I'm looking for suggestions on a low rpm, "realistic" gas engine.

[omj86]

Hi,

I'm looking for low rpm, "realistic" gas engines that can
be used to build a tamiya 14.5:1 truck to a gas insted og electric.
Does this exist? Thanks.

[modelman]

The short answer is-NO. Small gas engines are designed to run at hi-rpm. You could look at a 4-stroke engine like this- http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXXRH2&P=ML. These engines are made to run at lower rpm and have good torque. They are pricey but very good quality. The biggest problem you will have is cooling. All these motors are air-cooled. In airplanes they work okay but even in R/C cars running fast they still get very hot which causes short engine life. Also you will never get realistic"truck" sound from a gas engine, even the 4-stroke. Not saying that it can't be done but there will be lots of problems. Just my opinion- Good luck

[SmallHaul]

I made a nice little 1/10 scale 4x4 truck that is powered by a .26 four-stroke engine that runs very well. Modelman is right about the heat but, it is fairly easy to reduce the heat with an electric fan. My little truck has a belt driven fan and it keeps it cool fine even at low speeds. The biggest downfall with a nitro engine is the oily mess though. I would not want a nitro engine in a scale rig too messy for me.

A nice compromise might be an os 26 four stroke converted to gasoline with a powerful electric fan for cooling. The stock tamiya can motor has about the same power as a .15 2 strike nitro engine and the .26 gasoline four stroke would be more than enough power. You could probably even retard the timing a lot and run it at very low rpms so that it sounds nice. You would just have to make a very heavy brass flywheel to keep it running smoothly. You would also have to make custom clutch shoes full of weight to engage at very low engine rpm's.

It would be a lot of work but, it would be cool!

[ihbuilder]

there's a guy in japan that built a lonestar IH with 1 I've seen his y-tube vids . IMHO , to fast :eek:

[SmallHaul]

The OS 26 4-stroke is small enough for a 1/14 rig.

http://i240.photobucket.com/albums/ff66/scottmaxxin/IMG_3412.jpg

http://i240.photobucket.com/albums/ff66/scottmaxxin/IMG_3413.jpg

I put one in a 1/10 scale truck that has a 2 speed trans and reverse.

http://i240.photobucket.com/albums/ff66/scottmaxxin/IMG_3414.jpg

http://i240.photobucket.com/albums/ff66/scottmaxxin/IMG_3415.jpg

[Madda]

Hpi produces new gasoline engine, check it out too!

[RCP57]

The OS 26 4-stroke is small enough for a 1/14 rig.

http://i240.photobucket.com/albums/ff66/scottmaxxin/IMG_3412.jpg

http://i240.photobucket.com/albums/ff66/scottmaxxin/IMG_3413.jpg

I put one in a 1/10 scale truck that has a 2 speed trans and reverse.

http://i240.photobucket.com/albums/ff66/scottmaxxin/IMG_3414.jpg

http://i240.photobucket.com/albums/ff66/scottmaxxin/IMG_3415.jpg

What or where is that motor from? I likey:D Looks better than dead batteries to me...:D

Reg

[mack kid]

I not sure how far you want to go but there is a lot of scale engines out there the problem is there very expensive

http://www.gpdealera.com/cgi-bin/wgainf100p.pgm?I=OSMG1330

[Hondajd7]

This might interest you. This company makes diesel conversions for nitro motors.

http://www.davisdieseldevelopment.com/home.php

[SmallHaul]

What or where is that motor from? I likey:D Looks better than dead batteries to me...:D

Reg

The hi-performance pull start OS26c's and OS40c's are no longer made and are very hard to find. Even used they go for over $400 on ebay. You can use regular airplane 4-stroke motors but, they don't rev very high (around 11k) and you'll need a way to start it. They sound great, just like a 4-stroke
dirt bike.

[omj86]

tanks for good respond.
But all engines I find dont go lower than 1800 rpm, isnt there any engines that start up at as low as 500/600 rpm? That would have been the pefect match ;)

[Trackerman]

Smallhaul,
the pull start on the four stroke in the 4x4, did you add that or was it part of the engine new. Interested to know as the concept of live diesel power interests me.

Cheers

Paul

[SmallHaul]

Smallhaul,
the pull start on the four stroke in the 4x4, did you add that or was it part of the engine new. Interested to know as the concept of live diesel power interests me.

Cheers

Paul

Paul,

It is an OS-FS26S-CX car engine that came with the pull start installed. Unfortunately they are no longer made. If you find one all of the parts are available to rebuild it if needed though.

Scott

[Trackerman]

Scott,
thanks for the info.

Cheers

Paul

[TURBOTWIST]

I also was looking around at this type of idea,what I found is that there are now some new four stroke weed wacker motors out.honda and reyobe.have one and also I think I seen them at surplus supply web site.but I don't know what the spec are for them.

[rcman]

I have often thought of installing a nitro in truck myself... I think the stock tranny could handle it ....i to love the sound and smell of nitro in the morning!

[omj86]

Seems to be kinda hard to find a gas engine with lower rpm then 2500.
Is still need to be a small size so it will fit inside the Tamiya.
I guess I will try my first project with the Ford Aeromax, it will be good
to have the space avalibale in the hood and under the house, i guess it will be needed :)

I will have a engine that can fit in the hood, with the shaft facing backward, and have a fan in the front under the hood to cool it down.

How is it to have low and high gear on this?
I'm thinking lowgear on forward and rev, and allso a high gear on forward.
I know Tamiya have 3 gear speed controller on the el, but how is it to get this on the gas system?

How is the FS-30 4stroke to convert to gasoline or diesel?
How will the specs on the enignes be when convertet? Same RPM and tourqe?
Or will this change?

[SmallHaul]

Seems to be kinda hard to find a gas engine with lower rpm then 2500.
Is still need to be a small size so it will fit inside the Tamiya.
I guess I will try my first project with the Ford Aeromax, it will be good
to have the space avalibale in the hood and under the house, i guess it will be needed :)

I will have a engine that can fit in the hood, with the shaft facing backward, and have a fan in the front under the hood to cool it down.

How is it to have low and high gear on this?
I'm thinking lowgear on forward and rev, and allso a high gear on forward.
I know Tamiya have 3 gear speed controller on the el, but how is it to get this on the gas system?

How is the FS-30 4stroke to convert to gasoline or diesel?
How will the specs on the enignes be when convertet? Same RPM and tourqe?
Or will this change?

You can use a single gear clutch bell to drive the stock tamiya trans but you will have to research/find a reversing unit to go after the tamiya trans to go backwards.

You will have to research what carb would be needed to run gasoline in the OS 30 4-stroke. You will aslo have to find a good way to mount this carb.

A very heavy rotating mass will be required to keep the engine running at very, very low rpm's. You could make a 2inch or so brass flywheel that is mounted beside the engine and driven by belt... the flywheel would have a small (about 3/4inch pulley) on the front of it so that it would turn over twice as fast as the engine providing a really nice smooth idle.

The first step would be to make a test stand and get the engine, ignition, carb, flywheel assembly and fan working great and then tackle the drive train.

[sparkycuda]

Might look at this site. http://www.dieselrc.com


Ken