408lq4

iTrader: (1)

i have a 6.0 with stock crank 6.100 h beam rods and wisco pistons to match the rod. is it possible to take the 3.622 crank out and put a 4.000 crank and use the same rods and piston?

S10xGN

iTrader: (11)

No, the pistons will be 3/16" out of the bore at TDC.

bww3588

iTrader: (49)

You will need a 6.125 rod with a piston with a 1.115 cd to run a 4 inch crank.

Sales4@Texas-Speed

iTrader: (4)

Pistons would come waaay out of the hole on that one. You want to make sure the pistons are set up for the crank you are putting them on.

redtan

iTrader: (5)

Rule of thumb here...whenever you change the stroke and leave everything else the same (sleeve length/width, deck height) you will need to change both the rods and the pistons. In order for the piston to not jump out of the cylinder with the longer stroke something else has to give, in this case different length rods and different sized pistons.

PREDATOR-Z

Yes, you could shave the pistons.

KCS

iTrader: (20)

I don't think that would be a good idea. That would be a pretty thin top ring land.

PREDATOR-Z

Depends on piston brands, we used to do that to reduce weight as well. In hotroddin' one thinks out of the box. Compression used is a factor as well, no boost or nitrous.
While it is not common practice it is doable.

KCS

iTrader: (20)

You used to trim .160" off the piston tops?

I understand thinking outside of the box, but that seems like its asking for trouble. Most ring lands are less than .300" thick, so trimming half of that off would drastically reduce the strength of the ring land, not to mention increase the heat the top ring is subjected to. Without knowing how much power the engine is meant to make, that suggestion should at least come with a disclaimer.

Kaase did something interesting in a very similar combination by using a very thick head gasket (like .250") and then put spacers under the manifold to effectively lengthen the runners.

But then again, if the correct pistons aren't in the budget then custom gaskets probably aren't either.

PREDATOR-Z

Actually 1/2 that .0875 to be exact and that would leave the piston .100 out of hole. Quench would also be an acceptable .048 with stock gasket.

KCS

iTrader: (20)

.100" out of the hole and you get .048" quench with a stock .052" gasket?

PREDATOR-Z

Yes, .100-.052=.048= quench

Sales2@Texas-speed

iTrader: (5)

A piston .100 OUT of the hole and a gasket .052" thick puts your piston .048" ABOVE the gasket...that's not the same as .048" quench. .048" quench would be a .052" gasket and the piston just .004" out of the hole.

KCS

iTrader: (20)

Exactly.

PREDATOR-Z

Yeah, complete brainfart, and a massive one at that.
That is some good **** though

Sales2@Texas-speed

iTrader: (5)

I literally thought to myself "What has he been smoking today?"

PREDATOR-Z

Indika

bww3588

iTrader: (49)

No ****. Usually pred is on the money...totally dropped the ball this time. Now what's the explaination for that nonsense?

PREDATOR-Z

overload!!
Too stressed, lack of sleep. long work hours, no sex, lack of focus.

BKsNHRA

iTrader: (4)

Yep. Couldn't have come up with a better excuse myself. Lol. Perfect.