SVX Engine cooling "Again & Again"

[svxistentialist]

Originally Posted by svxistentialist

My point about bubbles, cavitation, steam, voids, whatever we call it, was in support of Tom's theory above and relating to your earlier hypothesis on pressure drop boiling, which Trevor dissed.

The whole system may be equalised by a relatively small bore interconnecting pipe at the top of the heads that would bleed any superheated gassy coolant back to the better circulating right side and vent any gas to the tank. With adjustable ball valves if they are a help.

Joe

Originally Posted by Trevor

It should be kept in mind that a limited section balance pipe, between circuits at any critical point, will balance pressure and flow. There should be terminals where one or more could be fitted, without too much strife. It is a matter of fluid mechanics, not an airy fairy mystery.

What you suggest here Trevor sounds a lot like what I mentioned earlier, and what YT is saying. I do think the core of the problem is fluid mechanics. Two separate heads being cooled by a pump on one side.

Joe

[svxistentialist]

Also I agree with Tony's analysis.

Too much heat on one side, or ineffective cooling on one side, however you want to see it.

[I'm sure Tom meant to agree with Tony, not Harvey? Tom?]

Joe

[yt]

Originally Posted by oab_au

Don't like the wording, but yes I agree.

Harvey.

Originally Posted by yt

Agree with Harvey here. Wording is not ideal but the idea is there. I agree that this is main focus point we need to pay attention to

Tom

Yes, do agree with both if thats what you meant

Tom

[svxistentialist]

Originally Posted by yt

Yes, do agree with both if thats what you meant

Tom

I meant that Tony was the one who asked for a specific Agree/Don't Agree answer.

[shotgunslade]

Agree. Lower flow through left bank. Probably causes local boiling.

[Dessertrunner]

Okay, today (it is now Sunday 6.30am) I will change the pipe on the top of the engine. Based on what we all agree if the tempreture of the left bank runs cooler then the right bank it means that the flow has become higher then the right, if on the other hand we get the same tempreture in both heads we would assume that the flow is constant. So lets see what what happens will tell you at the end of the day.
The reason for asking if everyone agrees is that we can"t flow test left and right bank that easily so we need to all agree that there is a different method to find the answer.

The Biggy for the day,
Second point I need some Hp power numbers of the standard engine at different rev, 2,000rpm, 4,000rpm, 6,000 & 8,000. I would also like them for the target engine. I have been thinking about what Rally Bob said and think we need to build a quick & dirty, Tony "type" rough computer model to show us what would happen under different scenarios. It won't matter is the Hp number are right or not just that they are indictive of the engine.
The model will deal with the follow variables and I was going to us excel.
Change in Engine Revs,
Changes in air tempreture past radiator,
Change in coolent flow rate,

If anyone feels like giving it a go please speak up, other wise I will start on it tonight. Have a great day team.
Tony

[oab_au]

Originally Posted by Dessertrunner

Okay, today (it is now Sunday 6.30am) I will change the pipe on the top of the engine. If anyone feels like giving it a go please speak up, other wise I will start on it tonight. Have a great day team.
Tony

What are you changing the top pipe to?
What modification have you done to the pipe?

Need To know.

Harvey.

[Dessertrunner]

Harvey,
Think of the moded one that Tom posted a photo of first. Haven't got the time and parts to build a "T" one today but want to see how the simple mod goes as step 1.
Tony

[Trevor]

Originally Posted by RallyBob

One concern I have is that the standard cooling system has proven to be substandard for even a bone-stock engine that is run continuously hard (6500 rpm max).

The crux of the problem is that cooling efficiency deteriorates as RPM rise, i.e. as pressure rises. Increased pressure does not equate with an efficient increased steady cooling flow. This is not difficult to comprehend, but is being ignored. All other issues transcend this fact and should be accorded similar status, but the cart is before the horse.

The pressure does not rise at a linear rate. Cooling deteriorates accordingly on a slippery slope, at hot spots and points of resistance, as a result of increasing pressure. Balance within the system is upset to an increased degree, as a result of increased pressure. Cavitation at the pump is more likely at increased RPM, against what is a fixed resistance.

Increasing pressure in line with RPM, is surely the essence of the subject.

[Dessertrunner]

Harvey,
Forgot to ask, any ball park guess on the HP numbers, it just needs to be a best guess.
Tony

[yt]

A stock engine generally produces somewhere in the ballpark of 175 wheel horsepower if it is in good shape w/ a std. trans. Around 160 w/ the auto

Tom

[Dessertrunner]

Well the cross over pipe didn't fit, its to high as was suggested. I need to cut and weld to get around the problem.
Any way I will photograph the fix when done and keep you posted.
Tony

[SilverSpear]

Crap... is he gonna pay you for it?

[dynomatt]

Post edited

[Dessertrunner]

Sorry for going off before I was unfair.

Good news, I got the pipe changed this morning and drove the car to work and guess what the left and right bank were running at the same temp. It was possiable to sometimes see 1c difference but was either way, above or below right bank temp.
Other interesting thing is that the dash temp guage ran slightly lower which would indicate to me that the thermostate is functioning better.

Hooray team we have progress, we are heading in the right direction on this project.
So what next? Have a great day.
Tony