Dynoed my WC Video

Thats pretty good!  My series IV 17 did 50 horses.  Some guy said that the live hyd pump takes ten extra horses away from the motor.  Any truth to that?

Nice! That's a sweet sounding old WC!

Yeah, I'm not happy about the find'em or grind'em clutch on the old girl.  It's set up right, but seems to have some drag.  As for the 175 pistons, that was a setup that Tom Obrian at Ellis imp in Coggon suggested for me.  Claimed more power than stock pistons, but less than on a 4.5" crank.  I'm not sure I'm man enough to roll her over with 175 pistons and a 45 crank.

AGCO OEM 4 inch bore model 175 pistons will pretty much equal WC/WD gas pistons in compression ratio and give you the Power Crater bowl for a little different sound. The fact that it has 32 HP instead of 28 HP would sure indicate that compression is just fine with a 4 inch stroke crank.

Thanks for the info, Dr Allis.  I knew Tom wouldn't steer me too wrong, he bled orange 15 years ago when I put her together.  it is an AGCO kit, so they are 4" 175 Power Crater pistons.  Always wanted to put it on a dyno and see what it'd do.
AaronSEIA

DrAllis wrote: AGCO OEM 4 inch bore model 175 pistons will pretty much equal WC/WD gas pistons in compression ratio and give you the Power Crater bowl for a little different sound. The fact that it has 32 HP instead of 28 HP would sure indicate that compression is just fine with a 4 inch stroke crank.

I agree 100% with DrAllis. I put 175 pistons in my WD using the stock 201 crankshaft. Never dynoed it but the compression ratio is around the 110 psi. The 175 pstion is about a 1/4" taller than the WD piston but with a cup that has just a bit over 1/4 depth to it. It works out to be about the same amount of material above the wrist pin and so about the same compression is achieved with the benefit of a power crater piston, if there is much benefit. 

A-C repair manual spec is 110 psi for a WD with 5.75 to 1 compression pistons.

Lonn wrote: I agree 100% with DrAllis. I put 175 pistons in my WD using the stock 201 crankshaft. Never dynoed it but the compression ratio is around the 110 psi. The 175 pstion is about a 1/4" taller than the WD piston but with a cup that has just a bit over 1/4 depth to it. It works out to be about the same amount of material above the wrist pin and so about the same compression is achieved with the benefit of a power crater piston, if there is much benefit.  Going a little off topic, some hot rod mopar magazine I read many years ago claimed an engine designed for a cupped piston gave better performance over an engine designed for a domed piston with all else being the same. The cupped piston would hold the exploding gasses better vs the domed piston letting more of the exploding gasses past the rings. Makes sense to me and I think the same would apply to a cupped piston vs a flat piston to a lesser degree.

  You can't always believe what you read. I  asked three piston manufacturers the same thing the article sugested and they said no way of proving one piston design made power over the other . simple factor is compression ratio makes power acording to the three . compression starts with ring placement and seal .Arias J&E Ross were the three i asked. ps one of the old pwer tricks on the 440 mopar was to swap the domes from left side to right vise versa the extra comp. really woke the 440 up.  final answere the piston that squeezes the air  fuel mixture into the smallest area makes the most donkeys . some where in the archives on this forum the 175 piston on 4 inch crank was determined to have as dr allis said again the comp and lonn mentioning the mopar article and me stating that i had asked three piston manufactures yada yada .but now Aron knows the fruit of his labor.

Edited by mlpankey - 08 Sep 2012 at 9:35pm

mlpankey wrote:   Arias J&E Ross were the three i asked. ps one of the old pwer tricks on the 440 mopar was to swap the domes from left side to right vise versa the extra comp. really woke the 440 up.

Its a dome piston swap side to side get the piston pin offset. pin offset .090 from factory emgine will rattle cold but goes awat when warm. Racers say its worth. 2 in a quarter in a 13 second ride.

Edited by mlpankey - 09 Sep 2012 at 2:41pm

M@w offset to be quiet to so tunning them 180 would make the the power to like it does on the mopar swaping sides no homework posted that before you came to forum.putting the piston so that the first compression ring is position the highest it can be in the bore makes compression and taking away pin offset does just that.forged pistons suppose to be noisy.  If you believe in quench and squish a flat top does just that with the most piston top area to not to mention flame propegation is not impeeded across the flat either. if you like flames out the exhaust run dish pistons the fuel thats unburned do ti the insufficiency of the dish will do just that for you.

Edited by mlpankey - 09 Sep 2012 at 6:45pm

dished pistons are ineffecient when compared to  flat tops in combustion  the flame out the exhaust from the unburned trap fuel by the dish pistons  proves just that. m@w pistons in 4 1/8 overbore made 8 more hp on a wc according to their advertizement . thats verry little increase due to design of piston / pin location when you take the cubic inch increase away from the over bore. only two ways to make horsepower on a naturally aspirated engine. compression is one cubic inches is the second way.everything else is just to support those two things.

Edited by mlpankey - 09 Sep 2012 at 7:01pm

short rods make more torque by achieving right angle sooner. long rods are for sustained 8000 rpms or more. all torque engines have low rod ratios  its a trade for the increase cubic inches . The  800 inch big blocks have a low rod ratio its the facts of life . if high rod ratio is a  power secret then the 201 should of made more hp than the 226 but it didnt did it.

Edited by mlpankey - 09 Sep 2012 at 7:09pm

we havent been to eagleville in a while .  how did you do . its not hard for me to txt tracy reed or call cody so no need to exagerate acomplishments.