Cylinder bore tolerance

TDiLisio

Member
:
2002 Protege LX
Does anyone know the cylinder bore tolerance before it needs to be bored out? (2002 Protege LX 2.0L FS engine) I can't find a mention of it in the manual.

I'd like to get an idea what the shop will tell me when I take the block in for evaluation... specifically if I can get away with throwing a set of standard rings in and go... or if it's too out of tolerance and needs to be bored for oversize pistons and rings.

I measured 4 places at the bottom, mid and top of each cylinder.

Angle=position of bore gauge in cylinder (ie 0-180 =12 clock to 6 clock position)
Measurements in mm:

(Sorry about the formatting... won't let me align the columns)

angle 0-180deg 45-225deg 90-270deg 135-315deg Max Diff
Bottom1 83.01 83.03 83.05 83.01 4/100mm
Mid1 83.01 83.02 83.02 82.97 5/100mm
top1 83.04 83.01 83.02 83.04 3/100mm

Bottom2 83.01 82.98 83.04 83.01 6/100mm
Mid2 82.96 82.99 83 83.02 6/100mm
Top2 83.03 83.01 83.01 83 3/100mm

Bottom3 82.99 83.04 83.03 83.02 5/100mm
mid3 83 82.96 83.02 83.02 6/100mm
top3 83.02 83.02 83.01 83.01 1/100mm

bottom4 83 83 82.99 83 1/100mm
mid4 83 83.02 83.01 83.01 2/100m
top4 83.03 83 83.01 83 3/100mm

Is there anything else I need to measure?
 
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TDiLisio

Member
:
2002 Protege LX
Seems as time goes on I'm answering my own questions. Maybe it will help someone else.

Anyway... from onlinemazdaparts...

Standard bore is 3.2659"-3.2667".
3.2659"=82.9538mm
3.2667"=82.9741mm

Mazda does offer oversize pistons

.25 F3Y311SB0
.50 FSY311SBX

The largest measurement I obtained was 83.05mm

So the difference between my largest measurement and the upper end of the standard bore is .0759mm or .002988" ..

Does that constitute boring it and going to oversize pistons/rings?
 
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2001 Mazda Protege ES 2.0
You are fairly technical which is why no one is chiming in. You are over everones head! With that being said the easiest and safes way to go about it is to go .25 over to be sure. Yeas it costs a bit more but no guessing! :)
 

njaremka

Wiggity-Wack-O-Tack
Contributor
:
2011 MX5 GT
you need to check the engine rebuild manual. it will have the cylinder clearances and tolerances.
 

TDiLisio

Member
:
2002 Protege LX
you need to check the engine rebuild manual. it will have the cylinder clearances and tolerances.

Thanks for the info. I just found mention of that on "another" Mazda forum. Will contact Jason at onlinemazdaparts and get one.
 

TDiLisio

Member
:
2002 Protege LX
You are fairly technical which is why no one is chiming in. You are over everones head! With that being said the easiest and safes way to go about it is to go .25 over to be sure. Yeas it costs a bit more but no guessing! :)

Thanks for the advice. It does "seem" like I'll need to go oversize... so I'll see what the shop tells me and post the results.... probably in a couple weeks.

The motor/trans is ready to pull... just need a hoist and stand.

If I have to go oversize... then that brings up a whole new set of questions that I'll need answers to....

First things first, though... I'll get the manual.
 

TDiLisio

Member
:
2002 Protege LX
First things first, though... I'll get the manual.

Ouch!!!! $50.50 including the $8 shipping.

Inflation Sucks.... My paycheck sure didn't go up 40 percent in the past 2 years.... the manual was $30 including shipping 4/10/2010... FROM THE SAME PLACE!!!
 

TDiLisio

Member
:
2002 Protege LX
First things first, though... I'll get the manual.

Just an update....

Received the engine manual. It's an invaluable item for a rebuild. Thanks for that advice.

I got the engine out, apart and plasti-gauged the main and rod bearings... all were within the tolerance listed in the manual. So, I threw new standard sized bearings in there just for grins.

All the rings were really funked up and most seemed to be frozen in their respective slots. The oil rings especially. I removed the rings, and cleaned the ring slots until they were nice and bright. I installed new standard sized rings. The new ring clearance/gap was under max tolerance when I gauged them per the manual. So I figure I'm good for at least another 100Kmi... if everything else goes okay.

I decided against taking the block to the machine shop... mostly because my measurements seems to be within the books max tolerance. Plus... the more work they do, the more they charge me. I would probably think different if I had a friend that worked in a machine shop.

I'm in the process of putting the engine back together now, and getting ready to pull the transmission (note to others... pull the engine and trans at the same time like the manual states... much easier than trying to separate the 2 in the engine compartment).

I bought the transmission manual and should be purchasing the overhaul kit within the next couple weeks. There's no way in hell I'm paying a trans shop $1700 to bench rebuild a transmission.
 

TDiLisio

Member
:
2002 Protege LX
Update... She's back together and running. Just gotta figure out why the A/C compressor won't turn on.

Otherwise... new rings, seals and main bearings in the motor. Replaced the spark coils, blocked off the EGR, rebuilt the transmission with new steels, friction plates, pistons, seals, replaced the torque converter, Installed new bearings on the front axle/steering knuckle, new left and right CV axles, new dust boots for the lower ball joints and tie rod ends, new sway bar end link connector rod thingy.

So... I don't know if I'm still eligible to be in the high mileage club... but she's back on the road with 365,000+ miles. Engine sounds good. Tranny shifts good... fingers crossed.....