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Trysix
 Post subject: How High The R.P.M.'s
PostPosted: Sun Jul 14, 2002 10:05 pm 
Since I gained 40 H.P. I've been experimenting with my red line.I started throwing the belt above 5k. Anyway asking about the belt on the other web site, brought up the subject of Rev limit.
I have confidence this engine is built right. It was restored to factory specs., and the recipricating parts are balanced.With a three speed and 3.23 gears this car runs good at 5.6k....seems to built speed even though the power band is flat at this RPM..

So what's the limit on RPM. for a slant six?
Am I fixing to start chunking parts all over the road?



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Dart270
PostPosted: Mon Jul 15, 2002 11:07 am 
Quote:
: Since I gained 40 H.P. I've been experimenting
: with my red line.I started throwing the belt
: above 5k. Anyway asking about the belt on
: the other web site, brought up the subject
: of Rev limit.
: I have confidence this engine is built right.
: It was restored to factory specs., and the
: recipricating parts are balanced.With a
: three speed and 3.23 gears this car runs
: good at 5.6k....seems to built speed even
: though the power band is flat at this RPM..
:
: So what's the limit on RPM. for a slant six?
: Am I fixing to start chunking parts all over
: the road?


I consider 5500 pretty safe for a well built engine. I have twisted my '64's 0.060"-over 225 to 6000 many times and no problems yet (OK, bent pushrods before I got HD ones). It is balanced and has rebuilt 225 rods and cast MP pistons - 40k so far and lots of racing. My '68's 225 has cast pistons and rods balanced, but not crank, and I have imposed a 5500 rpm limit on that one. It has 100k on it so far...

Lou
Lou
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dschumers
PostPosted: Mon Jul 15, 2002 4:29 pm 
Unless you have a really good cam, I'd bet the motor is not really making any more power above 5000. I've had mine up to 6000, but it ET's the best when shifted at 5200. Dennis

slantzilla@excite.com
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Doc.
PostPosted: Mon Jul 15, 2002 5:56 pm 
Quote:
: So what's the limit on RPM. for a slant six?


That depends on which SL6 (stroke) and how you build it. For the combo you discribed, 5500 redline seems about right. (the cam may "run-out" before that)
DD
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bud L.
PostPosted: Mon Jul 15, 2002 6:12 pm 
Quote:
: Since I gained 40 H.P. I've been experimenting
: with my red line.I started throwing the belt
: above 5k. Anyway asking about the belt on
: the other web site, brought up the subject
: of Rev limit.
: I have confidence this engine is built right.
: It was restored to factory specs., and the
: recipricating parts are balanced.With a
: three speed and 3.23 gears this car runs
: good at 5.6k....seems to built speed even
: though the power band is flat at this RPM..
:
: So what's the limit on RPM. for a slant six?
: Am I fixing to start chunking parts all over
: the road?


Why are you losing the belt? Is there a mis-alignment problem? Bent pulley? Insufficient belt tension?

fglmopar@aol.com
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Trysix
PostPosted: Mon Jul 15, 2002 6:34 pm 
Thanks guys, I think I'll settle on 5.5k.I think I need to build as much speed, in each gear , as I can because of the man 3 speed. I plan on
converting to a A833 OD or an automatic in the near furture, but I want to make a couple of 1/4 mile runs before hand.
I still don't know why It's shucking the drive belt. The pullys look straight and aligned. I guess I'll have to mount a video camera under the hood...it only throws the belt under a load.

Thanks again David/Trysix

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Trysix
PostPosted: Mon Jul 15, 2002 6:37 pm 
Quote:
: Why are you losing the belt? Is there a
: mis-alignment problem? Bent pulley?
: Insufficient belt tension?


Bud, I don't know about the belt yet. Everything seems straight and aligned. It may be as simple as belt tension...but I'm having to tighten it excessively...I think.

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Trysix
PostPosted: Mon Jul 15, 2002 6:49 pm 
Thanks again guys,

Lou, I finally got a copy of PH magizine the story was very good. Question ? Is that hood on your 64 stock? If it is,have you considered making that hood scoop functional?

Trysix/at 5.5k

soupitup@msn.com
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elam
PostPosted: Mon Jul 15, 2002 8:06 pm 
Quote:
: Unless you have a really good cam, I'd bet the
: motor is not really making any more power
: above 5000. I've had mine up to 6000, but it
: ET's the best when shifted at 5200. Dennis


Mine has a 252 comp cam. They say it quits at 4500 but seems to pull good till 5000. I've wandered if i'm rideing a hand granad my self.


melam@nxs.net
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Trysix
PostPosted: Fri Jul 19, 2002 5:23 pm 
Quote:
: Mine has a 252 comp cam. They say it quits at
: 4500 but seems to pull good till 5000. I've
: wandered if i'm rideing a hand granad my
: self.


Thanks again guys.
I think I'll compomise and shift at 5300 and rev limit at 5500.

David/Trysix

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