jdm d15b mini me swap getting spark knock

[chriskruger81]

Hey guys im new to the whole mini me section i usually just turbo it and be done. but i decided to go ahead and do the swap since i got the head from a friend.
heres my setup:
d15b7 block
d15b jdm head
adjustable cam gear
d16z6 distributor
header. cat., 2.5 exhaust
cold air intake
phearable chipped ecu

I thought it may be the ecu but i swapped back to the p06 and im still getting the spark knock. any help would be great.

 

[chriskruger81]

Also should i be running a different spark plug now? if so which one?

 

[RoughKnight]

Umm...I dunno if this is correct...but
the jdm d15b has a shorter stroke than the regular usdm d-series, i think 27.5 to be exact. Might be the problem

Spark knock is usually caused by the dizzy and/or timing issues. Play with the cam gear a bit and see how it goes.

 

[chriskruger81]

i retarted the timing with the cam gear about 4 degrees and it has helped a bit so im going to try more later. I just dont want to go too far and effect the performance of the swap

 

[RoughKnight]

regardless of the preformance, you need the engine running smoothly, not performance oriented at the moment. Fix the problem at hand, then work your way up. running too rich is better than running too lean. Get NGK plugs, and play with the timing a bit. +rep if it helps

 

[d-mon]

Also should i be running a different spark plug now? if so which one?

for plugs, try the NGK ZFR6J-11.
all d15's have the same stroke (84.5mm) usdm, jdm, edm, xyzdm, etc.
put the stock cam gear back on.
set your base timing at 16*btdc

 

[chriskruger81]

i already tried swapping the cam gear and setting the timing in a few different spots. the knock was worse with the stock cam gear so i went back to the adjustable. i guess im basically just going to have to keep messing with everything alittle bit at a time

 

[RoughKnight]

sounds like it. keep it up and report you're progress.
or maybe that shorter stroke issue has something to do with it hmmm

 

[GlassHeadlights]

Do you know what compression ratio you're at? I'm at 10:1 with my Mini-Me and it runs really smooth, my compression test showed 210 PSI.

Also with all of that done I'd get it tuned, that would net in more HP, make it run better and get rid of the knock.

 

[chriskruger81]

im going to do a compression test today. I used a d15 head gasket, should i have used a d16 instead? I heard that would affect the compression ratio

 

[chriskruger81]

did a compression test today every cylinder shoot over 300 psi and pegged the gauge. the timing is dead on with all the marks. bad head maybe???? i can get another for cheap should i get it?

 

[GlassHeadlights]

300 psi, I didn't know you had a cummins in there. It can't be 300.

 

[chriskruger81]

trust me it is past 300, it pegged the compression gauge. i used 2 different gauges to be sure, i have been a mechanic for years. like i said i never did the mini me swap i would usually just boost, nos, or motorswap but i got this eg hatch cheap and the parts practically free so i figured why not. i am here asking questions about this swap since alot of people have done it, has no one ever come across this situation??? i have access to another head but honestly i dont want to waste the time or money on new gaskets if it is going to be the same issue. im looking for possible problems im missing??

 

[D15Beater]

Sounds like someone milled the shat out of the head, stock pistons?

 

[chriskruger81]

yeah the block is completley stock, im not sure if the block was ever milled though and i talked to my friend i got the head from and as far as he knows the head was never milled either. im going to look more into the block tomorrow morning for signs of being removed and sent to a machine shop. i know the original d15b7 nonvtech head had been milled since the guy overheated the engine before i bought it. it has the overheat tab stuck on the side of the head but i didnt notice one on the block and when i changed the head before the block looked pretty normal.

 

[chriskruger81]

so i swapped the head for a d16z6 today, compression is 210 across all four, spark knock gone! just alittle smoke hopefully just coolant and oil burning off the inside of the header. im going to drive it for a bit tonight and see how it goes.

 

[GlassHeadlights]

If it keeps on smoking I'd look into the rings because that's a shit ton of pressure on them, but I guess a turbo would be similar.

 

[stinksause]

I dont mean to thread jack, but does anybody know of a US-spec obd2 ECU that can be gotten to run all 3 stages of vtec with the D15b (95- 2000)? Or do you know the code of the M/T jdm one?