Time to go Stage II!
- Thread starter Alky V6
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Squid4life
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- Jul 5, 2004
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So, basically what you are saying is that you will probably end up using none of the original intake?
And, for the record, I would love to see the car stay small tire. Maybe try some drag radials for the next set of tires.That would be interesting...
9,500 - 10k? Yikes... What RPM have most of the fastest SII V6 guys turned normally? Seems like you are definitely going to push the RPM envelope with this motor!
My buddy breaks alternator housings at 10k rpm on his SII motor. That's not normal rpm but he pushes 9k plus all the time.
I'll keep that in mind, Mike. Thanks.
That's a good point. I'm going to have to check my pulley ratio to make sure I don't overspeed the alternator. My driveshaft may need to be upgraded too. I think my present shaft has a natural frequency that's under 9000 rpm.
If you're talking about the crank caught in one of the latest pics, it's my well seasoned Moldex. It's the 3.06 stroke crank I've been using in the Stage I, and the crank I plan to use in this build. I do have a fresh, never used, BMS crank. But, I'm not sure what the stroke is. I think it's a stroker.Trade work for that crower billet crank? Found out my bms is junk.
edit: Just caught up. I guess you were referring to another crank.
Sorry, yes that was meant for Squid4life.
I just checked and my driveshaft should be good to about 8560 rpm. I'll just keep that in mind until I find out what this engine wants to do.
No crossing the finish line above 8500 rpm!
I'm pretty sure the alternator is going to need a pulley change.
Can an evac pump be blown up by overspeeding it?
No crossing the finish line above 8500 rpm!
I'm pretty sure the alternator is going to need a pulley change.
Can an evac pump be blown up by overspeeding it?
My alternator pulleys are 2.5" alternator and 5" on the crank. A pulley ratio of 2.0:1. The Stage I spun to 7,800 rpm. That put alternator speed at 15,600 rpm. The Stage II alternator speed will be;
9,000 engine rpm = 18,000 alternator rpm.
9,500 engine rpm = 19,000 alternator rpm.
It is recommended not to exceed 18,000 rpm with the alternator, according to Powermaster.
18,000 / 9,500 = 1.89
5" / 1.89 = 2.64"
I will need no less than a 2.64" diameter alternator pulley.
Powermaster has a 2.8" alternator pulley. Part# 181. That will make me good for over 10,000 rpm.
9,000 engine rpm = 18,000 alternator rpm.
9,500 engine rpm = 19,000 alternator rpm.
It is recommended not to exceed 18,000 rpm with the alternator, according to Powermaster.
18,000 / 9,500 = 1.89
5" / 1.89 = 2.64"
I will need no less than a 2.64" diameter alternator pulley.
Powermaster has a 2.8" alternator pulley. Part# 181. That will make me good for over 10,000 rpm.
Thanks for the tip, Mike. The taper is not going to be drastic, so I can most likely handle putting that in with basic porting tools. We're talking about a little over 1 degree taper per wall over about a 3/4 inch distance. I'll just calculate it out, scribe it out onto the outer surface and take it out with a tapered sanding roll. Piece of cake.
I'm shooting for an included intake runner taper of 5.4 degrees.
Instead of coming up with a large complicated compound angle fixture to mount the flanges to cut the ports, I'm going to mount the flanges for one of the port angles, and undercut the holes for the other angle so that I can take that angle out by hand. It will be good practice for my porting skills.
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