Hi guys.
I drooped of my 4g64 block, crank, i beam rods and wiseco 1800 hd 87mm pistons at the machine shop to get bored out, honed, balanced, crank micro-polished. The instructions say to do a P2W clearance of .0035. Being a honda guy and knowing that .0035 is a little on the tight side. I have been doing research and cannot figure out what P2W clearance will be adequate for my build. I want a engine that i can make 600-800awhp and not worry that my clearances are to tight. Like they say "Build it loose only you will know, build it tight, everyone will know".

Setup consists of:
-87 mm wiseco 1800hd 10.1CR
-manley TT i beam 156mm
-100mm crank micro-polished and balanced.
-balance shafts eliminated
-SI stainless steel valves
-272 HKS cams
-Brian crower valve springs and retainers
-id2000cc
-Bosch 044 inline fuel pump and walbro 255 intank
-SLS custom built turbo manifold with precision 48mm waste gate
-Precision PT T67/65 mm turbo with forged billet wheel
-Tial V-band blow off valve
-Custom 3" intercooler piping with an AMS 4core 1000hp intercooler.

Thanks guys.

 

.005"-.0055" is a good range.

 

P2W = piston to wall. Gap between piston and cyl. Wall.

 

Keep in mind wiseco has a coating on the piston on the skirt taking up some of the P2W clearance so they are taking that into consideration. I would follow manufacturer reccomended clearances. They know the expansion rates of the design of the piston so they know better. My ROSS pistons asked for an .008 ptw at like 800hp. If you have a question for your car I would contact wiseco tech support.

 

And my ross at .008 were perfectly quiet under all driving conditions. I would rather go a little looser to cover if you make more power than anticipated.

 

.008" is totally insane! i have arias pistons set to .005" and mine is built for 800+whp and doing standing mile runs.

 

skirt coatings are rarely ever thicker than .0005".

 

Can I go with .0045?

 

I went with .004 with 85mm pistons. I would say at least .005 with your setup.

 

+1 on this P2W clearance.

 

Manley pistons, I'll be running .003-.0035 for sub 500whp.

 

That's really tight man. I think you'd be better at .0035-.004

 

Apex automotive, which is the shop that does most of AMS's non CNC work set my wiseco 1400HD's at .0045" for around 600 HP. The skirt coating usually allows for tighter piston clearances than an uncoated piston like the ROSS's

 

Ok I told my machinist to do .0045. Eventually I would like to hit over 600 whp to get into the 9's.

 

It did seem very loose to me but like I said they never made noise and there was little to zero leakdown and they were run hard for 35000miles while I had the car and the car ran perfect. It was a crazy experiment I did in 2002. I got flat top pistons and bored my 4G63 .080 over to 87mm and used a cometic HG. After a while the cometic leaked into the coolant chambers like every 4G64 cometic I used from 2003-2006ish until the felpro mls was introduced. At that point I installed an MLS and it ran great for a long time after that until a friend who owned the car sold it. It was quiet and the cylinder walls were great. I never ended up using n2o like I had planned so it was overkill but no issues.