ls rods with p30's?

[JDM_DA_MAN]

hey im new to this forum stuff so please be patient. im building an na ls/vtec using the b18a1 block and a jdm b18c itr head. ive read around this site that p30 pistons are what i should put in the block. just wanna make sure i can bolt them to the ls rods and that the rod ratio is gonna be right. will it bring the p30's to the deck. they are the same bore size as the ls pistons aswell arent they? 81mm. also what rings should i be using?

 

[JDM_DA_MAN]

anyone have any info at all or a site i can check out. that would be helpful. thanks

 

[Taco15]

hey im new to this forum stuff so please be patient. im building an na ls/vtec using the b18a1 block and a jdm b18c itr head. ive read around this site that p30 pistons are what i should put in the block. just wanna make sure i can bolt them to the ls rods and that the rod ratio is gonna be right. will it bring the p30's to the deck. they are the same bore size as the ls pistons aswell arent they? 81mm. also what rings should i be using?

well that is going to be a sick lsv first off. yes you can use the ls rods just make sure you use arp bolts. you will have really high compression unless you go with a 3 layer or HG. even then its still pretty high.

the only thing you need to worry about is piston to valve cleareance. I believe the p30's are the really tall dome shaped. My friend had a similar setup and ran just fine. I just dont know what he used for a hg or what. i know he was up in the 12.1 compression range.

 

[JDM_DA_MAN]

awesome thanks. ya ive got arp rod bolts and head bolts. replacing the water pump, oil pump and t belt with type r parts. what rings do i go with though? ls or b16 or what

 

[Taco15]

p30 pistons are 81mm i believe. inless you buy them new aftermarket. Then i think they are .5mm larger I dont think it matter too much since the bore is going to be the same. Just make sure you cut the rings right to make sure they seat properly.

 

[JDM_DA_MAN]

ya the oem ones are at 81mm or you can get .25 oversized. there is also 2 different types of rings i believe just for those pistons.

 

[LightWeightChamp]

Good thing I found this thread before you went and got everything, and went to assemble it and it won't fit. You need to machine the ls rods to accept the p30 wrist pin. I'd you use a ls wrist pin, you will FUCK everything up, if you use a p30 wrist pin, it won't fit into the ls rods unless you machine them. I'm guessing it won't be very expensive at all. Just find a local machine shop to make them a little bigger. You will be very satisfied with this build. Good luck.

 

[LightWeightChamp]

Good thing I found this thread before you went and got everything, and went to assemble it and it won't fit. You need to machine the ls rods to accept the p30 wrist pin. If you use a ls wrist pin, you will FUCK everything up, if you use a p30 wrist pin, it won't fit into the ls rods unless you machine them. I'm guessing it won't be very expensive at all. Just find a local machine shop to make them a little bigger. You will be very satisfied with this build. Good luck.

 

[JDM_DA_MAN]

awesome thanks. im sending it all away to get everything resized and balanced anyways. so ill look into that aswell. just cant wait to drive the damn thing.

 

[1990rexjake]

awesome thanks. ya ive got arp rod bolts and head bolts. replacing the water pump, oil pump and t belt with type r parts. what rings do i go with though? ls or b16 or what

dont waste ur cash on type r oil pump. just up the oil psi...with a .025in shim.....