Hi Guys,

So I recently dropped an all motor '99 Spec JDM B18CR into my '99 Civic Coupe. I couldn't decide if this post belongs here or in the Civic thread anyway my motor has a "slight" (slight is an understatement) oil consumption problem. Actually it's so bad that when I hit VTEC I'm no longer watching the road, instead I'm watching the cloud of smoke out my tail pipe to gauge how much oil I'll need to put back in when I get back home Long story short I've decided to pull the block apart and rebuild it.

"Supposedly" it has about 50k miles on it, so someone in Japan made love to this motor without changing the lube, EVER... My oil is full of carbon deposits after 500 miles of driving. I add 0.5 - 1 quarts of oil every week, and change it every 1500 miles when it starts to run like crap due to dirty oil.

4000 miles ago when I bought the motor I replaced all the seals/gaskets, had the head machined, and put it back together. The machinist at the shop said the cylinder walls looked good, well lesson learned... That didn't indicate the state of my rings.

So here is my list of parts after some research:
Cometic Head Gasket 81MM BORE .036 / 0.9144MM THICK
One question about this head gasket is, I have the stock ITR Honda head gasket here next to me. It measures 81.6864 millimeter bore and 0.762 mm thick. Will this 81mm Cometic gasket work? The thickness is not so much of an issue, they removed 0.254 mm when they machined the head. I'm more concerned with the bore

I might as well rebuild the head while I'm doing this so there are no more disappointments down the road.
Skunk2 Valve Springs + Retainers
Supertech Valve Seals
Supertech Bronze Valve Guides
Skunk2 Pro Dish Valves
Skunk2 Stage Tuner Stage 1 Camshafts
ACL Bearings Main, Rod Bearings, Thrust Washers Type-R

Now that I've addressed everything, but my oil burning problem let me start with my dilemma. From what it looks like I have two sets of options. I can keep my JDM P73 pistons and use a stock set of rings, and just hone the cylinders (cheap option, but I don't know if this will be the most reliable option). Or I can get a new set of .25mm over pistons with matching rings and bore out the cylinders 0.25mm. What do you guys think would be the most reliable option? I'd rather keep my current pistons if they are okay to re-use, assuming my cylinder walls only need to be honed and not bored. I guess that is the real question...
NPR Piston Rings or .25 mm Over Sized Pistons with rings On a side note the only .25mm over-sized pistons I found are USDM spec, so I'd lose my JDM compression if I go that route

While I'm down there I was thinking I should swap out the rods with:
Eagle H-Beam Connecting Rods, with ARP Rod bolts
Is this over-kill? Should I just keep my stock rods? I'm going for all motor build, and I'm keeping the stock rev limit

How about replacing the wrist pins. I didn't see anyone selling aftermarket alternatives. I bet Honda wants $40 each

Here's the cost of the options:
Total cost reusing my JDM P73 pistons with new rods = 2251.06 with tax
Total cost reusing my JDM P73 Pistons, reusing my rods = 1962.06 with tax
Total cost using .25mm over-sized pistons with rings = 2472.54 with tax

Let me know what you guys think of the list of parts, or any ideas you have for the questions.

Thanks!

 

Keep the stock rods and go overbore.

 

^^Agreed, I'm in the same boat as you and will be doing what he said. My car looks like a James Bond movie when I hit Vtec.

Let me know if you find JDM ITR .25 OS pistons though, hard to find piece and I want a set.

 

Yeah the JDM over-sized are discontinued. I just ordered USDM spec P73 A0 .25mm over sized pistons with rings from here:

http://www.inlinefour.com/usspecintypp.html

I'm going to re-use my ARP head studs, they have about 4000 miles on them.

I also ordered the following top end parts:
Supertech Valve Springs + Retainers
Supertech Valve Seals
Supertech Bronze Valve Guides
Supertech Black nitride coated Dish Valves
Skunk2 Stage Tuner Stage 1 Camshafts
Skunk2 Pro Cam Gears

What's left are:
ARP Rod Bolts
Head Gasket - still looking for a 81.25mm bore x .79mm thick (OEM specs @ .25mm over on the bore)

My head has .254mm removed from machining so my adjusted thickness using a stock head gasket will be 0.53mm. With the USDM pistons this should yield 10.905:1 compression.

I need to have the crank mic'ed to see if it is still in tolerance before buying new bearings.
I was thinking of using a set of ACL Bearings, but that may change if the crank needs work/replacing.

Is there any place that sells the special tools needed to remove the valve retainers? Also is a hydraulic press manditory for removing the wrist pins, or can it be done safely with other tools?

 

Does anyone know if the main seals from a B16A will fit a B18C? I have some left over from a build.

 

im in the same position have a b18c block with p73 pistons what did you end up doing mine is smoking like a mother ****er lol a hugee cloud of blue smoke

 

damn a lot of us are having the same problem. 1qt per 1000 miles. 30,000 miles on my ls/vtec.

I'm planning on just honing and putting new rings. Then take it back to the tuner and have it tuned and break in at the same time.

 

I rebuilt mine with a fresh hone and rings in 2008. late 2009 it consumed a qt of oil a week. The motor eventually blew in Jan 2010 due to a tuning error.
I bought a JDM long block and oil problem gone.

Still deciding on what to do with the old block (needs new pistons).

