kccord

Hi lads,

Murphy's law has kicked in for me. I have just finished building a B18CR bottom end, B16R head that has the following bits and work into it:

1. Wiseco 81mm 12.5:1 pistons
2. Eagle rods
3. Toda spec B and jun cam gear, cams dialled with dial gauge and degree wheel etc
4. Hondata S300 (I used friend's s2s2 map to give it a start) and obd2a to obd1 conversion harness
5. Head reconditioned with new seals, valve re-cut, milled, pressure and vacuum tested
6. Block decked and re-honed (machine shop advised that bore was still good to use standard bore piston and only needed a re-hone)
7. Toda 1mm head gasket

Story is, 90% of the engine is assembled by me and the other 10% was my friend installing the piston/rods into the block by himself as nobody was available that day. The whole engine is assembled and installed into ek civic and ran into a problem the moment of start up (oil pressure pre start and base timing was done) where it sounded like it is misfiring, hard/very rough to idle and it ran pig rich (no problem after I adjust the fuel trim in hondata). The diagnosis we have done:

1. Pulled spark plug wires out one by one, Cyl #4 is the culprit as it made no change on idle but there is spark coming out.
2. Check fuel from injector 4, injector is operating fine (it ticks)
3. Check distributor, no issues and we pulled it off a running B18c car the same day. We also made sure the positions of the leads are correct on the dizzy.
4. Could it be the cam timing since we dialled it? We don't think so because cylinder 1-3 is healthy and we dialled it in correctly to toda spec b sheet
5. Could it be the engine harness? We don't think so as we removed it and checked continuity of critical wires on it. All good.
6. Could it be the Hondata? No, we plug it into another car and it ran totally fine.
7. Could it be the obd2a to obd1 harness? no, we plug stock b18c ecu in without conversion harness and it still sound the same
8. Leak down test, too difficult to hear where it is coming out from....
9. Compression test....now here are the numbers:

Cyl #1 = 270 psi dry
Cyl #2 = 270 psi dry
Cyl #3 = 270 psi dry
Cyl #4 = 220 psi dry and it took longer amount of cranking to get there

So now what could it be? valve, valve seal or crack in the cylinder head (which we doubt since it was pressure and vacuum tested). We decided to do a wet test on Cyl #4, numbers shot up to 300psi. My friend thinks that he installed and clocked the rings correctly but nobody was there to witness it (we normally do double or triple cross check our work but not this time). He also said he checked the ring end gap and it was perfectly normal.



My question is, based on the story above, what do you think is the culprit? Could it be the rings stuck or installed wrong where gaps line up or something more sinister? After taking it for a drive (with the hope to seat the rings) with the issue, the car felt responsive and have insane power, the misfire is less apparent above 1500rpm. Pulled back in, the same stuff.



We were pretty bummed as this is the first time it happened, we countlessly built K20, B16, B20vtec, B18, F22, H22, CA18, SR20, Rb26, Rb25 in the past and never had an issue. Joked around and said the blinker fluid or muffler bearing must be shot in this ek9....lol



Edit: We also checked to make sure we didn't lock the VTEC rocker arm piston on all cylinders during final assembly, the rocker arm swings independently. All the V2V, P2V clearance and cam degreeing was done on Cyl #1 with rocker arm piston swapped around to lock VTEC. We also set valve lash to 0.2mm intake and exhaust as per toda's spec.

Edit: No issue with the Toda 1mm head gasket, no apparent gasses/dirty bubbles coming out of the coolant, cylinders are totally dry beside the carbon on the spark plug from running rich, no milky coolant, no milky oil, no apparent blow by. We also O-ringed the cylinders top, this was done at most attention and triple checked where the machinist cut an accurate circle grove around the bore with the width as per spec to the copper wire used. Copper wire installed at good detail and they sat nice and flat before we put the head gasket over it. And yes, every bolts are torqued to spec, even down to the engine mount bolts.

Edit: Just did a leak down test 15 MARCH 2014.

Valve clearance were confirmed and was 0.2mm IN and EX as per TODA specification,the rocker arm can be jiggled when the piston is at tdc meaning the cams are not contacting it.

