Balor_Gr

Ok. I did a ton of research about this.
My head and block are milled for a total of 0.7 mm or 0.030" total milling. My engine is B16 and its currently turboed 100% stock longblock part wise.
Im sleeving the engine soon and going 84x77. Im planing of maxing my turbo setup here: https://honda-tech.com/forums/forced...sults-3297362/)
Until the HP bug bites me again and get more cash to go for what ever 93(+water meth later) will give me with a big **** turbo.

I found the K567M84(10.1:1) local at 50% discount and can find the K623M84 (9.4:1) at a very good price.
But as you can see these pistons on the b16 have 0.16mm "Deck clearance"( isnt that "piston to deck height?)
BUT all other piston engine combos have 0.33 to 0.5mm piston the deck clearance.
Those pistons probably will come out of the block.





I know that around 0.4mm piston to head clearance must exist on steel rods.
My questions now.

-On a 0.000 piston to deck piston without head gasket whats the piston to head of a b16 head? I never managed to found this.

I talked to my machinist for this isue and told me piston is ok to come out of the block we can mill the head inside.
-Anyone has experience with combustion chamber milling to give better piston to head? I dont know about this really.

I also found an arias piston with 1.175 compression height 29.845mm compared to 30mm all other pistons had.
This should give extra 0.15mm extra piston to deck clearance.Thats the pistons they are around 9.1:1 as stated by Realst.





I kinda love wisecos and the k567 will give me around 10.7 - 10.8 : 1 compression which i like.
But i would rock arias too no problem they state heavy turbo too so they must be stronger from the wisecos.

What would you do?
Thank you for your time.

turbomaniac

Deck clearence is not so important if its a little positive (higher than block surface) or little negative. Normaly, deck clearence should be closer to stock piston deck clearence, a little less or more is not a problem,much more and much less could be a problem.

Ιn Μy Οpininion milling the combustion chamber its not the best thing to do. Also try not to go for much oversized pistons unless it is ABSOLUTELY necessary (the cylinders are f...d). A honing procedure with new pistons and rings could be just fine if the cylinders are in good condition (wear not more than 0,06mm). If wear is more than +0,08 mm than you should use +0,25 ovresized piston and not more. ΙΜΟ 84mm bore is out of the question for stock sleeve, i believe also honda suggests to replace the block if more than +0.25mm bore is needed.

Finaly, not that i don't like the wiseco pistons, but i d prefer 9.8:1 cp pistons at standard 81 mm bore (or a liitle more). I would suggest also to very cearfuly choose the machinist to do the piston fitment and bore measurments cause thats the MOST important job of the engine assemply.

Balor_Gr

Its impossible on the stock sleeves the engine will be darton sleeved.

turbomaniac

stock sleeves are ok for 500-600 hp though.

motoxxxman

the chambers in the head are not round. the quench zone of the chambers in the head are flush with the mating surface. so if the pistons are level with the deck height, without a gasket that means the clearance would be zero.
Do NOT mill the chambers in the head to add piston clearance, that will destroy the efficiency of the quench zones, one of the biggest reasons vtec heads work so well.
use different thickness headgaskets to alter piston to head clearances. you can buy the gaskets in different thicknesses, or you can buy multiple stock gaskets and add or remove layers to make a "custom" thickness gasket.
keep in mind that the block will be shaved again a little more when it gets sleeved. so when you take measurements of the piston to deck height, wait until the engine is actually assembled, then figure out a HG thickness from there.
piston to head clearances needs to be at least 0.040", not 0.4mm. 0.4mm is only ~0.015", that's nowhere near enough clearance. it'd smash the piston into the head before the engine even warms up and expands lol.
If your machinest told you that 0.4mm clearance is acceptable, find a different machinest.
If your machinest offered to mill out the chambers of the head to alter piston to head clearance, find a different machinest.

Balor_Gr

Yeah but cant you just replicate the quench areas by making new quench area since the new piston will be 84mm?
Like this video.

bigG

iTrader: (6)

Thicker headgasket, simple fix. You are over complicating things and wasting your time and money.

Balor_Gr

Is there any thick HG that gives good results?
Cometics are very iffy.

turbomaniac

there are a lot of custom head gasket manufacturers. A good after market thick head gasket is built from metal inforced permanite and st. steel rings. Don't use more than 2mm thick gasket.