 

i wouldn't do this. you're decreasing quench and reducing compression. a stock gasket will put you just over 11 but also should be less likely to detonate since you will have a tighter quench area and should have better swirl in the chamber.

moving this little will not make cam gears mandatory since you'll be moving cam timing like half a degree to one degree tops

i also wouldn't waste your money on skunk 1s, you'll probably have to tune to make them run correctly, might need cam gears if they are ground off and they barely are bigger than oem itr cams. either go big like endyn bumpstix and the matching VT or stay stock. bumpstix should put you at or over 200whp with a nice exhaust and a touch over 11:1 compression. they also will make more power most everywhere compared to the oem itr cams.

also, check those valves ! dished valves normally drop compression compared to oem. the oem honda valves really aren't a bad way to go and have a proven track record behind them. ferrera also makes a nice valve but it's dished at will drop you a quarter point in compression.

 

I just realized I had a reply to this thread (2 months later)

I am going with OEM thickness, I was saying the adjusted thickness with my resurfaced head will be the same as using a HG at 0.53mm even though it is stock.

As for skunk1s, in the spirit of California, I have very limited options as to what cams I can install in the motor and keep it legal. Although I doubt a smog tech would be able to tell the difference as long as the idle speed is within spec.

As for the valves I got Supertech dished. I guess that means I'm getting a slight drop in compression

 

oh noes! here come the itr gods going to rain down there hellish 'gtfo's" and "wrong fourm dumbass" post everyone take cover!

 

see what you mean about skunk1s but this compression problem is going to be a hp killer. the thicker gasket method is going to reduce quench and make the car more prone to detonation. now you have dished valves which drop much needed compression. those valves need to go and you should be using flat face or oem. still don't think the thicker HG is wise, there is no benefit to it other than cam timing staying exact. trying to remember the numbers but you have to move .020 if i remember right just to move the cams 1degree. this engine would be easier to tune and burn cleaner near 11:5-1 not 10:5-1 which is where it appears to be going

 

I'm curious where you're getting 10.5 from. OEM valves are dished just like the super tech valves. I'm calculating 10.87:1 compression assuming OEM dished valves.

The motor came out of an ITR, and since we are only talking about the motor we should be good :D

 

FYI you're not going to be able to find JDM ITR pistons, all of the sites have them listed (i4, jhp, icb, etc) but they quit making them. I went through that hunt in July, I went with USDM B16 pistons instead.

But definitely go .25 over and have it done by a reputable machine shop.

 

You still can buy them , the question is : Are you a baller LOL $$$

Spoon itr oversize piston = oem jdm itr oversize piston , they go for $550 (with the ring lol)!

 

measure the dish, the supertech and ferrea valves both have a good deal more dish than oem. you also won't know the compression untill you cc the chambers with the valves in and get actual numbers. if you're just guessing off specs...well...who knows what you'll have.

you're engine though, if you want to spend cash on skunk1's and make a compression blunder all to make less power than a stock jdm itr, have at it. i'm just pointing out you're making a mistake with parts selection.

 

whats the point? and where can you get them? I called everywhere last summer, the few that have them are hording them to jdm idiots that care about "baller" parts.

just get usdm b16 pistons.

 

Interesting. Well it's not too late. I'll look into getting oversized P30s and trade in my USDM P73s. I guess I could measure the difference in volume in the OEM dish vs Supertech Dish.

This is all good info, thanks guys

 

Pm me i`ll get you a set of the overzise jdm .25 for 350 bnib!

 

boom, this will fix you in a jiffy, with p30s those valves you own are just fine, measure it up but it should be north of 11:1

when you measure the valves it really should be done with them set in the head with a valvejob, then you can cc the chambers and get exacts. not all heads are cast alike either. in fact if you want a few free hp get your die grinder and some standard abrasives cartridge rolls. blend the bowls to the runners. it should only take you 2hrs at the most. if you have no exp porting a head just remove casting flaws and do not try to make the intake smooth. a swirly finish is perfect.

don't spend 350 on jdm itr pistons, that's forged piston money for a cast slug. not that cast is bad, it's actually nice not rattling when it's cold in a street car. a set of nippon or rs p30s is perfect for you.

 

I'm going to sound like an idiot, what an "rs" piston? The shop I got my P73-A0s from offered a discount on over-sized P30s, which I'll probably end up going for.

How effective/necessary is the Molybdenum coating on the type R pistons?

 

i got mine from here they look great just like in the pic i got oversize 81.5mm cause i had a scratch in cylinder 4 that had to be bored out great quality i liked them better then the pr3s i bought and returned because i needed oversize they are nippons http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWNX%3AIT

 

rs is short for rs machine. cast pistons are a benefit in street motors due to the longer ring life they allow. forged pistons are both stronger and lighter but need greater piston to wall to operate. they are the cats meow for race engines but have drawbacks on the street. OE forged pistons are always 4032 and generally designed for a fairly tight PWC, something like .002 to .003, a cast piston will setup at .0015 in a performance build and could be set as tight as .0010 if everything is perfectly true. remember ALWAYS favor looser vs tighter when building motors.

honestly if i was doing a build i would get nippon over RS just for the cost, nippon is half the price and a cast piston is just that. a cast slug in a mold. no real rocket science behind it.

as for the coating. if it's available, get it, if not, don't sweat it. i'm trying to remember the 18c factory spec on piston to wall, think it's .0008 to .0020, correct me if i'm wrong. at any rate, if that's the case it means you aim for .0015 and stay under .0020, if the machine work comes out at .0017 or something, you're right on.

 

That's great information. Thank you for that. I'm looking at IL4 Pro_Cast PR3 Pistons, and they also have a moly(MOS2) coating on the skirt, for $225.00 w/rings shipped.