Less Compression = Mass. Emissons pass

03-06-2001, 10:39 PM

Is it true that that less compression (or running rich) equals less emissions? I'm trying to find a crank/piston/cam combo for a 393 stroker that will pass emissions test in Massachusetts with a set of BBK cat/H-pipe and Fuel Injection. Any advice would be appreciated!

MiracleMax · 03-07-2001, 01:18 AM

Well, high compression tends to promote the formation of Nox (oxides of nitrogen) as well as spark knock which tends to increase emmisions also. As far as running richer, that would also increase emmissions even though it might help to reduce Nox production (by simply cooling down the compbustion process).

Now if your emmissions tech guy isn't all that savy and thinks your hopped up 393 is a 302 it would probably fail by virtue of the fact that a 393 will produce a greater volume of pollution simply by being larger than the 302.

A better choice might be to run an oxygenated fuel or fuel supplement and bump the timing down so that the apparent compression ratio is lower delaying the onset of Nox production (if they do a high speed steady state load test under part throttle conditions where the combustion chamber is prone to high combustion temperatures and lean air fuel ratios)

dinomite · 03-07-2001, 03:47 PM

I posted this a couple days ago, an idea I had to pass emmisions is to remove a couple of injectors, can someone tell me if this would work, or what it would do? I would think that making your car into a v6 would create less emmisions, and I don't think it would hurt anything

rj_stang · 03-07-2001, 04:30 PM

I honestly don't think that that would work well. First of all it wouldn't run well at all will be very loopy. Which will cause alot of engine shake. Also if you remove the gas line to the injector you will still have pressure in the rail... it will just pi$$ gas all over the place. I don't advise doing this.

SmokeyDP · 03-07-2001, 04:32 PM

NJ has tough laws too. The cats on my H-pipe are bad for some reason(its stock and i only had the car for 8 months so who knows). I passed everything cept for NOX. I got a 1850 when i needed like 900 to pass I belive? The timing was set at 15 degrees and by retarding it to around 6 I was able to pass with flying colors. The car did run like crap though until I was able to get to a timing gun. Good luck!

------------------
1992 GT 5.0L Convertible
BBK Shorties
Flowmasters
All Power
Super Chip

03-07-2001, 06:03 PM

Thanks for the advice. Please keep it coming. As we all know these projects are very time and $$ consuming. I have to be able to drive this car on the street.

dinomite · 03-07-2001, 09:14 PM

Quote:

Originally posted by rj_stang:
I honestly don't think that that would work well. First of all it wouldn't run well at all will be very loopy. Which will cause alot of engine shake. Also if you remove the gas line to the injector you will still have pressure in the rail... it will just pi$$ gas all over the place. I don't advise doing this.

oh, i know that it would make for a rough running engine, but just do it long enough to pass. Also, i was saying remove the electrical conection to the injector, not the line.

mustang17 · 03-08-2001, 12:32 AM

I hope you can't pass. I don't want to meet your 393 stroker on the street!

I've been hatching a plan to pass if I make an engine change(not as big as yours) or rid my car of cats.

If you are friendly with a mechanic and have some mustang friends who can help out that's all you need.

You have to get a mustang that had the same motor that your car did stock. I'm assuming a 302.

Hook up that car to the tester and have the mechanic scan the VIN from your car.

Get yourself the quietest exhaust around. If this car sounds like thunder rolling down the street the machanic may be afraid to help you. This could be his A$$ if you get busted.

------------------
1995 GT Black sleeper
Edelbrock 6037 heads,Edelbrock proformer intake,Edelbrock cam, 70mm TB,75mm pro-m mass air,Taylor wires, Underdrive pulleys,Equal length headers,K&N filter
Flowmaster cat-back, Eibach pro rate springs
lower control arms
3.73 gear Centerforce clutch

[This message has been edited by mustang17 (edited 03-08-2001).]

Unit 5302 · 03-08-2001, 06:35 PM

I don't know about there, but here emissions is measured in ppm or %. The more exhaust flow, the more emissions that would be acceptable. Otherwise a big *** 8.0L Dodge Viper would NEVER pass.

Displacement has nothing to do with the emissions factor.

