Water Pump Speed

Naja · #1 (**permalink**) 08-02-2002, 02:18 PM

I have heard from several "classic" car builders that a Ford water pump (at least for a 429/460) should turn 1/3 faster than the crank. Opinions?

I have a March set with the large water pump pulley. The water pump is turning slightly slower than the crank. I figure that I can get better cooling at residential speeds if I get a smaller puller for the water pump. March makes a smaller pulley, but that only brings the pump to 10% faster than the crank. I haven't been able to find anyone with a 429/460 stock pulley to find out its diameter. If 5 inches or less, I can probably use it. Otherwise, I need to have one made for $$$.

Any thoughts?

Thanx.

Frank

Hotfingrs · #2 (**permalink**) 08-02-2002, 03:05 PM

you want between 7 and 12% overdrive on the water pump..

Jack21 · #3 (**permalink**) 08-03-2002, 10:23 AM

March makes two pulley ratio setups. High Performance, and Street Rod. For some reason, they don't make a big deal out of the Street Rod ratio, you have to ask about it. The HP ratio uses a larger diameter water pump pulley and underdrives the water pump. Good for reducing high RPM water pump parasitic HP loss, but not so good for low RPM cruise flow. The Street Rod ratio uses a smaller diameter water pump pulley (same crank pulley) that runs the water pump faster, and pushes more water through the engine at low RPM. Great for keeping engine cool at street RPM. Another help is an aftermarket, rather than OEM Ford high volume water pump.

The pulleys are about $50 or $60. Get one of each. One for the street, one for the track.

Naja · #4 (**permalink**) 08-03-2002, 12:21 PM

Thanx Jack and Jack.

Any idea why some of the older BB builders have told me that the pump should be about 30% overdrive? (speaking as though that is common knowledge).

I have the March 5.75 inch crank pulley (they make a 5.25, also), and the 6.25 inch water pump pulley (as part of the HP set). They also offer a 5.5 and 5.25 inch water pump pulley for $95 each. Right now I am running about 8% underdrive. With the 5.25 inch water pump pulley I would be running 9% overdrive. If I have one made, I safely could probably go as small as 4.75 inches, giving me a 20% overdrive (for $140).

I am also curious about the diameter of the stock crank and water pump pulley on the 429/460, but I haven't been able to get that info (to see if it is around 30% overdrive). Any help would be appreciated.

Frank

Jack21 · #5 (**permalink**) 08-05-2002, 04:49 PM

Just a guess on the 30% overdrive waterpump pulley on a big block.

"Typical" end use is 4,000 pound sedan, or 6,000 pound PU with air, and auto trans pumping a lot of heat at low RPM.

In this case, you're loading the engine less, and pushing more water through, so you need less overdrive to the waterpump.

Probably the 5.25 on the water pump, Edelbrock, or somebodies aftermarket high volume water pump, and good electric fan (Spal)with a dash mounted manual-on switch should keep your BB cool in beach traffic in the summer.

Mr.Fixit · #6 (**permalink**) 08-05-2002, 06:00 PM

I always had fine luck with the March underdrive pulley sets on 460's. No overheating problems even on showqueens that almost never get past first gear. Moving water faster doesn't hurt, but the most important thing in a cooling system is to exchange heat and that's the job of the radiator and fans. Don't forget the need for a rad cap that holds pressure, a worn out rad cap can cause heating problems.

Naja · #7 (**permalink**) 08-06-2002, 06:57 PM

Thanx for your comments, guys -

I've had a variety of problems (including exhaust gases in the coolant), but I think I am at the point of 'fine tuning' now. To make cooling as efficient as practical, I'm pursuing a couple of things, such as the water pump speed.

A guy just sent me the pulley sizes from a late '70s 460, and the water pump is 25% overdriven. He will be sending me an early '70s 460 measurements in a couple of days for comparison.

I anticipate that most of my driving will be between 40-55 mph (1500-2000 rpm). That means that at 40 mph (with my current 8% underdrive pulley), the pump is turning about the same speed as at idle with a 9% overdrive pulley, and airflow through the radiator may not be significant. I figure that if most of my driving will be at these rpm's, I might as well configure the water pump pulley to give the coolant flow that the engine was designed for - apparently requiring something akin to 20-30% overdrive. Sure, if I do a lot of racing, or want to run around at 3-4000 rpm (making a racket and wasting gas) constantly, an underdrive pulley makes sense.

I've got a heavy Cobra (perfect for the touring that I intend to do), a C6, and a/c (that I have'nt been using, yet), an .080 overbored engine, and the temp around Houston is over 90 for much of the year, meaning that I have the potential for very high heat loading of the coolant system. Therefore, I want to get as much out of my 7 core radiator, 16 lb. cap, and 2800 cfm Flex-A-Lite fan as possible. That means optimizing other system components. (I've also moved my trans cooler to the rear with its own fan - both fans are switchable). I am just now plugging the holes in the shroud I built to direct all of the air that enters the front through the radiator, rather than having a significant portion going around by the tires. I am also going to investigate the effect of opening the hood slightly. If it makes a significant difference, I'll look into ways to allow hot air to escape with it closed - louvers in the hood, ? ? ?, etc.

