HEMI

Yeah. I finished the HEMI prototype. I just gave it a quick run with 2 lego air tanks, to see if it's ok. Seems fine. Tomorow morning i'll give it the first test run to see how it goes.

Why HEMI? The original engine has hemispherical combustion chambers. Well... in lego we don't have combustion chambers, but the switches have a bionicle ball joint attached to them, and thus, the name HEMI is fully justified :)

Comments

Number of valves

Did you ever try any of the old-type V8s with just 4 valves?

It's easy to dismiss the number of valves when taking into account friction etc, but these large cylinders take a hell of a lot more air than the smaller ones. Direct comparisons to Ivan's engine for airflow requirements are meaningless.

only 1020 rpms :(

That's what it made. I will try other valve setups, but it doesn't look too promising.

Hm, I also expected more

Hm, I also expected more rpms out of it.
But still, how fast was your previous fastest V8 and how is the torque of this one? Have you removed the bushing infront of the cams.

Good

Good looking Alex, i have an idea how to make it roatate faster. You have one valve for each cylinder, right? Why dont yout try 2 valves, to get better airflow? I think it should work faster than!

where

And where do you reckon, should i put them? In the trunk? This has little to do with the number of valves. Tis engine has just 4 valves.

And if you had take a look

And if you had take a look at ivan's engine you'd have noticed he used 2 switches for 4 cylinders too. So I don't think there will be a lost of speed. I know why you think this: more valves means more airflow, but more valves also create more friction for the engine.

So you went with the ball

So you went with the ball joints! This will be interesting, can you do me a favour: could you also try it with normal 2X1 liftarms half a stud lfrom the switch structure, no balls of course. I would be very interested in what results would you get. My hunch is that with V8 ball joints could proove to be a better solution.
And one more thing, I believe that you will have problem with balls rubing against the cam axle, specificly onto that one bush before the cam. Maybe you should remove it. The cams will not slide back sice thay are hiting the top of the ball and therefore have tendence to slide away from the switch, where they are stoped by the structure.




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