Cyclocross - Converting roadie to cyclocross?

I just inherited a semi old (not sure on the year, probably mid 80s) Lotus road bike. Frame says its "manganese alloy," and the bike seems to work pretty well. Ill be using it mostly as a commuter (college student). I assume manganese is a mix with some type of steel. Anyone know anything about these bikes, and could it possibly make a good conversion for cyclocross? What would I need ( I assume new fork, wheels, tires?). Thanks

edit:

It looks just like the left bike pictured here:

http://i166.photobucket.com/albums/u92/epicurean_rider/Lotus1.jpg

Except the shifters have been moved up and a flatbar was put on it by my father. I assume its an excelle? Were these decent?

Take some better photo's and make a post in the classic vintage section and those guys will probably tell you all you need to know about the old Lotus. I think they made some decent bikes in the day. Down Tube shifters usually indicate a better bike. You can probably make a good cross bike out of it. I wouldn't bother getting a new fork. The only problem is that you have side pull brakes. IF they are long reach then that is better but you won't be able to fit fat cross tires in there and they will clog up if you are racing in mud. Are the wheels 700c or 27in? You might be able to fit some 28's or even 30's. It might help if you know some one with some tires to try first.

But I've seen it done many times. In fact my first rig was an old touring bike but that had canti's. It should be good enough to get out there and try cross racing.

Those look like reasonably old bikes. The brakes are likely to have a lot more clearance than most modern sidepulls. But clearance is going to be your limiting factor. I would try and borrow someones wheels/tyres and have a go at fitting them. The places to watch are normally the brakes, the fork, and the chainstays.
Remember to check what size wheels you have. You might well have 27" wheels, which would limit you tyre choices quite a lot.

Good luck. I hope you give it a go!

Those look like reasonably old bikes. The brakes are likely to have a lot more clearance than most modern sidepulls. But clearance is going to be your limiting factor. I would try and borrow someones wheels/tyres and have a go at fitting them. The places to watch are normally the brakes, the fork, and the chainstays.
Remember to check what size wheels you have. You might well have 27" wheels, which would limit you tyre choices quite a lot.

Good luck. I hope you give it a go!

It's true that there aren't many 27" tire options... but in my mind, a frame intended for 27" wheels is perfectly ripe for some new 700c hoops and awesome tire clearance. Get some old Dia Compe Centerpulls, throw some Kool Stops on them, and ride the hell out of it.