Hi everyone, i currently have a 170 waiting for rebuild. I plan to put it in my '67 Dart when the other one stops breathing.
I don't have any skills in porting but i'm willing to learn so... What can I do to my head to get more torque without losing too much mileage. This is going to be a daily driver so with the 1.70$/L gas here in europe, I do worry a bit...
Should i just smooth out the ports or enlarge it?
What about pistons? Are hypereutectics really improving something?
Thanks for your help

Marc

Get a 225. With that short little stroke 170s have you will have to spend a lot of money to try and turn it into a torque monster.

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82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

if a 170 is all you have then buy a set of seal power np244,0.080 piston in it and shave the block so you have 0.025 deck high then gasket match the ex and int ports and open the area in the valve pocket just to the edge of the valve seat. the over bore and the increase in compression will help tork and milage if you dont use your new power level to much, 340 type valve spring will help to good luck.

Uh...

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

A 170 will never be a "torque monster".
If the goal is low RPM torque, a swap to a 225 is the way to go. (longer stroke = torque)

If the goal is smooth running engine with good gas milage, you can get a 170 to do that.
Port clean-up work, back-cut intake valves & gasket matching will help along with the large over bore and a compression increase, as already suggested.

A focus on low engine friction - less mechanical drag set-up will help. (straight main line bore, roller timing chain, light valve springs, oil system porting, loose clearances, etc.)
In the end, cam selection will be the key to the combo, a cam with a short overlap event will get the best low speed torque and milage but it will not rev into the RPM range.
Note, small displacement engines use high RPMs to make power so this is a big "trade-off" when using a 170.
DD

That's it. Anyway, getting a 225 is hard for me, here, most /6 are 170.
I just wanna rebuild the engine in a way it works a bit better than stock and still get reliability and mileage.
First, thanks for your replies.
I didn't get a few points, i don't know all the porting vocabulary in english : What do you mean by large?
What's that?
didn't get that one too, does anybody has pictures? or further explanations

hi again, 0.080 over bore is the biggest stock piston for a slantsix the extra cubic inches will help in the torque and horse power department,as for the bowl or pocket area under the valve seat when the valve is removed the edge of the seat will be smooth and shinny,use a die gringer with a round burring tool to smooth and shape the bowl and giude area,with the valve itself look at the back of seat area the small rise or bump should be removed untill it is flat to the seat edge.when i said to use a 340 type valve spring is to control the valve from floating especially when decking the block for higher compression, i hope this is a little clearer

see

http://www.sa-motorsports.com/diyport.shtm

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Hi everyone, i recently read something about windage tray, supposed to free more than 10hp! Are there anyone available for /6s? What about the number figures? I guess it's 10hp at full throttle and on a 1000hp engine no?

Marc

You will find conflicting numbers claims for trays, but the man who builds the copy of the Mopar one claims 7 horsepower above 3500rpm. He also says they are a waste of time on the street.

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Official Cookie and Mater Tormentor.

A windage tray probably doesn't make economic sense on a daily driver, considering how little time most of us spend at higher RPM . It takes some money and some time that you might spend elsewhere and get better results.

On the other hand, will it hurt anything? I figure it's chicken soup: Might help, can't hurt.
There are folks who say the same thing working on old cars in general and slant sixes in particular.

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"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO