I rebuilt my Honda engine last year and made it into an all motor high compression street engine. The CR should be around 13:1.
Cylinders have been bored out 0.5mm (75.5mm bore now)
New rings, pistons, valve guides, seals, valves, springs, cam, bearings, you name it. The only things that are still stock are the crank, rods and rocker arms, everything else has been upgraded
Now when I drive the car its fine when its cold, but it blows a lot of smoke when the oil is 70C or warmer. This only happens when the car engages in VTEC (puff of smoke) or after high RPM deceleration (letting go of the throttle at 5000+ RPM) and then flooring it (lots of smoke).
The engine only has 4000-4500km on it since the rebuild but it shouldnt be smoking THAT bad
Compression test came back positive: 250PSI on all cylinders
Leakdown test warm and cold with the worst value being 7.5% on one cylinder
Vacuum is plenty (21inHg idle when warm, 25+ when decelerating, needle pegs over 25inHg after 3000RPM, maximum what the gauge can show)
When building the engine the rings have been clocked correctly. I triple checked that
I hope anyone who had this before could inform me on what the issue could possibly be. I've lost hope in the rebuild shops in my area since nothing they suggested or did fixed it for me. I'm capable enough of working on the engine myself but I'm at a loss of what this could be
Complete speclist of the car
D16Z6 Engine
DNJ P29 pistons + rings 0.5mm over
ACL and King bearings
Comp Cam Stage 2 Camshaft
AEM adjustable cam gear set at 0
Ferrea 5000 valves
Supertech springs, retainers and guides
Skunk2 Viton valve seals
Skunk2 Pro intake
68mm TB
Header and catback exhaust with 200cell sport cat converter
Fidanza light flywheel
Well if it smokes on deceleration when warm you got to check the fuel system. The smoke can be from too much fuel which will make it smoke kind of whitish as the fuel is atomized and comes out. That's if it's really bad but if it's black smoke then it's running too. Rich but not outrageously rich. I would start by checking the fuel system first cuz it sounds like you get a good job on the engine
I have a video of the smoking. Can I post it here? The car isnt moving but it still does it when revving high. I do have an Air Fuel Gauge installed. At idle it seems rich like you said with 12.5:1, its a Bosch LSU 4.9 sensor. It has been acting up the last couple of days so the sensor might be bad but not sure
The car has been tuned so maybe something in the tune is bad? The smoke does smell like oil.
If you need any more info I'd be happy to provide it. This weekend I'll make a video of the smoke whilst driving
I drove it some more today. Made my brother film the rear of the car. After 5700rpm the smokeshow starts. It could be white smoke like you said, but not too sure. Take a look: https://youtu.be/rvOsW1sTHZ4
I have a video of the smoking. Can I post it here?
Yes. See the READ THIS FIRST post in the Notices section.
Posted the video. Sorry if it wasn't in a reply. New to this forum and not sure how the posting/replying works
Video of the smoking right here: https://youtube.com/shorts/Vj92-nbeLLE