Engine Building...How Is An Engine Balanced - Honda Forum / Acura Forum

Turbosi92 · 07-25-2002, 05:53 AM

The reason I asked is that I just got my built engine and my brother was concerned that the rod weights (Number on the rods in grams) is different on all cylinders. They are 272, 265, 292, 301 respectively. I guess my questions are:
How is the engine balanced?
Is this OK to have the rod weights like this?
Are all Honda engines balanced the same?
It is a D16Z bored to 1.8L with JE Pistons, Eagle Rods, Iron Sleeves, etc.

Thanks for the help.

:

Dr Drew · 07-25-2002, 11:50 AM

yeah it is ok for the weight to be off a little. When the engine is running the oil on the reciprocating parts (rods, pistons, crank) changes the counterweight balance considerably. So I wouldn't worry about a few grams. But if it bothers you, you can take the assembly to a machine shop and have them balance it.

babyvtec · 07-26-2002, 02:08 AM

it is VERY important to have the engine balanced. it is one of the most important processes in engine building. it will give you more power believe it or not compared to the same engine unbalanced and it will last longer also.

Honda_Guy · 07-26-2002, 02:43 AM

The rod weights shouldnt be off nearly that much. Usually if you buy a matched set, they come balanced to +/- a couple grams, not +/- 30 grams.

As for how an engine is balanced, if the builder is really thorough, they will make sure that the rods are not only the same weight, but that ends are all even too. For the pistons, they just make sure they are all the same weight. Then they put the crank on a balancing machine, and depending on whether the engine is internally balanced or externally, they may bolt the flywheel/clutch/crankpulley on too.

Is the engine assembled?

Turbosi92 · 07-26-2002, 04:42 AM

Yes, the engine is assembled.

Honda_Guy · 07-26-2002, 05:22 AM

Hmm, did a reputable shop do all the work? Maybe you should call them and see what they say before you run it.

Turbosi92 · 07-26-2002, 05:24 AM

JG Engine Dynamics. I have tried to call at least 15 times and I either leave a message or no answer. Trust me, I am pissed.

Honda_Guy · 07-26-2002, 05:34 AM

Well, this wont make you feel any better, but I've heard horror stories about JG. Dont know how true they are, though. Sucks that you had to ship it all the way out here to CA too. If you lived closer you could drive over and bitch at them. Whatever you do,, dont assemble or run the engine or anything until you get this sorted out.

Dr Drew · 07-26-2002, 06:20 AM

Quote:

Originally posted by Honda_Guy
The rod weights shouldnt be off nearly that much. Usually if you buy a matched set, they come balanced to +/- a couple grams, not +/- 30 grams.

My bad I didn't realize that they were off that much. I must have been half asleep yesterday. Like I said in my post B4. I wouldn't worry about a few grams, but 30 is a lot !! Definitly do something about that...Somebody has to file a lawsuit against JG, that guy rips off way to many ppl.