Why are there more guides on a fly rod, then on a spinning rod?

On rods of similar length, there usually isn't. Or at least there shouldn't be.

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My father gave me an old bambo fly rod, with 14 guides, its 11'6. It fishes good, I love the action, as it locks up the fish in streams with a lot of brush, Thought may-be I could do the same with a spinning rod?

Are you talking Factory rods compared to Custom built rods ?? There is a difference.
All depends on the flex of the blank. Stadic test up in the library

I've never thought about it until I read your question, but this is my take on it:

1. The guides on a fly rod are lighter in weight than those on a spinning rod.

2. The line shooting through the guides on a fly rod follows a straighter path as compared to a spinning rod where the line spirals off the reel.

3. Because of reasons #1 and #2, the rod can afford to have more guides. The greater number of guides allows the line to follow the rod's flex profile more closely. Of course there is a tradeoff between this and other factors, but reasons #1 and #2 allow the tradeoff to lean towards having more guides.

With a fly rod, your casting the line as opposed to a spin rod where you're casting a heavy lure. You need better transferance of the rod load to the line during a fly cast. More guides, better transfer of power to the line, up to a point.

Thats all fair, but the rod blank I have is 2-6 lb. 10.6 noddle. useing a #16 guide, then down to #6. I should be very close to the number of guides as the flyrod, useing the Stadic test. Once the line is started down the guides, I am to understand that the number of guides should not effect the cast distance. What effect does having a certain # of guides hinder???

More guides = more weight and the blank has to carry that weight. Starting and stopping the rod takes longer and you lose energy that could have gone into your cast.

It would be rare that any extra friction from an extra guide on two has much effect on the cast, but the extra weight the blank has to carry (start and stop) may very well have an effect on the cast, among other things.

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Is this a fast action blank ? If so it should hold the guides but don't over do it.
When you think the spacing is good, TAKE one guides off. Respace again, bet you may like that better.

Ron
Have you done a static test on that bamboo rod ??