Building a 10,000 rpm NA engine.

[svxfiles]

As an old school guy I know that when you increace compression ratios at low ratios(8 to 1) you get a BIG increace in Hp.
But as you go from 10 to 1 up, the improvement is not as great
.

[Dessertrunner]

My early Subaru GSR had 10:1 as it was a rally car but when we shave the heads it flew. The good thing is I still have the engine and car.

Harvey will update us as to what he has found.

I had intended to do things in steps when we got the dyno going but I think we will skip and go straight to a main act of sorts.

So I want to get all the bit for the new engine,

What I will do is,
ECU Wolf
Replace rods,
Cams
Injectors 550cc,
Oil pump,
Shave heads to 14:1
and most likly buckets on valves.

Not convinced that I need to change pistons.

By the way I have been talking to a number of people in the plastics game about, is it possiable to build a plastic individual throttle bodie. Have even talk to a guy about using carbon fibre, it seems they have some hi temp resins now so this maybe possiable as well. Given vacum moulding it may not be as expensive as it seems. Also my CNC skills today are a planent better then a year ago. I cut steel today faster then I use to cut alum.

Tony

As I was just saying to Harvey don't think I will be walking away from SVX's for a few years yet.

Tony

[SVXRide]

Tony,

Have you considered 3D printing? The folks here at Goddard are doing some pretty impressive work that you couldn't even begin to figure out how to do on a CNC machine. I was just talking with a young engineer here who was presenting his R&D project in which he did a miniature vacuum pump via 3D printing and actually welded the connections into the 3D piece.

Bill

[oab_au]

Originally Posted by Dessertrunner

So base case was 10:1,
My guess is 14%

Originally Posted by svxfiles

My best guess is less than 10%.
For example;
Bowling's Compression Ratio -> HP CalculatorComputation Results:
Engine Horsepower (peak) is 230
Old Compression Ratio is 10.0
New Compression Ratio is 14.0
Computation Results:
Computed New Engine HP is 249, a 8 percent change

Did the run with only the compression ratio changed from 10:1 to 14:1.
The torque increased by 7.45% at 6000, 10% at 7000, 9.79% at 8000.
So Tom was right there. The old book still reads right for us old blokes.


While we gained a 10% increase in torque, I found that we lost 2% in the Volumetric Efficiency, dropped from 112% to 110%.
This means that we are not filling that cylinder as well as we were. I spent sometime looking through the data to see why, but finally found it, by looking at the pressure at the inlet valve at closing, it had dropped.
So it means that due to that raise in the ratio, the pressure on the compression stroke rose faster than before. This then pushes air out of the cylinder back up the inlet tract, before the valve closed.

When we set up the valve timing, we wait till the pressure in the cylinder, equals the pressure in the inlet tract. That is when we time the valve to close, trapping the high pressure in the cylinder. With the pressure rising faster it reached equalisation earlier, to leak back out of the cylinder. We could close the valve earlier, but the would cost us in filling the cylinder, so it would be a case of, back to work on the inlet tract, to bring its max pressure on later, and get back to 112%.

Harvey.

[oab_au]

Originally Posted by SVXRide

Tony,

Have you considered 3D printing? The folks here at Goddard are doing some pretty impressive work that you couldn't even begin to figure out how to do on a CNC machine. I was just talking with a young engineer here who was presenting his R&D project in which he did a miniature vacuum pump via 3D printing and actually welded the connections into the 3D piece.

Bill

I read an article where they are doing prototypes by using three lasers to weld up a 3D solid model, in a box of sintered metal. The three lasers are focused at a point at the bottom of the powder, fusing the metal as it built up the model, building it from the bottom up. Just shake it out of the box, all done.

Harvey.

[SVXRide]

Originally Posted by oab_au

I read an article where they are doing prototypes by using three lasers to weld up a 3D solid model, in a box of sintered metal. The three lasers are focused at a point at the bottom of the powder, fusing the metal as it built up the model, building it from the bottom up. Just shake it out of the box, all done.

Harvey.

Harvey,
The miniature vacuum pump I spoke of was actually done with sintered metal. The junior engineer doing the work actually did tensile tests on the 3D material to demonstrate the relatively small loss in strength versus bar stock (due to the small voids you'll get in the printing process). Just came across an article discussing using 3D printing on the moon in lieu of transporting hardware from Earth.
Definitely the wave of the future.
-Bill

[Dessertrunner]

I had heard they were getting to do metal but didn't know it worked till now, it would be a great way to go Bill if we could find some one with a machine to do it.

Harvey, the intake and exhaust ports in the head have you changed them in the model, if so did the change increase the power at higher rpm.

Tony

[oab_au]

Originally Posted by Dessertrunner

I had heard they were getting to do metal but didn't know it worked till now, it would be a great way to go Bill if we could find some one with a machine to do it.

Tony there is an article in RET a few months ago on Prototypes, that covered this, both in metal and polymer.

Harvey, the intake and exhaust ports in the head have you changed them in the model, if so did the change increase the power at higher rpm. Tony

No I haven't changed the port shape, as they are as good as you could want. The only fault is that they are too flat to the cylinder center line, a problem of the flat engine design, or they would have the inlet and exhaust manifold pointing out to the wheels.
The best we can do, is to do a very good job on the port valve throat area, to get the best flow through that area.

Harvey.

[SVXRide]

Originally Posted by Dessertrunner

I had heard they were getting to do metal but didn't know it worked till now, it would be a great way to go Bill if we could find some one with a machine to do it.

Harvey, the intake and exhaust ports in the head have you changed them in the model, if so did the change increase the power at higher rpm.

Tony

Tony,

This has got my creative juices flowing, so I'm going to see if I can get the engineer I talked to do some design/fabrication work "off the clock". Stay tuned.
Bill

[Dessertrunner]

Have been trying to get more space cleared so I can get the dyno going, so I built a number of racks for the engine.
Tony

[SVXRide]

Tony,

Show off!

Now, get back to work on the dyno!

Cheers,

Bill

[icingdeath88]

Hey does anyone know if the EG33 oil pickup would have the same problem?: http://www.killerbmotorsport.com/ind...ickupStory.htm

http://www.killerbmotorsport.com/ind...teOiPickup.htm

I'm afraid to even ask, but does anyone know whether the EJ oil pickups are close to the EG one?

[Crazy_pilot]

I've never heard of an EG33 pickup failing. I have one sitting on the floor at home from my blown engine but can't recall if it shares the EJ's design.

[icingdeath88]

Originally Posted by Crazy_pilot

I've never heard of an EG33 pickup failing. I have one sitting on the floor at home from my blown engine but can't recall if it shares the EJ's design.

Yea come to think of it, I have one that I can measure too, but not an EJ one. I wonder if Bazza or someone with EJ parts can compare them.

[Dessertrunner]

Pretty sure Bazza posted photos of the two a while ago and the EG33 was larger. He made a good point at the time about people chanign pumps but not suction on the EJ.