Have a bud with a '04 Rancher 350 that wants more power. How much more can be gotten out of a pipe /air filter /jet mod? For the money spent does it make a large enough gain or is it to little to bother? Other than going into the engine (high comp. piston, cam, ect..) what is the best approach to this?

 

Pipe/Jetting/and filter is the best power gain for the money. It makes a huge difference once it's set up properly.

 

A pipe, filter, and rejet makes a noticeable difference.

 

get a 400ex

 

400EX + Mud hole = anchor

 

I'm curious how many people on here (if any) have gone big bore on the Rancher. After all, if the 400AT can add around 70cc without any overheating issues why couldn't the 329cc Rancher benefit from such a displacement increase. The autoclutch of the FE/FM with a big bore would make it much preferred to the 400AT IMO.

Thank you for that wholly worthless contribution.

 

i was just looking at a the at, if my memory serves me correctly, its a completely different engine, sure as heck don't look like my 350

 

The foreman and rubicon use different engines, the 400 AT is just a bored and stroked Rancher 350 engine.

 

Rancher big bores are very tricky. Many people who have gone that route have had a lot of problems with dependability. The old 300s were wonderful to bore but not the Rancher. If anyone was to go the big bore route with a Rancher, they'd need to do some major research and find an expert at it.

 

Usually most gas engines are nowhere near their potential for horsepower, it's easier to massage them a bit than to make major changes. Getting the right parts to do it with can be something else altogether however. More power means more stress, and more heat. Time for synthetic oils, frequent oil changes, maybe an oil cooler, that kind of thing.

Something else to consider, you may get more horsepower, but the percentage of time the engine can maintain peak power without damage may be considerably shortened due to the increased forces. An example of this (not a perfect one) is the Caterpillar 3126. We have a few of these at work, is the reason I use it. A small 6 cylinder diesel, turbocharged, intercooled and unit-injected, the models we have produce about 425 horsepower at 3500 rpm. Not shabby for an engine around the same size as the Cummins turbodiesel in the Dodges. One thing I didn't mention, it's only rated to maintain peak horsepower for 12 minutes out of every hour.

Put two of these in a jet boat, add a Navy operator who wants to get where he's going in a hurry, and isn't aware you can't pin the throttles at full for an hour, and you better hope the VHF works or you're going to be swimming home.

You can coax more power out of almost anything, but it will shorten the lifespan, and the "duty cycle" for lack of a better term.