As far as passing, it's hard on the car for a few miles, but dump a 2-3 bottles of "ISO-HEET" or isopropyl alcohol (fuel line deicer) into your tank at a nearby gas station. Drive a block to the emissions testing facility with very little gas in the tank and test your car. Then fill your tank back up on your way out after passing. Fill it again as soon as there is enough room to put some gas in. Take it easy on the car until you're sure all the alcohol has cycled throught the system.

Iso-alcohol doesn't make any emissions, burns super clean, it's just hard on your EFI systems and cylinder walls due to lack of lubrication. Just don't run it for very long like that and you'll be fine.

03-08-2001, 07:39 PM

Thanks for the advice guys!
Ford guys are the best! Too bad this whole town is full of guys that so stupid stuff like restore a 40's Ford coupe and put bowties in em.

Well here's the story. I had a 87GT with no cats and a friend of mine told me to drive to the next town where a shop was and tell them that I know a certain person. I did, and the guys response was "Well, all I know is that you got a set of exhaust for Monday thru Thursday. And a seperate set for Friday through Sunday" He pulled the car in, we talked, and he slapped a sticker on her. But I didn't need to dyno it due to the year of the car. See, every other year we need to get dyno'd depending on if the year your car was manufactured was odd or even. This year it's time for the odd numbered and I have a 93. I called the shop before I got knee deep into this project and he told me to just come up when the car was done. But you never know how things change. Do you think I should remove the parachute before I go up (because it covers the license plate)?? Any ideas on how I could mount the license plate and still be able to run a light for nighttime riding?
Should I run an AOD or C4 tranny??

mustang17 · 03-09-2001, 12:34 AM

Unit 5302- They do enter your engine size into the computer(of the car stock). I was thinking that if you hooked up a four banger or v6 to the dyno it would have a lot less emission than a 302. Maybe this would trigger something in the state computer system? I'm paranoid about this stuff.

So would it even matter what type of car I used as the "dyno car"?

I thought that a honda(or other small displacement) would easily pass and mustangs and others would struggle by. Is this just a myth?

03-06-2001, 10:39 PM	#1
stroker393 Guest Posts: n/a	Less Compression = Mass. Emissons pass Is it true that that less compression (or running rich) equals less emissions? I'm trying to find a crank/piston/cam combo for a 393 stroker that will pass emissions test in Massachusetts with a set of BBK cat/H-pipe and Fuel Injection. Any advice would be appreciated!

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03-07-2001, 01:18 AM	#2
MiracleMax Registered Member Join Date: Apr 1999 Location: Hayes, Va, USA Posts: 798	Well, high compression tends to promote the formation of Nox (oxides of nitrogen) as well as spark knock which tends to increase emmisions also. As far as running richer, that would also increase emmissions even though it might help to reduce Nox production (by simply cooling down the compbustion process). Now if your emmissions tech guy isn't all that savy and thinks your hopped up 393 is a 302 it would probably fail by virtue of the fact that a 393 will produce a greater volume of pollution simply by being larger than the 302. A better choice might be to run an oxygenated fuel or fuel supplement and bump the timing down so that the apparent compression ratio is lower delaying the onset of Nox production (if they do a high speed steady state load test under part throttle conditions where the combustion chamber is prone to high combustion temperatures and lean air fuel ratios)

03-07-2001, 03:47 PM	#3
dinomite The Dude Join Date: Feb 2001 Location: Arlington, VA Posts: 1,262	I posted this a couple days ago, an idea I had to pass emmisions is to remove a couple of injectors, can someone tell me if this would work, or what it would do? I would think that making your car into a v6 would create less emmisions, and I don't think it would hurt anything

03-07-2001, 04:30 PM	#4
rj_stang Registered Member Join Date: Jan 2001 Location: Villa Park, IL Posts: 36	I honestly don't think that that would work well. First of all it wouldn't run well at all will be very loopy. Which will cause alot of engine shake. Also if you remove the gas line to the injector you will still have pressure in the rail... it will just pi$$ gas all over the place. I don't advise doing this.

