junkyard racer

I bought a used motor, D16y7 all forged internals.

take a look at the piston to wall clearence:






if you look closely in the #1 cyl, you can accually see part of the ring.
and look at the tops of cyl 3&4

i have been told both ways, to much "piston slap" and others say, you want a little gap like that for room for expansion when the motor warms up.

what is your take on it?

Bailhatch

may take on it is measure it. Pictures just don't cut it.

junkyard racer

something else i should add to this, the person who i bought it from says the compression when pulled was 180-180-180-179...

hondaguyef

You're going to have to measure it but, I see your point with the #1 cyl. It looks like alot of gap.

Phil

Bailhatch

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by junkyard racer &raquo;</TD></TR><TR><TD CLASS="quote">something else i should add to this, the person who i bought it from says the compression when pulled was 180-180-180-179...


</TD></TR></TABLE>

what's with the you can't have it much closer to perfect than that.

FERIOkid

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

what's with the you can't have it much closer to perfect than that.</TD></TR></TABLE>

exactly what i was thinking... if the last cylinder was a 105 then you would have a problem.

my d15b7 read 175 all across the board so your lookin good

junkyard racer

my point with was that much gap, but such good compression.

and no scoring on the cyl walls, pistons are good

but...the bearing was &^#!ed.

junkyard racer

so another question, do forged pistons expand? if they do, how much?

the person who I bought this from said it was assembled from the "best assembler in town" -my point, maybe theres a reason there is so much clearence?

2muchPSI

yes, they will expand. How much depends on the silicon content in the pistons(different brands have different amounts). Check the specs published from the company who manufactured them.

*Boostwerks*

It actually doesn't look that bad. It of course depends on what pistons are in there, but if they are low silicon type, they are going to expand a lot!

I could see the ring of my GE built motor when the piston was at the bottom of the bore. I have Arias pistons, to which are said to expand quite a bit.

JDMs1eeper

looks good to me.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bryson &raquo;</TD></TR><TR><TD CLASS="quote">I could see the ring of my GE built motor when the piston was at the bottom of the bore. I have Arias pistons, to which are said to expand quite a bit. </TD></TR></TABLE>

my bottom end was the same way somewhat. I also use Arias. Seems to be just fine

ATS*Mark

different piston makes call for different piston to wall clearances. arias's slap like a mother ****** . while cp's dont.....its because of their specs.

leadfoot78

The top part of the piston doesn't even matter that much, piston to wall clearance is always measured one inch below the oil control ring, on the piston skirt. The piston skirt is quite a bit bigger than the top part, when I had 81.5mm pistons the top of the piston could fit in the 81mm bore easy, but the skirt didn't fit in at all. Have it measured at a machine shop, they can do it in minutes and usually don't charge for something like that.

junkyard racer

soo....should I not worry about this. Im gonna call SRP this afternoon and see what they have to say, maybe there should be that much gap?

also, i am ASSUMMING that when the guy who built the motor looked at the specs SRP sends with there pistons he went off of that. that would be a good assumption i would think.

I searched around a bit and found that forged pistons warm up and expand so I think it would be safe to say this motor is ok?