This is a street motor going in my 2000 Durango. Bores are good no need for overbore. OEM pistons only have 35k on them not afraid to reuse. This engine will never see NOS or north of 5500 rpm.

All other things being equal, would you have the block squared and decked to bring factory pistons to even w deck, or would you buy KB107 and have the rotating assy rebalanced?

Thanks in advance.

There is a third way, grasshopper!

The KB pistons will remove about 90 grams per hole. So yes, balancing would be advisable.

Stock pistons will require something like 0.060 off the decks. That isn't free.

The Third Way
The Speed Pro H116CP is a stock replacement piston with same weights as stock. It has a 1.660 comp height so it'd end up 0.005" below a standard deck of 9.578. Much as I hate to recommend a heavier product, I think this is the best way. The pistons cost exactly the same as the KBs.

When you're getting prices, if you ask for a price of squaring the decks you will get one number. If you ask about squaring the decks and removing an extra 0.060, you will get a higher number. So get your options written down.

R.

Every Dog has its day!. I would see how far in the hole you are right now for a baseline/start.

Oh i dont like this...

I just bought a 2000 5.9 too, and i have yet to pull the heads. It had better not be bloody .070" down... I was told .030" to .050" down... THAT much i can shave off the block (for zero deck)... any more seems excessive. I am not buying pistons.

If you mill .070 off the block you will have to run a really thick head gasket to keep the piston from hitting the head.

I have a set of KB107 pistons that are .030 over and they are a hair heavier than a stock magnum piston, can't speak for a std bore kb107. I would not run a new piston in a used block with 30K miles on it if the new ring moves higher up the bore than the old ring, there will be a slight distortion that can unseat the ring when cylinder preassure is at its highest.

If I was in your boat I would have it squared, then .035 milled off and run the .039 fel pro and not the .054 that comes in all the kits or you could mill around .030 and run the mr gasket .028 one.

The Silvolite catalog shows the stock replacement piston for '93 - '01 5.9 Mags as 1.605 compression height.
IIRC, the blueprint deck height for Mags and the later LAs, like my '86 block, is 9.577 - 9.578"

9.578 - 1.605 - 6.123 - 1.79 = 0.060.

The Federal-Mogul equivalent stock replacement piston is listed at 1.612", so then the piston would be 0.053 in the hole.

That's the facts, Jack! (channeling Bill Murray)

R.

My numbers come from actually measureing engines as assembled by chrysler with a depth gauge and feeler and straight edge methods not a bunch of "supposed to be this way" numbers. I don't know where the difference is but I have messed with tons of 5.9 mags and that is the normal numbers for deck clearance.

I shoulda bought the 318...

I'm not sure why you'd do either? Sounds like a street/daily driver? The issue is the lack of valve reliefs(not a problem for your situation). Put a thin head gasket on it(if you want a bit more comp)and go. The stock pistons are approx .050" in the hole,no big deal.

I think his point (i know mine is) is to have zero deck, and quench... but without rebuilding the engine.

LOL I got that. Id guess as a 40yr veteran mopar racer I'd ask where are the important gains in any build? "quench" is waaay down the list,but on this site its just like gold(lol),not close and Id gladly give a point of comp for the better ring pack of the factory piston all day. We have made over 600hp on the factory junk short block,yep it only made it 6yrs but it had no quench.lol Some folks would trip over a nickel and miss a quarter.

I know that if you swap out the PCM of a stock Magnum 5.9 V8 to the Mopar Performance PCM that advances the ignition timing 12 degrees it will ping in hot weather at full throttle begining around 3500 rpm... even if you use 95 AKI Sunoco Premium gasoline.

I have wondered if the quench clearance was tightened up to something less than the typical 0.093 inches whether it would run ping free.

I remember reading where Honda claimed in a published technical paper that the original VTEC cylinder head combustion chamber needed 0.75 millimeter quench clearance to work like they wanted it to work.

Could you close up the quench clearance a significant amount on the factory stock parts by ceramic coating the quench flats of the combustion chamber, and the quench flats of the piston crown, instead of changing pistons, decking the block, or offsetting the con rod pins?

I used to "sputter coat" items like fatigue cracked bolts to go into an electron microscope with pure platinum.

I wonder how thick chrome, copper, zinc or nickel could be coated onto cast iron cylinder head surfaces and aluminum piston crowns?

My 318 magnum I went from the factory .086 quench distance to .038 made it ping a lot less as well as better MPG TQ and HP. That was the only change at that time, I even took it to LA and pulled a car up those big hills on my open trailer at sea leval and no pinging on 87 octane california crap gas. After that experiment I am a big fan of maximizing quench area and minimizing quench distance.

My goal with this 2000 360 Magnum i just bought is .030" quench. Might take some decking... but i paid very little for the engine, so i think its worth an experiment. I kinda wanted to go with the 318... seemed a better choice for less machining, more tolerance, better piston shape... many details... but i just got such a sick deal on this 360 i couldn't pass it up.

360view... i think you'd just be better off with the machining. Thats a lot of thickness to ask from coatings and such... and (it would seem to me at least) a little hokey.

What was your SCR before and after? & nothing else was changed/adjusted/altered?

Maybe with a homemade cooled EGR system the pinging would go away despite the 0.093 Quench Clearance.

Maybe with an internal hole drilled from the interior of the intake manifold plenum into a runner at just the right angle, the swirl would increase enough that the quench jet action would not be needed.

Maybe with the right fuel injector cleaner amount added to every tank of fuel the combustion chamber surfaces would stay cleaner of carbon deposits and peak chamber temperatures would drop enough to eliminate pinging.

Almost certainly water/methanol injection like Aquamist would eliminate the pinging and increase power with cooler cylinder filling.

Robert I think I calculated it went from almost exactly 9.0 to 10.0 and no other changes, I even used the rings and bearings again. Later I tried a few of my other tricks (ford injectors, 205*tstat, electric fan...) but it seems to get to a point of diminishing returns adding MPG tricks. About the only one I didn't try that I really wanted to was going from a 3.55 to a 3.21 rear gear. I am about to do the same zero deck/tight quench experiment on my 2011 5.7 hemi truck.

EGR adds to the total amount of gasses being pumped through the engine therby increasing pumping losses (This is why chrysler went to the MDS system for increased MPG). It also slows down the burn speed requiring earlier ignition and more negative work on the crank. I am still not buying that it can help MPG HC TQ or HP or anything except reduced NOX, same with watter injection except in that case it also removes a lot of heat from the chamber as it evaporates, heat increases pressure and increased pressure means more power instead of burning fuel simply to evaporate water. All my expereminting backs up my theory. Getting the right fuel or tuning would be better.

You nailed the difference in viewpoints when you said as a mopar racer.
This is a street vehicle that will be used for occasional towing.
Torque and efficiency improvements in the street rpm range are the goals.
Properly set up quench does both of these nicely. Also, the hot rodder in me always tries to make things better than the factory did. Paint job, engine build, whatever. Over the span of 100,000 miles I am sure to recoup the cost of machine work via fuel mileage improvements. As long as I have it out of the car and have the heads off, I see no real reason not to try it.

You got good quench/went from 9-1 to 10-1 & more power/no pinging on 87/no other changes. that is incredible! what a success. Makes a believer out of me.

Me too... i think its worth the machining. We're not talking numbers 340's here... screw one up, you're out a couple hundred bucks and the machining.