Posted By: Confusedcuda
340 water pump and pulley questions - 05/22/08 04:13 AM
Okay guys, I have a 71 340 I am putting in my 67 barracuda. My cuda had a 273. Can I use my 273, water pump(cast-iron)pump pulley, and crank pulley? I ask this because, I would have to have my radiator switched, if I go to the 340 wp. Also the 340 had a/c powersteering,etc. so it has a 3 groove pulley, where my car has none of. The 340 wp will not work with any of this because it is a longer pump. My 273 water pump is an after market that has 8 blades, wheres the 340 only has 6, but it is aluminum and has a little more area to it. If I use my 273 pulleys and water pump, will it cool enough? I noticed that from 68 to 69 the 340 and 273 used the same pump. Does the more blades help? Will my smaller pulleys be okay on my 340? Thanks
Posted By: 69Cuda340S
Re: 340 water pump and pulley questions - 05/22/08 10:01 AM
The older WP will bolt right to the newer timing chain cover and work correctly. The lower hose will block the timing marks some what but you'll still be able to see them. The 6 blade WP is for AC cars and must be used with the AC pulleys because they spin the fan/WP faster on AC cars. Therefore less WP blades are used to prevent cavitation (condition where water stops flowing at higher RPMs). Everything will work assuming you have a "thin" crank damper with the proper offset pulley bolt holes. You also need to use the older alternator brackets so it will all line up.
Posted By: Confusedcuda
Re: 340 water pump and pulley questions - 05/22/08 12:23 PM
Yes, my crank pulley does line up to the 340 dampner.I do have the timing gauge on the drivers side but my 273 water pump has a slide on one that goes on the pass. side. Don't know how accurate that is, but may work. My stock 2 core radiator should be good enough to work I hope. I love the stock look of it. I may try to find a fan shroud that works, do you think this would help? Thanks for taking time to answer.
Posted By: 69Cuda340S
Re: 340 water pump and pulley questions - 05/22/08 12:31 PM
Fan shroud will make a big difference but you will probably need a three core to run it on the hot days.
Posted By: Confusedcuda
Re: 340 water pump and pulley questions - 05/22/08 01:36 PM
So you don't think it matters that my crank pulley is smaller than the 3groove crank pulley that was on the 340? Could this add any power, like a underdrive pulley?
Posted By: GO_Fish
Re: 340 water pump and pulley questions - 05/23/08 02:31 AM
My
Like everybody said, the early small block WP and cover will bolt up directly to the 340.
I've bolted up my '68 318 timing cover and water pump to my healthy '74 360 installed in my '68 B'cuda. I am having problems running hot with my 2 core 22" radiator in weather over 70*. To attempt to combat the heating, I'm adding a deep pan with cooling tubes to my 904 to help shed heat from the 9.5" convertor (literature says the pan can shed up to 20*) before it can get to the radiator. I have high oil pressure right now running 20w50 Rotella, so I'm going to switch down to 10w30 and ZDDPlus to reduce some heat there also. Last move would be to replace the water pump with a HP unit with a disc attached to the impeller to reduce cavitation. If none of these 3 work, then I'll be looking at an aluminum radiator. FYI, I'm running a 22" shroud off a /6 (mounted upside down with minor mods), and a 5 blade viscous fan presently.
Posted By: Anonymous
Re: 340 water pump and pulley questions - 05/23/08 02:45 AM
Quote:
So you don't think it matters that my crank pulley is smaller than the 3groove crank pulley that was on the 340? Could this add any power, like a underdrive pulley?
You need to see if the pump is the bigger diameter, 8 blade, or the smaller diameter 6 blade to determine the speed it should run. The big diameter impeller should be at .95 ther crank rpm and the small diameter impeller should run at about 1.3 times the crank rpm. Be sure to measure the pulleys at the pitch diameter (not outside diameter) when you do your calculations. Pitch diameter will be about 2/3 of the way up the belt thickness.
I can't think right now. 
My temp seems to creep highest at 30-40 mph speeds, cooler at idle and cooler on the highway... (yes this would be a hi-jack) 