#Cyl 1 & 4 has major leak on the exhaust valve (very minor on CYL #3 & #4 but NOT %100 perfect), we took out the exhaust manifold to confirm. We even put degreaser on all exhaust ports and re-confirmed that YES #cyl 1 & 4 are not sealing correctly, it wasn't a pissy soft bubbles but it was literally squirting out. Cylinder 1 appears to leak the most and TO ADD THE CONFUSION we re-did the compression test (cold and dry) and the numbers are as follows:

CYL #1 - 240psi
CYL #2 - 250psi
CYL #3 - 260psi
CYL #4 - 220psi

If cyl 1 appears to have the worse leak, I do not understand why CYL #1 to #3 has consistent numbers and CYL #4 being down when we did hot dry compression test yesterday....shouldn't CYL #1 have the worst reading???

Additionally, we did hear leaks on the bottom through the rings but it is acceptable as this is a spanking fresh engine and rings haven't seated.

We did end up removing the head and removed all the pistons whilst the bottom end still in the car. We re clocked the rings and made sure (there was 3 of us triple checking things) that everything was 100%. Using the piston compressor we made sure the rings stayed the same orientation as we tighten it and all pistons went in super easy with no effort. The rings are perfect with no damage and everyone checked it was right side up, right position and correct ring orientation. We also checked the ring end gap and it was consistent with all cylinders, it was on the looser side of the specs but all consistent.

We put the cylinder head upside down and poured water on the combustion chamber, nothing out of ordianary to be noted. Sucked it with a vacuum cleaner on the intake/exhaust ports, nothing.

There was no sign of compression leakage through the head gasket or even past through the rings (no carbon smuge). So we put everything back together and torqued it to specs. We then did a leak down with the cams out and still the same problem with cyl #1 & #4. We installed the cams and timing belt and re-did compression test and the numbers CAME OUT THE SAME AS ABOVE.



We all sat down and had our lunch. There are a quite bit of twist on this cylinder head, the story are as follows:

1. This EK9 originally had B16a type R with JUN 1.8 stoker kit in which the first owner installed, the car later smash valves and was taken to my OTHER friend's workshop (Perth is very small comunity for honda's so we know one another). During tear down, 1/4 of the timing belt's length has the tooths completely stripped out, there were indentation on the pistons but very minor, all the valves were bent and no other visible damage. Not knowing why the engine smashed valves (over rev doesn't cause a section of the timing belt, toda belt, to have stripped tooths), the engine under goes a full rebuild top to bottom and a machinist carried out all the machining job. The car was sold after this rebuild.

2. Second owner (who is the current owner of this car and engine) had symptoms of misfire on #cyl 4 from the first day he bought it. He took it to our workshop and we did a tear down. We suspected that the rings were worn on the CYL #4 so we did a quick job of honing and re-ringing on all cylinders. We installed the head as is, we cleaned it and machine shop faced it. Everything was good and we reinstalled it in the car. Injectors were sonic cleaned and flow tested by third party and all good. We re-install the engine back in the car and start it up. ****, same misfire on cyl #4. It had the same symptoms as current problem. The said owner wanted the car back so he can take it to track, we cannot resist him from taking it as money was paid therefore by australian law we cannot hold his property. HE THEN TOOK IT FOR A TUNE AND WENT TO TRACK. Then boom there it goes, took it back to my workshop and same problem from the first owner where 1/4 of the timing belt's (honda oem belt) length has the tooth completely stripped out. Further investigation shows THE DISTRIBUTOR has failed or has been problematic since the first owner (same distributor), there was so much axial and radial play on it and we suspect that it may have caused pre-ignition that may instantly lock up the engine. Since there are still momentum at high rev, the cams must of kept turning and it stripped the tooths out. And yes, valves were bent. We decided to throw away the bottom end.

3. Now with the original JUN stroker kit B16A type R bottom end IN THE BIN, we got a B18CR full re-conditioned block to suit the forged parts (top of this post). We used the same B16A head but completely recondition again, everything was changed to brand new except the casting.

