Power Crater vs Flat Top

I've see some discussion about flat top WD pistons giving more power to 226 engines than the Power Crater Pistons. Is it only because of the higher compression or was the Power Crater a bust?

It comes from the compression increase when people install the flat top pistons for a 4" stroke in an engine with 4 1/2" stroke.

I have Powercrater pistons from an AGCO 175 kit in my WC with a 4" crank and all WC components (carb, intake, etc).  M&W dyno at Old Threshers put her at about 32 horse for what it's worth.  My WD has WD45 powercrater pistons on a 45 crank and all 45 componets, made 50 on the same dyno the year before.  Wanted to run them both this year, but didn't get the chance.
AaronSEIA

Wi have you had the head off that motor so you could see if there were any errosion of the piston top caused by the tight quench. We tightened a two stroke up it ran like a scoulded dog but when we tourn down for a freshening we saw our flat top had a slight dome from the errosion of the piston edge shaping its self to the cylinder fire ring creating a poor mans dome in the two cycle world.

That wasnt the question. The question was is your quench after running the same as it was or did the turbulance errode the piston top. I also have picture of turned down pistons that were heavily pulled and they broke after third season. Would have lasted longer if sit in the barn and only made two pulls a year.

Edited by mlpankey - 21 Nov 2012 at 6:13pm

mlpankey wrote: That wasnt the question. The question was is your quench after running the same as it was or did the turbulance errode the piston top. I also have picture of turned down pistons that were heavily pulled and they broke after third season. Would have lasted longer if sit in the barn and only made two pulls a year.

What's your point? Turned down pistons broke. Detonation kills. Another failure.

M and W pistons are quite thick and have a huge dish to start with. Others are not so well suited.

I bought a wd45 that was not running. When I pulled the engine apart I found flat top pistons in it with every ring land broken. It was a work tractor, my guess is someone unknowingly overhauled it with the wrong parts.

The pistons were .380" down in the bore if I rember correctly. I'd have to measure a piston sometime and figure it, but that's way to much compression for cast pistons and low octane gas.

I set my M&W's up to be 11.25 :1. I took right about .050 0ff the top to get the quench height.   I think I trimmed the original 70cc bowl out to 88 or 90cc which didn't take that much other than take the little vane out of them, taper the sides and true up most of the bottom. Then with the valve relief machined in I think the total volume was something like 92cc.

I buy a few gallons of 114 race gas and blend with a little 92 for it. It probably went to 6 or 8 pulls this summer, dad and my hired help take it out if there's time. I went to a couple with it a few times and try to find a kid to drive and let have some fun.    


Edited by wi50 - 21 Nov 2012 at 11:54pm

You're full of bs pank. You've got a different argument than you had last time on this subject. Had anyone other than Marty posted the same things you wouldn't give 2 hoots.

It's easy to see how little you know.

Ever look at an m&w and see where the top ring is located? Better yet show us.

We can't help it if you didn't adjust the timeing and had the wrong clearance on your 2 stroke.

We can't help it if you use soft rods, weak pistons or poor design. All of your failures are a result of your own thoughts and actions.

A compressed head gasket is .052". With the .010" piston protrusion that engine is right on the money.

We are not talking about domes or chambered heads.

Time for pank to try and fool someone else. His contradicting arguments go round and round.

Edited by Rod B - 25 Nov 2012 at 8:46pm

Posting different numbers now than other times. Getting caught lying quite often.

A compressed fel pro is .045". But with your measureing and math skills it's no suprise that you can't give an honest answer.

The expansion rate of steel is more than that of iron. Aluminum expands more than steel. Pistons don't erode from being in a well designed quench engine and valve lash tightens slightly when the engine warms up. No matter what pankey thinks all these things are prove facts.

I think of all the race engines built to run on tight quench. If pankey was right the clearance would increase as the engine warms up. We all know it decreases and good builders target a tight quench.

At least pank can now admit he was wrong and valve lash tightens with heat.

Edited by Rod B - 22 Nov 2012 at 8:25pm

Yep doc it takes verry little timing when high static ratio are involved rod ithe am glad that you now see wi quench running is less than his cold measurement. So yours and his calculation would be off no more than. 010 one would have to make a hot oil bath and measure the rods center to center after thermal growth and have that number equated in like race engine builders do with a little fudge factor for rpm stretch.

connecting rod grows more than the pushrods do . wi said it was .010 out of the hole . pistons errode from to tight of quench. Have marty since he states he uses a cam grinder in denver nc to  ask mr. jones about the valve lash issue . He was the one that brought it to my attention that lash increases hot instead of decreases and it got about the same responce when brought to my attention as it did when i brought it to somes attention on this site.  Yes your mad that you didnt figure thermal growth of the connecting rod in the above and i pointed it out . So once more you combat it with name calling as usual  butting in on a question that was directed to your boyfriend and not you in the first place . It was a simplistic question if answered we would have known if he hit the sweet spot or missed it by what he observed on the piston top. He didnt so around the world I went with you . Oh if you and marty arent the same person rod dont try to act like you know people in the same circle as I you proved that was just a fake try by the rawlings move instead of his correct last name rawls.  However feel free to keep reading my post your knowledge is coming along  fine with every read post  even if you miss up the names somewhat in a futile attempt to discredit .

Edited by mlpankey - 23 Nov 2012 at 6:53am

wi50 wrote: you two are downright creepy.  I seen Rod once at a GOTO and never seen Pankey that I know of.  Maybe they have more in common than they let on....  It's no wonder neither of you two have time to work on any engines or go to any events.  They make pills for these kind of of things.  I like women with low IQ, large breasts and low self esteam, I do not like guys with the same qualities.