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Old 12-27-2003, 12:54 AM
Dirt Track Dodge Dirt Track Dodge is offline
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Lightbulb /6 Performance Re-Build - Suggestions?

I usally tinker on V-8's, but now I'm driving this 72'Dart with a 6 and it's cool! I drive 60 miles a day to and from work.It has a oil leak, and the front end is shot. So I'm going to pull the engine and trans. I intend to use a overhaul gasket set to fix the leaks. I see on this /6 topic that a lot of times it is recomemded to mill the head. What is the CR of a 72' /6? What will a /6 handel on average octane of todays gas?(91) How much milling is required to reduce the chamber volume per cc? I'll do a pocket port in the bowls and backcut the intakes. I have a 268/.460 solid that I got cheap. I'll install it at 4deg advance to keepsome low end,
while watching piston to valve espiecially at the intake. The guys before me, about 50,000 miles ago, had rebuilt it with .030 over pistons,bearings and valve job. They also installed a 2-bbl carb and intake. It has a 904, 2.76 7 1/4 , with P185 winnies. The exhaust is stock. I cruise at 60mph. The mileage isin't that great.(18 mpg) Can anyone help me get better performance with what I have and not get any worse than 18mpg? What is the recomended total advance for this combo? Any other tricks?
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Old 12-27-2003, 02:16 AM
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dwc43 dwc43 is offline
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The 225 /6 runs 8 to 1 cr and .090 will take it to 9.5. About 32 degrees total timming will get you what you want.
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Old 12-27-2003, 09:36 AM
Slant Cecil Slant Cecil is offline
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No need to check the piston to valve with that cam. Even the 284/.528 Mopar cam that once was available would clear with .100 off the block and .100 off the head.
If you don't go with headers, make sure the heat riser flapper isn't rusted up in the closed position (I put them in the open position and weld the shaft so it can't close) and use a 2 1/4" headpipe and a muffler that you like.
30*-32* total is all that's needed for peak power, must have something to do with the small 3.40" bore. Most slant6ers run 10* to 12*, some as much as 15* intial, so mechanical advance needs to be 18*-22*. I've found 9*(=18*) advance plates before, but usually weld one up and file to size. The last one I did was a 15* plate I reduced to 9 1/2*(=19*).
dwc43s #s are probably right, .090 will give 9.5. .0066" off is supposed to reduce head chamber by 1 cc. 225 pistons average around .160 down in the bore. Of course, a smaller cut off the block will give the same increase.
Try going up 1 drill bit size on the Carter 1 1/4" BBD jets(hope you don't have the Holley version) with these mods. Also finding a good BBD with tight throttle shafts is hard, check yours, it may need to be bushed.
I see you think it's cool to run in a slant6! I've had 340s, 360s, 440-6s, Hemis and a 499 B1 the last 31 years (still have 1 Hemi and 3 440-6s), I got my got my first slant6 car in '00 and haven't hardly touched the V8s since. They are just as much, or more, fun to me!

Cecil
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Old 12-28-2003, 10:59 AM
Dirt Track Dodge Dirt Track Dodge is offline
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Default Pushrod Length

What would be the most the head could be milled w/o having to change pushrod length? What ever the adjuster could be backed out w/o the cup contacting the rocker?
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Old 12-29-2003, 12:59 AM
Rug_Trucker Rug_Trucker is offline
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If you are going to fart around with a slant go here.......http://www.slantsix.com and www.slantsix.org
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