SVX Engine cooling "Again & Again"

[Johnybeas]

So if I'm reading this right consensus of best idea so far is enlarged cross over pipe like tom did and enlarged outlet from radiator outlet?

[SilverSpear]

You got that right Johny, but you need to convert the cross over pipe to a Y pipe. Also note the additional AUX bypass taps to the heads.
The more the merrier

[Trevor]

Originally Posted by Johnybeas

So if I'm reading this right consensus of best idea so far is enlarged cross over pipe like tom did and enlarged outlet from radiator outlet?

Your confusion is understandable. As I understood it, the most important item of the many tried, was claimed to be an increase in the cross section of the inlet tract to the water pump. The problem is that each modification was not tested separately, so that no exact conclusion is possible.

[Dessertrunner]

I always sit back and read the comments with interest on this topic. Given the amount of work I have put into it I need to correct a couple of statements being made.

Trevor is partly right when he says that a partly moded top pipe was used in conjunction with inlet mods.

Steves buggy which operated at 7,200 rpm on a hot day had a slight mod to the top pipe but nothing like what Tom did. The big ticket changes Steve did
was to the thermostate cover changing it to 50mm and increaseing the size of the pipe from the bottom of the radiator

Matt ran a standard top pipe but cut into the bottom of the radiator moving the outlet to the centre to get better supply he also changed the pump/thermo cover to 45mm. Matt ran the engine up around 7,000 rpm and had no overheating issues, engine ran cool.

Tom and Dan have only the top pipe changed but have moved the thermostate to the top pipe to improve flow through the bottom pump pipe. In addiation correct me if I am wrong, they are targeting a rev range around 4-5,000 rpm. This means the problem of caviation to the pump is less of an issue.

Given the 100's of hour I have spent researching this issue and not meaning to offend anyone the soluation can be summed up as follows,

If you are aiming to rev your engine above 6,000 rpm on a continuse bases and you don't change the inlet to the pump as well as move outlet of the radiator to the centre of the radiator and inlarge the pipe size then you will blow your engine. I am afraid to say at higher revs changing the top pipe only will not solve your problem.

At around the 4-5,000 doing what Tom & Dan did will work and get you by. From my point of view I think its a lot easier to change the bottom thermostate/pump cover and move the radiator outlet then do all the work to the top pipe.

Any way that's my 2 bob's worth.
Tony

[shotgunslade]

Tom fabricated an enlarged Y-pipe and moved the T-stat to the inlet of the radiator.

[TomsSVX]

Originally Posted by Dessertrunner

I always sit back and read the comments with interest on this topic. Given the amount of work I have put into it I need to correct a couple of statements being made.

Trevor is partly right when he says that a partly moded top pipe was used in conjunction with inlet mods.

Steves buggy which operated at 7,200 rpm on a hot day had a slight mod to the top pipe but nothing like what Tom did. The big ticket changes Steve did
was to the thermostate cover changing it to 50mm and increaseing the size of the pipe from the bottom of the radiator

Matt ran a standard top pipe but cut into the bottom of the radiator moving the outlet to the centre to get better supply he also changed the pump/thermo cover to 45mm. Matt ran the engine up around 7,000 rpm and had no overheating issues, engine ran cool.

Tom and Dan have only the top pipe changed but have moved the thermostate to the top pipe to improve flow through the bottom pump pipe. In addiation correct me if I am wrong, they are targeting a rev range around 4-5,000 rpm. This means the problem of caviation to the pump is less of an issue.

Given the 100's of hour I have spent researching this issue and not meaning to offend anyone the soluation can be summed up as follows,

If you are aiming to rev your engine above 6,000 rpm on a continuse bases and you don't change the inlet to the pump as well as move outlet of the radiator to the centre of the radiator and inlarge the pipe size then you will blow your engine. I am afraid to say at higher revs changing the top pipe only will not solve your problem.

