KB944 pistons

[Shark]

im disappointed because i thought these were gonna save us money. its still cheaper to have a set of silvolites machined. am i missing something?

[Reelm n Rubi]

The KB944's are a forged set of pistons, 825's and 2229's aren't. The KB944's are $150 cheaper than the Diamond forgings. By the time you buy a set of 2229's and pay to have them machined to increase the dish your $300 invested into a cast piston then you need to buy a set of 258 rods as well.

[Reelm n Rubi]

Having trouble posting attachments, any ideas why? Says extension psf is not allowed.

[Muad'Dib]

Having trouble posting attachments, any ideas why? Says extension psf is not allowed.

What is a psf? Im betting not many people would be able to open it, thats why the board is rejecting it.

[Alex22]

AWWW man, what a bummer. I was excited to see that my stroker build might finally get a break in the budget and headaches, but it looks like KB didn't really help us out too much. Tomorrow at work I will get a price on the KB pistons (we are a dealer) and I'll grab a Diamond custom order form and maybe get it filled out within a few days. Personally I would rather have the Diamond pistons in my engine, Their quality is usually better than the KB's and you can also have the C-clip groove cut as well as having the dish volume and compression height exactly what you need.

Note: The single wire C-clip wrist pin retaining clips are better than the spiralocs. This has to do with how the force is exerted on the lock and transfered into the piston. With a spiralock all of the thrust is forced into the flat side of the lock which can cause the lock to bend and possibly pop out or start to damage piston. When the pin is thrust at the single round piece of steel (c-clip) the chamfer on the pin hits the round lock which will make the lock seat harder in the piston.

~Alex

[Flash]

I would like to see a true dollars and cents between the two
Keep us informed
And welcome aboard


Flash

[Alex22]

We do deal with Diamond very frequently and are happy with their products. Plus everyone knows its a lot cooler to have custom pistons in your stroker than to buy an off the shelf one. I'm going to start measuring all my parts soon and come up with some numbers for the pistons. Actual deck height, rod center to center -.001 to -.002 (resizing the rods) to come up with the pin height. I'm shooting for a zero deck and the .043 head gasket.

It was about time I came over to the stroker forum, since I have a mixed pile of 4.0, 4.2, chevy and maybe some ford parts that will get cobbled together in a month or two.

~Alex

[Cheromaniac]

I still haven't wrapped my head around the floating pin concept. I understand their 1.353" compression height if they allowed for the use of the eagle 6.150"rod, which would leave the piston .0045" below deck(my machinist shaved my head the bare minimum .004", so I would've done that as well had I been lucky enough to get the rods off ebay for $200 like someone did). Does anyone know if the eagle rod can be pressed on any 4.0 piston, or does it have to be a floating pin piston? Would/could you have to buy floating pins to put in the KBs?

According to my maths, the combination of KB944 pistons and 4.0 rods leaves the pistons 0.028" below the block deck. If you mill 0.020" from the block deck, the deck clearance is reduced to 0.008". Add the Victor Reinz 0.043" head gasket and you're left with a quench height of 0.051". With a +0.020" overbore, compression ratio comes in at 9.5:1. With a +0.060" overbore, compression ratio is 9.7:1. This assumes 57cc combustion chambers.
The extra cost of the KB944 pistons over a set of KB2229's is offset by the saving you make by not needing to buy a set of 258 rods.

[Alex22]

Just so you know, the suggested retail price on a set of KB944's or a set of KB945's is $660, and they only have .030 oversize right now. When I asked about custom pistons my boss said that a set of 6 custom diamond pistons will cost $500-600. Sounds good doesn't it? well there is one problem with custom pistons. If you ever need a new piston it is 2 to 4 weeks away and you have to buy a minimum of 4 at a time. Opposed to running an off the shelf piston, which is usually only a day away. Does anybody have the weight of a stock 4.0 piston and a stock 4.2 piston, the ones I have are all nasty and carboned up. The 4.2 rod weighs 628g and the 4.0 rod weights 600g (both weighed without rod bolts) which is nice because its much easier and cheaper to remove weight from a crank than add heavymetal. The eye of a 4.0 rod is too thin to bore/hone out and press a bushing in, the 4.2 rod looks thick enough for it. As of now I'm going to run the KB944 (.020 over) when it comes out.

~Alex

[Reelm n Rubi]

The last post is untrue. I just bought a set of KB944's for $450 + shipping and I got them in .060 over. Diamond pistons were going to be $650 +. I would have bought Diamonds for the same money , but the whole idea of KB producing these pistons is to make them a shelfable item and more affordable. I've played hell trying to get a set since they are so new, but a KB dealer should be able to get you a set in the >$500 range.

[Reelm n Rubi]

Here's their email they sent me.

[Alex22]

We deal directly with Keith Black (automotive machine shop) and that is the info I got. Where did you get your pistons from?

~Alex

[Flash]

Sure is nice to see a pic of then new KB piston, wish the attachment was bigger tho.


Flash

[Reelm n Rubi]

Here's some better pictures

[Flash]

Thanks, much better

any idea when your going to install them, so you can relay to all of us, what the true "piston to deck hight" is going to be on these new beautys!



Flash