Balance or not to balance on 383 stock rebuild

Posted By: VITC_GTX

Balance or not to balance on 383 stock rebuild - 07/19/11 05:56 AM

Rebuilding my 383 to stock-ish form (300-325 hp). The engine is standard bore and will be bored over .030" with new KB 162 pistons (~8.5:1). The engine was taken apart prior to me opening it up and they put the original pistons/rods back in the wrong locations. So, question is, since I'm replacing the pistons do I have to worry about the location of the pistons/rods? Also, for a low rpm stock build do I need to worry about balancing?

Posted By: None2Slow

Re: Balance or not to balance on 383 stock rebuild - 07/19/11 06:04 AM

Balancing makes it run smoother. I hear a balanced engine lasts longer. I would think that this would apply even to a stock rebuild. If you can afford it and its not a total low budget rebuild, then I would do it.

Posted By: nomore65BelvJim

Re: Balance or not to balance on 383 stock rebuild - 07/19/11 06:05 AM

cant hurt and shouldnt be very expensive.

Posted By: VITC_GTX

Re: Balance or not to balance on 383 stock rebuild - 07/19/11 06:21 AM

I'm sure it can't hurt but didn't know the real benefits for a low rpm stock engine. Would I even tell the difference over 40,000 miles?

"shouldn't be very expensive" I'm guessing $250-ish????

If I don't balance it does is matter what order the rods and new pistons go back in?

Posted By: None2Slow

Re: Balance or not to balance on 383 stock rebuild - 07/19/11 06:24 AM

When you say rebuild, are you getting the crank turned and rods resized if needed? If so, then it "shouldn't" matter.

Posted By: VITC_GTX

Re: Balance or not to balance on 383 stock rebuild - 07/19/11 06:30 AM

Quote:

When you say rebuild, are you getting the crank turned and rods resized if needed? If so, then it "shouldn't" matter.

I was not going to get the crank turned or the rods resized. Problem is when I removed the pistons I marked them with a punch as I didn't see the original marks. Once I got them out I realized that I had marked over the original marks so now I'm not sure where they go...

Posted By: DAYCLONA

Re: Balance or not to balance on 383 stock rebuild - 07/19/11 11:23 AM

Spend the coin to have it balanced, this is the time however to upgrade the pistons, and bore the block IMHO

I know building an engine, one thing leads to another, but put some money into the rotating assy, easier to do it now, then later

Posted By: 340SHORTY

Re: Balance or not to balance on 383 stock rebuild - 07/19/11 11:27 AM

2 fiddy is high,,, 1 fiddy to buck 75 is normal on the wet side...

Posted By: CompSyn

Re: Balance or not to balance on 383 stock rebuild - 07/19/11 11:34 AM

Quote:

Quote:

When you say rebuild, are you getting the crank turned and rods resized if needed? If so, then it "shouldn't" matter.

I was not going to get the crank turned or the rods resized. Problem is when I removed the pistons I marked them with a punch as I didn't see the original marks. Once I got them out I realized that I had marked over the original marks so now I'm not sure where they go...

If you were keeping the original pistons, rod bolts, etc., then the factory balance job would suffice.

However, since you're changing the pistons, I'd get it balanced for sure. And while you have to have a shop press out the piston pins to change out the pistons, might as well replace the rod bolts and have the rods re-sized; all of this cheap insurance to not having a blown motor down the road.

Posted By: Mapandjlp

Re: Balance or not to balance on 383 stock rebuild - 07/19/11 12:38 PM

I didn't balance mine and every time I drive it I wish I had. Nothing serious, just doesn't feel as smooth as it should. No one notices but me...but that's all that matters.

Balance it. It's worth it.

Posted By: VITC_GTX

Re: Balance or not to balance on 383 stock rebuild - 07/19/11 08:33 PM

Thanks all. It will get balanced.

Posted By: RemCharger

Re: Balance or not to balance on 383 stock rebuild - 07/19/11 09:13 PM

Try to put the rods in original locations as best you can. 4 go on one side , and 4 on the other. now if you can determine 3 locations then one has to go where it goes.

Posted By: JohnRR

Re: Balance or not to balance on 383 stock rebuild - 07/19/11 09:17 PM

Quote:

Quote:

Quote:

When you say rebuild, are you getting the crank turned and rods resized if needed? If so, then it "shouldn't" matter.

I was not going to get the crank turned or the rods resized. Problem is when I removed the pistons I marked them with a punch as I didn't see the original marks. Once I got them out I realized that I had marked over the original marks so now I'm not sure where they go...

If you were keeping the original pistons, rod bolts, etc., then the factory balance job would suffice.

However, since you're changing the pistons, I'd get it balanced for sure. And while you have to have a shop press out the piston pins to change out the pistons, might as well replace the rod bolts and have the rods re-sized; all of this cheap insurance to not having a blown motor down the road.

This ^^^^

Nevermind that the KB's are lighter than a stock piston, also not resizing the rods considering what you state above is just asking for trouble .

Posted By: HYPER8oSoNic

Re: Balance or not to balance on 383 stock rebuild - 07/19/11 10:08 PM

Quote:

Balancing makes it run smoother. I hear a balanced engine lasts longer. I would think that this would apply even to a stock rebuild. If you can afford it and its not a total low budget rebuild, then I would do it.

100%! Besides the smoothness and extended engine life, you might pick up an extra few hundred rpm's to boot. Less stress on the lower end (mains and rod bearings) and the oiling system, if kept clean, will be flawlessly efficient. BTW, nothing low rpm about the 383, they want to rev (read: peppy street performance).