jid2

iTrader: (62)

So I'm talking with the machine shop that is going to face, deck, bore and balance all my goodies for the 2.3L build I'm about to start on. The guys is telling me that I really should/need to have him polish all the bearing surfaces i.e. polish the crank, connecting rods, piston wrist pins etc.

To me the crank looks good as is, the connecting rods could be smoother for sure, but I'm wondering who else has done this? It's another $300, which part of me says just do it, and the other half is saying "this butt-rocker machinist is up-selling me"

Thoughts?

deadbeatrec

iTrader: (9)

if im not mistaken, David B made a quick video of how he does it. took him under like 2 mins to do it so $300 might be a bit excesive.

ps: i may be thinking something different so dont hold me to it.

Onyxeros

iTrader: (2)

it's certainly worth doing
the polishing that is done can't be seen with the naked eye.

The shop that did my polishing took a material that had the consistancy of leather and polished each journal then hot tanked and cleaned with pressurized air. It literally took him 5mins total while talking to me to get it done.

maybe you could see about working out a deal with him to do it for free since he is doing so much other work for you

jid2

iTrader: (62)

For free nothing. These guys have it as a line item. $100 for the crank and 160 for the rods. The guy I wanted to talk to wasn't there though, and should probably make sure they know it's a 4 banger and not a V-8.

Joshs EVO

iTrader: (46)

I bought a knifeedged crank that had been polished also. I have yet to install it in my car but for the most part anytime you polish the insides of the motor it helps with the flow of gas, air smoother.

03whitegsr

iTrader: (8)

Polishing rods, in the old V8 sense means polishing the entire rod, except for the bearing surfaces. It's done to remove stress risers. Some of the old factory performance GMs came this way (I think the originals were referred to as “Pink rods”). But most aftermarket rods (and I believe even the 4G63 factory rods) are shot peened. This compresses the surface layer of the metal by bombarding the surface with steel ***** at high speeds and is actually far better than polishing.

The rod journals should be precision honed to size, but not polished.

$100 for polishing a crank is pretty steep as they just toss the crank in a spinning machine and use a polishing belt to smooth the journal surfaces. Literally it is a two minute job.

I'd ask for a better explanation of what they are doing. I could see the $160 for polishing the rods, but you'd be better off just leaving the shot peened finish.

Unless you bought Pauters, then removing the machining marks is a good thing.

sabastian458

iTrader: (25)

I wouldnt bother. unless he has a micro polisher. Plus you dont want to run the risk of them taking too much off the surface.

Line hone, cyl bore, and a decking of the, um, deck and you should be fine. I would also go ahead and to arp mains when they do the line hone.

jid2

iTrader: (62)

That's some good info, thanks Mike! I just talked to the guy over the phone. The machine shop was referred to me by Cascade Autosport, they use them for all their rally car motors. I'll ask Cascade what sort of service they typically had done as well.