ls/vtec.

i have .0015" of clearance on the mains, with .0017" in the #3 cap. oem bearings. is that sufficient clearance or do you guys think i should step up to the next size bearing and get .0017"? i plan on spinning to 9000 or so. the motor is going to see quite a bit of mileage as it is my daily for the warmer months so i figured .0015" should be okay but i wanted to confirm.

 

I would think you'd be OK but I set up my build at about .002 after reading everyone's info online. Got me scared to go too tight. LOL I run 15w-40 now too just to make sure. And I have 80+ psi under WOT with my new oil pump. Most people tend to go a little looser for safety I think (after my research). Sorry, because I know this might not help much.

 

That is way too tight. You can rev to 9k, but do you make power to 9k? Is your motor balanced/blue printed to 9k?

 

yes it will make power to 9k. pro1s, 6265s. everything is balanced.

 

.0015 is fine that what I aim for on most of my builds... are you measuring this with plasigauge or doing the math?

 

Is this a daily driver or a tracker? You're running it on the tight side but it has worked. I'm not a fan of going tight, IMO but to each his own.

I haven't had issues in the .016-.018 range for my daily drivers and ran .002 on the Road Race b16 & it loved it. Then again, i had a '90 b20a prelude that ran 380k before blowing a head gasket then spinning a bearing at 450k & a '91 d16 that threw a rod at 80k both at stock clearances. If its going to go, it's going to go.

 

its definately on the tightest side of what i would do. i recently had a motor that had a main at .0014 and after about 3000 miles that bearing was showing considerably more wear than others. my mains are currently at .0018-.0021 with about 1500miles of 475 hp. no issues

 

Is .038mm wider then .025? If your running acl bearings its always alittle tighter from what I have read. My tuner told me to get the crank micro polished to open up the main and rods plus it will be nice to have a nice smooth surface

From a mathatical stand point isnt .038 larger then .025? Am i just thinking of this way to hard and should be thinking like 16 gage steel is larger then 20 gage?

 

the factory range is .0012-.0017 and when using green plastigauge that only has a scale for .001,.0015, .002,.003 your making a logical guess when they fall between sizes. Most motors I have built fall under the .0015 range so it make it between the 0015 -.002 and you will be fine with that

 

+1

 

Keep the bottom end clearances on the LOOSEr side, this ***** is gunna get hot! Get sum thick oil too talkin like 5w-40, hope that helps you can do the math.