for direct drive on the XM lower, they worked pretty good. The rebuild was done using parts from Rody Roem, unfortunately he sold out his batch of reverse cranks and pto housings, so those parts are no longer available to my knowledge.
If there`s a demand I`m sure somebody could make up a batch of the necesary parts for converting car engines.
Then you have another option that I`ve been using for quit some time, and that is the gearbox solution. It is in my point of view a very good solution as it let you use every car engine available on the market.
For those of us who have strict limitation on nitro content, a gearbox is very usefull as it let you use the engines powerband the way it was designed. Combine it with a floatchamber for stable fuelsupply and you have a very reliable outboard.

 

[JoachimRuess]

Thank you Joern for that great explanation. This was very helpful for us to prevent from further expenditure.

 

[Kris Flynn]

Hi Jørn,

I am killing the delrin spur gears on my gearbox, what material are yours using?

 

[Grimracer]

Ask Terry Keeley

 

[dave roach]

Kris
You are running the gears to tight causing the gears to get hot and the gear will grow larger.

 

[Kris Flynn]

I thought this Dave, but then I added extra shims and they actually die quicker with more spacing...

Maybe it is just too much power

 

[the german]

I thought this Dave, but then I added extra shims and they actually die quicker with more spacing...

Maybe it is just too much power

Kris
I had a conversation with Manuel out of Portugal about a year ago. He is using C45 steel pinions and Polyacetal spur gears. He also gave me this link :
https://www.norelemusa.com/en-us/Product-Overview/Systems-and-components-for-machine-and-plant-construction/22000/Spur-gears-racks/Spur-gears-plastic-module-2-injection-moulded-straight-teeth-engagement-angle-20°/p/agid.21482

Maybe this helps.

Alex

 

[Joern Markset]

Hi Jørn,

I am killing the delrin spur gears on my gearbox, what material are yours using?

Hi Kris
I’m using delrin, and they tend to last forever. Heat is the enemy as mentioned above, do you run in a very hot environment?
When setting up the gearbox there shoud be a tiny gap between the teeth, just enough to feel the «klunk» when holding one gear and flip the other one back and forth.
Do you see any wear on the gears, or do they break instantly?
What size spur do you use?

 

[Kris Flynn]

Hi Jørn

Mine are delrin, they tend to last 2 maybe 3 runs/tanks if I am very lucky.
I honestly think I must be pushing them harder than most people. I am after flat out corner speed...this setup is the best cornering setup I own, it is right up there with FE cornering...by this I mean it has a very low loss in speed compared to a traditional direct drive outboard setup. Not as good of a top end, but faster, more consistent lap times than my tried and true Novarossi beasts.

I even tried an aluminium spur and it only last 2 laps lol



Here is a video.

As for gear ratio I am running 23 pinion and 28 or 30 spur. My pinions are 1040 steel

If you have some I could buy of your brand I would love to give then a go.

 

[Joern Markset]

Kris, I know I made some brass spurs long time ago, I’ll look for them.
Probably have some delrin gears as well.