is this normal? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

benefitx · 05-26-2007, 10:23 AM

bought a set of some used pistons with rods...does this look alright??

sr20boostn20 · 05-26-2007, 10:41 AM

it looks like detonation. definatly not a good thing.

benefitx · 05-26-2007, 10:44 AM

thats what i thought...

benefitx · 05-26-2007, 11:02 AM

are they usable or what??

Big Bronze Rim · 05-26-2007, 11:20 AM

Yeah it looks like detonation. That piston was really close to losing its ringland completely. I would say that they shouldnt be reused. There is obvious pitting and erosion on the surface and around the ring land area. I would budget for new pistons. For moderate power rebuild, new stock pistons (54C) should be just fine.

benefitx · 05-26-2007, 11:26 AM

damn........

Big Bronze Rim · 05-26-2007, 11:35 AM

Well, if nothing else, get new pistons and have your machine shop install those rods onto the new pistons. IIRC when I was deciding what pistons I was going with i saw the 54C pistons were around $60 each and then you will need a ring set. I would make sure you dont need to bore before you go and order stock bore pistons.

s13gold · 05-26-2007, 11:32 AM

how much did you pay?

what was the sellers description of the pistons.

benefitx · 05-26-2007, 11:45 AM

Quote:

Originally Posted by s13gold

how much did you pay?

what was the sellers description of the pistons.

paid 85$ for the set...

i have my stock pistons that i pulled out in perfect condition...out of the SR im building that spun a bearing...crosshatched walls and everything , just one rod is bent maybe 4-5mm...so i bought these..oh and i bought a crank from him too which is in perfect condition...

i want to swap my good condition pistons onto these rods but i dont want to mess with the snap rings, then ill just have to replace them and no one sells them individually...

projectRDM · 05-26-2007, 04:16 PM

Snap rings take 3 seconds to remove, wrist pin another 10. You can swap all four pistons over to the new rods in under a minute.

babowc · 05-26-2007, 11:36 AM

stock pistons or performance pistons?

benefitx · 05-26-2007, 04:22 PM

yeah but i cant use the same snap rings right? my pistons are in real good condition...good coat of black on the top..ringlands look ok too...just one rod is bent...so i bought this set

projectRDM · 05-26-2007, 08:53 PM

Quote:

Originally Posted by benefitx

yeah but i cant use the same snap rings right? my pistons are in real good condition...good coat of black on the top..ringlands look ok too...just one rod is bent...so i bought this set

Why not? They're designed to be removed and reinstalled.

benefitx · 05-26-2007, 08:36 PM

seller exchanged the rods/pistons for a different set , teehee.

benefitx · 05-26-2007, 09:23 PM

because maybe it will lose its snappyness and come off? johngriff said to replace them in the other thread..

benefitx · 05-27-2007, 01:06 PM

the rods and pistons look really good, this set had bearings already on them to see if they were spun or anything...

benefitx · 05-27-2007, 01:09 PM

do i plastigage the rod bearings also?

Big Bronze Rim · 05-27-2007, 04:25 PM

Quote:

Originally Posted by benefitx

do i plastigage the rod bearings also?

Yes, you need to plastigauge both rods and mains.

benefitx · 05-27-2007, 06:02 PM

Quote:

Originally Posted by Big Bronze Rim

Yes, you need to plastigauge both rods and mains.

plastigauge green right...

i just lay down a strip of it on the mains , put the crank in , put the caps on and torque down the girdle... and then take it all of and measure the strip? if its between ______ and ______ its good??

Big Bronze Rim · 05-27-2007, 07:54 PM

Yes, you will need to lay a piece of plastigage on each journal. It should be used as confirmation that your on track with the bearings you ordered and any crank work that was done. Make sure its nice and straight along the journal axis. I did my mains at the same time and each rod one at a time. You need to make sure the is NO OIL on the journals when using plastigage. You will use the scale on the wrapper the plastigage comes in to measure its compressed thickness. The tolerances are in the FSM, but I set my engine up a little loose, running .0015" on the mains and .0018-.002" on the rods.

