[Mayberry]

Although my mechanic friend who is helping me isn't crazy about the KB's, I'm having a hard time staying away from them because of the price difference. He has seen one cracked KB from a guy running nitrous and I think it's kind of scared him a bit. Can anyone help me out a bit here?

 

[460 Tom]

use KB's with confidence, If you're on the bottle or a huffer step up to forged units, KB makes them both.BE SURE TO FOLLOW THE INSTRUCTIONS FOR RING END GAPS, as KB has huge ring gaps on the top ring!

_________________
1965 F100,460,c6,3.25 Sleeper "Farm Truck" 1965 Mustang 302,Toploader 4 spd,Work in Progress. 1998 Explorer 4.0 3.73L Michelin Tires!!!

<font size=-1>[ This Message was edited by: 460 Tom on 4/16/02 9:34am ]</font>

 

[654212spd]

just keep away from the hyperutetic pistons other know as hyper defective ive see someone drop one and it broke

 

[Mayberry]

Thanks Tom, I'm not going to spray them. Gonna shoot for about 525-530 horses and stay right there. I still want a very streetable ride.

 

[67stang]

I've run Ross for a while, (ugh), didn't like them. I run SRP's now, and love them to death. I've never run KB's, but I"ve not heard anything good about them. I think I'd rather spend the money on a known good entity.........My .002

 

[87stang460]

If I had to do my engine again I will go with JE pistons heard some good stuff about um quite exspensive though I also use keith black pistons

 

[mavman]

Use the srp's for a couple reasons: 1) they are lighter, rev faster, and is cheaper to balance the engine and 2) they have deeper valve reliefs for big-lift cams so there shouldnt be much need for flycutting. I built one with these pistons, 260-266 @ .050, .672 lift cam, makes 553 HP. Hope this helps

 

[PONY1]

I run SRP's now, and love them to death.

From the looks of that wheelie , I BET you do ! hahahaha

 

[PONY1]

On 2002-04-15 23:59, 87stang460 wrote:
If I had to do my engine again I will go with JE pistons heard some good stuff about um quite exspensive though I also use keith black pistons

Thats what came in my 408 kit. Plus I see a lot of racers with there contingency stickers on them.

Hope they hold up

 

[qtrhors]

Ford 392W uses hyper pistons. I dont see a prob with them NA. Ive run cheapo $140.00 FM/Sterling hypers in our mild 375 hp 351 for 4 yrs. Doesnt burn a drop of oil. In fact the extremely cheap 302 hyper pistons from FM/Sterling(under 12.00 apiece from summit) seem to work and have oversized valve reliefs(15 cc). Im considering running them. Some one on this list uses them in a 393W and run 11's NA and 10's with a 150 shot.

 

[RPM]

KB Hypers no good eh? Tell Project 11.99 that.

 

[85mike]

I've used the KB's and had no problems at all with them. Any piston can be broken with abuse. Follow the instructions and everything will turn out fine. The little motor that could is 9 years old and still turns 12.60's with its KB's in place.

 

[460 Tom]

The truth is Forged slugs are great for racing, hi rpm durability ect ect ect, However for a street motor be advised that you will wear out rings in short order with forged pistons,as ALL forged slugs must run looser in the cyl than a cast or Hyper.. I have KB hypers in my BUILT 460 and they hav performed very well for the last 5 years. I have driven it like I stole it, and not a bit of trouble. My take is that some builders can't or won't read the damn instructions, and blame the part when it fails.

 

[Just Jim]

So the "huge" top ring gap called out for the KB pistons isn't anything to worry about?
Both my Falcon 351 and Morris 289 are running the "cheap" FM/Sterling hypers and I haven't had any problems with either after years of abuse at the track.I was hoping to build a low buck 393 with some FM hypers but feel the compression would be too high so that leaves either KB's(still economical) or other more expensive pistons.

 

[65mustang393]

I run the Federal Mogul H273CP in my 393 and so far it's ok. Piston was heavy at 605 grams and combined with the heavy H-beam, it cost me 3 slugs of mallory.

If I had to do it again, I think I'd try the probes. I hear anywhere from 365$ for flattops and 375$ for dishes!

If you want to see what the 393 made, look at the dyno section. I placed my Dynojet run on there.

 

[RPM]

Hey 65mustang393, nice results with that combo. When I questioned my brother about the limits of the 1 5/8 headers, he pointed out your setup and results. Good job.

 

[R Code]

Those FMs are lots heavier than the KBs. RPM has a 393 built with <500gram KBs and stock rods that required no Mallory, actually some weight was removed from the counterweights to balance it.
The KBs I used in my 426 Windsor weigh about 450 grams.

 

[giddyup1]

i would run anything but kb hypers as i have a broken piston in my 347,it only has 600 miles on it so im not impressed

 

[89 coupe]

I ran my KBs for 5 years with 12:1 compression and nitrous without ANY problems but my Ross and Wiesco pistons broke easily which I bought to upgrade over the KBs but Ross never made it out of the driveway bumping the nitrous in neutral from idle like I did with the KBs all the time and the Wiesco pistons broke on my way to the track without using nitrous. My KBs were some tuff pistons indeed and they kept going like the Energizer bunny. Deep valve reliefs for my large solid roller cam and the $220 price is what got me to buy them in the first place and the fact that they out lived the Ross and Wiesco pistons is why I continue to use them in everything. 7800RPM shifts on nitrous time and time again without ever breaking. I gap my top rings to .032" and use .002" piston to bore clearance when running nitrous and high compression with high RPMs. KBs are the best pistons to use when you don't want to spend $500-$600 on a set of good forged. My KB 136 dome 351W pistons are very strong, durable, and take plenty of punishment. I used a set of dome 302 KB pistons for the 393 going in the Pinto with complete confidence and expect them to live for many years in that stroker. It will only be shifted at 7000-7200RPM without nitrous though (it's for my dad and he doesn't like nitrous). It is built to handle a big shot and top rings gapped accordingly with the same .002" bore clearance so if he ever changes his mind, we can put a 350 horse shot on there.