Hey Bill, just a little hydronic knowledge. If a pump creates pressure on
the outlet side(block), it would have a lower pressure on the suction
side(radiator). If this didn't happen you'd always be creating pressure and
it would blow apart the system.
The coolant wants to go back to area of lower pressure(radiator). I
sometimes don't think of pumps as pushing the water, but more as sucking
water.
In heating systems, the pressure can exceed the open point of a pressure
relief valve (radiator cap) if it's done slowly or if sharply as in a spike.
Also remember, you increase the boiling point of water when you pressurize
it, which means you can run higher temperatures with out it turning to
steam.
I use a 20lb cap from a Stag.
Charly
----- Original Message -----
From: "Bill Babcock" <BillB@bnj.com>
To: <triumph_marx@freenet.de>; <fot@autox.team.net>
Sent: Saturday, March 26, 2005 6:57 AM
Subject: RE: FOT Project Pulley
> Yeah, Peyote is plumbed that way, and it might help. I run 16 pounds of
> system pressure, but I have a non-standard cooling system. As I recall,
> someone said they put a pressure gauge on the block and it was as high as
50
> pounds. I don't understand exactly how that happens since the radiator and
> cap are on the outlet of the pump. Seems like block pressure should be
lower
> than radiator pressure. The radiator constitutes a big pressure drop.
Inlet
> pressure can't be more than 16 pounds because that's where the radiator
cap
> is.
>
> I've never really seen signs of cavitation in water pumps, and I don't
know
> why--seems like they should cavitate like crazy. But a pump that's
> cavitating shows erosion signs in a very short time, and I've never
noticed
> that. They are extremely inefficient designs--straight blades or even
blades
> hooked the wrong way. Efficient centrifugal pumps have s-shaped rotors
with
> the hooked ends of the S pointed away from the direction of
> rotation--exactly the opposite of the "scoop" design you might think would
> be effective.
>
> -----Original Message-----
> From: owner-fot@autox.team.net [mailto:owner-fot@autox.team.net] On Behalf
> Of triumph_marx@freenet.de
> Sent: Saturday, March 26, 2005 4:15 AM
> To: fot@autox.team.net
> Subject: Re: FOT Project Pulley
>
> To prevent cavitating coolant from the waterpump I raised the system
> pressure up to 10.5 PSI. That help's a lot.
> To prevent overheating of the #4 cylinder you can use the water outlet of
> the heater and shortcut it into the wateroutlet that is connected to the
> radiator.
>
> Chris
>
>
> ----- Original Message -----
> From: "Henry Frye" <henry@henryfrye.com>
> To: <fot@autox.team.net>
> Sent: Saturday, March 26, 2005 12:55 PM
> Subject: Re: FOT Project Pulley
>
>
> > At 07:45 PM 03/25/2005 -0800, Bill Babcock wrote:
> > > It would be a very worthwhile endeavor to get a smaller crankshaft
> pulley
> > >or a larger waterpump pulley. We probably need about 60-70 percent of
> > >the pump speed we have now. It would require some testing and some
> engineering,
> > >but it seems like a worth project. Ken--have you ever considered
> > >doing something to fiddle with the pulley ratios?
> >
> > Remember, slowing down the water pump will further reduce the coolant
> > pressure in the block. You want decent coolant pressure in the block
> > to quench the steam bubbles that will form, and the inherent poor
> > coolant
> flow
> > towards the rear of the block makes #4 the target for localized
> overheating.
> >
> > I'd be cautious with this approach to finding more ponies, especially
> > if you have had cylinder #4 overheating issues.
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