Taking a break for a while.

I'm glad of that. I can't imagine the computer down for a couple of days. lol
I'm glad your ok.

 

No computer would suck for sure, but with the temperatures plummeting to well below freezing tonight, my electric heaters not working would be my biggest concern.

So far, alles in ordnung.

 

I have a brother that works on the base down there...

He lives in Hopkinsville and said the weather was going to get pretty badray:

I'll be down that way for Christmas.

 

Where we are was right on the edge of where it was going to get bad, so I imagine the farther north you go from here, the worse it is. Hopkinsville probably got hit pretty good but there's places that are far worse. Mostly farther west, as much farther north and it was frozen precipitation before hitting the ground.

There was a northeast belt where the wind shear was that had the freezing rain farther northeast from here, so I imagine they got the brunt of it.

Icicles here are a couple inches long off the power lines and tree limbs. Seems it was trying to drip off more than freeze in place so most of it fell to the ground before building up.

Power outages in freezing weather is most non-triumphant.

 

Ok I've given this a little more thought. While I believe the camshaft you have now will function fine, I believe a combustion cycle with slightly less intake and a little more exhaust would be beneficial to your application, and I'll explain why. Bear in mind this is simply my opinion and observation with a conclusion based on what I know about these things thus far, and I'm not claiming to be right or better. It's just something to consider and I welcome all feedback.

Let's take a look at your current camshaft specs first.

212/212 112/110 LSA/ICL (2* advance) with .436/.436 lift

IVO is -4.0 BTDC ( - indicates ATDC)
IVC is 36.0 ABDC
EVO is 40.0 BBDC
EVC is -8.0 ATDC ( - indicates BTDC)
Overlap is -12

Then compare them to a list of specs I came up with. I went through several variants to see if I could find a better one than what you have, or if the one you have is optimal.

208/216 112/108 LSA/ICL (4* advance) with .434/.443 lift

IVO is -4.0 BTDC ( - indicates ATDC)
IVC is 32.0 ABDC
EVO is 44.0 BBDC
EVC is -8.0 ATDC ( - indicates BTDC)
Overlap is -12

As we can see, I left overlap the same with IVO and EVC events the same. What changes is the movement of IVC at 4* sooner and EVO at 4* sooner. What this will do is create a smaller intake charge, while giving a longer compression cycle. After combustion, the exhaust valve opens sooner which permits a longer evacuation cycle. Couple this with slightly less intake lift but a bit more exhaust lift.

Why did I do this? After the fuel charge burns and is expanding down the power stroke, the fuel only needs so long to burn, and leaving the exhaust valve closed unnecessarily long is pointless, particularly when this time span can be taking advantage of a needed longer exhaust cycle because of the forced induction.

The intake valve closes sooner creating a smaller intake charge, but longer compression stroke to take fuller advantage of the forced induction charge's fuel/air mixture making for a more efficient burn cycle, needing less distance between the ignition point and the exhaust valve opening point (see above).

This plays into the extra exhaust evacuation as well, since it will facilitate less intake charge contamination and therefore a purer intake charge on the next cycle.

Valve intensities can remain the same for a similar compression ratio needed so that nothing else on the engine would need to be modified. (EDIT: correction: lobe intensities would have to be widened by 4* on intake to retain the same IVC @ .006 (262* @ .006 intake = 54* intake lobe intensity), but this would give another added benefit of increased valvetrain life. It should have read: "IVC point @ .006 can remain the same for a similar compression ratio needed so that nothing else on the engine would need to be modified")

This would also cause power to come on sooner (less intake duration/lift and tighter ICL) and extend later (more exhaust duration/lift and wider ECL), as well as create a better suited I/E ratio.

Summary: Balancing out intake charge with exhaust evacuation by altering lifts and durations of I/E lobes with a wider power band, while increasing fuel efficiency resulting in more power and gas mileage.


Disclaimer: my views and opinions are not gospel and are subject to change with the introduction of new information.

If anyone has another viewpoint, opinion, can disprove what I say, or just wants to chime in with their 2c, please feel free to do so. I welcome all logical critiques and analyses.


Gary

 

Very good Gary, I'm suitably impressed. It's well beyond any analytical ability I'd have.
The headers I have on this engine are very, very good indeed. A custom build with true equal length primaries and tuned secondaries and a short and free flowing exhaust system which is little more than header mufflers.

If I am fortunate, I may not have to tear this engine down again for a very long time, although I may at some point put an exhaust system on it that goes to the back bumper. I have no plans to change anything, but I do have some options if I decide I want to later on.

Jim

Ponch, thanks. Changed laptops and needed to add a button to the screen.

 

Sounds like the cam you have will work just fine then. Everything can be close, but you can go nuts trying to sort it all out for that 'perfect' combination of parts, variants, clearances, tolerances, etc etc etc.

While I believe the cam I offered will milk it a bit more, the one you have will be a good performer as well. In addition, being a forced induction engine, the cam specs aren't AS crucial as they might be with a N/A engine, so that's even better for you.

As long as your power band and revs stay between 2000-(5500-6000) RPM I think you'll be just fine. I wouldn't recommend going much beyond that for very long, as the supercharger's design seems to be as such that it will begin to overheat quickly, degrading performance and longevity. This is in accordance with a source I consorted with about the supercharger's design, so I'm not taking credit for this information, though the source shall remain anonymous unless he wishes to reveal himself. I did feel it necessary to share it with you, however.

So two thumbs up on your build! VERY nice job.

Be careful in that thing! :TU:

Gary

 

Thanks, I will.
The only time I can see going past 6K is either exiting a long sweeper where I don't want to upshift, or just for the fun of it, neither of which should be severely demanding, and the car will undoubtedly go like a rocket so I'd never expect to be into boost for more than half a minute in the most extreme case. Typically it would be mere seconds. I expect a 0-60 time under 5 and 1/4 mile under 12 provided traction is adequate. (I'm not a drag racer though) That should limit heat buildup somewhat. Most of the time I'll just tool around smiling.
So now I'd better get out there and hook up a few more wires so I can fire the engine up sometime before Christmas!

Jim

 

I used Garys ideas and tested the Apollo. Seemed to work good. 9.01 148mph in the 1/4 with stock intake.
Dan