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Discussion Starter · #1 ·
Sorry to jump right in with a bunch of dumb questions, but I need fresh brains (mine are shot). I have been trying to tune a B16a1 with nitrous (65 shot) but have run into some walls (figuratively speaking).

Setup:
B16a1 stock injectors/FPR/fuel rail/intake-TB
Zex Nitrous Oxide @ 65 level engages @ 5200rpm
Home Brew ram air intake (which appears to work because it was leaning me out -according to the plugs)
Hasport 4-2-1 header
2.25" exhaust
Walbro 255 fuel pump
MSD Blaster Coil
MSD cap
Accel 8MM wires
**NGK BKR7E (one step colder the OEM)
**Zex plugs (supposed to be 2 steps colder)
Distributor was replaced in 2003 w/NEW OEM unit and shows no signs of wear.

Problem/ Ignition: Timing marks jump around @ idle (I'm guessing +/- 5º or ~8º-10º sweep- from base setting). So I can't nail the timing exactly where it's supposed to be. Checked wire separation, checked cap and rotor and timing belt, all look ok. Installed MSD 6AL which made no difference. Set timming back as low as physically possible and still had detonation (black and or silver specs on plugs -viewed with 10x lighted plug inspector). **Note: With the timing advanced ~-2º I still had small black specs on plug off the bottle

Problem/ Fuel: Installed Walbro 255 intank pump. Talked to RC Engineering and they felt that even if I went to the 75 shot the stock injectors should still be fine. They said that unless there is a drivability problem, no need to have them rebuilt and that larger injectors would probably cause idle/low speed drivabililty issues.

Observations: I have a narrow band (I know -stupid) A/F gauge running off of the secondary O2 sensor. At WOT it's always is 3-5 segments in the 'rich' section. I can hear no audible pinging. A compression test shows that all cyl. pressures are within specs on the differential but my pressures are in the 90PSI range (I think 130PSI is the service limit from Honda). I have found the black/silver specs both on and off the bottle. The nitrous kicks in @5200 (or at the VTEC switchover @ WOT).

**I went a couple of steps larger on the fuel side of the nitrous nozzle which didn't seem to help that much. But then again, I was getting specs on the plugs without the spray as well.

Anyone have a thought on this?

Thanks,

Sean
 

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First off are you shorting the shut off for the ecu on the advance? Its a yellow covered thing on the drivers side of the car under the hood that you have to put a jumper on before you time.

Doesnt Zex come withs its own fuel injector of sorts? The stock injectors should be fine.

The narrrow band O2 guage cannot be used to tune a car, just to see if your O2 sensor is working, nothing else.
 

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Discussion Starter · #3 ·
Richrowa said:
First off are you shorting the shut off for the ecu on the advance? Its a yellow covered thing on the drivers side of the car under the hood that you have to put a jumper on before you time.

Doesnt Zex come withs its own fuel injector of sorts? The stock injectors should be fine.

The narrrow band O2 guage cannot be used to tune a car, just to see if your O2 sensor is working, nothing else.
--Actually my timing advance jumper is in the passenger foot well next to the blower motor...but yes, I am jumping it.

--The kit I have is a wet system (forgot to mention that) so yes, there is a nozzle that sprays the nitrous and fuel.

--I know I need to switch to a wideband (hence the stupid part) but two wideband sensors AND a new gauge are in the works. :oops:

Maybe I should have approached this differently:

1) what do I need to look for (other than what I already did) to troubleshoot my timing marks jumping around.
2) what would cause me to get black/silver specks on the plugs (on and off the bottle) -even with the upgraded fuel pump and timing pulled all the way retarded.

The timing seems to stable out at higher RPM's, just at idle/under 2000rpms is where the marks jump the most. I'm thinking they may be related -which is why I'm asking.
 

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Can you idle it down to 600 rpms? Is it smooth?
If it is I will wait to see what the experts have to say.
My B16a is rock solid smooth at that rpm and thats where I set the timing.
I cannot understand with the ecu out of the equation how it could not be an issue of either the timing belt or the dizzy?
 

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first and i think the most important question, what type of EMS are you using?
stock? crome, uber, etc..?

when you are doing the timing is the car nice and hot?
dont attempt to adjust timing unless the motor is hot enough to a point where the rad fan comes on
once it comes on then do your timing, but dont do it when the fan is on as it changes the timing
check spark plug wire to make sure it is within specs, you might have a bad plug wire
do you have stock cams? after market agressive cams will be a bitch to set base timing with as well

as for the fuel, that idiot light (narrow band afr) doesnt mean ****
the last segments of the gauge just means you are 14:1 or richer
but on a semi high comp motor on spray you want to be way way richer then 14:1

you also mentioned you did a compression test on your car, when you did the compression test was the car at operating temps?
maybe i am reading it wrong but you mentioned that you had a reading of 90psi on all 4 cyclinders?
is that correct? if this is correct then chances are your motor is already done (possibly broken ringlands)
normal compression for a b16 should be 230ish psi on a healthy motor

last thing that came to me, if you are spraying you should be retarding your timing
 

