ojoemamao4o

is this to much bore for a turbo application? and do you know of any piston companys that make a piston of this size for an LS block? id like to here some suggestions before i purchase it, im guessing this is 2.0L

lanojp1

the GSR i am purchasing very soon is 84.5mm sleeved. Endyn makes pistons up to 86mm...

ojoemamao4o

are they alot more expensive than the average forged piston cost?...i just didnt know if 84.5 was to big, how many .0XXin is it over stock 81mm? thanks for helping me man

95GSRTT

most people dont recommend going over 84.5mm for a turbo application, b/c of how much weaker the sleeves will be. And if you start off at 84.5mm you cant exactly use the block again to bore out to 85 mm for a turbo app.

I mean you could, but its not recommended

RyanEJ8

A bigger bore also helps with deshrouding if you have oversized valves. Just another factor to consider other than the increase in displacement.

X-Mazda 3 Racer

When you sleeve an LS, the largest I would go is 85 mm on a turbo application. Arias has a shelf stock piston for this applicsation, and many more as well. You can send your block here for sleeving, we can supply the pistons from Arias and get the block bored and honed. We can also do the entire bottom end build. If you want more info, drop us a line at Sales@goldeneaglemfg.com . Hope this helps.

The 84.5 mm part # from Arias is 3320900 and that will get you from 9.0 to 9.3 depending on which head you will be using.

Chip

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lanojp1 &raquo;</TD></TR><TR><TD CLASS="quote">the GSR i am purchasing very soon is 84.5mm sleeved. Endyn makes pistons up to 86mm... </TD></TR></TABLE>

And when/if you blow that motor up, think of how gargantuanly fucked you're going to be because you want 60CC's more displacement by going 84.5mm instead of 83MM. Coming from a man who melted down some 84.5MM pistons and had to rebore the sleeves out to 85.5MM just to clean up the walls, it is not worth the tiny increase in displacement you get over 83MM. If I ran 83MM or even 82MM to begin with I could have rebored the motor to 84 or 84.5 the second time around, instead of having to resleeve or sell the motor for a N/A build.

White Smoke

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ojoemamao4o &raquo;</TD></TR><TR><TD CLASS="quote">do you know of any piston companys that make a piston of this size for an LS block</TD></TR></TABLE>
Allot of Co. offer that as a shelf piston.
You can get custom ones for a little bit more from most piston Co.

ojoemamao4o

thanks for the replies, i ended up boring my stock b18b to 81.5 because i didnt buy the sleeved 84.5 block. now when i buy my pistons and they dont specify the mm, is 81.5 like .020 over or what?

Chip

Correct, 81.5MM is listed as a .020" overbore

Takumi Fujiwara

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ojoemamao4o &raquo;</TD></TR><TR><TD CLASS="quote">thanks for the replies, i ended up boring my stock b18b to 81.5 because i didnt buy the sleeved 84.5 block. now when i buy my pistons and they dont specify the mm, is 81.5 like .020 over or what? </TD></TR></TABLE>

What kind of boost numbers would be pushing the limits here with a 81.5mm bore? I've read that stock sleeves will be reaching it's limits at 15psi. What would be a safe psi with this being such a minor overbore?

What compression pistons are you going to run on that b18b ojoemamao4o? I was thinking about running some 10:1 pistons. I ran some numbers on the compression calculater and 10:1 pistons will be .6 higher than stock compression, opposed to 9:1 pistons which will run .6 lower than stock compression (JE piston numbers used in the calculator).

ojoemamao4o

well as for psi i have a GE block guard (awesome ****) stock sleeves bought 18 psi, hondata S200 w/ B00zT cant decide between 8.5:1 or 9:1... i trust 9:1 since i see so many turbo b18 applicatons runnning this so i leaned that way, but my engine rebuilder recommended 8.5...says i can run more boost safely, dont know man, still need to purchase rods to, thinking of eagle H beams no clue

95GSRTT

If you go with 8.5:1 instead of 9.1:1 you are able to make more mistakes with a tune and get away with it. Thats the only real reason to do that. You will be able to run higher boost, but its not gonna be too significant compared to 9.1, you just may be able to run more on pump gas...

Chip

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Takumi Fujiwara &raquo;</TD></TR><TR><TD CLASS="quote">

What kind of boost numbers would be pushing the limits here with a 81.5mm bore? I've read that stock sleeves will be reaching it's limits at 15psi. What would be a safe psi with this being such a minor overbore?

What compression pistons are you going to run on that b18b ojoemamao4o? I was thinking about running some 10:1 pistons. I ran some numbers on the compression calculater and 10:1 pistons will be .6 higher than stock compression, opposed to 9:1 pistons which will run .6 lower than stock compression (JE piston numbers used in the calculator).</TD></TR></TABLE>

10:1 compression just makes your motor that much harder to tune, there is a smaller margin of error when it comes to detonation and pump gas with 10:1 compression, and detonation is what kills stock sleeves. Honestly, I didn't notice ANY drop off in how fast the turbo spools when I went from 10:1 compression to 9:1 compression on my old motor, I don't know about you but my motor at 9:1 compression has more than enough low end power to go stop light to stop light, and there is nothing wrong with off boost power, I think the "run high compression for more off boost power" idea is fatally flawed in a high performance car. What should be more important to you, the 1 or maybe 2 seconds after you hit the throttle hard in first gear before the turbo is making full boost, or for the rest of first gear and every gear after that when you want as much horsepower as possible to accelerate? Would you rather have more horsepower to accelerate fast, or would you rather have 5 more horsepower from idle-4000 RPM's when you are not pushing the motor hard and looking for quick acceleration anyways?

FWIW, I am running stock GSR sleeves bored .5MM, no block guard, no posts, 9:1 pistons and eagle rods, I run 16 pounds of boost daily on pump gas. Had it up to 23-24 psi on race gas. Nothing wrong with stock honda sleeves unless you detonate.

ojoemamao4o

yeah i have an excellent hondata tuner so ill see the least amount of detontation(hopefully) well so far the block i pick up on 10/20 and i got my eage h beams, arp head studs, cometic head gasket, ACL bearings, cp pistons 9:1, InlinePro block guard, gsr oil pump, hondata 200 boost, ACT XT-SS and a GM 3bar map sensor...i was currenty running vafc w/ DSM 450s at 7psi everything else stock.

so im sure this will be a more reliable setup now, no more melting pistons im still gonna upgrade to 650cc injectors, and a walbro intank fuel pump soon after it runs. then thinking of getting gsr tranny, bigger intercooler and some gauges finally lol...have a gauge cluster and a dual pod on the piller, but no gauges...im such a stunna

everything is on a personal deadline, running engine by halloween!

WREKONIZE V8 KLR

im runnin an lsvtec, darton sleeves, 84.5mm,10.1 comp,SC61-TO4S, with uberdata 2b

go big

ExospeedAMcrx

When it comes to turbo blocks, we evaluate the customer use of the engine. We usually suggest keeping it at 81.5mm on a street car so theres room for rebuilds later on if they decide to do somethign again to the block.

an 81.5mm b18 block can make over600hp already and a 2.0L setup is not necesarry.