Cam/emission?

JCSTTA

USAF
Joined
Sep 6, 2003
I currently have my car down for a timing chain and valve spring install. I have a edelbrock 204/214 cam that I am considering thowing in since I'm already there. My question is I failed emissions a few weeks ago and have to pass by July. How will cam effect things emissions wise? My failure result before were
HC
1.46
C0
11.1
C02
505.9
Nox
2.60

Only failed on the HC's

Imputs??
TIA
 
If the lobe center is close to stock, then you may be safe. I worry about cams with lobe centers higher than stock, because it creates higher cylinder pressures and may increase NOx. I noticed that cam is for non-computer controlled engines. What cam are you running now? If it is stock, and in good shape, you may just consider the stock unit. How close is the CO to passing, if it is on the high edge, you may be just a little rich and leaning the mixture out may be just enough to get the emissions to fall.
 
Lobe sep is 110 as were the factory is 107. I was wanting to replace it since I have a bad lifter or a bad cam. I already have the cam and new lifters so all I need to get is an intake gasket. how much would the difference of lobe seps change things?
I failed HC with a 1.46 passing was .8 passed everything else. FP was 44 with the line off so that didn't help any. Plus the guy got into boost on the accel test wich casued a spike.

TIA
 
Do you have room to raise CO (richen the mixture)? If you engine is running lean and you raise CO, HC will fall, CO will rise a little and NOx will fall. But if you are already rich, then raising CO will increase HC and decrease NOx. That is the reason (in the previous post), I asked if there was room to adjust CO (preferably higher). You need the remember that the 5 gases (HC, CO, NOx, CO2 and O2) work in a relationship and adjustments will affect emissions according to a stoichiometric graph.
 
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