In summary, we think that there must be a defect on the head from the first incident. We think that there must be a crack that eyes cannot see and typical pressure/vacuum head test cannot detect on the CYL #4 combustion chamber near the spark plug hole. The leak down test showed a great leak on CYL #1 & #4 exhaust valves I wonder how the machinist didn't pick this up on his tests...

I don't know now....We just spent from 9am to 11pm today in the workshop doing this having to take the head off again tomorrow and send it back to the machine shop on Monday....I feel that we should use another head, let the machinist do the acid bath and machining and WE ASSEMBLE it using the perussian blue to ensure we have 100% contact valve seat.

****....




Sorry for the long essay but thanks for any help in advance.


[EDIT] Solved the problem like a day after I made the last post. Cyl #4 intake secondary lobe had not been grind-ed. It has the same profile as the VTEC lobe. I didn't even believe it in my eyes that Toda had missed that lobe. Customer confirmed that the problem was there since the day he bought the car, basically, the car was idling on VTEC.

1998GsRIntegra

Damaged a piston ring during install? What kind of ring compressor do you use?

kccord

He used the typical ratchet type compressor (I hate that ****, rings actually turn when you tighten it), I should of bought the wiseco tapered sleeve one for $30 usd...

He also mentioned that abrupt force wasn't used to shove the piston in but then again nobody was there to make sure....

1998GsRIntegra

Yea the tapered compressors are the way to go. No chance of having rings accidentally line up on you and much less chance of damaging a ring during install. If he came out on his own and said that no excessive force was used to install the piston then he may have fucked it up. He probably knew it was in your mind so he said it to remove blame from himself. It's fairly obvious that you have a ring issue on that cylinder. I'd say the wet compression test confirmed that pretty definitively.

kccord

Thanks man. Though I still welcome any other opinions.

Since the engine and everything else is installed on the car as if it is ready to go, might pull the head out tomorrow, drop the sump and remove cyl #4 piston/rod whilst the engine still in car....

93egSLEEPER

Pop the head off and check the cylinder wall. It will be obvious whats going on at that point.
Keep in mind if a ring was damaged, it could have damaged the piston or cylinder wall as well

jimbo slice

I had similar issues on a fresh rebuild. Turned out one of the intake valves was adjusted too tight. Caused the valve to hang open, and resulted in a pretty nasty misfire and one cylinder really low on compression.

The old style ring compressors work, just don't try and gorilla slam the piston into the bore.

soaringchimp

Don't take the head off....not yet anyway.

What you need is a leak down test.

You will roll the engine until the valves are all shut on the cylinder that is reading low. You then remove the spark plug for that hole and thread in the hose of the leak down tester in its place.

Basically you will be pressurizing the cylinder with air to try and determine where the air is leaking. If you hear a hissing in the intake manifold you know an intake valve isn't sealing. If you hear hissing out the exhaust you know an exhaust valve isn't sealing. If you hear hissing lower in the engine your rings aren't sealing. Lastly remove your radiator cap. If the water level starts to come up and/or you get bubbles, you know either the head gasket is leaking or you have a crack in the cylinder.

That will give you an idea of where the problem lies. THEN take it apart and fix it.

Also valve lash should be .006" Intake and .007" Exhaust. Always leave exhaust a bit looser to allow for heat expansion.

kccord

Today's update guys!! (also edited the first post)

Once again, I greatly appreciate your opinions and your time in reading this. It is a long essay but I wouldn't ask something that I already know. We are not noobs, we are honda and nissan specialist workshop in Perth, Western Australia. We've built countless of engines but this damn one got our head spun around. Please hear me out on this one.

You can find us at BTMotorsport and Team Doriemon in facebook


It is currently 12.40am so I'm over and out guys.

kccord

Sorry, have to add this. The fact that when we squirt oil into the cylinder #4 and the compression went up to 300psi, could it be that the oil was thick enough to not pass though the fine crack as if it is sealing it?

93egSLEEPER

Stuck ring is my guess. I had the same issue in the past. I put a couple drops of ATF down the hole and it popped it loose. But I cracked a ring land a couple months later. That was on a boosted motor though.