I dropped off a set of stock pr4 LS rods at the machine shop to get some arp rod bolts pressed in and re-honed, shotpeened, and then have a set of pr3's pressed on. Well, the guy broke one of my pr3's trying to press it off the stock pr3 rod and said he wanted nothing to do with the other 3. He did manage to press a stock set of pr4's on the LS rods without breaking any, but I'm dissappointed in the compression loss I'm going to have. How badly will this affect my power output? It's not a tremendous build by any means, just a basic ls/vtec with a stock gsr cam set I picked up dirty cheap and some mild port work and clean-up done by your's truly. I was hoping before to get a 170hp range out of it, how bad will this drop me down from that? Maybe run a thinner headgasket to try and gain some compression back?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 89EF_Turbo &raquo;</TD></TR><TR><TD CLASS="quote">I dropped off a set of stock pr4 LS rods at the machine shop to get some arp rod bolts pressed in and re-honed, shotpeened, and then have a set of pr3's pressed on. Well, the guy broke one of my pr3's trying to press it off the stock pr3 rod and said he wanted nothing to do with the other 3. He did manage to press a stock set of pr4's on the LS rods without breaking any, but I'm dissappointed in the compression loss I'm going to have. How badly will this affect my power output? It's not a tremendous build by any means, just a basic ls/vtec with a stock gsr cam set I picked up dirty cheap and some mild port work and clean-up done by your's truly. I was hoping before to get a 170hp range out of it, how bad will this drop me down from that? Maybe run a thinner headgasket to try and gain some compression back?</TD></TR></TABLE>

Every machine shop i have been to has told me they cannot remove stock pistons without breaking them.

Also, in any engine build, use NEW PISTONS AND RINGS. they are only $140 from topline and honda rings are $100.

dont use used pistons EVER.

 

I used to press D-series pistons on and off all day long and re-use them without any problems. Just didn't feel like playing around with these (I also have the wrist pin driver tool from honda) so I took them down, guy told me "oh yeah, no problem...I do these all the time." This is the last time I ever try and use stock rods/pistons...all aftermarket from here on out. Floating wrist pins are much nicer anyway.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 89EF_Turbo &raquo;</TD></TR><TR><TD CLASS="quote">I used to press D-series pistons on and off all day long and re-use them without any problems. Just didn't feel like playing around with these (I also have the wrist pin driver tool from honda) so I took them down, guy told me "oh yeah, no problem...I do these all the time." This is the last time I ever try and use stock rods/pistons...all aftermarket from here on out. Floating wrist pins are much nicer anyway. </TD></TR></TABLE>

im not saying its not possible, but the majority of people who run machine shops ( an we deal with a bunch) say the cast pistons will crack when taking them off.

I have tried to remove them and ive had them break on my self as well.

just going by what machinists tell me, and i cant really argue with them.

Buy some new PR3s. if your gong through the trouble of doing the rods with arps an such, might as well through new pistons in there.

 

I would but I'm getting to the point where (A) I'm starting to run low on cash, (B) I need to get the car back together and running even for the simple fact of gas prices. I drive around 95 miles in one day back and forth to work, and my '04 wrx just isn't cutting it on the gas mileage. I'm hittin' close to 30 years old now, and I'm starting to get worn out with the honda game after almost 10 years of dealing with it.

 

cut corners now and it will cost you more down the road...

 

get some rs machine pistons for like 160 shipped with rings

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Spoon07 &raquo;</TD></TR><TR><TD CLASS="quote">cut corners now and it will cost you more down the road...</TD></TR></TABLE>I'm not really cutting corners. The block is in good shape, I had them check to see if the sleeves were out of round and they were still in tolerance, no scratches or pits. Just honed it good to break the glaze and measured the clearances. All new honda oem bearings for the crank and rods, and I had the crank balanced and micro'd while I was at it. All ARP fasteners, main studs, rod bolts, head studs, etc with everything align honed. I just had the head decked ever so slighty to make it flat (was an auto b16a head) and pretty much the pistons swap was all I really wanted to do. It's not like I keep a motor in the chassis for long periods of time...this will be motor #8 for this car in the past 2 years.

 

They will come off without breaking if you put some heat on the rod before pressing them off. Same thing putting them on if you want to reduce the force needed

 

It’s not the compression that I would be worried about but valve reliefs on the pr4's, especially down the road when you decide to upgrade to more aggressive cams. With pr4's be sure you clay the motor, even with gsr cams..
Pistons, shouldn't break when pressed off correctly, especially a set that you are considering in using for another build.

googluck with your build.

 

next time dont take ur motor work to a boot leg shop !

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by moehp &raquo;</TD></TR><TR><TD CLASS="quote">They will come off without breaking if you put some heat on the rod before pressing them off. Same thing putting them on if you want to reduce the force needed</TD></TR></TABLE>That's how I used to do my d-series piston swaps...pins usually slide right out.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by toekneevwj &raquo;</TD></TR><TR><TD CLASS="quote">It’s not the compression that I would be worried about but valve reliefs on the pr4's, especially down the road when you decide to upgrade to more aggressive cams. With pr4's be sure you clay the motor, even with gsr cams..
Pistons, shouldn't break when pressed off correctly, especially a set that you are considering in using for another build.

googluck with your build.
</TD></TR></TABLE>leaving the pr4's in gives me just a hair under 10:1 c/r. I really don't think I'd see a great improvement in power jumping to a larger than oem cam with that low of a c/r. For now it's just going to be gsr cams. Maybe later on down the road I might drag out one of my spare LS blocks and really do something with it, but if that's the case I don't want to use stock rods/pistons.