Just hone it, or bore it .010" over?

[Sum0n3]

Hi all, I'm new to the forum so I hope this is the right section..

Last week I had a small meltdown due to a bad oil injector. Long story short should I go .010 over or just hone it and call it a day? There is no noticeable deep scratches or gouges, but there is some aluminum from the piston stuck on the wall. Just wondering what you guys think as I want to get a jump on this and order a piston..

Thanks in advance for any help

 

[timsyfz]

Your machinist should be able to tell you whether it needs to be bored or not... If it does not.. then just hone it.. Its cheaper, and there are no benefits really to going .010 over.

 

[djack12]

^^^thats what i would do^^^

i hope your ditching that oil injection system this time around.

 

[Sum0n3]

I will have to swing by a local place I have seen. What is the going rate for boring and/or honing a cylinder?

The oil injection is the first thing on the list to be ditched.. That brings me to another question. What does the block off kit consist of? I know there is a plate, but i have seen a few small bits along with it. Just wondering as I can just fab a plate to block it, but I'm not sure if there is more to it than just that.

 

[BaBarossa]

If there was a meltdown, allways bore it over!!!!

 

[timsyfz]

Locally around here Honing is $15, and boring is $45.

Along with the oil injection block off kit is the plate, new gaskets, a cap (for the line going to the carb), generally new bolt or nuts for the cover and instructions.

 

[bkg479]

here to hone is 20 and bore is 50, but I am in Ct, probably a little more expensive.

 

[jfblasterboy65]

when i got my jug bored and honed it came to like 60 65 dollars and im from NY

 

[blaster20001]

here in mi it cost 32.00 bux out the door to bore where i go and id say bore it

 

[quam]

i'd say bore it too.
i blew up my piston too and i'd say you should prob crack your cases and clean all the bits of metal out of the crank bearings, rod bearing and the case.
plus i caused the piston to blow up because i had f*cked up the rings prior and decided to just put in new rings and deglaze the cylinder, but after about 5 hours of riding the piston was flapping around inside the cylinder due to too much clearance caused by the honing and the piston skirt kept catching on the exhaust port. that led to having to crack the cases and buy a new piston along w/ a bore....

 

[Sum0n3]

Thanks for all the info guys. Looks like I'll go .010" over to be on the safe side.

This brings me to another question.. What would be the exact diameter of the cylinder with a .010" over piston? I wouldn't want to take a chance and have it bored too big or something.

 

[timsyfz]

the size would be 66.25mm. The machine shop would request you bring in your new piston so they can match it up perfectly for you.. Be prepared for that..

 

[Blaster200UK]

hi, when just doing a normal piston and ring change do you have to bore or hone the cylinder?
i havnt blown a piston or nothing, just changing it to be on the safe side?

 

[Surfrjag]

have a machine shop size it and tell you... to be on the safe side. if its not out of spec u can just hone it and install new piston and rings

 

[Blaster200UK]

as i am new to all of this,
how come you have to hone a cylinder when changing the piston and rings?
and it is a fully standard blaster

 

[Surfrjag]

break the glaze on the walls. honeing gives crosshatch scratches that hold oil and help ring life. over time these hone grooves will wear down. even more so if you get dirt or water in your engine. try this read..http://www.realclassic.co.uk/techfiles/tech05010600.html

 

[Blaster200UK]

thanks surfrjag.
so how do i tell if i need my cylinder honing?

 

[Surfrjag]

when u look at cylinder walls you will notice smooth areas and areas with the cross hatch. should look like
http://image.popularhotrodding.com/f/9051574/0612em_06_z+cylinder_head_honing+crosshatch_angle.jpg

 

[Blaster200UK]

so it should look like that picture, if it looks smooth do i need it honing?

 

[Surfrjag]

probobly so but remember your also loosing some material in the process, not much but some. would be a good idea to have a machine shop measure it for you and make sure your within spec. excessive piston wall clearnance typically results in piston skirt failure due to piston slapping the cylinder walls. if you dont have a whole lot of time on the engine your probobly good to just hone it and re ring and keep on gettn it!!