Kind of a novice engine builder question, but Ive been seein some pix of built SBCs and the only belt the got is for the water pump. THere isnt an alternator! how is this possible? Or is this just for show purposes to clean up the engine bay? Forgive my "noob-ness"....

 

where?

 

bah! I forget, i saw em on one of my late night web searches. Ill search for em again to show ya.

But, is that even possible? Seems to me you'd have to have a hell of a battery to keep up with it. And, if u cud do that, then get an electric water pump and run a beltless motor!!

 

An engine will run w/o an alternator/generator...until the battery cannot supply enough juice for the ignition to work.

You may have seen "show" setups where the accessories were mounted down low with a custom bracket..in effect "hiding" then...this is done to show off all the chrome and polish on the top of the engine and give the appearance of a clean bay.

 

Probably a bad idea. You would be better off not to have a battery and just run the alternator, because the ammount of HP an alternator will steal will not be as much as the ammount of weight the battery will add.

I dont think it can be done.

 

It's done at the track everyday.

 

Temporarily, is how you run an engine without an alt.
How long it runs depends upon what type of ign system you're running, and how much charge the battery is holding.

 

The only place I have seen engines running with just a water pump belt is on the dyno, but the dyno has it's own 12 volt power source. Another option would be to run a magneto ignition that supplys it's own power, but then you would have to run several batterys in the trunk and charge them often for running any accessories. Not very practical!!!

 

I thought thats all they do run is an alternator...Electric water pumps seem to be useful on those cars

 

I disagree.

Usually the cars that do this are all-out drag cars. The battery lasts for 1-2 1/4 mi blasts max and then they recharge it or swap it.

Batteries are heavy, but alternators aren't light either. And when being used, they create quite a drag on the belt. I'd imagine it makes a bit of a difference.

 

True. I was thinking more along the lines of Formula One though. And the differences you would see on the street.. Whatever.

 

Lot of the guys who run without an alternator run a 16V battery to keep the voltage up under the load of the ignition and whatever else is drawing juice during a run. Obviously, short term dragstrip use only.

I have seen belts that only go between the crank and the water pump, too. I believe they either have a link in them so they can be opened up for installation or you would have to loosen up the water pump and/or pulley to install them.