SVX Engine cooling "Again & Again"

[Dessertrunner]

The lastest is,
we put the modified top pipe on the buggy but it didnt help the cooling, Steve, the guy with the buggy felt his problem was the Motec not doing the timing right at high revs thus causing the engine to over heat. He has riped the Motec out and changed to a different unit.

His personal opinion is that the top cross over pipe will improve the engines cooling issue when he fixs the timing. This beleive is supported by the fact that the moded pipe is now a fixure on the buggy and not coming off.

This is were I am at :-
Still trying to get a price on a water flow meter so I can put solid numbers on what rate the water pump is putting out at the different engine revs.
Next challange is to get a correct left & right head tempreture, currently I have a coolent temp gauge on the outlet of the top pipe which gives the combined tempreture on both heads & I have the standard guage on the left head. The only way I think that I can get correct data is to drill into the aluminum head on each bank and insert a probe to measue the actual head tempreture this will be proposanel to the coolent temp.
After I get all this info I will then start the mods such as change the top pipe to see if I can reduce the difference is each head.

We have a saying at work and I think this is the time to bring it up:-
"Do we know this to be a fact or is it just an assumption as every time we ASSUME we know the answer and its not support by FACTS it bites us on the arse". I am afriad that I need some facts in the form of data before I can go any further with fixing the problem.

Have a great day.
Tony

[SilverSpear]

Originally Posted by Dessertrunner

This is were I am at :-
Still trying to get a price on a water flow meter so I can put solid numbers on what rate the water pump is putting out at the different engine revs.
Next challange is to get a correct left & right head tempreture, currently I have a coolent temp gauge on the outlet of the top pipe which gives the combined tempreture on both heads & I have the standard guage on the left head. The only way I think that I can get correct data is to drill into the aluminum head on each bank and insert a probe to measue the actual head tempreture this will be proposanel to the coolent temp.
After I get all this info I will then start the mods such as change the top pipe to see if I can reduce the difference is each head.

We have a saying at work and I think this is the time to bring it up:-
"Do we know this to be a fact or is it just an assumption as every time we ASSUME we know the answer and its not support by FACTS it bites us on the arse". I am afriad that I need some facts in the form of data before I can go any further with fixing the problem.

Have a great day.
Tony

Tony... you've just became my HERO!

[dynomatt]

Danny, I hadn't seen the block without the crossover pipe on it, so thanks. I see they are exactly the same size (visually).

Why wouldn't we go to the option of dual outlets (and inlets in the radiator) like the EZ30? To me, the combination of that and the slightly different pump and capacities points to Subaru solving this problem for us?

I had a look...admittedly real estate under the manifold on the starter side (can't say left or right, or driver or passenger due to globalness) is complicated by vacuumn and fuel lines, but easily manageable.

I'm thinking this is pointing us in the right direction.

Matt

[Nevin]

After having read several pages of information and conclusions that I entirely agree with, I just have one very small suggestion (let's call it a drop in the bucket, if even that.)

A fellow I know who does engine competitions (Got #5 in '06 In the Jeg's Engine Master's challenge in "Popular Hot Rodding" magazine) mentioned to me that a lot of the V-8 guys are now going to reverse-flow cooling systems with electric water pumps. What this does is first cools the heads instead of the block. In our cars, it seems like this could possibly help in addition to the modified X-over pipe (which is a GREAT idea.)

It seems that a reverse flow system, in our case, would keep the temps down as well as releasing the restriction of the X-over being unequal. It's unequalness it seems, would not be as bad since it would be the side first being pressurized instead of if being the side where the coolant is being "sucked" from. Pardon my lack of being able to put my thoughts into mechanical terms, and I do realize there are a few other obstacles that would need to be overcome also to do this, but... has this crossed anyone else's mind, or am I just way out of the ballpark on this one?

[TomsSVX]

That is kinda the point of running two auxiliary 1/2" ID cooling lines to the cylinder heads directly from the pump.

Tony you are saying the modified X-over on the buggy did not help at all, made it worse, or helped a little?

Tom

[Nevin]

Originally Posted by TomsSVX

That is kinda the point of running two auxiliary 1/2" ID cooling lines to the cylinder heads directly from the pump.

Tom

In that case, wouldn't this be easier? Instead of running auxiliary lines, if you're already using an EWP, why not just reverse it to get the same cooling effect? Not to mention the extra power you could gain with a standalone because you could run more timing (since the head is cooler.) As I was informed, that was the biggest reason they V-8 guys started doing it.

