01fm

Has anyone had or know of the real differences between a alloy and cast iron waterpump for a 351C. I have a choice of either for about the same $'s and both are good quality units. The alloy pump has a fully open impeller on the rear, where as the cast pump has nearly a enclosed ( flat plate type with vains pointing back to the body) impeller. Is there any gains or loses with water flow.

xdc351

The flat plate w/vane type is 30% more efficient and doesn't have the cavatating issues at high RPM the impeller type does. How much have you found one for?

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Just like a Tsunami.

brenx

Only downfall to cast iron is it holds heat. Alloy quickly releases heat. xdc351 is correct about the pumps.

Brenden

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XB Fairmont (street car) 11.07@123.02mph.

xbgs351

Best pumps are from John Bennett at what was called Ecotherm. He still modifies pumps, but I think he may have moved or changed company names. Water pumps are a bit of a sideline for him. He converts diesals to run on Natural gas. He used to be involved with Allan Moffat back in the heydays. Bit of a Mad Scientist.

One trick of his that I have heard about involved plumbing into the coolant passages at each cylinder of the heads. This relieves pressure stopping distortion of the head which adversly effects valve seal.

ESP

I have one of John's modified pumps on my car.
Works a treat, combined with the 4 core custom rad I've got.

John's an interesting if not eccentric bloke for those of you who have not spoken to him. He knows his stuff and his products do work better than the standard and many aftermarket offerings. My impeller is bronze and has the disc enclosed / flat impeller design.

The alloy housing I've got was made in Japan !!!! and John put his own design impeller on it. Well over $150 off memory, and that was over 3 years ago.

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XE ESP The last of the CLEVO's
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pracy

01fm where are you getting these from?
iu am looking for one now aswell.
looking at sydney speed shop and KB engines.
but they dont know the design of their waterpumps etc...

01fm

I went and checked today and bought the cast pump ( paid $100.00). They said that they were unable to get any more as they had this one in stock for over 2 years (bag was still sealed), and hadn't dealt with that distributer for quite some time. The brand on the box is "SHEFFIELD" and is labelled "MADE IN USA". I suppose I just got lucky.

xbgs351

It is not uncommon to get a noticeable increase in horsepower after fitting one of Johns pumps.

Another idea of his involves relocating the thermostat to the bottom hose. This controls the temperature of the water going into the motor and stops the front cylinders running colder and at more erratic temperatures than the other cylinders.

ESP

This does work especially well for a Clevo. Have you ever noticed when you've pulled your motor for a rebuild that the back cylinder bores are nearly always 1 or even 2 thou more worn than the front bores. This is the result of poor water circulation / cooling in these ALL iron Block/head combos. The heat just can't be dissipated effectively enough and the back bores expand and contract on a much more disproportionate level to the front.

Of course this becomes more prevalent over time and I've seen it first hand on my Clevo that had done approx 60,000Klm since the last rebuild.

If your temp gauge shows hot, imagine what the actual water temp in the back cylinders is !!!!!!!!!!!!!!!!

Most temp probes are right up the front of the block where the water enters from the rad.

John's system and logic is much more ideal, but much more expensive and hence a less attarctive proposition considering that a well serviced cooling system will do an adequate job 90% of the time.

The key is stability................temp fluctuation is the biggest problem. Going from cool to hot and then cool again is NOT good.

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XE ESP The last of the CLEVO's
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