frankenstein Honda engine theory i had...
 

This idea would be based around the vtec-e d15z1 or y5 head/fuel injection setup. But my basic idea is to use one of these setups on either a 1.2 or 1.3 liter d series block. Or....if the heads are uncompatible...to use the crank from of these motors. Im sure something has to be cross compatible...anyone know for sure? Next, would have to prob have a custom cam ground, with less overlap and less duration to get a little more torque and take advantage of the atkinson cycle a little bit, along with extensive dyno tuning and a hondata or other style ecu. I know all this would cost more than any fuel ever saved, but it sure would be neat to see! any input? or similar frankenstein setups for the cause of fuel economy?

The 1.3 liter is a pre-1988 engine (as far as I know!) and those are not compatible with the 1988 and later D-series heads. I don't know what the differences are, but it will not be a simple bolt-on.

I don't know about the crank. But traditionally, shorter stroke is used for higher-revving motors, so it might make more sense to sleeve a later motor down? Not sure what the issues would be with that.

-soD

well the d13b style motors were in a lot of newer european cars like 92-99, but i still have no idea if those are compatible with the vtec-e heads. Im sure even with its standard head and a custom cam for low end though it would still be able to run very efficiently.

The 1.3L came in the 96-98 series Civic's called the EL model, a base model hatchback in Japan and Europe.
It's a de-stroked D15B(compression ratio drops but bore is the same IIRC), and does accept the D-series heads.
I have 2 in my garage(the only 2 I ever got while importing engines)....and sorry they are not for sale:)
If you can find one of these you could bolt your head onto it and maybe gain a couple more MPG.

well i do not own any of these, so its just a theory. I would not mind just having a stock vtec-e car for now, as my friend regularly gets 35-36 mpg just driving fairly normal, no ecodriving style

I am one of those that believes it takes the same fuel to move the same weight and aero drag down the road, it's my opinion that the 200cc downgrade wouldn't yield minimal if any improvements unless you are talking about a very light slippery vehicle.

That is a good point, i guess the time and energy is better spent elsewhere. its just a cool idea i had

Downsizing your engine is only effective if your current engine is capable of making too much power for the RPM/vehicle speed you need to be at.

The mileage gains aren't all that high, that I can tell, either, because the only thing you're really lessening is the internal resistance of the engine, pumping losses and frictional losses. Sure, that accounts for a large bit of engine power lost, but there is much lower fruit ready to be picked.

[QUOTE=Christ;136563]Downsizing your engine is only effective if your current engine is capable of making too much power for the RPM/vehicle speed you need to be at.

The mileage gains aren't all that high, that I can tell, either, because the only thing you're really lessening is the internal resistance of the engine, pumping losses and frictional losses. Sure, that accounts for a large bit of engine power lost, but there is much lower fruit ready to be picked.[/QUOTE]

Very well said.:thumbup:

I had this long book I was going to post, but you covered it all, in just one paragraph. LOL

Speaking of Honda engines.. you're doing great with the Turb'Sol, man!