I bored out my B20 block to 85mm, it looks real clean. I'm installing new pistons and rings, does the block need to be honed since it's been bored?

 

If there are any scratches that you can feel with your finger nail, yes, otherwise no.

 

YES YES YES...the idea of honing is one that promotes proper ring break-in and sealing. honing is not just there to clean up cylinders, it is necessary for your motor to run. the degree of the hone (angle) matters too.

 

I agree... if its too smooth its not good either. Must hone!

 

BUT...most machine shops hone the block after they bore it so make sure it has not already been done

 

Yes, honing is the final cylinder wall finish. Most machine shops will hone after boring. If you are not sure, measure your cylinders to see if they have met your desired diameter. Un-honed cylinders should be approx. 0.003" smaller, because honing will take that 0.003" out.

You should also make sure you see crosshatch pattern in your cylinders (30 and 60 degrees). Smooth cylinder surface does not retain oil well, and can lead to bad sealing.

 

.003 or .0003? .003 is huge

 

thing is, NO machine shop can hone your block until the get your pistons and the clearances needed for them.

Get a block bored/honed without them mic'ing the pistons = JUNK! The engine shop will even mark which piston goes in which bore.

 

 

Okay, I found out that the machine shop honed it after they had it bored. But what's "mic'ing" the pistons? Please explain.

 

mic'ing is using a micrometer.

 

a GOOD machine shop will measure the diameter of the pistons before boring/honing. There are small differences in size. They then mark with piston goes where, then bore/horn that cylinder to the size needed including the piston clearance spec.

Bore size = piston + clearance

 

I'm not sure if they did they or not, but I have 85mm JE Pistons. Is that necessary with custom pistons?

 

has to be done with ANY pistons, even with .25mm overbore.

 

With the tolerances in the engine, they should definitely hone the cylinder walls with the pistons in house and mate them with the holes.
='s longer ring life and even compression


[Modified by KingDsi, 3:16 AM 12/25/2002]

 

With the tolerances in the engine, they need to hone the cylinders with pistons in house and mate them with the holes
='s longer ring life and even compression accross the cylinders

 

The machine shops actually do that for you? Then I need to quit wasting my time--I was always taught to mic all my own cylinders so I can figure out what size of pistons to order and then mic the pistons and mark the size w/ a felt tip on the piston dome and then send it all in to the machine shop.

 

A GOOD machine shop.

 

Has this 85mm CRV block you have been resleeved??? What kinda setup are you thinking of running if not?? Latez

 

No, it's a B20 bored to 85mm. I'm going all motor. Here's my setup:

B20B Block
-11:1 CR JE pistons
-Shotpeened/free floating rods
-All new bearings and rings

B16A
-P&P head
-ITR cams
-ITR valve train
-STR cam gears

GSR Tranny
-8.5lb flywheel
-New performance clutch

Other
-310cc Injectors
-ITR ITM+64mm TB
-AEM fuel rail
-ITR ECU

Only planning to use stock ITR redline. Feel free you give me suggestions. Thanks.

 

ya proposed setup sounds good to me.