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Discussion Starter · #7 ·
BlackCRX said:
dont attempt to adjust timing unless the motor is hot enough to a point where the rad fan comes on
once it comes on then do your timing, but dont do it when the fan is on as it changes the timing
check spark plug wire to make sure it is within specs, you might have a bad plug wire
after market agressive cams will be a bitch to set base timing with as well

you also mentioned you did a compression test on your car, when you did the compression test was the car at operating temps?
maybe i am reading it wrong but you mentioned that you had a reading of 90psi on all 4 cyclinders?
is that correct? if this is correct then chances are your motor is already done (possibly broken ringlands)
normal compression for a b16 should be 230ish psi on a healthy motor

last thing that came to me, if you are spraying you should be retarding your timing
first and i think the most important question, what type of EMS are you using? stock? crome, uber, etc..?
**stock

when you are doing the timing is the car nice and hot?
**Yes it is up to normal temp. I should note it takes an act of god to get my fan to come on. I have a full width (stock) radiator and my temp NEVER under ANY circumstances goes higher than a notch or two below half on the temp gauge. (which pisses the V8 guys off to no end).

do you have stock cams?
Yes.

as for the fuel, that idiot light (narrow band afr) doesnt mean [crud]
the last segments of the gauge just means you are 14:1 or richer
but on a semi high comp motor on spray you want to be way way richer then 14:1
**I thought about the possibility of doing something stupid when I bought it and went ahead and did it anyhow. This is in the winter plans to replace.

you also mentioned you did a compression test on your car, when you did the compression test was the car at operating temps?
**I tested both hot and cold. Pretty much the same readings.

maybe i am reading it wrong but you mentioned that you had a reading of 90psi on all 4 cyclinders? is that correct? if this is correct then chances are your motor is already done (possibly broken ringlands) normal compression for a b16 should be 230ish psi on a healthy motor
**Yes that is correct the are all in the 90psi range. I looked it up and it says the service limit is 190psi. Oddly enough, I noticed this long before the nitrous, the guy who was working with me said as long as the cyl. are all w/in 20% of each other not to worry about it. Was I misinformed?
 

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Like BlackCRX said if you are getting cylinder pressure readings of 90 psi your motor is going bye bye.
A healthy I4 should read right around the 200psi region.
IMO anything under 140 is getting really weak,and at 90 psi your motor is in need of new rings,or possible other internals.
Ever taken a vacuum reading at idle? 2K?
You have bigger problems than a timing issue.
Let us know what you find.
 

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Discussion Starter · #10 ·
Actually 95, 90, 85, 95 (1-4)

That actually explains why I got spanked so bad the first time out this spring. So what would be a better way to go, long block or rebuild?
 

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Well what is your budget would be a better question..
Another longblock B16 can get a lil pricey.
If it was my car I'd look at the option of tearing the motor down and letting a qualified engine shop look her over.You may only need a bore and rering.
I mean just cause the pistons are probably shot doesn't mean the heads junk..
If you decide to buy another motor let me know I'm looking for a nice B16 head.
 

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Discussion Starter · #12 ·
I don't know, I can find a long block (with shipping) for about 850.00 and I was up to 1800.00 just to do rings and pistons. (Majestic lists a gasket kit for 1200.00 alone). I can probably find a cheaper gasket kit but that was just a quick price list. Hmmmmmmmm
 

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Better yet get a b18 or B20 and do the LS Vtec option. Then you will have some great power. I would not spray the b20 however. I don't thinks its unusual to get a b20 long block for about 800 shipped.
At Hmotorsonline.com, a great place to get engines, the b18b longblock sells for 749 plus shipping and the b20 longblock 649. You would have to take you head off and make sure it is salvageable, but if you are still running I bet it is.
 

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Discussion Starter · #14 ·
So let's say I rebuild, what are the defining qualities of a nitrous engine? Most times all I see are more fuel, less timing and not much on what piston and ring combinations are best suited for nitrous.
 

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As for N²O....You can inject nitrous in moderation in a stock engine(properly metered).Id say no more than say 65 shot on a stock engine running premium fuel and retarding the ignition.Ok so maybe lets get a better fuel pump as insurance.

As for running a higher shot system...I'll defer to nitrous express knowledge.

"Generally, forged pistons are one of the best modifications you can make. Retard ignition timing by a few degrees. In many cases a higher flowing fuel pump may be necessary. Higher octane fuel may be required as well as spark plugs 1 to 2 heat ranges colder than normal with gaps closed to .025"-.030". "
Does this help?
 

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Discussion Starter · #16 ·
As I understand it...

50 shot, no changes needed
65 shot, retard timing 2º (total)
75 shot, retart timing 4º (total) and 1-2 step colder plugs.

The maximum 'shot' you can run on an engine would be 50% of rated output. So a rated output of 160hp (IE B16) that works out to an 80hp. The other common method is 20hp/cyl (20x4) -which is also 80hp.

When I set mine up I stopped at the 65 level. I had serious trouble with traction up through 3rd gear. Then I used the VTEC circuit to engage the NMU at the switchover point (~5200RPM) which all but eliminated my traction problems -except the 1->2 shift (as you may have noticed in the video). In a race situation I would get walked in first, then by mid track (1/8 mile) the car would come alive and would act like a turbo charged car.

So I guess if I do rebuild, forged pistons and moly rings? I'm not a huge fan of moly since it takes so long for break in. I already put in the high volume fuel pump and 2 step colder plugs. Then find out why my timing jumps so much and so on.
 
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