JAX04

iTrader: (17)

So i called wiseco today to talk about K1 connecting rods, specifically the billet H beam rods with arp 2000 bolts.

After that conversation, we got to talking about my pistons, and i asked him,

How do you feel about the 6.125" rod with the correct piston vs. the 6.098" rod with the correct piston.

Assuming that each piston was different, he told me, they are not different at all. That they are infact the exact same piston with the exact same compression height...

Said, "you are free to use which ever rod you want, 6.125" or 6.098".

Said with a stock deck height it would raise compression by something like .1 or .2.

Any thoughts on this? I know the guy from wiseco said this and i should listen to him, but i really didnt expect him to say this...

bww3588

iTrader: (49)

This is true. I have noticed these pistons are more versitile. In my case, the pistons i bought are "for" a 6.125 rod, however, I had to remove so much from my deck, that I used a 6.100 rod and it brought it back where it should be.

Basically, it makes you be an engine builder. if you have a stock deck height block (9.24) and you use a K447X3903 wiseco piston with a 6.125 rod, your piston will be .004 in the hole, so it leaves you with some material to clean up your deck. (thats good)

or if you use that same piston with a 6.098 rod your piston will be .031 in the hole, which is good for someone like me that had to take .030 off the deck.

JAX04

iTrader: (17)

Thanks for that response man, maybe ill wait to order my rods until ask the engine build what he has to do to the deck to make it true again, if anything.

Thanks, Like i said, i was a bit surprised by this. Im happy at the same time, one knowing i have one the leading pistons in the industry for boost

and 2. knowing that i have some room to clean up the deck. I like that.

Thanks again!

ljsracing19j

An old school SBC is .025 in the hole. But you can zero deck them. So really if you had say .005 taken off the deck you would end up around .025 which is fine. Or if you left it at .004 thats ok too. (granted there is tons of differences between the two but still same principle)

i use eaglerod.com for compression calculator.. its pretty close. Maybe .1-.2 high but it will get you the rough idea of how much it will change.

bww3588

iTrader: (49)

the thing with that is, optimum quench area is around .030. that is where a lot of your power lies. stock, LS engines are anywhere betweeen .003 and .006 out of the hole. some being more some being less.

.025 in the hole is fine with a old school small block, when they were more worried about power than emissions and other bullshit, simply because they used .015 steel shim gaskets, insted of .030 graphite/composite gaskets used on the 80's/90's small blocks (TBI carb...etc)

.025 in the hole with a .015 gasket gives you .040 quench, which is good, not great but good.

same applies to stock LS engines. roughly .005 out of the hole and a .051 gasket gives you .046 quench. again, good but not great.

again, when dealing with compression heights on rod/piston assemblies, a lot needs to be taken into account. you really dont want to run the piston .030 in the hole then turn around and put a stock .051 gasket on it and have .081 between the piston and the quench pad on the head.

when your going with a shelf piston, it's best to have your block checked to see how much it needs taken off the deck, if any and go from there. then you can decide to have this amount or that amount taken off to bring your piston exactly where you want it in relation to the cylinder head and deck surface.

.025 in the hole with a .015 steel shim head gasket

Sales2@Texas-speed

iTrader: (5)

While it is true you can run a 6.098/6.100" rod with any of these pistons (assuming the correct small end sizing), it is less than ideal to run the piston on an NA or nitrous combo in the hole like that. They are, for the most part, setup to put the piston zero deck at or near 9.240" with a 6.125" rod though, and for most combos, that is preferred to running them in the hole .025" or so. Also, keep in mind your stock rods have about a .945" small end diameter, whereas the aftermarket pistons are generally .927" pin size...so you're still looking at buying a set of aftermarket rods and it would make better sense to setup quench and all closer to zero deck.

drain89

iTrader: (13)

Both of the last two responses were spot on. Quench area is a key factor in determining how octane sensitive your motor is. The better the quench, the more compression you can get away with on pump gas.
If this is not an area you understand fully, I would talk to a reputable builder with proven results and let them select parts that are spec'd to what your needs and goals are. Otherwise you can quickly spend a ton of money on results that are nowhere near you're expectations.

JAX04

iTrader: (17)

Thanks guys, i wont be doing anything my engine guy tells me not to do, lol.

Im sure he will get all that stuff figured out, but i certainly wont be ordering any rods until he gets ahold of my motor and heads and tells me what to get.

ljsracing19j

Im not saying it would be ideal... just putting into more of a perspective of what they are saying. Also depends if its a "stock rebuild" or something you want 400+ out of. But yes i totally agree with their posts.