The fan/impeller necessary or not?

stonemonkey · Post by **stonemonkey** » Thu Dec 04, 2008 12:21 pm

I will admit that I am a complete newbie when it comes to diesel engines. I can do basic maintenance on a petrol, but have no experience with diesels. My main interest is to make a biodiesel bike which is why I am here. To improve my learning curve.

So this might be a dumb question. It looks like the only job the big fan/impeller does is to move air over the cylinder heads for cooling. As a stationary unit I can understand the need for this. But on a motorbike you will get airflow anyway (unless stopped at lights). So is it necessary? On some of the smaller 400/500cc engines that thing takes up space, so removing it would be beneficial. OR do you need that thing to keep the engine ticking over?

Thanks.

oldbmw · Post by **oldbmw** » Thu Dec 04, 2008 10:42 pm

whether you need tha fan or not probably depends on your ambient temperature.. But you may well need the flywheel effect of it.

taildraggin · Post by **taildraggin** » Fri Dec 05, 2008 8:38 am

There's a whole lot of flywheel there. You would definitely need to work out a replacement, but it could be of lesser diameter.