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 Post subject: MP268 cam - RPM range?
PostPosted: Fri Nov 27, 2009 7:24 am 
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EFI Slant 6
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Joined: Tue Aug 19, 2003 3:52 am
Posts: 264
Location: Helsinki Finland
Car Model: 1966 2D Dart
What is the typical RPM power range of 225 slant six with MP268 cam?

Concept: 10:1 compression, oversize valves, light porting, Dutra Duals. If the max power is less than 5kRPM I will choose small BBD from 318. If the cam put my slant fly over 5kRPM, I rather choose a big 2bbl from big block.


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 Post subject:
PostPosted: Fri Nov 27, 2009 8:37 am 
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Joined: Fri Nov 08, 2002 4:48 pm
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Location: Burton BC canada
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Ill bet you will be happier with the smaller BBD.

The 318 BBD in my similar build runs out of steam about 5000

The mid range torque is where a super 6 shines. You will want to recurve your dist.....

Your idle will be better with the smaller carb.

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 Post subject:
PostPosted: Mon Nov 30, 2009 5:56 am 
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Joined: Mon Oct 21, 2002 11:08 am
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Location: Blacksburg, VA
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You can make that cam rev to 5500 or a bit more, if you have a big enough carb. I consider that a fairly docile cam for a Slant, and it's a very good street cam. BBD will probably run out around 5000, as Sandy says.

Lou

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 Post subject:
PostPosted: Mon Nov 30, 2009 12:25 pm 
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EFI Slant 6
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Joined: Tue Aug 19, 2003 3:52 am
Posts: 264
Location: Helsinki Finland
Car Model: 1966 2D Dart
Ok, thanks for advise. I will start with a small BBD which I already have and rebuilt it. Depending of the feelings after break in, I maybe test a bigger carb or not.

The car is 1966 Dart and it has 1:3.55 gears and a TF904. A 225 with 1:8.4 compression and MP244 cam (small BBD, big valves, Dutra Duals) I have got 16.48s 1/4 mile. Now it has 1:10 compression and a MP268 cam. How much will be the improvement?

(I cant test it before next summer).


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 Post subject:
PostPosted: Mon Nov 30, 2009 1:19 pm 
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Turbo EFI

Joined: Tue Jan 06, 2004 11:21 pm
Posts: 1391
Location: long beach ca
Car Model:
15.764


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 Post subject:
PostPosted: Mon Nov 30, 2009 1:50 pm 
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That seems reasonable.....but could you be more precise?

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 Post subject:
PostPosted: Mon Nov 30, 2009 5:03 pm 
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Turbo EFI

Joined: Tue Jan 06, 2004 11:21 pm
Posts: 1391
Location: long beach ca
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Precisely a guess,Thats all you can do without a bunch more info.Even then you might not get a closer guess.Mark


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 Post subject:
PostPosted: Mon Nov 30, 2009 5:07 pm 
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Guru
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Joined: Mon Oct 14, 2002 4:32 pm
Posts: 4880
Location: Working in Silicon Valley, USA
Car Model:
15.764 ET @ 86.464184078518 MPH :wink: :lol:
DD


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 Post subject:
PostPosted: Mon Nov 30, 2009 11:05 pm 
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EFI Slant 6
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Joined: Tue Aug 19, 2003 3:52 am
Posts: 264
Location: Helsinki Finland
Car Model: 1966 2D Dart
Finally I have get the discussion opened :D . NEXT QUESTION :Any Idea how much I will loose of the 15.764 ET with a big BBD and the flat spot in the start :D ?

In reality: With MP244 cam there was nothing above 4500rpm and the peak power was somewhere 4000 (ass dynoed together with the G-tech accelerometer to 16.5s / calibrated that measurement to well known new cars in the same performance level at the city traffic lights). As the 318BBD is worth of 4800 rpm with 80% VE in 225 slant and if I can raise shifts from 4000 to 5000, the difference from 16.5 to 15.8 would be reality.

In the "Slant Sickness" article few years ago the peak power was much below 5000 rpm even with more radical cam and with the HyperPak. I will be happy if a combo of MP268/SuperSix with 318BBD goes to same. More bang for the bug.


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 Post subject:
PostPosted: Tue Dec 01, 2009 8:38 am 
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Turbo EFI

Joined: Tue Jan 06, 2004 11:21 pm
Posts: 1391
Location: long beach ca
Car Model:
.001 to 1.00.Wilfred


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