SVX Engine cooling "Again & Again" - Page 14

FriendlyTurkey · #**196** 10-11-2009, 08:12 PM

Great Job! Thank you for taking action and doing experiments for the group!

I think the next thing to do would be the following:

Observe temperature of each bank at different rpm points: 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500. Record temperature, and difference in temperature between banks.

Observe under which conditions that the present combination will overheat. (rpm, temperature, time)

yt · #**197** 10-11-2009, 08:21 PM

I thought you had said the modified water manifold did not help?? Now it does?? What is going on here?

Tom

Dessertrunner · #**198** 10-11-2009, 09:18 PM

Tom the last time we tried the manifold was on the dune buggy (sand rail), that was what we were talking about. This is the first time we have tried it on a SVX car. You and I have a bit of a challange to get them to fit under the intake as the idle valve plug hits and the vacum chamber hits at the front. But other then that its all good and works well.
Tony

oab_au · #**199** 10-11-2009, 11:44 PM

Quote:

Originally Posted by 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

OK that is what it is like on high speed commuting. Now we need to test it under racing conditions. Take it out on your favourite test track, use say 3rd gear (don't want to run too fast

) do a full throttle acceleration up to top revs, off the throttle, jump on the brakes, down to 5000, then back to full throttle, to full revs again, jump the brakes, etc, etc. Try to keep going, watching the temps.
Don't spend too much time off the throttle, you need to have a high pump speed and good heat input from the engine. Just like you are racing. Don't run off the road, don't hit a roo.

Harvey.

Dessertrunner · #**200** 10-12-2009, 01:37 PM

It was hot yesterday and the car cooling did some funny things, I have made some changes overnight and will see today. I will come back to you guys with an explanation tonight after we see how it performs today. In short the engine ran cooler yesterday but the radiator went to high, so I am checking things out.
Tony

SilverSpear · #**201** 10-12-2009, 03:22 PM

Nice progress Tony, please keep taking pictures of the progress you are making...

Dessertrunner · #**202** 10-13-2009, 01:27 AM

I have been talking to PWR today about radiators and I am going to get them to build a radiator with some differences.
Top and bottom pipe to be larger as I think the current size is to small for the flow at 6,000 rpm (200lpm). On the bottom feed pipe to the pump it could cause the pump to cavate so to get round any possiability of this I will change the pipe on the pump as well. Harvey's diagram of putting the top pipe return in the centre is the way to go so while I am at it I will do that change and increase the pipe size.
Next change is the number of fins per inch. Currently when you slow down the return tempreture of the coolent going into the pump shoots up. Also if I am traveling at 110kph and turn on the fans the return coolent temp drops which means the PWR air flow is poor. I read that a formula 1 car has 26fpi but if that was put in a normal car it would boil at normal travel speed on a average car. PWR told me they have 16fpi in the SVX ones they build and suggest that the OEM unit would have the same. My concern is that the PWR is twice as thick as the orignal but same fin number. The air can't flow through it properly this has the added effect of causing of the whole engine bay running hotter. I noticed that the SVX I have with the PWR boils the water out of the battery more often then the car with the standard. If you feel both bonnet under the same driving condiations you will find the PWR engine bay hotter.
Guys with the sand rails tell me they are going away from PWR as they don't cool the engine as well as other brands. If I get stuck behind a truck on a hot day the return coolent temp goes up to a dangerous level as well. so what would happen on a race track.
Sorry to have such a long post but needed to share my thinking. I am going with 12fpi reason 2 surfaces twice as think as the OEM means 48 equlivant to the existing 32 surfaces but maintaining airflow(got the quick crazy logic). Have a great day team will keep you posted (Are you still out there Trevor).
Tony

oab_au · #**203** 10-13-2009, 03:08 AM

Sounds good to me mate.

Your car is a bit different to the normal SVX, in being raised on the suspension. This reduces the negative pressure that is generated under the car by the venturi effect of the airfoil shape of the under body.

This creates a negative pressure in the engine compartment to enhance the airflow through the heat exchangers.
So it may well be different to the std one.

Harvey.

Dessertrunner · #**204** 10-13-2009, 03:16 AM

DO you happen to know how many FPI on the standard radiator?

Trevor · #**205** 10-13-2009, 04:07 AM

Quote:

Originally Posted by Dessertrunner

Have a great day team will keep you posted (Are you still out there Trevor).
Tony

I have given up posting, as a result the lack of logic being recorded. From afar one can only base thoughts on what is stated. Your very first post, all of which I took in, advised:-

Quote:

What I have found recently is the following:-
- Multiple pass radiator "DID NOT" slove the problem.
- A bigger Radiator "DID NOT" slove the problem (buggy radiator is 3 times bigger then my PBR).

You are spending many dollars, I hope in the right direction. You are making several changes at once, which is not good practice. Therefore you will be unable to detect which has made any improvement which takes place, or the exact reason for same.

I wish you well, Trevor.

Dessertrunner · #**206** 10-13-2009, 05:02 AM

Hi Trevor good to see you are alive.
Not spending that much, my current PWR radiator is reaching the end of its life so it time to get a new one. Last one only lasted for 250,000k.
My wife says I don't explain myself well, I am doing one step at a time, we have fixed the flow to the heads but now shifted the problem to the radiator. Coolent is coming back to high in temp so instead of buying the same radiator again I am looking at something different.
Need to ignore the work on the buggy as I have no control over it and there are to many different factors to compare it to here.
I figured out a way to test air flow in different radiators so I want to give it a go. Will keep you posted.
Tony

yt · #**207** 10-13-2009, 05:09 AM

If your radiator is faulty, thats one thing. I still feel we are barking up the wrong tree with it as a solution though

Tom

Dessertrunner · #**208** 10-13-2009, 05:29 AM

Tom,
I think we need to have an open mind and try different things. If the pump flow is low we don't have much room to move in the radiator department.
May be I have confused the issue the big change has to be the pipes to try to get more flow through the system at high revs. Ignore the rest.
Tony

Trevor · #**209** 10-13-2009, 02:35 PM

Quote:

Originally Posted by Dessertrunner

Tom,
I think we need to have an open mind and try different things. If the pump flow is low we don't have much room to move in the radiator department.
May be I have confused the issue the big change has to be the pipes to try to get more flow through the system at high revs. Ignore the rest.
Tony

Tony,

Thanks for the run down on the radiator. This makes good sense. Also good that you are making any changes separately.

What factual evidence do you consider indicates that, "more flow through the system at high revs." is required?

You will get there, Trevor.

yt · #**210** 10-13-2009, 04:33 PM

Couple reasons I thinkwe should steer away from the radiator being the issue...

Jack is running a different rad in the EG33 RS

Almost every dune buggy is not running our radiator either. While there may be inherent flaws in the radiator you are using, this may also be tainting the test procedures...

In the engine you are using, have the head gaskets ever been changed?? At this age, every EG33 w/ original gaskets is suspect to needing a refresh. I think a proper test bed will need to have them done before we can take anything as an absolute

Tom