so Im talking to RR steve and he says he runs 10:1 on the street in his 440..anyone done this in a slant six.

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slant six's RULE!
http://www.usajon.com

It's easy to do as long as you close the intake valve late enough to drop the dynamic compression ratio. Smaller combustion chambers will generally support a higher CR so it should be easier to run 10:1 in a slant than a 440. If the 440 has quench combustion chambers it will be able to support a higher dynamic compression ratio.

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Joshua

10:1 on the street is not a problem, I run a 236 degree cam at .050 with the intake centerline at 102. I usually use the best grade of gas 91-93 octane but I am not sure you would have to, knocking has never been a problem but I also run a standard transmission which tends to not lug the engine as much.

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If you didn't drive it there, it's not a street car.

how's that puppy run? any pics? car/engine?
thanks!

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slant six's RULE!
http://www.usajon.com

As it turns out, I'm pretty close to 11:1

A slight error was made with the stroke of my crank as it turns out.
Premium fuel only.

Works fine. The locker makes a racket though.

CJ

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Part of Tyrde-Browne Racing

I have run several motors between 10:1 and 11.1:1 on premium gas. Big cam and careful ignition timing is the key.

Lou

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Home of Slant6-powered fun machines since 1988

talking to RR steve he did say you can run hi comp but you ghave to retard the timing and that is the wrong way 2go...you should run as hi comp as your fuel does not ping..he did say aluminum heads cool faster alowing another .5 in comp.but there are no aluminum heads on slants.
so...trying 2figure on a seperte motor build for the treet.
looking@ all options including funding which seems the BIG factor...ha!

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slant six's RULE!
http://www.usajon.com

For a daily driven car your going to be better off with lower compression.

I've got 28.5° all in. That's not going to get me into the mpg club.

It goes like a scalded cat at the strip though.

CJ

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Part of Tyrde-Browne Racing

so what times/speed there..type o car et al..

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slant six's RULE!
http://www.usajon.com

I have pulled down 23-26 MPG hwy in my '64 Dart running 10.6:1 and mid 14 sec 1/4 miles. Cast piston 0.060" over w/225 rods and. Good enough? All about the combo and tuning...

Lou

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Home of Slant6-powered fun machines since 1988

93 octane?

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slant six's RULE!
http://www.usajon.com

91-93 octane, yes. If it were *just* a street/strip car, would likely run 13s, but set up more for handling/roadcourse.

Buildup specs:

http://slantsix.org/forum/viewtopic.php ... ht=64+dart

Some pics:

http://www.flickr.com/photos/16910097@N ... 013976355/

Lou

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Home of Slant6-powered fun machines since 1988

The engine I had in my Valiant and Swinger had 9.8:1. I got 21mpg at 70 mph highway with 3.23's and a LU904, I ran 89 octane. with 93 Octane I could run more advance. it had 39cc chambers and with a basicly stock cam I got a best of 16.35@83 in the 1/4 running 3.91 gears. It was a daily driver.

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how did you like those Clifford Street Rod headers .

what was your RPM's on the 1/4 mile track gears..

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slant six's RULE!
http://www.usajon.com

1974 4dr Valiant "Hooptie." Class III hitch, usually with the stinger still in it.
~20 MPG. Best of 15.66 sec quarter. ~3620# all buckled in. 3.50 gears and a locker behind the A904.

We'll see how it does at Woodburn now that I've taken some weight off and solved some serious head flow issues.

CJ

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Part of Tyrde-Browne Racing