really poor mans stroker.... Balanced ??

[johnnybebad]

Hi i`m thinking of putting together a stroker the only way I can afford.... cheap lol.
I have a 91 shortblock with low mileage and no ridge on the cylinders, and a 4.2 crank and rods from a YJ that also had low miles. I plan on plastigauging all the bearings and was wondering if anyone has just...well..slapped one together without having it professionally balanced ? how long did it last or is it still going ???
I have 4 blocks and 3 cranks and rods, and only 1 needs to be turned so if it did blow up i`m not screwed. wondering if I can get away without having the rotating assembly balanced or should I just keep saving and have it done. thanks for any and all input !

[BADASYJ]

Go for it man, I would polish the mains on the crank and make sure no mud dauber made a home in one of the oil passages on the crank. Swapping the pistons over on the rods might be a lil tuff.
Have you polished crank mains before?

[johnnybebad]

yes I have actually . and I know a guy at the machine shop who can switch the rods over for me. Thanks for the reply , I now have a winter project for the race truck comanche lol

[Cheromaniac]

I have a 91 shortblock with low mileage and no ridge on the cylinders, and a 4.2 crank and rods from a YJ that also had low miles. I plan on plastigauging all the bearings and was wondering if anyone has just...well..slapped one together without having it professionally balanced?

Since the rods are coming as a set from one engine and the pistons are coming as a set from another engine, I suggest you weigh them all individually and pair up the rods/pistons to make the rod/piston assemblies as equal as possible in weight.
If the 4.2 crank is in good condition, a micropolish of the journals should be enough to make it serviceable.
Have a machine shop check the condition of the cylinders for roundness and taper. If they're within specs, just have them rehoned if the crosshatching is no longer visible so that you'll get a good seal with new piston rings.

[johnnybebad]

already thought of weighing them out, thanks very much for the info. I`ve got a bore gauge and a smooth hone too, been a few years since i built a motor from scratch and i`ve never tackled the jeep stroker set up , but i`m planning to build it this winter. thanks again !

[Retlaw01XJ]

Something I learned when I built my first Jeep was that an inline 6 doesn't require the same spin balancing that a 'v' engine does.
As mentioned, all that is really required is for the components of each cylinder to be fairly equal in weight. The crank should have been spin balanced (by itself) when it was manufactured, it should still be okay.

[SilverXJ]

As said all that is needed is weight matching of the rods (on both ends) and pistons. I would definitely get the crank balanced though as the stock factory tolerances aren't that great.

[johnnybebad]

all very informative tech. thank you all very much for your advice ! will post pics this winter when i finally dig into it !