J-Rat

iTrader: (2)

Unless you have a better idea, I am probably going to keep messing with timing. Why would retarding it make it worse? this makes NO sense whatsoever.

BDoty311

What kind of intake temps are you getting? I believe thats how I blew my motor, lots of hard driving at one time.

J-Rat

iTrader: (2)

Well, I really have no way of testing intake temps. I cant imagine they are that bad. Temperatures here are in the 70s.

The thing is, I have been running in the SAME configuration for a LONG TIME, and this just came up outta nowhere.

Bad2ndgen

Ok I will probably get flamed for this but try running less 100 octane. The reason is that you are not running enough ignition advance for that high of octane. Higher octane fuel burns slower and thus requires more advance than pump gas. I think it is knocking beacouse you are carrying heat into your next combustion cycle and the hot face of the rotor is preigniting the next intake charge and that would explain why retarding it is making it worse. I think your a/f's are fine but I would check the color on your plugs.

ddub

Ok, just making sure it hasn't been in there for a while because with the normal bosch wideband O2 that comes with the LM-1 is not made for greater than 1300º F UNLESS you have the heatsink O2 adapter on it. Because of this, if you are running at higher than 1300º, which rotaries do pretty easily, the sensor can read inaccurately and your AFR's that you're getting could be slightly off. The longer you run with that same O2 sensor at these higher temperatures the more off it will get. The LM-1, though, has a built in program that should show "error" when these temperatures are exceeded. I just thought it was some food for thought.

As for the timing, IIRC turning the CAS clockwise causes timing to advance, and turning it counterclockwise retards. Easy way to check is do this. Put the timing light on the L-1 plug wire and set it back to the 5º YELLOW mark. Then put the timing ligh on the T-1 plug wire and make sure it is on the 20º RED mar. Setting one SHOULD show that the other is already aligned, but a good way to check is to set it to the other one and make sure it is. Now on either L-1 or T-1, keep the timing light on it and turn the CAS counterclockwise (I think) untol the needle moves to the left of the mark, then verify by switching the timing light to the other plug wire. Afterwards when checking timing on BOTH plug wires you should see that the needle is in between the two marks on one, and to the left of BOTH marks on the other. Hope that makes sense.

RETed

If you're shooting the pulleys from the front of the car...
If the set of marks move to the left, trying to go behind the water pump pulley, that's advancing.

If the set of marks move to the right, it's retarding.


-Ted

J-Rat

iTrader: (2)

thats what I thought... Timing was returned to stock, and the pinging went away.. WTF?

Bad2ndgen

Advance the timing a little....Say two degrees. How are you reading knock anyway?

J-Rat

iTrader: (2)

Its audible...

Car is down until the FMIC install, which is tonight.

hondahater

iTrader: (2)

what fmic did you get??? Just interested

jon88se

Timing...the key is in the term. As I understand it, you can get pre-ignition from timing that is too advanced OR too retarded. You need the burn to occur in the right range of timing. Stock =

Bad2ndgen

Audible Huh? At what rpm's? Are you sure it's knock?....It is very hard to distinguish the sound of knock at anything other than very low rpm's, there is simply too many other engine noises. If this is occuring durring low rpm conditions than I will retract to my previous statement of either use less race gas or advance your timing alittle. You can get detonation or preignition from to much timing or too little. You can also see these simptoms from being too rich, I don't think this is your problem though.

Ok this is going to be really hard for me to explain but here goes.

Standard 92 octane gas burns at around 900 feet per second, the higher the octane the slower the flame front travels. Ignition advance is how long before top dead you are starting the fire to obtain full combustion at some point after top dead. The point that you need to hit after top dead depends on the caricteristics of the engine, every engine is differant. Ok now lets say that the factory has found a motor to perform at its best at a given amount of advance, lets say 15 degrees of advance at 5000 rpm's. now lets say that this yealds full combustion at 10 degrees after top dead, this is when you will reach peak cylinder pressure and peak torque at a given rpm tuners call this the sweet spot. now if you introduce a fuel that burns slower with the same amount of advance you will not be getting full combustion untill some point after out sweet spot of 10 degrees ATD depending on the flame speed of the fuel. The problem with this besides less power is that you are burning fuel in the combustion chamber for longer wich is heating up the components inside the engine ie: pistons/rotors. If your internal components don't have enough time to cool before the next intake charge is ingested, the hot components can pre-ignite the next intake charge. This can also happen if you are running overly rich because the extra fuel takes longer to burn as well. If you dont have enough advance and you are overly rich it will compound the issue.

I have had more people ask "why did my engine blow up? I was running really safe at 10.0:1 AFR and race gas!"

Just my .02