Big Bronze Rim · 05-27-2007, 07:57 PM

Yea, please don't use the blue, it isn't the shit and will look like butt. Get Permatex Grey like johngriff recommended.

johngriff · 05-27-2007, 04:33 PM

You can re-use them.

And the SR's are probably better than the CA's. That was ME erroring on the CA.

But remember, I am knuts. As attested to by other forum members, I over complicate things. I'll only buy hardware from McMasterCarr for example. Replacement parts only from the dealer. It can be nauseating to some people how thorough I am.

Russ is probably right, they will probably be fine being re-used. As I say "if you've got it, drop the coin for it". You'll have to remove them anyways. And lord only knows i did something dumb like not get it all the way into the groove.

benefitx · 05-27-2007, 06:00 PM

not getting it into the groove will probably cause problems...

i just bought some engine assembly lube made by permatex...its red in color in a little bottle...from autozone

and some blue rtv for the oil pan and water pump and stuff...

is this right??

johngriff · 05-27-2007, 07:48 PM

yeah, more or lesss, but you should plastiguage AFTER specing the crank/rod/journals.

Get permatex grey for all the everything. Chuck the blue or return it.

benefitx · 05-27-2007, 07:50 PM

what!! everyone has told me Blue RTV is the shit...my brother said something about some black shit because its high temp...never heard of permatex grey tho..

johngriff · 05-27-2007, 07:54 PM

http://www.permatex.com/products/aut...sket_Maker.htm

Nissan stopped selling/stocking/making (whatever), their grey RTV sealant, and simultaneously Permatex released this. It is certified by Nissan.

Blue is only supposed to be for Thermostat housings and waterpumps iirc, but it fails at all of those. PLUS grey looks the cleanest on a build, much more so than orange/blue etc...

**edit** or this, but its more expensive, and the can dies if you dont use it a whole lot.
http://www.permatex.com/products/aut...sket_Maker.htm

benefitx · 05-27-2007, 07:59 PM

ahh. alright..should of posted it earlier before i went out

benefitx · 05-27-2007, 08:03 PM

when i go to buy plastigage ill get some ultra grey. thanks for the info

projectRDM · 05-28-2007, 09:22 AM

Ultra Grey or Ultra black is fine, black is high temp but you won't see a need for it anywhere except the oilpan. Grey is sensor safe, so you can use a dab of it on the CTS or other sensors/switches that thread into aluminum to seal them without the need for teflon tape. I use both for each purpose, then wait a day and go back with a razor to trim any excess off. Nothing looks worse than a gob of RTV hanging out between two parts.

benefitx · 05-28-2007, 11:56 AM

thanks...so i need ultra grey AND black??

05-26-2007, 10:23 AM	#1
benefitx Banned from the Marketplace Join Date: Oct 2006 Location: suwanee ga Posts: 670 Trader Rating: (0) Feedback Score: 0 reviews	is this normal? bought a set of some used pistons with rods...does this look alright??

05-26-2007, 04:16 PM	#10
projectRDM Post Whore! Join Date: Dec 2002 Location: Atlanta Age: 51 Posts: 13,812 Trader Rating: (12) Feedback Score: 12 reviews	Snap rings take 3 seconds to remove, wrist pin another 10. You can swap all four pistons over to the new rods in under a minute. __________________ FORMERLY R240NA Learn what's really going on and protect your assets now before they're gone forever: www.paypalsucks.com

05-27-2007, 01:06 PM	#16
benefitx Banned from the Marketplace Join Date: Oct 2006 Location: suwanee ga Posts: 670 Trader Rating: (0) Feedback Score: 0 reviews	the rods and pistons look really good, this set had bearings already on them to see if they were spun or anything... Last edited by benefitx; 05-28-2007 at 04:09 PM..

