I have always been under the assumption that when installing PCT pistons into a B16a (PR3), I would have to machine the wrist pin side of the connecting rod on each side for it to fit between the PCT piston wrist pin bosses. Upon doing so, will this metal removal compensate for the additional weight added by the PCT pistons, which means that I won't have get a balance job?

Regardless, I feel that if I am at the most +/- 10 grams from what it originally was, then I should be okay. Right?

I guess it would be best to know the difference in weight between the PCT piston and the PR3 piston. I'd be nice to be able to not have to get my crank and everything rebalanced.

 

IMO its not worth the risk. I would always get the rotating assembly balanced especially if you are having the piston machined.

 

I really just need to know how many grams a PCT piston weighs. I know I have to remove at least 4 grams (hopefully more) from the wrist pin side of my B16a connecting rod, then this could put me back into my 10 gram window.

I really can't find anywhere on the web about how much a PCT piston with the standard bore size actually weighs. I know that the PR3 piston that I currently have supposedly weighs 299 grams.

 

Pistons dont always weigh the same. Even oem out of the box pistons can very thats why they need matched up a rod of +,- weight to try to even it out.

 

So true, i had a set of OEM ITR pistons vary 6.2 grams from lightest to heaviest

 

6.2g for itr pistons?? so my f23a pistons are more accurate than...quite weird...

 

6 grams off is odd for a bvtec piston set. The pct and p30 sets Ive measured were within 1 gram each.

 

2 were pretty close, about 1 gram apart, but the heaviest and lightest varied 6.19 grams, I used a digital balance accurate to 0.01 gram. I was shocked myself.

 

So are you watching them balance these rotating assemblies? LOL... that is some funny stuff. Unless you mean matching weights. Just match the weight as close as possible by grinding some off of the rods/pistons. There is no little end big end weights like the V8 cars you guys are misinformed.

 

1 sheet of paper towel weighs 2 grams. Not a big deal if the pistons vary by 3 - 4 grams. What happens to the weight when there is oil and carbon on the pistons???

Scale capacity of 300+ grams to the 0.01 gram? That is an expensive scale.

 

 

I was told by the guy I just dropped my stuff off at that they don't even balance the entire rotating assembly together they just balance the crank itself because honda motors (excluding the v6s) are 180* motors unlike v8's like mentioned above....I mean i'm sure this goes out to a certain extent of course if one cylinder is just for an example 100 grams and one is 130 grams something needs to be done

 

Listen to your guy.

Who knows more? The balancing professional or the comittee of idiots here?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Master of the Universe &raquo;</TD></TR><TR><TD CLASS="quote">1 sheet of paper towel weighs 2 grams. Not a big deal if the pistons vary by 3 - 4 grams. What happens to the weight when there is oil and carbon on the pistons???

Scale capacity of 300+ grams to the 0.01 gram? That is an expensive scale.</TD></TR></TABLE>

Yeah, I do research at a CSU. I have access to Graduate Lab with balances with .1-.01 gram accuracy. Some cost over $1k

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Master of the Universe &raquo;</TD></TR><TR><TD CLASS="quote">Listen to your guy.

Who knows more? The balancing professional or the comittee of idiots here?</TD></TR></TABLE>

the balancing professional?

 

Tite. I have a 1,200 gram scale reads 0.1g. Very good stuff. I also have the calibration wieghts to recalibrate the scale should it not read correctly. This scale doesn't quite cost $1,000.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b20sedan &raquo;</TD></TR><TR><TD CLASS="quote">the balancing professional?</TD></TR></TABLE>

BINGO!!

BEE - EYE - EN - JEE - OH
BEE - EYE - EN - JEE - OH
BEE - EYE - EN - JEE - OH
and Bingo was his name-oh

Okay circle time is over we've got the new hall monitor.

 

they guy that assembled and machined my motor also said that it really wasnt nessesary. he said he would weigh each rod/piston for any substancial variation,but he said honda does a damn good job from the factory.
same with the crank since its inline not like a v6/8 its not as critical,again he said the way honda does it you could spin it and it may not even need it. he just polished the journals and checked it for any bends. so far so good vtec going on soon so we'll see

 

Yeah, some of these balances are 10kg, 50kg 200kg. I had to order a 20kg calibration weight for the 200kg balance and that thing alone cost $50. Its a food chem. lab and sometimes we do product development, so we make 50kg or 200kg batches of product.

But yeah the 6 gram variation was nothing, so when it came time to balance my rotating assembly the machinist said he didn't even have to do much so he didn't charge me

 

A matched set of Honda pistons, as you take out of your engine should be with-in a gram. Buying from a dealer, where they get 4 individual pistons off the shelf, can be off by 5-6 grams. Just weigh them. They can also be different sizes, but that is too much to get into here.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DonF &raquo;</TD></TR><TR><TD CLASS="quote">A matched set of Honda pistons, as you take out of your engine should be with-in a gram. Buying from a dealer, where they get 4 individual pistons off the shelf, can be off by 5-6 grams. Just weigh them. They can also be different sizes, but that is too much to get into here.</TD></TR></TABLE>


thats some good information.
i didnt know that about the pistons. i guess honda matched them up with the closest weights[cough,spoon,cough].
i cant remember what the piston sizes was but he had them wrote on top the pistons,he did say he wouldnt bore them without each piston in his hand