03-07-2001, 04:32 PM	#5
SmokeyDP Registered Member Join Date: Jun 1999 Location: Middlesex, NJ Posts: 212	NJ has tough laws too. The cats on my H-pipe are bad for some reason(its stock and i only had the car for 8 months so who knows). I passed everything cept for NOX. I got a 1850 when i needed like 900 to pass I belive? The timing was set at 15 degrees and by retarding it to around 6 I was able to pass with flying colors. The car did run like crap though until I was able to get to a timing gun. Good luck! ------------------ 1992 GT 5.0L Convertible BBK Shorties Flowmasters All Power Super Chip

03-07-2001, 06:03 PM	#6
stroker393 Guest Posts: n/a	Thanks for the advice. Please keep it coming. As we all know these projects are very time and $$ consuming. I have to be able to drive this car on the street.

03-08-2001, 12:32 AM	#8
mustang17 Registered Member Join Date: Sep 2000 Location: Concord, MA, USA Posts: 264	I hope you can't pass. I don't want to meet your 393 stroker on the street! I've been hatching a plan to pass if I make an engine change(not as big as yours) or rid my car of cats. If you are friendly with a mechanic and have some mustang friends who can help out that's all you need. You have to get a mustang that had the same motor that your car did stock. I'm assuming a 302. Hook up that car to the tester and have the mechanic scan the VIN from your car. Get yourself the quietest exhaust around. If this car sounds like thunder rolling down the street the machanic may be afraid to help you. This could be his A$$ if you get busted. ------------------ 1995 GT Black sleeper Edelbrock 6037 heads,Edelbrock proformer intake,Edelbrock cam, 70mm TB,75mm pro-m mass air,Taylor wires, Underdrive pulleys,Equal length headers,K&N filter Flowmaster cat-back, Eibach pro rate springs lower control arms 3.73 gear Centerforce clutch [This message has been edited by mustang17 (edited 03-08-2001).]

03-08-2001, 06:35 PM	#9
Unit 5302 Registered Member Join Date: May 1999 Posts: 5,246	I don't know about there, but here emissions is measured in ppm or %. The more exhaust flow, the more emissions that would be acceptable. Otherwise a big *** 8.0L Dodge Viper would NEVER pass. Displacement has nothing to do with the emissions factor. As far as passing, it's hard on the car for a few miles, but dump a 2-3 bottles of "ISO-HEET" or isopropyl alcohol (fuel line deicer) into your tank at a nearby gas station. Drive a block to the emissions testing facility with very little gas in the tank and test your car. Then fill your tank back up on your way out after passing. Fill it again as soon as there is enough room to put some gas in. Take it easy on the car until you're sure all the alcohol has cycled throught the system. Iso-alcohol doesn't make any emissions, burns super clean, it's just hard on your EFI systems and cylinder walls due to lack of lubrication. Just don't run it for very long like that and you'll be fine.

03-08-2001, 07:39 PM	#10
stroker393 Guest Posts: n/a	Thanks for the advice guys! Ford guys are the best! Too bad this whole town is full of guys that so stupid stuff like restore a 40's Ford coupe and put bowties in em. Well here's the story. I had a 87GT with no cats and a friend of mine told me to drive to the next town where a shop was and tell them that I know a certain person. I did, and the guys response was "Well, all I know is that you got a set of exhaust for Monday thru Thursday. And a seperate set for Friday through Sunday" He pulled the car in, we talked, and he slapped a sticker on her. But I didn't need to dyno it due to the year of the car. See, every other year we need to get dyno'd depending on if the year your car was manufactured was odd or even. This year it's time for the odd numbered and I have a 93. I called the shop before I got knee deep into this project and he told me to just come up when the car was done. But you never know how things change. Do you think I should remove the parachute before I go up (because it covers the license plate)?? Any ideas on how I could mount the license plate and still be able to run a light for nighttime riding? Should I run an AOD or C4 tranny??

03-09-2001, 12:34 AM	#11
mustang17 Registered Member Join Date: Sep 2000 Location: Concord, MA, USA Posts: 264	Unit 5302- They do enter your engine size into the computer(of the car stock). I was thinking that if you hooked up a four banger or v6 to the dyno it would have a lot less emission than a 302. Maybe this would trigger something in the state computer system? I'm paranoid about this stuff. So would it even matter what type of car I used as the "dyno car"? I thought that a honda(or other small displacement) would easily pass and mustangs and others would struggle by. Is this just a myth?