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There was one guy that removed the limiter on the 3 banger and started getting slapping, hammering, tapping and other bad sounds at high rpms
 

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There was one guy that removed the limiter on the 3 banger and started getting slapping, hammering, tapping and other bad sounds at high rpms
I bet probably due to the valve train since I would assume that the ECA1 being an economy motor has low rates for the valve springs since anything higher than what is needed will just rob efficiency.

Inquiring minds would love to know how they removed the limiter.
 

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I bet probably due to the valve train since I would assume that the ECA1 being an economy motor has low rates for the valve springs since anything higher than what is needed will just rob efficiency.

Inquiring minds would love to know how they removed the limiter.
An aftermarket stand alone ECM could easily remove the limiter.

The biggest barrier to high revs would be the valvetrain.
Then the Insights puny rods.

An application like the Insight would require getting the maximum torque available off-idle. Its camshaft is spec'd for this function. Id venture a guess that the ECA1s cam lift and duration are small and its intake runners thin and long. At high RPM the engine will choke.
 

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An aftermarket stand alone ECM could easily remove the limiter.

The biggest barrier to high revs would be the valvetrain.
Then the Insights puny rods.

An application like the Insight would require getting the maximum torque available off-idle. Its camshaft is spec'd for this function. Id venture a guess that the ECA1s cam lift and duration are small and its intake runners thin and long. At high RPM the engine will choke.
Yea that's probably a good guess. Is there a stand alone that can also run the hybrid system as well? I'd love to be able to extend the rev range just a little more so when shifting I can stay higher in the power band. It for sure feels like power ends at the specified peak power, but it doesn't feel like the engine dies either afterwards. Feels flat up till the fuel cut. Having another 400 rpms would be so much appreciated. The ECA1 sounds so much like a B16 when above 5k rpms :LOL:
 

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I haven't done the math but at a glance the Insight should have pretty low piston speeds. It's a square design, small displacement. I'm certain this helps with efficiency at part throttle and in lean burn, where flame speed is significantly lower too. I might revisit this after work and check to see what piston speeds it actually has at redline.
 

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I haven't done the math but at a glance the Insight should have pretty low piston speeds. It's a square design, small displacement. I'm certain this helps with efficiency at part throttle and in lean burn, where flame speed is significantly lower too. I might revisit this after work and check to see what piston speeds it actually has at redline.
This is also where knowing the rod ratio would come in handy. Since just knowing the stroke doesn't give the whole story of what's going on. Maybe Honda offset the crank so that they could keep a relatively low rod ratio for better low end tq? Or conversely they might have gone with a higher rod ratio for further less side loading of the piston, but then again they'd probably would have mentioned it as part of their marketing.

Either way, does someone have a connecting rod out to measure? Would be fun to know just academically.
 

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The Insight engine isnt square, it's an undersquare engine (longer stroke than bore).

The highest I've revved my ECA1 out was 6500 RPM, I think it could probably go up a few hundred more fairly safely, but it's really not making much power up there.

I have a set of connecting rods sitting in a box. What do you want measured on it?
 

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The Insight engine isnt square, it's an undersquare engine (longer stroke than bore).

The highest I've revved my ECA1 out was 6500 RPM, I think it could probably go up a few hundred more fairly safely, but it's really not making much power up there.

I have a set of connecting rods sitting in a box. What do you want measured on it?
That's good to hear. You could get some supertech light weight steel valve spring retainers to help preserve the life of the valve springs.

For the connecting rod if you can measure the ID of the the two ends as well as the distance between them. Then we can calculate the center point to center point of the connecting rod to get the rod length.

In this example
You see the two IDs are 21mm and 14mm and the distance between the two is 67.4mm. So if you take the radius of the two ends (10.5mm and 7mm) and add them to the distance between the two you get the 84.9mm like in the example.
 

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I think you meant that the other way around...

Formula 1 engines have incredibly short strokes to allow the 19,000 rpm's they typically run to.

The short stroke in addition to the high revs, means that the piston velocity in feet/second is still very high.

The old Norton 750 on the other hand, had a relatively long stroke and only revved to about 8000 rpm or so, if I recall correctly. Longer stroke combined with lower rpm's still means high piston velocity.

___

Just an aside note: the highest I have spin the Insight is about 3500 rpm's. That's it. Have had no reason to run higher for my driving style and route to work.

Jim.
Just in reply to your aside...I've gone (and go) above 3500 rpm regularly (though not by much) because I know that the flattest part of the Insight ICE's torque curve doesn't even start until 3500 +/- (we could quibble) and goes on to about 5000. At the low end of rpms, the torque curve falls pretty steeply under 2800. The gearing of the 5M is such that the rev fall-off when shifting up will regularly drop the rpms down under 2800....which is what I try to avoid. And, yes, I know that the engine/IMA motor combo produces max (and flat) torque right up to about that same mark. I just like to keep the ICE singing above that on upshifts.
 

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Alright, this took me way longer to do than I meant for it, but I kept forgetting about it.

Unfortunately I can't find my nice caliper sooo we're not going to have decimal places, but all the measurements seemed pretty dead on the line.

Hole on rod (smaller upper one) for wrist pin: 17mm
Larger hole at bottom of rod (attaching to crankshaft): 36mm still had bearings in, didn't think to take them out till I came inside
Distance from bottom of small hole to top of large hole: 106mm

Soo if my math is correct, the effective rod length is 132.5mm
 

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Nice, thanks for measuring. Also doesn't surprise me if more parts are shared with motorcycle motors, lol.

With your measurements that puts the ECA1 with a rod to stroke ratio of 1.63. That's pretty nice for revving. That's a higher ratio than a B18 and around the ratio of the K20.
 

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Man, I don't know what happened to the last part of my post...oh well, you saw it. lol

So far, that's the only part I've found that is shared with a motorcycle engine, but I'm wondering if different pistons could be swapped in, not that pretty much anyone would want to do that.

Maybe some day I'll really try and see how far this little engine can be revved.
 

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Another member on here got custom pistons made from Diamond Pistons, so if someone wanted custom pistons they should be able to order from them.
 
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