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Mopar Polyspherical (Poly or Polyhead) 318 Motor Head Work

Bruce writes from Toth Performance: A little update for all you Mopar Poly faithful, it has been a little over two years since Roland Osborne of Chrysler Power and I discussed the potential of the Poly heads and what I felt was a possibility as far as horsepower that could be made with the Poly engine. Roland talked me into doing the R&D on the porting of the 318 Poly heads and the rest is history. The good news is we now have stroker kits available, new larger stainless race grade valves and all the Poly accessories that Roland makes the super torque-making Wind Tunnel Poly intake, cast aluminum Poly valve covers and the econo Poly stroker kits. And if you have been keeping abreast of some of the dyno results coming in you know that Darryl Whitmerís Poly made 481 horse power and 487 foot pounds of torque. That is a motor that he built for the street not a full race motor, so all you guys with an old Mopar with a Poly engine no longer have to think about changing it over to a big block.

With all the research we have been doing and the new parts we are having produced you now have the ability to make serious tire shredding power with the 318 Poly. There is no need to pass up a deal on an early Mopar just because it is a Poly engine car, buy it and build it into a screamer that will turn heads, and have everyone scratching their head when they look under the hood and see the scalloped valve covers!

If you want to get started on a Poly that you already own feel free to contact me I will be glad to assist you with what you need to make your Poly a respectable performer. I ported the heads for Darryl Whitmerís Poly build and I will tell you that no matter what you plan on doing with your Poly, two of the main thing that you will need will be a set of well ported heads and the correct cam for your intended use of the car.

So if you want to up the horse power of your 318 Poly the only thing you have to do is decide how much power you desire to have. If you want 300 to 350 horse power that can be accomplished with your stock stroke crank. You will need a set of ported heads the Wind Tunnel Intake and the correct cam. Want 400 horse power you will need a stroker crank and a little more camshaft. I am in the process of building a 396 cubic inch stroker from the original 318 Poly for my 1962 Dodge Dart 330, we will be covering the build in segments in Chrysler Power Magazine so all of you can follow along.

Iím just glad to be a part of the new Poly program and helping give all the Mopar faithful some new options that they didnít have before. If you donít have a Poly-powered car buy one and build it, you wonít be disappointed with the results if you do it right the first time. If you have a friend that has one let him know what is available, and have him contact me for assistance in making the correct choices for their build.

Poly 318 head Poly 318 head
Poly 318 head porting Poly 318 head porting
Poly 318 head porting Poly 318 head porting

Flow sheet: Head flow numbers of head ported (318 Poly heads 1.94 and 1.60 valves ported)

Head flow numbers of head ported

Contact Bruce Bruce Toth 724-791-2514.
The best kept secret in Butler County, PA

May 23, 2016

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