abnaasefmb

I'm finally ready to build up a b16 for some mild boost duties. Here is the bottom line up front.

New wiseco 81.5 mm coated 9:1 pistons. What size do I tell the machine shop to bore/hone the cylinders to?

The sheet that came with the pistons states 3.2086 which converts to 81.5mm.
Suggested clearance is .0025, do the pistons come .0025 smaller than 81.5mm (3.2086) or do I need to add that to the bore and have them cut at 3.2111?

.0025 seems kinda low on the clearance I saw on jeff evans website http://forums.evans-tuning.com...build where he put CP’s that call for .0030 in with .0040 clearance. Should I add another thou of clearance so I’m running .0035 (this will be on stock sleeves)?

I believe I should ask the machine shop to cut them at 3.2096, can anyone confirm that for me?

Thanks in advance!

Here is the set up:
B16a
Stock head
ARP headstuds
Wiseco 9:1 pistons
Eagle rods
Gt2871R
Dual stage boost controller
I’m shooting for 275hp LB and 325HP HB just a basic set up.

heres a couple pics so people will look

Turbo O

nice setup. your car should smash out when done.
heres an easy solution to your problem.
find a GOOD machince shop to do the work. take all the parts to them. (the bare block, the new pistons with the rings of course, they shouldn't need the rods yet unless you are letting them build it for you.) then you just show them the pistons and tell them to bore the block to fit the piston. if they can't bore the block .50mm over or even have a problem understanding then get the hell out of there and find a real machine shop.

abnaasefmb

sorry, i don't really trust anyone to do the job they promise that's why i do my work myself. Believe me if I could afford a boring machine, I would do it myself as well. I would much rather drop off the block and say hone these out to 3.2????. I have found the less thinking required on there part the better. thanks for the reply!

BoostedEG6

whos doing the machine work???? DO NOT GO TO TEDS!!!!!! they will fukc your stuff up. I have personal experience from there. I use to live in Pear City and I now have to do a total rebuild due to them over boring the cylinders... all of them where a different size and had major piston slap after 500 miles and a cherry tune.... all the walls where scared from that so now I have to get the block sleeved

abnaasefmb

well i was going to go to ted's, see what i mean!

BoostedEG6

I hate to say it but you are 100% better off sending to to the main land to get everyting done. I wish I had done that to begin with!! now I have a set of CP paper weights ..... look into Import Builders or Earls, Jeff from IB is a great guy and does awsome work. Earl and Jeff get from me.

abnaasefmb

Yeah I think that is the sad reality I’m facing. I could get the job done twice with the cost of shipping

abnaasefmb

ok so back to, .0025 or .0035 clearance?

ccivic

Each cylinder should be bored in coordination with ONE piston (one for each), and each piston should be labeled for a certain cylinder. .0030 is a safe number.

abnaasefmb

I know that jeff evans runs .0040” on his big power stock sleeve engines. It makes since under a lot of load the pistons will expand from the heat and the extra clearance will keep the pistons off the cyl walls.

abnaasefmb

bump for some insight