Re: SVX Engine cooling "Again & Again"
 

The problem as suggested has no relevance with the flat head Ford V8. This had twin water pumps and complete circuits, so that pressure difference between the two banks was not a problem. In those days the stylists did not dictate available engine space. :rolleyes:

This not in fact a matter of one flow overcoming another flow, it is a matter of two unequal pressures, presented with a single outlet. ;)

Re: SVX Engine cooling "Again & Again"
 

Trevor, with all due respect to your thinking and judgement, and we all know that your reasoning is without doubt logical. But wouldn't you think that for a high performance EG33 you should be shooting the other way around? Instead of pausing restriction on the "higher" flowing end, why don't you amplify the "less" flowing end? Your performant EG33 will require more cooling in that sense.

This is what I am thinking about, a system where you can have twin water pumps without any resistance or restrictions, each cooling one bank and both of them equal in performance to the OEM pump. This way you will cause cooling balance inside the engine.

Trevor, can you show us a diagram about this V8 you are talking about? Or is it general to all Ford V8's?

Re: SVX Engine cooling "Again & Again"
 

For the recod the big book says 100lpm @ 3,000rpm and 200lpm @ 6,000rpm.

I have cut my manifold as you can see from the image the next plan if that doesn't fix the problem will be to put a new pipe inthe centre were the ruler is. That pipe will be 40mm as opposed to 30mm it is now. Next change the water pump inlet pipe from 30mm to 45mm if possiable. Also both inlet and outlet on the radiator changed to suit

I feel sure the inlet and out lets of the motor are both 30mm will cause a problem. Centrifugal pumps always have a larger inlet then outlet to prevent caviation.
Great the way everyone is jumping on board I think if a few of us run tests we will beat this problem finally. Have a great day or night.
Tony

Re: SVX Engine cooling "Again & Again"
 

Restricting the right side by a quite small amount, will result in the left side being increased. An adjustment of balance is involved, not a simple overall reduction. Evidence does not suggest a lack of flow and the opposite could be the case.

Coolant circulating too quickly, was the accepted diagnosis, in respect of the old flat head V8 Ford. This I know because in the early 1950s, I did very well in club competitions, using one of these engines in an AC sports car of 1935 vintage. Incidentally, a fan was not used and the car also served as family transport.:D

There is absolutely no way, anything resembling the arrangement used on the Ford could be replicated. For a start there is not room for separate outlet tubes for each side. A quick look will show why the designer had problems with space. As I pointed out, this is exact reason for the existing set up.

The Ford dual pumps were far too efficient and the cure was to reduce this quite radically. Drill all the rotor blades, or knock off every other one. Cast iron made them easy to break. Water at high pressure and full of air, is not an efficient coolant. Recesses are passed over, pockets are formed and hot spots result.

Cheers, Trevor.

Re: SVX Engine cooling "Again & Again"
 

The restriction appears to be at junction of left and right. I can not see the enlargement you have made making much difference. If you could bring out a pipe in line with the ruler, that would be another story. You will have to explain how you will create the clearance required.

P.S. The fact that a flow has been stated for 6,000 RPM, is surely a sign that cavitation within the pump is unlikely.

Keep at it. :D

Re: SVX Engine cooling "Again & Again"
 

This would have been great if otherwise... :o

Re: SVX Engine cooling "Again & Again"
 

Why not run a bypass in the cross over pipe so that the left hand stream enters the flow of the right post headers...

or not even mix them at all until they hit the rad with a Y like junction? Radiator Tomyx?

-Sov

Re: SVX Engine cooling "Again & Again"
 

The position of the radiator inlet favors the right side bank in terms of length and position. The left side would be toooo long besides finding a way to make it reach there and clearance issues. It would be ideal though if possible. :o

Re: SVX Engine cooling "Again & Again"
 

I don't mean to sound like a non believer but centrifugal's pump curves don't double the flow when you double the speed. "Subaru has got slack and cooked the books".

By the way if you look at the manifold on the car water goes from the left bank throught the throttle bodie and in to the manifold on the right bank. The only way this can happen is if there is a pressure difference from one side to the other, eg a major restriction in the centre.
Tony

Re: SVX Engine cooling "Again & Again"
 

Did a quick calc and if the pipes go from 30mm to 42ID the flow will double.
Tony

Re: SVX Engine cooling "Again & Again"
 

Tony,
Have you confirmed that your modified pipe will still fit under the intake? If "yes", could you provide some dimensions on the pieces of Al you welded on?
Thanks.
-Bill

Re: SVX Engine cooling "Again & Again"
 

My understanding in respect of a centrifugal pump, is that the flow rate is directly proportional to speed, all extraneous contingencies being equal, so that I do not doubt the figures published by Subaru. A curve is not involved but rather a straight line. Please qualify your opinion and advise where you have found contrary information.

This relates to a situation where there are two passages in parallel, with one more restrictive than the other. The relative rate of flow will be in proportion with the resistance and that offered by the larger passage can be near zero. Only a very small flow will be required to heat the throttle body. There is no reason to construe that a significant restriction exists within the major passage.

Re: SVX Engine cooling "Again & Again"
 

The flow will not be increased by enlarging one section of the circuit. The most restrictive point in the circuit, will continue to throttle the overall flow. ;)

Re: SVX Engine cooling "Again & Again"
 

Trevor,
Would you accept that as flow goes up pressure has to increase as the restriction beomes a bigger issue. That said then all things are not equal and flow must be reduce in proportion to revs.
Tony

Re: SVX Engine cooling "Again & Again"
 

Here is a pump curve to explain