05-27-2007, 04:33 PM	#22
johngriff Post Whore! Join Date: Jun 2004 Location: Long Beach, CA Posts: 4,103 Trader Rating: (4) Rides Gallery: johngriff Feedback Score: 4 reviews	You can re-use them. And the SR's are probably better than the CA's. That was ME erroring on the CA. But remember, I am knuts. As attested to by other forum members, I over complicate things. I'll only buy hardware from McMasterCarr for example. Replacement parts only from the dealer. It can be nauseating to some people how thorough I am. Russ is probably right, they will probably be fine being re-used. As I say "if you've got it, drop the coin for it". You'll have to remove them anyways. And lord only knows i did something dumb like not get it all the way into the groove. __________________ [email protected]

05-27-2007, 07:48 PM	#24
johngriff Post Whore! Join Date: Jun 2004 Location: Long Beach, CA Posts: 4,103 Trader Rating: (4) Rides Gallery: johngriff Feedback Score: 4 reviews	yeah, more or lesss, but you should plastiguage AFTER specing the crank/rod/journals. Get permatex grey for all the everything. Chuck the blue or return it. __________________ [email protected]

05-26-2007, 10:41 AM	#2
sr20boostn20 Zilvia Junkie Join Date: Nov 2006 Location: Lake Tahoe, CA/ LI NY Age: 38 Posts: 425 Trader Rating: (1) Feedback Score: 1 reviews	it looks like detonation. definatly not a good thing.

05-26-2007, 10:44 AM	#3
benefitx Banned from the Marketplace Join Date: Oct 2006 Location: suwanee ga Posts: 670 Trader Rating: (0) Feedback Score: 0 reviews	thats what i thought...

05-26-2007, 11:02 AM	#4
benefitx Banned from the Marketplace Join Date: Oct 2006 Location: suwanee ga Posts: 670 Trader Rating: (0) Feedback Score: 0 reviews	are they usable or what??

05-26-2007, 11:20 AM	#5
Big Bronze Rim Zilvia Member Join Date: Jan 2006 Location: San Antonio, Texas Age: 46 Posts: 173 Trader Rating: (0) Feedback Score: 0 reviews	Yeah it looks like detonation. That piston was really close to losing its ringland completely. I would say that they shouldnt be reused. There is obvious pitting and erosion on the surface and around the ring land area. I would budget for new pistons. For moderate power rebuild, new stock pistons (54C) should be just fine.

05-26-2007, 11:26 AM	#6
benefitx Banned from the Marketplace Join Date: Oct 2006 Location: suwanee ga Posts: 670 Trader Rating: (0) Feedback Score: 0 reviews	damn........

05-26-2007, 11:35 AM	#7
Big Bronze Rim Zilvia Member Join Date: Jan 2006 Location: San Antonio, Texas Age: 46 Posts: 173 Trader Rating: (0) Feedback Score: 0 reviews	Well, if nothing else, get new pistons and have your machine shop install those rods onto the new pistons. IIRC when I was deciding what pistons I was going with i saw the 54C pistons were around $60 each and then you will need a ring set. I would make sure you dont need to bore before you go and order stock bore pistons.

05-26-2007, 11:32 AM	#8
s13gold Post Whore! Join Date: Jan 2007 Location: CARSON Posts: 4,240 Trader Rating: (79) Feedback Score: 79 reviews	how much did you pay? what was the sellers description of the pistons.

05-26-2007, 11:36 AM	#11
babowc Post Whore! Join Date: Nov 2005 Location: G.NET Posts: 2,659 Trader Rating: (9) Feedback Score: 9 reviews	stock pistons or performance pistons?

05-26-2007, 04:22 PM	#12
benefitx Banned from the Marketplace Join Date: Oct 2006 Location: suwanee ga Posts: 670 Trader Rating: (0) Feedback Score: 0 reviews	yeah but i cant use the same snap rings right? my pistons are in real good condition...good coat of black on the top..ringlands look ok too...just one rod is bent...so i bought this set

05-26-2007, 08:36 PM	#14
benefitx Banned from the Marketplace Join Date: Oct 2006 Location: suwanee ga Posts: 670 Trader Rating: (0) Feedback Score: 0 reviews	seller exchanged the rods/pistons for a different set , teehee.

