B2600i Engine Project

[jayratliff12@yahoo.com]

hey guys,

I've been awarded a small grant to do a project at school. I've decided to work on a spare G6 engine i have laying around. I was awarded the grant because i emphasized that my main goal was to improve the fuel economy of this particular engine. They like giving money out for stuff like that. Anyway, there were a few things i was planning on doing for this project: 1. do a full rebuild on this engine 2. perform a mild porting of the intake and exhaust ports. 3. weld and reshape the combustion chamber in order to achieve higher compression. (not 100% that i will actually do that yet)

other things i was thinking about:

changing out the fuel injectors to something more modern and hopefully more efficient
possibly having a custom camshaft made
design headers to improve exhaust flow
I may try and fit some larger valves to the head.
I probably will have the rotating assemble balanced
i want to try and fabricate some devices for the intake ports in order to increase velocity and turbulence of incoming air. (i may just try and shape the intake port in such a manner while i'm porting out the head.)
i may try some over the counter "fuel economy improving devices" available at your local parts house.

i originally wanted to do a forced air induction system for this project, but the time and money needed would be overwhelming.

we just upgraded our engine dyno with a new load cell and $10,000 computer system
we also just got a $10,000 exhaust gas analyzer that i get to play with
I will be able to get accurate readings on all the modifications i make.

If anybody wants to suggest anything else, please feel free. I am widely open to any ideas. I know you guys are always curious, so i have a spare engine, i have the time, and i have a little bit of money to play with.

[Tyranitar]

One of the common drains on the economy of the engine is cracks in the heads or valve seats. Mine used to get 24-26 mpg, but dropped off to about 18 mpg. The only thing that it can be attributed to is a cracked head that does not result in coolant leaks. Just something to be aware of so that they can be repaired if they are present.

The over the counter performance/economy parts are a waste of time and money. However one area when gains could be had is to use an MSD coil pack system instead of the stock distributor. This is a more complicated build, but gains are to be had by using a waste spark ignition. Just something you can look into.

Larger valves are usually conter-productive to economy. The reason is that they reduce velocity. Timing and placement of the valves is more important. Basically what you want is high velocities even at low RPM. That is why these engines use a 3 valve setup, it is an effort to improve volumetric efficiency at low RPM without compromising top end power. Larger vales reduce the velocity at low RPM, causing the induction waves to collapse.

[jayratliff12@yahoo.com]

the coil packs are a great idea. I might be able to use a coil off of something like a newer doge neon before i spent the money for MSD stuff. A megasquirt would have to be paired with that in order for success. My professor told me last night that the project can take longer than one semester, but i have to spend the money by may.

[jayratliff12@yahoo.com]

i got the engine pulled apart today and got a look at all the internals on this thing... its just asking for boost.

[Tyranitar]

To run boost you need forged pistons and stronger rods. On the coil packs, no you do not need a megasquirt to run them. Take a look at this.
http://www.electromotive-inc.com/products/xdi.html This setup is a COP with waste spark.

[jayratliff12@yahoo.com]

I don't think I would need forged pistons and rods. They are built like a tank. The rods look to be at least thirty percent larger than sbc rods. However, the pistons are a bit flemsy. i am in the process of modifying a 22re piston to fit. If i'm successful at that, piston options are greatly increased. Long story short.. i think this thing would take 6lbs of boost without any troubles. but, thats later not now.

[Tyranitar]

The problem is that once a hypereutectic piston or cast piston is exposed to boost, if it pings at all under boost, even inaudible pinging, the pistons can shatter. If you run boost you need forged pistons, otherwise getting it to work is just luck. Many of the people who report success running mild boost with stock pistons often do not report the damage that is done to their engines when something breaks cause they did it wrong. The rods should take mild boost ok, but I think more homework should be done on that. The factory fuel injection will not handle boost either, so you will be stuck with running a megasquirt. Considering how lousy the stock computer is anyway, that does sound like a good idea to just build a megasquirt system. And that will give you the power to fool with the timing and stuff electronically.

[jayratliff12@yahoo.com]

When i get the toyota pistons working, ill let you know the proceedure to do it. I will have a lot of options when that happens. I could get essentially any piston i want at that point. For now, i plan on running a stock 85-95 22re piston. It has more of a flat design rather than the deep dish design. It is slightly shorter than the mazda piston, however. If i offset grind the crank .030 and then deck the block, i should have the pistons level with the deck, ultimately raising the compression ratio. I have to CC the head and take some other measurements, i may not want to grind the crank that much.

[jayratliff12@yahoo.com]

i did a dyno run the other day. I did a 3rd gear run at red-line then we loaded the brake. It made 77horse and 220ft-lbs torque. we have a video that may be on youtube soon. i'm going to a few more before i pull the engine so that i can get the maximum reading, then i will put the new one in.

[Tyranitar]

So those are the readings on the stock engine? They are supposed to produce closer to 125 hp at the crank.