Stock Rebuild Question

[BoostedAWD91]

im looking to do a stock rebuild on the block since i dont really have the funds to do a built motor at this time. Is there any other good choices of pistons to use besides the 2g piston on 1g rods? Where is the cheapest place to get the 2G pistons? Anyone ever use the Topline pistons, is there a different company that actually manufactures them? Any suggestions on some good pistons that are cheap that will work on 1G rods?

 

[belize1334]

I've been planning on doing one for a long time and haven't had the funds. My research says that the cheapest source of reliable pistons is NPR pistons on E-Bay. NPR is Nippon Denso and the concensus seems to be that they're good stuff. You can get a set of 4 pistons with rings in either 1G or 2G for under $200. If you go 2g you'll have to have your rods machined to work and the cost will depend on your machine shop but shouldn't be more than another $50 a rod I would think. That's my $0.02 but I haven't done it so I can't actually vouch personally for the quality.

 

[BoostedAWD91]

i looked on ebay earlier and didnt see any of them, maybe i just missed them. if u have the link for them please post it. what exactly is the difference
and or benefits of using the 2g compared to 1g pistons?

 

[belize1334]

Supposedly the 2G pistons are a bit stronger on the ring lands, but I can't give personal testimony to that. It is certainly the case that the 2G pistons have a higher compression ratio (8.5:1 vs the stock 7.8:1). This makes the engine a little peppier off boost and gives you a slightly more efficient combustion cycle (for mileage purposes). Whether it's better or worse for a turbo application seems to be a matter of debate and depends on what you're looking for. To make the 2G pistons fit you'll need to have your rods machined.

click

The seller lists them as 93-99 4g63T pistons but then goes on to say 7.8:1 compression ratio so you'll want to make sure you're getting what you pay for. I found that by just searching ebay for eclipse pistons . That guy isn't the only seller and you can find others who have these for 1G or 2G and with or without rings.

 

[slugsgomoo]

it's about the same price to get wiseco's for 1g rods as it is to buy 2g pistons and have them machined (usually).

I definitely like the higher compression better, but it does make for a challenge tuning if you don't have timing control, since you'll need a less aggressive timing map (like a 2g).

didn't the 92.5-94 have the small rod 7 bolts with 7.8:1 compression? could be what the ebay seller is referring to.

 

[belize1334]

Show me where to get Weiscos with rings for < $300 or even $400 for that matter. I've never seen it.

 

[BoostedAWD91]

i probably will just go with 1G pistons cause i dont really have the $ to pay to have the rods all machined to fit the 2g pistons.
Any ideas on the topline pistons? Is it a good or bad idea to use Arias or JE... and so on pistons on 1G rods?

 

[belize1334]

Many people have run forged pistons on 1G rods with good success. I would steer clear of topline.

 

[BoostedAWD91]

what kind of power or boost can the stock rods handle? if doing forged pistons on 1g rods will work very good and handle more boost than stock pistons, that might be the route i take

 

[belize1334]

I can't answer that exactly. I think people have pushed past 400whp on stock pistons and rods so I imagine that it'd be there or slightly more.

But, regardless of whether you use 2G pistons or forged pistons, it is very important that you have some way to tune your timing. This can be done through the use of a standalone or by getting a DSMChip burned. If you go to a higher compression ratio (7.8:1 being stock) and you're still using the stock timing maps you WILL NOT have a good running vehicle. Either you will have bad detonation under high boost, or you'll have to retard the timing and it'll drive like a pig at low boost.

 

People always say it is expensive to machine the 1G rods to fit 2G pistons but this surprises me. When I had the machining done for my motor the shop reconditioned my rods (grind the caps down and rebore the big end), installed ARP bolts (I supplied the bolts), balanced the rods, and installed my Wiseco pistons, all for $150. I would think machining the small end of the rods would cost less than that, or did I just get a killer deal?

 

[BoostedAWD91]

there is more work needed to fit the 2g pistons on 1g rods, thats why its more expensive.
im not sure what all is needed to be done for them to fit... can anyone explain this better?

 

[1941Galant]

The wrist pin bore needs to be opened one millimeter, and the smaller end of the rod needs to be narrowed .100" for the 2g pistons to fit. That was taken from dsm talk.

Hill

Here is a picture

 

Quoting BoostedAWD91:
there is more work needed to fit the 2g pistons on 1g rods, thats why its more expensive.



I already know what's required to fit 2G pistons to 1G rods, that's why I don't understand why it would be so expensive. My rods got more work and only cost $150.

 

[fivestardsm]

Here was a set that was on flea-bay just to let you know they can be found.

click

 

Sorry for stealing this thread /ubbthreads/images/graemlins/blush.gif /ubbthreads/images/graemlins/banghead.gif

But the stock pistons with rings on ebay, are they real denso quality parts or just some cheap ass parts that breaks our engine??

They do look somehow cheap /ubbthreads/images/graemlins/dunno.gif But maybe these ARE the OEM pistons and rings without the mitsu loggo on the package??

 

[BoostedAWD91]

i have a complete block that is gonna need new rod and main bearings. Its a stock block w/ balance shafts still in it. It wouldnt cause any problems just replacing the bearings and putting it back together would it? Obviously ill be checking all the clearances as i reassemble but i wouldnt think it would be to much of a deal to just replace the bearings would it? any suggestions?

 

Whats wrong with the bearings that necessitates replacing them? If they failed, they failed for a reason.

 

[BoostedAWD91]

the one rod bearing i took off was scored pretty good. The crank journal was ok, no major marks or edges on it

 

[boostedinaz]

When I had my short block machined and built the machine shop only charged me somethign like 15.00 a rod to fit 2G pistons. Perhaps it was because I was already having them machine the whole block, but I also have never understood the "it cost so much" argument.