Building a 10,000 rpm NA engine.

[svxfiles]

Sigh.....

[svxfiles]

Originally Posted by icingdeath88

Ok so the connection from the water pump to the radiator basically gets opened up wider? How did you accomplish this? (pics?)

I am guessing my bigass aluminum PWR radiator would be well enough suited to having a bigger outlet welded on?

Yes!, BUT You should also have the thermostat cover modified to 2" as well.
I have modified some "other" thermostats with a bigger "water flow opening".
Its time consuming, and it lets the actual water temperatures vary more than a stock thermostat would, but it will/does help flow!

[svxfiles]

As to oil flow;
I looked at a stock SVX oil pump,
specifically the opening at the O-Ring (#806919050)
On the SVX engine block the opening/hole is about 5/8". (about 16mm)
on the back of the oil pump the opening/hole is only 9/16".(about 14mm)
While this might not seem like much it is about 30% more area for oil to flow.

I am not sure that it would make ANY differance, but hey
What do we have to lose?!

And yes, I have already drilled/bored the/an oil pump out to 5/8".

[bazza]

Originally Posted by icingdeath88

Ok so the connection from the water pump to the radiator basically gets opened up wider? How did you accomplish this? (pics?)

I am guessing my bigass aluminum PWR radiator would be well enough suited to having a bigger outlet welded on?

PWR will work a treat I think (just ensure it has no grounds or it will suffer electrolysis death in no time flat which you're prolly aware of).

I took my stock pump inlet (thermostat cover) to a local fabricator, they created a new flange and welded on a 2" inlet. I then just bought an eBay radiator out of a Ford F350 for $215 which was same type of design as stock. The reason why I used Ford F350 radiator was mainly the 45mm inlet / outlet pipes stock and the 56mm thickness. I used a 45mm ID (x 1.5 inches long) hose on the radiator outlet which then spaced it out to 2" which allowed me to then use silicon hose as per any 2" intercooler pipe setup.

At the top it comes out of the engine at 38mm then I just found a reducer at the local auto shop which went from 45mm ID to 38mm ID and just made it all work.

Very easy, very basic and thank goodness for Tony's research

I'll get some pics on the weekend - hard to understand when written I know.

[icingdeath88]

Originally Posted by bazza

(just ensure it has no grounds or it will suffer electrolysis death in no time flat which you're prolly aware of).

I was not aware of that actually. It's not grounded, but I will pay attention to that in the future.

[svxfiles]

http://www.subaru-svx.net/photopost/...php?photo=2559
http://www.subaru-svx.net/photopost/...php?photo=2560
http://www.subaru-svx.net/photopost/...php?photo=2561
I went ahead and ported one of my oil pumps.
It could not hurt to reduce restriction to flow,


(if there is one.)

[Dessertrunner]

It will certainly make it easier for the pump to suck at high revs, my guess it may even decrease airation of the oil due to bett flow.
Tony

[oab_au]

Originally Posted by Dessertrunner

Sorry it took so long Harvey had to make some parts for the factory on the mill.

Your answer,
The 2 galleries along the top are 14mm diameter, the one feeding the back bearings is the same length all the way throught to the back. No real reason why the back would run short of oil.

Tony

That part of the galleys look good, there should be no problem there. The galleries are big enough to maintain the same pressure right through both galleries. The drillings that feed the main bearings should all have the same pressure to feed them. The only difference is that the No. 6 main feeds both No. 4 and 5, pins, the same as No.2 main, feeds No. 2, and 3 pins. 1 and 5 big ends, are feed on their own. So I guess that if there were a low-pressure problem, they would be the first to fail.

That said I am starting to suspect if the problem is real. There have only been a couple of bearing failures, which have happened to engines that we have built. Ignoring normal failures from neglect abuse, and age, they are not too common. Shotgundan circuit raced his for a couple of years, reving to 7000, without a failure, and Bazza has not has a failure, just surge problems that can lead to one. Engines like Andy Forest’s and Rigoli’s are in a different world, using nitrous and nitro methane, does add new dimensions to the problem.

I think oil surge, has proved to be one, oil viscosity may be another. One of Toms was detonation related, the other, can’t remember exactly that was from. I don’t think that the oil pressure has a lot to do with it, other than a complete failure, the engine has ample pressure, pumping it up excessively, can lead to more problems. Although the fact that it is No.5 that has been failing more that any other, still needs looking at, to find a reason for it.

