Hey dudes, rebuilding my ls block because of a spun bearing. figured while im at it, putting in some new piston rings since im here. now I know the gsr pistons up the comp a nice bit. and I know there are a few threads on this. now, my question. planned to go lsvtec in the future (few months or more)with a nice bump of power from the pistons.

now, if I put the gsr pistons in now, I don't want to spend 400 on a tune then spend more on another tune later. is it worth putting in now? I understand I wont see power without tune. just would really like to avoid breaking down my block a second time when I get the gsr head. would I run into problems from running higher comp on no tune? thanks for the advice

 

ps. gsr pistons will be on the LS rods

 

if you're gonna do pistons, put some p30s in. don't bother with p72s.

before you buy new pistons, make sure first your crank is salvageable.

 

I got the crank at the machine shop right now, expect it back on Tuesday, getting a micropolish. what are the p30's off of, a ctr? the tegs gonna be a daily, I want to account for a gsr head on ls block with these pistons on ls rods/crank. not sure how much the cr will be with that combo, I just don't want it to be astronomical

edit:can I run the p30s on my full ls without having to tune? again, not looking for power on that only mod. just hate to break down the motor twice when I finally do get the gsr head

 

afaik those pistons will not fid on those rods. gsr rods are narrower at the small end.


Posted from Honda-tech.com App for Android

 

also, honda cranks can only be turned down .0010 inches because of the nitride coating. thats the maximum because the nitride coating may or not be .0010 thick or more.

unless you got lucky and caught the bearing going out early. I dont even bother opening up my spun engines because I know the cranks are toast and its easier to just get a new one.


Posted from Honda-tech.com App for Android

 

The crank somehow only shower light wear, on the main bearings there is a very small gap right in the middle for oiling. had grooves. Not sure how it happened. he said he prefers not to cut it for that same reason and thinks he might be able to smooth it out while keeping the same journal size. he is very knowledgeable on acura cranks so ill take his word on it. he said he will get back to me on Monday with info on what will have to be done.

but I know it's the GSR pistons that have a smaller gap for the rods to fit and they are a bit too big, I heard milling them down a bit on both sides makes them fit. other concern is clearance if I do use the p30 pistons on ls rods with a gsr head. I heard the clearance is extremely ridiculously close. how true is this? is it worth doing? id hate to put all this work into it to have my valves crushed lol

 

get the correct pistons for the LS motor. There is a difference between a VTEC and non-VTEC piston. It's visibly noticeable.

 

Id rather keep the same pistons than spend 500 on high comp pistons for an ls plus another 300 for rods...a lot of people have this setup. Why do you sat that?

 

I would stick with GSR pistons if your not going to get it tuned right away. I would suggest running mid grade gas after doing so. Seems like you know a little already, but figured I'd say it anyways: get some arp rod bolts. Well known weak point in the LS engine.

 

Yeah I already got some arp rod bolts for it. thanks for the heads up though. I have no problem running mid grade or high grade gasoline, just don't want to ruin my rebuilt engine. the current ls head was completely rebuilt from last owner. might be realistically a few months before I get the GSR head and a tune. would there really be that much of a difference between the gsr pistons and the p30's? Thanks for the help and info. just would've preferred running the p30's for a bit more power when i get the tune, but i don't want to risk my engine now.

 

If you don't mind advice from a girl I can tell you my exp on my nearly exa t build. We did the complete ctr bottom end rebuild on my ls. P30 pistons and we went with itr 249/238 cams. For two weeks ran without a tune on a p73 ecu mind you with cr of 11.4:1 no tune. Idk if it helps your decisikn but the car ripped even no tune and ran fine. Iddle issues but aside from that it was fine. We had to wait for a jumper and the p28 which is why I was forced to use my p73. A girls 0.2 cents:/

 

PR3 pistons is what I have on my LS, those are "plug and play" pistons, If you want to bump your compression that is the way to go... PR3 or P30

GSR pistons are trash on a LS motor, don't bother trying to put them into LS rods...

 

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