I recently got my gsr semi built, (i.e.- b16a2 pistons/rings, ITR cams, 3angle valve job) nothing outrageous but something to have fun with. I have been burning oil HORRIBLY so I got my mech. to tear it down and check it out. After taking the head off the pistons have alot of blow-by, and look almost like it's the wrong bore. So, off to the machine shop we go, to get ther cylinders checked and piston's checked, both are standard bored. Now does anyone have ANY ideas on what could be the problem. we re-honed the block before installing new pistons, i want to get it right this time so i would love any feedback. thanks alot guys

 

Why did your mechanic tear down the block instead of doing a compression test? How many miles were on your engine when you rebuilt it? Did you rehone the cylinders and used standard size pistons? Were there any deep nicks or scratches on the cylinder walls? These are all factors in blowby.

Since your engine is already apart, I would seriously consider going .25 over and getting new pistons and rings. Make sure the block is bored out by a reputable shop that knows what they're doing. You should have a nice, clean cross hatch pattern on your cylinder walls. If you have any flaws, that would cause blowby.

 

this sounds weird, the mechanic didn't forget to put some of the piston rings did he? lol.

i would take carma's advice and go .25 over on it, and then TUNE IT.

 

yes there are rings in it. It was his idea to just tear it down. there weren't any deep knotches or anything wrong with the walls. he just used the dingle-berry tree to smooth down any imperfections. but all seems ok and normal to him. (23 years expericance and 1 of only 18 100% certified honda mech in the nation) But he doesn't know alot about changing pistons for power so i'm just posting for ANY help. What would i have to do to Bore the motor? take the block out and take to machine shop??? i know it sounds retarded but i'm fairly new at all this

 

Keep in mind that even a slight imperfection could cause blowby. When I rebuilt my B18b, I had a shop bore out the cylinders to .25 over. They warned me that one of the walls has some scarring that couldnt be cleaned up by the overboring. Sure enough, I burn up oil and my engine smokes. It runs good, but it's smokey.

If he's a certified Honda mechanic, he should know what's he's doing. Installling high comp pistons isnt any different than installing stock pistons, but tuning is important.

Just to be safe, I really recommend going to a shop that deals with building Honda motors for power. Take the block out and take everything off. Take the bare block to a shop. I know you're in the sticks, but there has to be someone who deals with racing out Honda motors. If not, send the block out. Tell them that you want to use Honda .25 over pistons and let them do the rest. If the block has issues (i.e. they cannot get a clean bore due to scratches or whatever) they should tell you before hand.

 

did you do a compression check? It could be valve seals leaking....