Engine knocking noise in my 4G93 Mivec

[jefftzz10]

dear all sifus,

Just wana ask for opinion. Currently using Mivec 4G93, PnP, racing clutch, adjustable cam pully, light weight crank pully, adjustable fuel regulator,Simota open pod, original mivec piston, 390cc injector with Emanage inside.

Done dyno few weeks ago, but some how i still not statisfied and confident to rev my engine. As the tuner said my engine compression is too high (around 14 compression ratio) that cause the knocking noise. At certain rpm my engine will creates knocking noise and i don even dare to accelerate more. But, the tuner told me that my A/F ratio is good (11-12++) and the noise cause by my high comp piston.

Do i need to remove the ori mivec piston and install the 4G92 piston or i'l just drive like tat as the tuner told me just the noise and would not cause any damage to my engine? Is that true that wont cause damage to my engine?

 

[DanzEterna]

have u try pumping ron97?

 

[xtremeleo]

dear all sifus,

Just wana ask for opinion. Currently using Mivec 4G93, PnP, racing clutch, adjustable cam pully, light weight crank pully, adjustable fuel regulator,Simota open pod, original mivec piston, 390cc injector with Emanage inside.

Done dyno few weeks ago, but some how i still not statisfied and confident to rev my engine. As the tuner said my engine compression is too high (around 14 compression ratio) that cause the knocking noise. At certain rpm my engine will creates knocking noise and i don even dare to accelerate more. But, the tuner told me that my A/F ratio is good (11-12++) and the noise cause by my high comp piston.

Do i need to remove the ori mivec piston and install the 4G92 piston or i'l just drive like tat as the tuner told me just the noise and would not cause any damage to my engine? Is that true that wont cause damage to my engine?

first of all, if u r using a 92 original block, and mivec's complete internals, ur compression ratio willn ot rise to 14. weve tested with a much higher compression pistons and the max we got was around 13.5, its either ur mivec head had been skimmed beyond limits or sumone has been telling u bs sir. iam sorry for the blunt statement.

lets get down to business, pinging / preignition / knocking / or whatever u want to call it, IS THE NUMBER ONE ENGINE KILLER AND MUST BE AVOIDED AT ALL COST. fyi, a 3 bar of boost wudnt kill an engine as fast as detonation, so dat sound u r hearing IS VERY DANGEROUS. on this part, sumone is really telling u a big lie sir. when he tell u dat d knocking sound sourcing from preignition is not dangerous, please, please, please ignore it.

does the sound occur prior to the tuning process? i believe its because ur tuning is way off, but need to reconfirm on dis. please, pm me for details sir. i suggest u dont accelerate the engine hard sir. what fuel grade are u using btw? we have a b16 running on 95, no big when properly tune. 170hp on the dyno dynamics on std block

 

[93na]

sorry to treat starter for tumpang! i also havin that problem! was using half exz for a few month, so decided to used back normal exz, so now using 421, tabung tengah and muffler like those toda dezign... now i have knockin sound around rpm 1800 to 2200 only after that no knockin sound! IT SOUND LIKE THOSE 1.3 ENGINE when climing a hill but only at that rpm!

jeff sorry ah to butt in!!!!!

but as my forman said if wan to used mivec piston head must not been skim before! if not knocking is for sure! and ya when the engine is knocking dont rev it! bro forge piston! ha ha ha

 

[xtremeleo]

i didnt realized u are using a 93 block now, but dat doesnt change anything, pinging is still dangerous.

93na, if it pings at low rpm, den iam not worried.. well, maybe just a lil bit ler.. usually, an engine dat doesnt provide sufficient torque at a particular rpm pings at high load ie higher gear wit big throttle input. u can avoid dis by retarding the ignition, but will lose slightly at top end

 

[jefftzz10]

addition information, currently using Shell 97 (full time), mivec ori extractor,piping 2.3' to the end using RSR 2.3' inlet as well. when dyno time was ok, but some how i might think of hot weather or sth that might cause abit of knocking noise.
when cruising around 120km/h above, knocking noise is appear as well and low rpm 1000-2000rpm.
Headache la. Dyno results was good as i can get 194.4hp n 203.1Nm.

 

[xtremeleo]

seeing dat dyno reading, and taking all into consideration, i think its safe for me to assume dat u went on a dynojet for the tuning process? if dats the case, dat explains the pinging. please calrify sir

 

[Sapeqlaa]

seeing dat dyno reading, and taking all into consideration, i think its safe for me to assume dat u went on a dynojet for the tuning process? if dats the case, dat explains the pinging. please calrify sir

Sorry to interrupt, driving more or less d same spec with bro jeff...does dynojet's tuning instead of dyno dynamics will contribute to the pinging problem to exist?..i'm aware that dynojet tends to give a higher hp reading compare to dynodynamics..but pinging sir?...can u elaborate more on that please..tq.

 

[xtremeleo]

simple sir, a dynojet isnt a loaded dyno so u can obtain a higher hp on paper, because u can advance more on d dyno witout pinging occuring. its a different story altogether on the road, weve seen fueling leaned out and pinging occuring after being tuned on the dynojet machine. there are a difference between a loaded and non-loaded dyno, at least from the examples dat ive seen so far.

weve even seen a 70hp reduction on hp and at least the afr leans out 4 points (dats too much fyi) when tuned on a dynojet and clarified on the dyno dynamics. a satria GTi was making 230 on paper on the dynojet, but when the owner felt the power is sumwhat low, he then came to millennium motorsports asia for clarification, and true enough, the new dyno session gave a reading of 160hp and lean afr reading. the reading on the dynojet was very good fyi

 

[jefftzz10]

should i go for another tuning session? any nice place to intro for nice dyno session? before i need to hang my car for weeks to change the piston n do everything back, i hope will solve my problem by dyno tuning.
wana ask, if the ignition timing set as 5 degree currently and i wanted to adjust to 10 degree to eliminate the knocking noise. does it help?

 

[xtremeleo]

to confirm dis, u need to retard the ignition timing via the dizzy sir. please dont go changing anything yet.. i can assist u in checking both the ignition and fueling, easy jer. for adjustments, i can only adjust the ignition timing and not the fueling as u have a piggy back ecu for dat, u need to retune for dat. pm for more details, tq sir