Sorry for the novel, but to diagnose the issue I think the whole history needs to be known...

Ok, here is the scenerio...

I have a 92 Si with a B18C5 swap that was installed in the car about a year ago.... shortly after installing the motor I had an AEM Fuel pressure riser take a crap on me, the diaphram tore, it ended up feeding a ton of fuel back up through the vaccuum line into the intake manifold and going unburned in Cylinder #1. Got that fixed, changed back to stock, then noticed a puff of oil smoke. Again, this is about one year ago.

I inquired with my mechanic and worked through some trouble shooting and he figured the oil burning had to be associated with a scored cylinder wall from pushing all kinds of unburned fuel into #1 from the failed FPR. Ok, so.... I have my mechanic (using his machine shop) rebuild the bottom end, install .5mm oversized JE pistons, eagle rods and all new bearings. Good to go right... not quite.

Still getting that puff. ARGGHH... ok, so we go through more and more dianostic stuff... figuring it must be the oil seals on the valves. Go through the pain of installing new seals with the head on the car, good to go right.... not quite.

Still getting that puff. ARGGHHH.... at this point I am out of money. Then to cap things off I get laid off. Both my wife and I are autocrossers and I wanted to get into HPDE's and Lapping events. So we go through and analyze what is going on in our lives... we want to autox and with consultation of my mechanic the motor is not going to be hurt... so we run the car for the autox season. The whole season I monitor the oil after every run and when the puff occurs from outside the car when my wife drives.

Through this process, I learn that on high stress events the burn is on throttle lift when in VTEC, on the road (highway driving) the oil burn is on VTEC crossover.... hmmm, more consultations with mechanics and people smarter than I am on this type of thing... "It must be the valve guides." Ok, crap....

So I go back to work and start ordering the parts I will need to essentially completely rebuild the head. I figure I may as well have some extra work done on the head while it is out of the car to help me in a very competitive Street Mod class. Through a friend I get hooked up with a machineist who has a very good reputation in the area for producing some of the best V8 heads. I go meet him and discuss what I would like done...he fits the bill.

Ok, so in early November of 2002 with some help I tear the head off the car, tear the head down to the valves, take it to him. He replaces all of the guides (following the proper proceedures in the manual) and hand fits all of the valve to guide clearances at dead nuts on minimum spec. He also does a P&P on the intake and exhaust side of the head, beautiful work! While doing this work he notices a small hairline crack in one of the intake guide bosses. He examines it and determines that it can't go anywhere and writes it off as a casting crack.

I go pick up the head and he shows me the crack, he also explains that it really can't go anywhere. "Ok, cool." By this point the car has been in my garage for 6 weeks on jack-stands, and I am ready to get the beast running again.

Take the head home, build the head back up with the rockers and such. We reinstall the head this last Saturday (1/4)... take our time, do all the proper adjustments to cam timing to account for a milled head and thinner head gasket, adjust the valves twice, the whole nine yards. Recheck the timing and get her started... rough idle... ok fixed that by plugging the IACV in... DOH!

Start it up... runs like a CHAMP. Warms up and all that good stuff. I go to bed with a wonderful feeling. Get up the next morning, work on the other little stuff I want to get done on the car before I take it for a test drive. Get on the road at about 5, it gets dark in Seattle this time of year at about 4:45.

Run it around nice and mild, calmly let VTEC engage and all that good stuff. WOW, does this thing pull now... holy crap. Make one aggressive pass down my "test" road and am amazed at how this thing pulls... that is the good part.

I decide I should drive the car to work yesterday (1/6) to work the assembly lube out of the head. My commute is 65 miles each way so this is a nice easy way to take care of that. I drive to work (dark) and decide I want to meet a buddy for lunch, on my way to pick him up I get on it.... PUFF - ***! So I am like now what...

I am utterly depressed and don't know what to do. I drive it home nice and easy...

Since day one I have been running 5-30 conventional oil... when the early problems arose I tried higher weights to no avail. All year I ran 5-30 conventional. I was running 5-30 yesterday to condition the seals. After all my reading on H-Tech I decide it is time to change to a heavier oil... so last night I change to Mobil 1 10-30. Drive it to work again this morning, PUFF - ***!

Ok, the puff is at VTEC crossover, big enough that I can see it in the mirror.

I am totally frustrated and depressed right now, after pouring this much money into the motor and not fixing the issue I at my wits end. Please help.

Setup is this.....

B18C5 running ~11.6:1 compression
JE Pistons
Eagle Rods
Spoon Head Gasket
Fully P&P'd head (no work in chamber)
Fresh 3-Angle valve job
Jun Valve Springs
Skunk 2 Retainers
3" custom intake
Spoon Header
Test Pipe
OEM ITR B-Pipe
Spoon N1 rear section
Kenji Chipped P28 ECU

This motor make very nice power but the oil issue has me miffed. Your thoughts?!?

My only thought is that there is an oil passage that the crack leads to and under high load (VTEC) the oil is finding a way into the intake passage and PUFF there is the burn.

Thanks in advance!

Nash


[Modified by rambler, 7:49 AM 1/7/2003]

 

What color is the "puff"?

 

Looks blueish to me.

Nash

 

Oh, additional information that should have been included....

I have an oil catch can off the oil box on the back of the block that is NOT looped back to the intake, just has a breather filter on it.

My breather on the valve cover also only has a breather filter on it.

These were both part of the diagnosis phase of the project. So the only vaccuum lines on the intake manifold are the brake booster and fpr.

Nash

[edit] for clarity [/edit]


[Modified by rambler, 7:41 AM 1/7/2003]

 

a little FYI, 5-30 and 10-30 are the same weight
the first number indicates cold viscosity and the second hot viscosity
you will want to try 10-40 or 20-50 to get a heavier oil

 

very good point!

Nash

 

I have been discussing this latest issue with some folks who are not on this board and they have another thought....

I could be seeing fuel... which will look grey through a mirror in headlights...

I really need to get someone to follow me!

Nash

 

top

 

yes fuel smoke will appear gray or black
just have to make sure theres no BLUE in it