158 rods

[BustedNut]

My brother recently purchased a crank with hot rods. He asked me to build his engine for him, but when I went to install the top end, the pistons cam up out of the cylinders. I measured his rods compared to the old ones and they are too long. The rods say c.k. 158. If possible, what do I have to do to make this work?

[badassbanshee479]

is this a 4 mill crank or a stock stroke crank?

[swrbansheeboy]

this is all i could find with the ck 158 rods...

http://www.bansheehq.com/forums/index.php?...mp;#entry872853

 

the only time i've had this problem it turned out to be a long rod set up....

Edited April 2, 2009 by swrbansheeboy

[4stroker]

does the piston stick out approx 5mm?

[vulvafan537240]

it could be a 4mm stroker, a 5mm long rod, or a longrod stroker

[Bansh-eman]

depending on how far it's sticking out, it is either a long rod crank or a stroker or both. Its a simple fix for any of them, it's just going to cost you more $$$. Just need to know what crank it is so you get the correct pistons and have the head machined right.

[BustedNut]

does the piston stick out approx 5mm?

 

The piston actually sticks out 7mm. So does that mean that its a stroker crank and rod?

Some guy he has been talking to says that he just needs a spacer. I think if he is going to do it like this, we should check his port timing and set it up right.

I was wondering what the benifit of doing this is? Is it just to fit more fuel in? If its just a longer rod and you add a spacer, you aren't changing anything but the size of the crankcase, thus adding inlet volume. If it is a stroker crank, does it give you more torque?

Edited April 11, 2009 by BustedNut

[sled]

if its a stroker its gonna make more power, but not rev as high. you need 795 series pistons and a spacer plate or the head cut. I would call a builder like Herr Jugs racing or F.A.S.T and talk to them about it. It's probably a 4 mill crank with long rods. you need to have the cylinders ported, get the head cut, different piston. trust me it's way worth it!

[rubberneck]

If it sticks out 7mm then you have a 4mm stroker + a 5mm long rod. (2mm extra travel up + 5mm extra rod) You are going to need 795 series pistons to compensate for the longer rod. The 795s have the pin moved 5mm closer to the piston crown to compensate for the rod length. There are 2 ways to deal with the extra stroke. The cheap quick way will be to run a 2mm spacer plate below the cylinders. This plus the 795s and you have a running motor. The better way would be to have the cylinders ported to compensate for the stroke and run stroker domes that are recessed 2mm to compensate for the pistons coming out the top of the cylinders the extra 2mm. (either way you need the 795 pistons though)

[LS1Inferno]

OR you could sell the stroke crank to me haha JK, yeah you are going to make a lot more power then you though.

[BustedNut]

If it sticks out 7mm then you have a 4mm stroker + a 5mm long rod. (2mm extra travel up + 5mm extra rod) You are going to need 795 series pistons to compensate for the longer rod. The 795s have the pin moved 5mm closer to the piston crown to compensate for the rod length. There are 2 ways to deal with the extra stroke. The cheap quick way will be to run a 2mm spacer plate below the cylinders. This plus the 795s and you have a running motor. The better way would be to have the cylinders ported to compensate for the stroke and run stroker domes that are recessed 2mm to compensate for the pistons coming out the top of the cylinders the extra 2mm. (either way you need the 795 pistons though)

Spot on bro. Thanks for the tips! Got a 2mm spacer and 795 wiseco pistons. I am still gonna have the cylinders ported professionally to be able to flow and make the stroker worth it! What kinda jetting do you think I should go with?

[badassbanshee479]

I think you should skip the spacer and just get stroker domes cut... have who ever ports it set the domes up as well....