18hp V-Twin 4-cycle vs. 40hp Inline twin 2-cycle...

[1975 Argo 8x8 2-Stroker]

Hi guys!

I want to replace my Old Chaparal G44B 40hp (Not sure of exact horse power, I think it's 40+) 440 2 cycle, with a Kohler Magnum V-twin 570cc 18hp 4 cycle engine.

The G44B is a nice, smooth running engine (for a s-stroke lol), but it's REALLY LOUD, that I can even handle, but the engine gets extremely hot... it's time for it to go, so...

I have 2 questions;

1. How well will the V-twin fit, and how much am I going to have to modify?

2. Will there be a (large) "noticeable" difference in power and throttle response?

I know a 4-cycle engine produces more torque than a 2-cycle, but can an 18hp 4-cycle "compete" persay with my old 40hp 2-cycle?

Thanks!

[hydromike]

I don't think Kohler made a V-twin Magnum. All of the Magnums are flat-twins from my understanding. The Command series is Kohler's V-twin line.

1. Member Evil8x8 has a big flat Kohler in his Argo, and it came as stock equipment. I don't know what the difference is between his model and yours , nor how the engine compartments may differ.

2. Yup. You're working with about half of the rpm range, too. You'll need a new drive clutch with the Kohler, and more than likely need to change the spring in the driven clutch. Under 3,000 rpm, your Chaparral engine was probably only making around 18-20hp, anyway. That magical fourty-whatever horsepower number is arrived at waaaaaaaaay up in the rpm range.

Overall, it's not a bad swap for the large machine. The flat engines are low rpm tanks that seem to chug along quite fine....

[1975 Argo 8x8 2-Stroker]

The Kohler comes with a primary clutch, will I have to change my secondary clutch on my transmition???

[hydromike]

I don't imagine you'll have to change the entire clutch out, but the spring in that secondary clutch is designed to engage for the power profile the G44B delivers. You might actually be fine. I swapped a four stroke into one of my Attexes, and kept the two stroke spring for a few years before changing it out, just to see if it made a difference. It did make a difference, but the performance with the two stroke spring wasn't horrible. It's just something to keep in mind if you end up having any issues with top speed or low end power.

[1975 Argo 8x8 2-Stroker]

Okay, Thanks Mike!

[shane]

Okay, Thanks Mike!

I'm pretty sure the engine is to high for our body style as I just scrapped an 85 for part's and the upper body is a fair bit higher for the twin flat engines.The tecumseh 16 single will fit with just hood modifications, you can measure to be sure but I think the upper body is to low for that engine, I have the earlier 17 kohler twin sittin here for future project's lol.

[1975 Argo 8x8 2-Stroker]

I'm sure a tecumseh 16 single would seem pretty DEAD after driving it with my 440 Chaparal twin...