Just looking at these two engines, there may be a related problem, in that they both had solid lifters, by gutting the hydraulic lifter and fitting shims. I don’t know for sure if the oil holes in the lifter were blocked or not, but if they were left open, there would be a drain on the galleries, that would affect it more at low engine speeds. The feed for the RH bank lifters run off the gallery where the drilling, for No. 6 main is. These lifter feeds have a restrictor in them to prevent a large flow, but with 12 lifters bleeding pressure off the gallery at No. 6 main, it may be enough to affect those two big ends.
What you all reckon?

Harvey.

[Dessertrunner]

Harvey,
"engine has ample pressure, pumping it up excessively, can lead to more problems"

What problem will be caused by raising th oil pressure from 45 psi to the blow off at 85psi? I would like to understand?
Tony

[oab_au]

Originally Posted by Dessertrunner

What problem will be caused by raising th oil pressure from 45 psi to the blow off at 85psi? I would like to understand?
Tony

Just the pressure in hoses, coolers, O rings. They are all placed under more stress that can lead to a failure.
There is really nothing to be gained by raising the pressure. You can't force more oil through the big end bearings. They have there own, hydrodynamic oiling system, that relies on the rod moving up and down on the pin to pump the oil up to the top of the pin. More pressure won't make this work any better.

Harvey.

[bazza]

Originally Posted by oab_au

Just the pressure in hoses, coolers, O rings. They are all placed under more stress that can lead to a failure.
There is really nothing to be gained by raising the pressure. You can't force more oil through the big end bearings. They have there own, hydrodynamic oiling system, that relies on the rod moving up and down on the pin to pump the oil up to the top of the pin. More pressure won't make this work any better.

Harvey.

I'm also not sure about the Subaru pressure readings in the manual. My understanding it that 43 psi is the lowest allowable pressure - not the actual pressure.

Reason being is from my various setups and incar camera footage where you can see the same gauge and various pressure readings. The gauge indicator vertical is about 90 psi. Gauge halfway is around 45 psi. These videos show exactly this. My gauge sensor location is also where Subaru state to measure from.

EG33 had 75 psi originally (before epic surge ate away the bearings and dropped pressure) and the gauge was tee'd into the turbo feed line so most likely actually gauge pressure without turbo draining some of that pressure would be closer to 85 psi. Stock bearing clearance of around 0.8 thou or thereabouts:
http://www.youtube.com/watch?v=r5zTXhclvEA

EJ257 2.5L is also stated in the manual as having 43 psi @ 5000 rpm, however here it's about 85 psi - this engine also had AVCS (intake) - bit of surge under acceleration, ACL HX race bearings, 1.8 thou clearance in the big ends:
http://www.youtube.com/watch?v=s9yLpDNqwOY

EJ208 2.0L is also stated in the manual as having 43 psi @ 5000 rpm. However again it's closer to 85 psi - touch of surge when turning, stock bearings (0.8 thou or thereabouts):
http://www.youtube.com/watch?v=2xt4eY8XjdQ

I've mostly used semi synthetic Penrite HPR10 (10W-40 or 10W-50) btw.

[Dessertrunner]

Interesting, it makes more sense what you are saying.

What bearing clearance do you think is ideal, seems to be 2 schools of thought one says normal clearance other says large clearance to get more oil between the bearing and the crank.
So whats your thought?
Tony

[oab_au]

Originally Posted by Dessertrunner

Interesting, it makes more sense what you are saying.

What bearing clearance do you think is ideal, seems to be 2 schools of thought one says normal clearance other says large clearance to get more oil between the bearing and the crank.
So whats your thought?
Tony

I was not in favor of opening the clearance up. That is really 'old school'. The clearance is worked on the rod's eye deformation, and is set to suit the oil used. The old way of opening them up, was due to the heaver viscosity of the oil that was used then. We now have oil that has all the property's, at a low viscosity, so the clearance that the Eg33 has, is set up for the low viscosity, that they recommend.

Harvey.

[bazza]

Originally Posted by oab_au

I was not in favor of opening the clearance up. That is really 'old school'. The clearance is worked on the rod's eye deformation, and is set to suit the oil used. The old way of opening them up, was due to the heaver viscosity of the oil that was used then. We now have oil that has all the property's, at a low viscosity, so the clearance that the Eg33 has, is set up for the low viscosity, that they recommend.

Harvey.

Yeah I'm not to sure on the matter either. I think he current theory is to enable more heat expansion which comes with heavy racing.

Never really seen any differences in oil pressure or performance personally so I don't know - I do know Subaru engineers are pretty good and clearances haven't changed in 20 years, hmmm.

[Dessertrunner]

Understand your point Harvey but don't know if you remember a while ago we found a artical on F1 engines and they open it up so it may not be as old school as we think.
Tony