They probably wont have any from the rogue or new altima, but Im sure they will have some from a frontier

We've never had any problems with the 2.5 in the frontier at my dealer to warrant taking a motor out. We only see 2-3 through the shop in a month though.

a first year at my school tore apart a QR25 i believe for his engine mechanical project, but the head and intake and exhaust were totally different ill take some pictures tomorrow and post them so
#1 we can figure out what application its from
#2 what its pistons look like compared to ours (ive yet to see a b15 piston cuz i havent dug into my engine yet)

total lack of boobs as well

Last edited by snowghost440 (2008-10-08 21:57:38)

lol not gonna lie, i only clicked cuz it said boobs

i deffintely remember that black coating on the sides of the pistons from looking at them quickly on a table, dont remeber a brown coating, and for some reason i think the dome of the piston was caved in making it look like a lower comp piston compared the the ones in your picture but im probably remeberin that wrong, ill take pictures first thing tomorrow when i go in and i hope i can post them from school.

boogerboy72 wrote:

ill do some research tomorrow on the assist thing at school, hopefully dig up some info,

assist is wicked cool, i have it at school too. do you find it harder to navigate than alldata? obv gives manufacturer specific stuff, but i find it harder to get what i want from it.

EDIT:my bad total

Last edited by snowghost440 (2008-10-08 22:27:46)

Big J wrote:

you're my hero. See, kids, research if fun.

Get some pics of the head and the block so we can take a guess as to what it is from.

alrightyyy
hell yes research ftw

so bad news... upon further inspection i found out the first years' teacher was wrong in saying that it was my POS 2.5L... its a QG18... once i dug out the block from the mass of shit piled everywhere i could tell immediately the block looked too teeny  and stamped right on it says qg18.. sorry for the dissapointment i wanted to help

I went to that Nissan shop and they didnt have any of the pistons on hand that we were looking for. I talked to the manager and he said if he gets some in, he would be more than happy to give me a call so I can go take some shots of them for our comparisons.

Also, since it wasn't mentioned.  If you're looking to measure the top contours of your pistons, what you can do is put a ring of grease around the bore of an empty block and install the piston into the bore.  Make sure that the piston is fully contacting the grease, and is at a measured depth below the top deck of the block.  From there just fill the cylinder just as you would a combustion chamber, measuring how much alcohol you used.  Since you have the piston at a known depth, you can calculate what the theoretical cylinder volume of that depth would be with the bore's diameter, and compare that to the used alcohol, and the difference will be your dome height/volume.

I get the point, I just think the efforts are misguided.

textureofreality wrote:

I phoned about 4 Nissan dealers in Vancouver Canada and they all said the same thing sorry we don't stock engine parts because everything is rebuilt by nissan or ordered in long blocks complete engines!!I asked about part catalog pictures of a various pistons and the pictures are all just generic pictures of pistons! So I asked the closest dealer for about ordering pistons and they said unless u purchase nope!! I asked them where the f**k are they stocked he said the pistons for the Xtrail would have to come from Japan!! WTF!  Sorry Big J I tried!! I think we are going to have to talk directly to Nissan for answers because its going to be to hard for dealers to bring in stock that won't sale just for personal interest or looks!!  The piston are all very cheap in comparison to paying $800 f**k who can afford  paying $4000 for engine that my or my not last 100,000 miles of abuse before tear down is required!! People don't realize that even if u have the best engine components u will still need to rebuilt engine at very short intervals!!

people also don't realize that when you double the power output of a car, things will break, and that if you're wanting to play, you must be prepared to pay.

beefy aftermarket pistons cost $460 per set + rings.

I could take 5 different car manufactures and all are cheaper to build serious hp and even more readily available!! But I still stay loyal to Nissan and the Spec!! Hey they should be paying us to build engines!!!

textureofreality wrote:

I could take 5 different car manufactures and all are cheaper to build serious hp and even more readily available!! But I still stay loyal to Nissan and the Spec!! Hey they should be paying us to build engines!!!

sell your car, buy a honda, run stupid quick
sell the honda, buy a mustang/camaro/muscle-mullet and order a crate engine from jegs or put a 50000000000000000000 nitrous shot on it, run way faster than you could ever dream of running in the spec.

textureofreality wrote:

I agree about having good parts for power output but only at reasonable prices!! Nissans are soooo f**kin expensive to build period!!!

ebay: honda pistons = $450(buy it now $600) http://cgi.ebay.com/ebaymotors/H22-PREL … 0095868904

honda rod piston combo = 730 ; http://cgi.ebay.com/ebaymotors/Eagle-Ro … 0299603099


the list goes on. nissans aren't outrageously expensive, you're goign to have to spend the money everywhere, it's the choices in parts that you have.

donspecv02 wrote:

With some factory 07 parts, and some nice pistons, the build can be fairly inexpensive.  $2k probably, which isn't all that bad.

crower rods = 700
cp pistons = 460ish
rings = 80
best swaintech coating = $200 total for all 4 pistons.

seems under 2k.

I am not saying its nissan is general is expensive but for the QR there is this mentality that we can charge what ever we like because there are not enough people buying!!

Big J


What kind of compression is better for boost?  Aren't these pistons we are discussing all around 10 and up compression??

A 170-180* thermostat IMO is ideal, any lower than that and there are efficiency issues, plus in the long run your temps will wind up rising to the 180+ temp anyway.  I really think if you guys are able to do some pistons, aim for lower CR and have some form of timing control (Don't run an Safc) and you will really see some solid boost/power figures.  Try to get something below 9:1, ideally in the mid 8's for a great all around street setup.  You'll lose a small bit of efficiency vs the 10+ CR setups, but the amount of boost that you will be able to run will be far far greater.

Last edited by 16g-95gsx (2008-10-16 09:06:19)

Big J wrote:

is it that no one gets as excited about this as me, or do people figure I'll get around to doing this eventually and will just wait?

I will see tomorrow the cost of 1 piston and I will buy if u Big J buy one piston also!! The debate is which one do u want me to purchase? I am in Canada so we may not see it for 1 week if in Japan!! So if we buy I would like to purchase and use the other 3 obviously if this is going to work out!! When I receive the piston I do the proper measurements to see if usable and if not it will make a nice ashtray!!

might help if you got a car group that has money justin.

we seem to be a bunch of broke college kids..