05-26-2007, 09:23 PM	#15
benefitx Banned from the Marketplace Join Date: Oct 2006 Location: suwanee ga Posts: 670 Trader Rating: (0) Feedback Score: 0 reviews	because maybe it will lose its snappyness and come off? johngriff said to replace them in the other thread..

05-27-2007, 01:09 PM	#17
benefitx Banned from the Marketplace Join Date: Oct 2006 Location: suwanee ga Posts: 670 Trader Rating: (0) Feedback Score: 0 reviews	do i plastigage the rod bearings also?

05-27-2007, 07:54 PM	#20
Big Bronze Rim Zilvia Member Join Date: Jan 2006 Location: San Antonio, Texas Age: 46 Posts: 173 Trader Rating: (0) Feedback Score: 0 reviews	Yes, you will need to lay a piece of plastigage on each journal. It should be used as confirmation that your on track with the bearings you ordered and any crank work that was done. Make sure its nice and straight along the journal axis. I did my mains at the same time and each rod one at a time. You need to make sure the is NO OIL on the journals when using plastigage. You will use the scale on the wrapper the plastigage comes in to measure its compressed thickness. The tolerances are in the FSM, but I set my engine up a little loose, running .0015" on the mains and .0018-.002" on the rods.

05-27-2007, 07:57 PM	#21
Big Bronze Rim Zilvia Member Join Date: Jan 2006 Location: San Antonio, Texas Age: 46 Posts: 173 Trader Rating: (0) Feedback Score: 0 reviews	Yea, please don't use the blue, it isn't the shit and will look like butt. Get Permatex Grey like johngriff recommended.

05-27-2007, 06:00 PM	#23
benefitx Banned from the Marketplace Join Date: Oct 2006 Location: suwanee ga Posts: 670 Trader Rating: (0) Feedback Score: 0 reviews	not getting it into the groove will probably cause problems... i just bought some engine assembly lube made by permatex...its red in color in a little bottle...from autozone and some blue rtv for the oil pan and water pump and stuff... is this right??

05-27-2007, 07:50 PM	#25
benefitx Banned from the Marketplace Join Date: Oct 2006 Location: suwanee ga Posts: 670 Trader Rating: (0) Feedback Score: 0 reviews	what!! everyone has told me Blue RTV is the shit...my brother said something about some black shit because its high temp...never heard of permatex grey tho..

05-27-2007, 07:59 PM	#27
benefitx Banned from the Marketplace Join Date: Oct 2006 Location: suwanee ga Posts: 670 Trader Rating: (0) Feedback Score: 0 reviews	ahh. alright..should of posted it earlier before i went out

05-27-2007, 08:03 PM	#28
benefitx Banned from the Marketplace Join Date: Oct 2006 Location: suwanee ga Posts: 670 Trader Rating: (0) Feedback Score: 0 reviews	when i go to buy plastigage ill get some ultra grey. thanks for the info

05-28-2007, 09:22 AM	#29
projectRDM Post Whore! Join Date: Dec 2002 Location: Atlanta Age: 51 Posts: 13,812 Trader Rating: (12) Feedback Score: 12 reviews	Ultra Grey or Ultra black is fine, black is high temp but you won't see a need for it anywhere except the oilpan. Grey is sensor safe, so you can use a dab of it on the CTS or other sensors/switches that thread into aluminum to seal them without the need for teflon tape. I use both for each purpose, then wait a day and go back with a razor to trim any excess off. Nothing looks worse than a gob of RTV hanging out between two parts. __________________ FORMERLY R240NA Learn what's really going on and protect your assets now before they're gone forever: www.paypalsucks.com

05-28-2007, 11:56 AM	#30
benefitx Banned from the Marketplace Join Date: Oct 2006 Location: suwanee ga Posts: 670 Trader Rating: (0) Feedback Score: 0 reviews	thanks...so i need ultra grey AND black??