RDNK 4RE

Just wondering if there has been any complaints or problems with Speed Pro's. I am looking for a good set of hyper pistons for a juicy street 406, no cheapy, cheapy pistons or claimers. I am looking at the KB's or Speed Pro's for the selection and of course KB name.

Don't suggest cast of forged not planning on either, this is a street motor. I have good rods no sense putting on cheap pistons or forged as I won't be racing it.

I'd really appreciate any 1st hand complaints on either Speed Pro's of KB's more then recommendations. Everything is great until it breaks! I will take any suggestions on other hyper pistons to look at, currently planning to go with a dished piston to keep the compression down. Heads aren't chosen but narrowed down so there is some room on flat or dished pistons right now.

Any 1st hand info????

Mkos1980

iTrader: (8)

I currently run them in my 383 with 0 problems. I've had it up to 6700 rpms also on the dyno. They came in a kit I bought.

midniteplowboyy

iTrader: (1)

I have a set KBs in my BB work truck, used almost totaly for towing, built 11 years ago and close to 100,000 miles on it now. Half of those miles were with gross weight loads of 30,000 to 44,000lbs. and the other half being 15,500 - 16,000lbs empty wieght. I built 2 more engines similar to mine for other guys one with speed pro's. I have used speed pro's and KB's in a couple small blocks also, no complaints or problems with any of them, but none have saw any nos. A friend of mine had a set of KB's in a 350, I think he busted a couple of ring lands, but it wasn't the pistons fault, he ran it hot, water pump went out, also melted about 5 exhaust valves and cracked both heads. You should be ok with them as long as you are careful with detonation, I would get forged if they didnt cost much more.

CRZYTRN-92Z28

I run the speed pro's and they are great. Got the lower compression/ lightweight version and they get the job done.

ditchbangr

iTrader: (1)

Hard to go wrong with the speed pro coated. I just bought a 12.5cc dish set for my 406. Some shops like KB's and some wouldn't take a set if you gave them to them. Gotta follow their ring end gaps or they will butt and break. The speed pros are a lil heavier but on a street car that probably won't see over 6K it doesn't matter. Good luck.

ZZ28ZZ

The KBs have the upper ring up higher on the piston, therefore requiring the larger ring gap like ditchbangr said.
KBs got a bad rap for a while because people were ignoring the rings gap requirement and were breaking pistons.

The Speedpro hypers have the top ring a little lower on the piston and use a normal upper ring gap.

I had one of my SpeedPro piston break in the ring land area, but I'm starting to think I broke it during the install cause I had excessive blow-by as soon as the eng started.

RDNK 4RE

good info....thanks everybody.

Is it me or has federal mogul changed from speed pro's to sealed power now. Same piston, even look exactly the same just new name for the pistons to match the rings. I know at federal moguls site there is no info for speed pro and the summit catalog is full of sealed power pistons now.

Apeiron

They do seem to be trying to rationalize their numbering and naming somewhat, for a while Federal Mogul was selling pistons as TRW, Speed Pro, Sealed Power, Sterling, and who knows what else.