So is anyone using the rs machines itr replica pistons in an lsvtec? I used the 84.5mm ones in a b20 build and was happy but don't hear much about 81-82mm setups

 

B16 pistons

 

You should not touch a motor thinking you will run it on crap gas. That's the craziest thing I've ever heard. I'd do the p30 pistons, idk what would make you want to run only 11.1, when it comes to all motor, the most useable compression possible, the stronger the motor will be.

 

PR3's if you go 82mm or P30's if you stay smaller.

 

i dont want p30/pr3 pistons. any talk of them will not be acknowledged. the question is about rs itr replicas.

 

The RS machine ITR pistons are based on the USDM pistons 3.64cc dome with a 30.23mm compression height I have used them in a LSVtec 81.5mm ones the engine has a STD B16a head std cams it drives perfect the owner loves the torque and has done around 20,000klms in 12 months.I now use the PR3 pistons as they sit down the bore a little and with there 30mm comp height and 6 odd cc dome seem to work nicer in the 89mm stroke engines.

 

He doesnt want what works best, he just wants to know why he should run ITR's when we have all sorts of info that will help him out in the long run. Duh silly.

 

thanks man, glad you see it my way.

seriously, and this may be hard to grasp but i'm not looking to or trying to make a lot of power. i couldn't give a **** if i make great power with this motor provided it runs well, doesnt give me any reliability worries and starts up every time. i have a 500 something hp civic in my garage that i'll go drive if i want something with power. this build it just to make my life slightly easier when i have to merge into traffic and partly to give me something to do this winter. my block and quite possibly my head have to be resurfaced. the combination of that along with pr3/p30 pistons is likely to put my static compression in a range that i quite frankly dont want to deal with.

now back to my question at hand... yes, you guys have used the rs pistons or no, you haven't used these pistons.

 

Yes I have used both the RS Machine ITR and PR3 pistons only thing I could fault was they are 1 to 2 10ths of a thou different in the sizing other than that all the engines I have built are still running perfectly with them in it.

 

Apparently my sarcasm was overlooked. Oh well.

 

ive used them on a couple different engines. worked good but i would recomend you go higher compression like the other guy said. b16 pistons or even ctr's if you have e85 somewhere near you.
my lsvtec 82mm rs itr pistons with sk2 pro cams made 193whp 146tq on stock intake mani,tb and cam gears. GL

 

not at all

 

It was, I had a stupid busy day yesterday and have a cold on top of that..

Uncle dave, when you say difference in sizing are you referring to bore size?

 

I am using the 82mm RS ITR pistons in my ls/v, not my first set of RS ITR pistons either, they work fine and are reliable.

 

What he is referring to in terms of "different sizing" is the compression height of the pistons. Compression height is the measurment from the wrist pin to the top of the piston. The B16 pistons have a shorter compression height allowing them to sit lower in the hole, adding clearance, while still giving higher compression due to the domes they use. The ITR pistons sit higher in the hole but just have a flatter dome and lower compression. Its a trade off you can make either way, it's more of a preference what you want. What we are saying is running higher compression and still having more clearance is the best of both worlds. IMO the PR3's in LSV's are the best piston available. They have the second to tallest dome and on top of that its flat compared to the P30.

 

When we measured the pistons skirts they where all different on the 81 to 82mm pistons there 84+mm pieces are perfect,we used a 0.001 p2w figure and every bore was matched to a piston not a common size.What we are trying to tell you is the PR3 version even with the highter dome but lower comp height is a better piston choice in a LS/Vtec.The last 2 LS/Vtec engines I have built have PR3 pistons in them and the engine just feels nicer on part throttle when driving in traffic its very hard to explain its just very smooth and responsive even with STD head and cam package.

 

ok, i see what you mean about sizing. i always bring my pistons to my machine shop with the block so the desired ptw is met as accurately as possible. ive chosen to go with .0015 ptw. the last high comp. b20 i built used those specs and the engine ran great and had no issues.

the head im using is a bone stock b16 head, just with gsr cams instead of b16's. those are the extra parts i have lying around, and thats what im going with.

i understand what you guys are saying about the pr3's. i still havent bought any parts, guess im just making you work hard to convince me lol. one of the reasons i dont want to go real high on compression is that the thing has to run on a stock ecu to pass inspection. id like to get that to happen without pulling back a lot by clocking the distributor. for the remainder of the time, it will run on a tuned neptune ecu


ok another question: has anyone had any bad experiences by adding another layer to the hg to reduce compression?

 

If you where using a B18c block there is room for decking with the B18a block they are around .6 to .9mm shorted than the Vtec block and with the higher compression height of a ITR piston you have less room to play around.The ITR piston normally gives a 0 or positive deck height with the PR3 they are 0.010 or more down the bore.

 

Excellent information!

 

Just run an OEM gasket. Don't use a thicker gasket as a "band-aid" to what you are building...everyone knows a band-aid gets ripped off eventually and hurts like a bitch.

 

it would be an oem gasket, just with another middle layer.

the block im using is a b18b. i was a little curious with the p73 sitting out of the hole if you will. the .010" below deck surface of the pr3 will keep my piston below deck level after milling

 

Yes I am in the middle of putting one together at the moment B18a block/89mm crank/STD rods/PR3 pistons,block decked 0.010 to clean the deck nicely after it has not run coolant and the deck was a mess the pistons are still 0.008 down the bore on this block.