At around the 4-5,000 doing what Tom & Dan did will work and get you by. From my point of view I think its a lot easier to change the bottom thermostate/pump cover and move the radiator outlet then do all the work to the top pipe.

Any way that's my 2 bob's worth.
Tony

Our target powerband was meant to be arond 6400RPM bt the design and theory for the water pipe had very little to do with this. We wanted to increase and balance flow out of the engine which the stock manifold fails to do in any shape or form. With the balance of flow and increased volume out of the engine I felt there was no need to modify the system further as many other engines use similar designs which don't experience our problem with similar parts albeit the terrible water manifold that was stock for the EG33... So change the part in question to make the system more like what other engines are using... The problem ceases to be an issue.

Biggest issue I ever had with your testing is none of them ran a thermostat which is required to keep an engine within operating temps for proper ring seal, thermal expansion, and to maintain the use of heat in the car.

Tom

[Dessertrunner]

Tom I agree we need to run a thermostate up the top like you did. In my road car I still run one in the pump and haven't had any overheating issue since the change.

Different paths or opinion are always good to find a soluation, all we need to do now is find the answer to the bearing problem before we blow more motors.
Tony

[JONES OFF ROAD]

Gday all,
As Tony has already explained, his mods (thermostat housing) are what eventually fixed my buggy.
What I have found in preparation for a race, was that if I blocked of the outlets that I fitted to the rear of the heads, and ran the system standard (save for thermostat housing and slightly modded crossover) that temps started to fluctuate again.
So now I have the larger inlet, slighty larger crossover, and 1/2" fittings in both heads with hoses running to to top radiator hose inlet.
I dont run a thermostat, and engine sits constant around 75-80 deg c.
This is what worked so far, but will know for sure next week when I try to race 700km non-stop?

[Nevin]

Originally Posted by JONES OFF ROAD

Gday all,
As Tony has already explained, his mods (thermostat housing) are what eventually fixed my buggy.
What I have found in preparation for a race, was that if I blocked of the outlets that I fitted to the rear of the heads, and ran the system standard (save for thermostat housing and slightly modded crossover) that temps started to fluctuate again.
So now I have the larger inlet, slighty larger crossover, and 1/2" fittings in both heads with hoses running to to top radiator hose inlet.
I dont run a thermostat, and engine sits constant around 75-80 deg c.
This is what worked so far, but will know for sure next week when I try to race 700km non-stop?

Maybe it has been asked before, but I'd love to see pictures of the buggy or engine if you have any. Sounds very interesting!

[AGREENTREEFROG]

Originally Posted by JONES OFF ROAD

This is what worked so far, but will know for sure next week when I try to race 700km non-stop?

SWEEET
Ill see you there



need a hand throw me an email

Andy
@DOMS MOTORS

[JONES OFF ROAD]

Gday Andy, see you there. Can sign you on for pit crew if you like.....just in case. Have you got the keys for the spare parts shop in case we need some?

Nevin, trying to place pics, but dont know how to reduce sizes. Meantime, check out
www.offroadracingaustralia.com.au
to get an idea of what its all about. The MTG Griffith 700 is the race next weekend!

[JONES OFF ROAD]

see if this works?

[Hocrest]

Looks cool, but it seems as if you can barely see over the steering wheel?

[AGREENTREEFROG]

Originally Posted by JONES OFF ROAD

Gday Andy, see you there. Can sign you on for pit crew if you like.....just in case. Have you got the keys for the spare parts shop in case we need some?

yeah Steve got the keys workshop too

ill call you during the week mate

[JONES OFF ROAD]

GUESS WHAT?..............
Engine still overheats, definately time to scrap these engines.
Have improved temps significantly, can travel approx 180km now before refilling coolant, but am tired of all this when any other engine wont do this.
Simpler to change engine brands than re-engineer a massive subaru design fault.
And yes, I am a bit cranky

The race was still fun, needed to stop after 350km due to a rear hub failure that was not serviceable/preventable-just one of those things!