How fast does the cam belt on a 348 travel at 7000rpm?

Roughly 40mph

Pulley is closer to 38mm radius... So ~31mph

 

It's actually not hard to calc, rpm to linear requires knowing the radius of the circle, in this case it's the cam pulley. V=r×w
W= radians per second, angular velocity

Off the top of my head I used 50mm radius. I'd have to measure one to get exact. 50mm might be too big, thinking about it

 

As long as you ise 3500 rpm for cams.

 

Actually all you need to know is the circumference of the crank pulley. If it's 12 inches in circumference than the belt travels 12 inches per rpm. At 7000 rpm it would be moving 7000' a minute. Take that times 60 minutes =420,000 feet a minute. Divide that by 5280' in a mile and you get 79.55 miles an hour.
That is all assuming a fictional circumference of 12 inches. If someone has the actual circumference just plug that number in and do the math and you will know.

 

Never mind, I should always read the post before putting in my 2 cents. I see it has already been said. I just explained it with my layman's brain.

 

Except I like your explanation better because you are using the crank.

 

I screwed my explanation up because the belt is connected to all of them so same speed but its easier to understand when explained by using the crank pully diameter.

 

Camshafts turn at half of engine velocity, hence 3500rpm.

 

I dont think crank turns cams though. I just looked again I forgot they are driven by the other pulleys.
So only way is to use cam pully diameters and use the half rpm on our engines.

 

Wait, I just had to delete my response. I thought the 355 had the gears that split the crank to two pulleys that then drove the cam belts and that the 348 single belt was off the crank pulley. But you're right the cam pulley is a different pulley that is chain driven off the crank on a 348. I think it's a 1:1 drive though. If you have the circumference of any of the pulleys and know it's rpm then that's what you need to calculate it whichever pulley you use.

 

Lol, I actually just went and looked at a schematic and see the drive looks more like 2:1 so the speed reduction might be done right there and the drive and cam pulleys might all be the same size and speed. Now I really want to go out and drop the cradle in my 348 and tear into the engine. Inspired by Dave Rocks 355 restoration project I am planning to strip down the 348 this winter and restore it ground up. Then I'll know every nut and bolt personally.

 

Just do it. Ha ha.

I also thought they came off the crank. I feel kinda foolish. But if your not making mistake your not learning.

No big deal we all corrected ourselves.

 

And why do you wanna know the speed of the belt Bruce? What spurred the curiosity?