Power Differences Among Stock Zenoah Engines

[Terry Heddin]

How much real world difference (seat of the pants, not specs, so to speak) is there between the G260, G300, and G320 engines in stock form? I have searched the internet, and cannot find any real comparison.

 

[David Ashcroft]

Not much ,but I have seen 260 engines run faster than a 320 engines and vice versa.
Depends on the application .

 

[john v]

I would guess that the 32 will have more torque than the 26
From what I heard, the 32 is heavier and uses different mounts than a 26
In stock form you will probably see more 26s than other displacements

 

[Mark Anderson]

If somebody wanted to send me stock 30&32 motors for a couple of days, I could dyno them and compare to 26 with real numbers.

 

[LohringMiller]

We dynoed a lot of 26 cc engines. The only difference we found in stock 26 cc engines was due to break in. Design differences like using the same outside dimensions with larger bores and longer strokes with the same connecting rod length will cause some power loss in higher displacement engines. Otherwise the there was no difference detectable within the precision of our dyno. The mass production methods Zenoah uses make the different engine parts very close to identical.

This was not true for Quickdraw engines during that time period. We always ran carefully selected Quickdraws. (Thanks Mitch) Even the cylinder hone pattern could make a difference.

Lohring Miller

 

[Steve Smith]

We dynoed a lot of 26 cc engines. The only difference we found in stock 26 cc engines was due to break in....

Lohring Miller

Hi Lohring,

Can you elaborate? Did you find that engines with more run time (more broken in) made more power, or were you seeing differences because of 'how' an engine was broken in?

 

[Terry Keeley]

If somebody wanted to send me stock 30&32 motors for a couple of days, I could dyno them and compare to 26 with real numbers.

Last you posted on the dyno was you were getting rid of the freewheel, it sounds like it's working for you now? Are you getting any weird "upswings" in your curves?

Care to put a little update (maybe some pics or video?) in the dyno thread?

https://www.intlwaters.com/threads/run-in-stand-dyno-build.78248/page-40
I'm going to do some testing soon now that I've cut the wheel down a bit more.

 

[LohringMiller]

Not a stock engine, but this series of tests shows the power gain after an afternoon of dyno runs on an M&D engine. This engine had zero drag seals so they weren't part of the break in. I don't find such a direct comparison with a stock engine, but similar power gain still happens.

Lohring Miller

 

[JoePeters]

How much real world difference (seat of the pants, not specs, so to speak) is there between the G260, G300, and G320 engines in stock form? I have searched the internet, and cannot find any real comparison.

Terry I would start with a g300/28.5 cylinder platform. The bottom ends will use standard mounts and should be very simple to set up and will accept a lot of hop up parts when its time. The g320 is a torque monster but its size and weight should be considered.

 

[David Ashcroft]

Terry ,,, John Finch on Jims runs a large Gas hydro similar to yours using a 260 size engine and he is getting speeds of 70+
A 260 will eat a Big block if you prop it well use a good pipe and set your hull up correctly. A 260 can run with and beat the Bigblocks .

 

[DON MAHER]

The same can be said for the big blocks!