Like I say, I think I am OK at this point, but I would rather tweek a few things to give myself a cushion, than to be running 'at the edge'.

Any other ideas will be appreciated.

Regards,
Frank

Mr.Fixit · #8 (**permalink**) 08-07-2002, 09:53 AM

Exhaust gas in the coolant? Is this fixed yet? Done a leakdown test on that motor to see if you ventilated a cylinder wall?

Naja · #9 (**permalink**) 08-07-2002, 11:32 AM

The exhaust gas in coolant was determined very early on after it became runnable (in December) - actually, the day after I got it safety stickered, because that was the first opportunity to run it for longer than 5 minutes. And, yes, #7 & 8 were 20% and 30% on the leakdown test.
No definitive cause(s) for the exhaust leakage, so the builder thought it may have been several small points. He also thought that the block was slightly twisted, causing the cylinders to be very slightly out of round. Of course, the engine was pulled and torn down. Heads and block re-levelled, and cylinders re-honed.
That was 6 months and 1500 miles ago. The various overtemp problems have kept me from having 5000 miles on it. It's been in shops for at least 4 of the last 8 months. (It's in the shop right now to rebuild the transmission because of metal particle damage - source unknown as of today).
Having a continuous string of problems for years sound familiar to anyone???

Mr.Fixit · #10 (**permalink**) 08-07-2002, 02:56 PM

Out of round cylinders won't cause exhaust gasses to get into the coolant. A cracked cyl wall will, warped head, bad head gasket, those will. I wouldn't be surprised to find a cyl sleeve in that motor. Make sure the tranny shop flushes out the cooler or you'll be seeing them again.

Naja · #11 (**permalink**) 08-07-2002, 04:29 PM

Right On!
Out of round cylinders will cause you to fail a leakdown test, though. In my previous post, I was referring to 2 separate and distinct problems diagnosed at the time when the serious overheating first became apparent.
Yes, I do have 1 sleeved cylinder. That block was the best of 3 blocks thoroughly tested before the engine build started.
Some of the items that you mentioned relating to the exhaust gasses were suspected as being the culprits - nothing stood out as saying, "I AM IT."
I'll remind the shop tomorrow about flushing the cooler. Stall converter is expected back Friday or Monday.
Regards,

wadesdad · #12 (**permalink**) 08-08-2002, 09:30 PM

Naja,

I have a C-6 and nearly cooked my newly re-built trans with a bad TCI torque converter. I shut it off quickly, but it still produced a lot of heat and smoke. Summit had "excessive returns" on them and replaced it with a B&M. It put a lot of crap in the entire trans and my cooler.

I am the reigning king of bad new/rebuilt parts.
Master cylinder, proportioning valve, torque converter, steering rack.......

All is well now and I've been tooling around Ohio for a week now.

Good luck!

Naja · #13 (**permalink**) 08-09-2002, 08:10 AM

Hi, ...dad -
I have a TransKing converter. They just cut it open yesterday to check it out. They said that there was no evidence that any of the parts in the converter were the source of the metal particles that scored some rings and the pump.
I had them adjust (?) and/or change some parts in it to bring it from (an advertised) 2500 stall to about a 2100 stall. (With well over 500 ft-lbs. below the old stall, we figure that the true stall was between 2800-3000 and it would be generating a lot of heat at any speed below 90 mph. Now, it may be 'locked up' at around 60 mph). Unfortunately, the source of the metal parts will remain a mystery. The only remaining source that I can think of (assuming the honesty of all who have examined it) is the outfit that originally moved my cooler from the front to the rear. They would have had to drain the fluid and replaced the fluid after they placed the cooler in their "god-awful" location. They may have used contaminated fluid - ??? (It was moved again - to its present location - but I trust the person who did that to have used fresh fluid (but one never knows). It was shifting a little differently after the first move (and subsequent overheating), but not any differently after the final move and 2 subsequent overheats.
Here's hoping.
By the way, I plan to drive near Strongville (on I-90) on my way from Detroit to Watkins Glen on Oct. 3. Should be around there about noon - ??? Maybe we can link up for a few minutes.
Regards,
Frank

Tom Wells · #14 (**permalink**) 08-09-2002, 09:16 AM

Hello wadesdad & Naja,

Funny you guys should bring that C6 stuff up!

While all the distributor gear crap was going on and the engine was pulled etc., I had to replace my TCI Saturday Night Special converter and have the C-6 rebuilt after only 812 (that's right, eight hundred and twelve) miles.

Guess what? The trans was full of something that looked a bit like bead blasting sand!

Where did it come from? I don't know. I bought the trans from one source and the converter from another. The guy who redid the trans opined that the junk could have come from the failed converter, but could not say for certain.

Education is never free - some just costs more than others.

The car now has an Edge Racing converter which I hope will stand up better. So far the trans seems fine but it only has been 500 miles or so. We'll see.

What's up with TCI???

Regards,

Tom