[Trevor]

Originally Posted by shotgunslade

It is very simple physics. It is the same on the water side as it is on the airside. You can't tell me that when the car is overheating, you can ever improve the problem by reducing airflow through the radiator.

Apples/apples. The radiator is engineered for maximum flow of both fluid and air. The block is a complex convoluted combination of many port sizes; various restrictions; tight bends; blind spots; and parallel circuits are also involved. As flow speed and pressure is increased, so does the ratio of flow difference between open and restricted spaces. Open gain at the expense of restricted.

P.S. On the practical side, it has been shown that in the case of many cars, removing the thermostat in the hope of increasing flow and therefore cooling, has had the directly opposite effect.

[Dessertrunner]

Tom the mod is benficial in Steve opinion, its just that the ECU problem didn't give it a chance to shine. We need to test it in another way when do you think you will give your pipe go.
Tony

[Trevor]

Originally Posted by TomsSVX

That is kinda the point of running two auxiliary 1/2" ID cooling lines to the cylinder heads directly from the pump.

Tony you are saying the modified X-over on the buggy did not help at all, made it worse, or helped a little?

Tom

Tom,

You always view things from a practical aspect and this is an absolute must. Twin auxiliary lines as you suggest could provide a simple means of balancing as well as directing flow. As an experiment, hand valves could be included for adjustment. The thermostat housing lends to this end, via the heater circuit outlet.

No one has mentioned the two parallel circuits involved, i.e. the manifold and heater. These will have an unequal effect on each leg, much so in respect of the heater. I would presume that these are blanked off in the applications being discussed. However this should be confirmed, or otherwise should be given serious consideration.

Keep your thinking cap on, Trevor.

[TomsSVX]

Originally Posted by Nevin

In that case, wouldn't this be easier? Instead of running auxiliary lines, if you're already using an EWP, why not just reverse it to get the same cooling effect? Not to mention the extra power you could gain with a standalone because you could run more timing (since the head is cooler.) As I was informed, that was the biggest reason they V-8 guys started doing it.

H-6 cooling path = Block-->heads -->block --> radiator. It would not really matter much

Tom

[Dessertrunner]

Update,
Have purchased two temp senders that I can fit into the back of each head were the 20 mm plugs that Tom is talking about are. Once they are in we should be able to see some numbers on the tempreture in each head.
Coolent flow is proving more problmatic as the flow meter I want to use cost $700 so I need to go back to the start and find a cheaper unit. I will keep you all posted as we collect the data.
Tony

[SilverSpear]

Tony, can we help in sourcing the units for you at least used?
If you want provide us with details...

[Myxalplyx]

Just read this whole post! Lots of information. Very informative and technical. Since I'm the anti-technical.....here it goes.

Seems most people have been focusing solely on coolant flow, with the assumption that the left bank is flowing less and causes the car to overheat at sustained high rpm. Makes sense!...

Have we broadened our view to look at other factors that may come into play, which could cause the left bank to heat up? Here's a bone I'll toss out. The side that the left bank of coolant is supposed to cool. What cylinders is it cooling? Is it 1-3-5? Have we considered whether these cylinders are getting the proper amount of fueling from the injectors? If say...injector #1, #3 or the combination is not putting out the proper amount of fuel (or too much), could this simulate the same overheating of coolant that is being experienced?

Just throwing this out there since the cleaning of my Subaru's injectors (Old school and new) always resulted in #1 and/or #3 being worse than the rest, until I had them professionally cleaned. Increasing the coolant flow of the left bank may be like taking more headache medicine for the headache instead of removing the cause of the headache. Could only be prolonging the inevitable.

If this is far fetched, besides coolant flow, try to examine what else could simulate heating up of the coolant flow of the left bank, something other than just the flow.

I'll crawl back into my reading/lurk state and continue to learn now. L8Rs...

[Dessertrunner]

Help:-

During the week I contact 3 companies to find a flow meter to measure the coolent flow but all options have been to expensive, around $700. Any suggestion or equipment to use to measure the flow would be appricated. Have thought about weighing how much coolent is pumped in 5 minutes. This seems the cheapest overall as I have all the materials. The negitive will be that the water pump wont be pressure feed.
Thinking of plugging in the engine to a 31,000 litre tank to the engine water pump then the outlet from the engine into a tank on the scale. I fully understand that the result will understate the true flow but it will be better then what we have now which is "Zero" knowledge.
Tony

[Dessertrunner]

Here is a image of the top coolent pipe clearance.
Tony