- Apr 21, 2005
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i need to know if 10:1 compression will pass emissiions.i am about to trade fro a stang with the compression and neeed to know if it will pass with the stock h pipe and no air pump
will 10:1 compression pass emissions.help
- Thread starter diponyou50
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- Apr 21, 2005
- 138
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crash
Founding Member
True. CR is not a determining factor, the TUNE is.
For example, if you have a dyno graph showing say 12:1, it should be OK.
Lean enough to not cause excess Hydrocarbons (Too much fuel), and not be too lean and cause excessive Oxides of Nitrogen (Not enough fuel).
Everything else they check for should be just fine.
For example, if you have a dyno graph showing say 12:1, it should be OK.
Lean enough to not cause excess Hydrocarbons (Too much fuel), and not be too lean and cause excessive Oxides of Nitrogen (Not enough fuel).
Everything else they check for should be just fine.
- Apr 21, 2005
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i dont have a cam and heres a list of stuff on motor
edelbrock perf intake
24 injectors
76 maf
ported heads 1.6 rockers
70 mm tb
headers
i herd that the air pump dosent do anything for smog anymore,and as long as it has the cats its all good.but i was mainly concerned aobut the compression
edelbrock perf intake
24 injectors
76 maf
ported heads 1.6 rockers
70 mm tb
headers
i herd that the air pump dosent do anything for smog anymore,and as long as it has the cats its all good.but i was mainly concerned aobut the compression
- Apr 21, 2005
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nosmatt
Founding Member
high NoX is from high combustion chamber temps, not neccisarily from being lean, being lean will sometimes cause a high chamber temp......unfortunately, unless your have access to a mustand dyno that can simulate load at steady state driving, you will never know your true a/f (aside from a WBO2).... rw dynos measure at WOT, well EGR is not used at WOT, thus ya know nothin from a dyno a/f reading....
i hope your egr is functional.......or there is no way to pass. EGR lowers combustion chamber temps at cruise, and thus reduces NOX emmisions......
i hope your egr is functional.......or there is no way to pass. EGR lowers combustion chamber temps at cruise, and thus reduces NOX emmisions......
nosmatt
Founding Member
diponyou50 said:
sorry, but i disagree.
the smog pump puts fresh air into the h pipe, and thus converters. the converters get hot, the un burned HC's get burned in the cats, UNLESS there is not enough O2 for cumbustion to occur........... no smog pump, with stang cats means not all the unburned HC's will be eliminated, and your tailpipe emmisions will be high.
newer, more efficient converters do not require additional air to be pumped in, but the old dogs on our cars certainly do.
- Apr 21, 2005
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how can i find some diagrams that can show me how all the smog stuff is connected.and how hard is it to connect the smog pump,and is it nessecary.any help please
CrazyCobra
New Member
9.7 to 1, e-cam, aluminum performer heads, 1.7 rockers, 75mm TB/EGR, 19lbs injectors @ 42-44psi, all emissions control devices installed and functioning. This passed with flying colours.
I would put the air pump back on.
stang22
Active Member
nosmatt said:
I thought the smog pump took "hot" air from the back of the heads and pumps it to the cats to help them heat up quicker, therefore burning more HC's?
Tim
Nopers.. The smog pump pushes fresh air into both the exhaust ports on your head AND into the exhaust system before the cats.. It only goes one way.. 
From what I remember, air is pumped into the heads only near startup for reduce cold-startup emmissions.. And fresh air to the cats all the time..
From what I remember, air is pumped into the heads only near startup for reduce cold-startup emmissions.. And fresh air to the cats all the time..
- Apr 21, 2005
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well i have all the stuff for the smog pump i just need to get it installed so im taking it to a mustang shop and theya re gonna do it.(i know i know i should do it but i have absolutly no place to work on it).
what about the egr?what do i have to worry about there
what about the egr?what do i have to worry about there
Michael Yount
Mustang Master
Biggley's pretty close as usual. I'd add - the air pump is the source of excess O2 that is required for chemical reactions in the exhaust stream that are catalyzed by the cats. The reactions convert enough HC, CO and NOx remaining from the combustion chamber burn into harmless H2O and CO2 to allow the vehicle to meet the emissions standards. So the air pump and cats work hand in hand.
The cats have to reach a certain temperature (light-off) to be effective. In order to allow them to reach that temp ASAP on a cold start up, the thermactor valves divert air injection (cold air/excess O2 from the smog pump) to the back of the heads which connect with the exhaust ports of each valve. This allows excess O2 to enter the exhaust system and still allows the cats to heat up as quickly as possible. Once things are warm enough and the cats are working, the thermactors divert the air/excess O2 directly into the cats. There are conditions when the air pump bypasses all or a portion of the air - and then virtually none gets injected.
The cats have to reach a certain temperature (light-off) to be effective. In order to allow them to reach that temp ASAP on a cold start up, the thermactor valves divert air injection (cold air/excess O2 from the smog pump) to the back of the heads which connect with the exhaust ports of each valve. This allows excess O2 to enter the exhaust system and still allows the cats to heat up as quickly as possible. Once things are warm enough and the cats are working, the thermactors divert the air/excess O2 directly into the cats. There are conditions when the air pump bypasses all or a portion of the air - and then virtually none gets injected.
Michael Yount
Mustang Master
...oh, one more thing--all else equal, higher static compression ratio increases cylinder pressures AND temperatures - increasing production of NOx. Be sure your egr and cats/air pump are there and working - you'll need them for NOx reduction.
wake
New Member
crash
Founding Member
Yup. EGR is a BIG player, and don't tune it rich (Best to have a flip switch, one race, one street)
You can go to high flow converters and be good too. CR HAS NO FACTOR... AS LONG AS YOU BURN ALL THE FUEL. (HC emissions). Most high compression engines do... That is the point after all. Heh!
Careful with the air pump.SOME (FEW) inspectors will know it should be there and at least LOOK operational... HINT HINT... So if you do a delete, you may want to get it dirty so it doesn't attract attention.
Yes, I am a licenced inspector (Expired when OK did away with inspections), along with all the rest of the crap in my head...
I DO NOT recommend "Running it through" unless you are confident. In TX, the machine is online with the DPS database, and you can get a fix it ticket, which means you will have 10-30 days to correct. Not always cost effective.
You can go to high flow converters and be good too. CR HAS NO FACTOR... AS LONG AS YOU BURN ALL THE FUEL. (HC emissions). Most high compression engines do... That is the point after all. Heh!
Careful with the air pump.SOME (FEW) inspectors will know it should be there and at least LOOK operational... HINT HINT... So if you do a delete, you may want to get it dirty so it doesn't attract attention.
Yes, I am a licenced inspector (Expired when OK did away with inspections), along with all the rest of the crap in my head...
I DO NOT recommend "Running it through" unless you are confident. In TX, the machine is online with the DPS database, and you can get a fix it ticket, which means you will have 10-30 days to correct. Not always cost effective.
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