so i'm in the middle of a cam selection for my HCI. i'm most likely just going to go with an e cam and call it a day. i know the e cam is "emissions legal" but i'm wondering how much lift i can have before it won't pass a snuffer? i was thinking of going for 1.7 RR on the combo to so yeah, would the extra .03 lift throw my lift too high for emissions? Some please explain!:SNSign:
lift/emissions
- Thread starter -=Red5.0GT=-
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darthcual
Member
srothfuss
Last night I stabbed the same guy 7 times in a row
The cam isn't the only piece that makes you pass emissions. Your engine needs to be tuned really well and have all of the proper smog equipment functioning....
Duration plays a big factor in emissions: Smaller duration means less 'scavanging.' Scavanging uses the exhaust vacuum to pull the intake mixture into the cylinder for better fill properties. At the same time, some of the intake mixture also comes out through the exhaust. This is what really hurts your emissions. So the less duration, the less intake mixture you can pull out through the exhuast.
Duration plays a big factor in emissions: Smaller duration means less 'scavanging.' Scavanging uses the exhaust vacuum to pull the intake mixture into the cylinder for better fill properties. At the same time, some of the intake mixture also comes out through the exhaust. This is what really hurts your emissions. So the less duration, the less intake mixture you can pull out through the exhuast.
vikingpower
New Member
Overlap between the intake and exhaust lobes is the biggest factor in the emissions quality of a cam, the bigger the overlap the more unburned fuel that gets into the exhaust (especially at idle)... You could probably get away with a bit more duration as long as the LSA is still pretty wide
18mustangs
New Member
vikingpower
New Member
18mustangs said::Word: Stock HO cam with 1.7s is still e-legal unlike the B cam with 1.6s!
I dont think the CARB Nazis would let you do that in a car that didnt have the HO cam as OEM equipment... such as swapping an HO cam into a Cobra... of course what they dont know wont hurt you, as long as you still pass the sniffer... Thank God I left SoCal this year, too much B.S!
Like mentioned above the major factor for emissions is overlap. You should be ok opening up the lift as much as you want, within reason (but I am making that judgement based upon theory not experience), so long as the increased lift does not mean that the early ramp rates are increased. Increasing the ramp rates in the early stages of lift could increase effective overlap.
If you ask companies like Comp Cams, Lunati, etc for a cam card on specific cams they will provide you with the valve timing events.
What are the valve timing events for the Ford E cam?
What is the overlap?
We should be able to use these specs to help determine how much overlap can pass emissions.
Does anyone have specs for other emissions legal cams?
If you ask companies like Comp Cams, Lunati, etc for a cam card on specific cams they will provide you with the valve timing events.
What are the valve timing events for the Ford E cam?
What is the overlap?
We should be able to use these specs to help determine how much overlap can pass emissions.
Does anyone have specs for other emissions legal cams?
18mustangs
New Member
The Crane website has some other e-legal cams, even under the Voodoo line. You might want to check that out.
Tim
Tim
It is my understanding that going to a 1.7 RR will effect mostly lift not duration and should pass emissions pretty easy if you have high output cats. I am not sure that the E cam is your best bet though. I am going to use my stock cam and Cobra RR from Crane with new balve spings. I think the stock cam is OK for me since I am going to stay with my stock heads and I have an SD car.
87gtconv said:
well i was going do use the stock cam but i'm getting a “new” short block too, so i figure why not cam it while i'm at it. plus i'm using iron gt40 heads and performer manifold so i figured the e cam would work will with them. the RR were an after thought. since i'm getting new heads i was thinking why not get 1.7 RR too. i'm still thing about the 1.7's right now, i might just go with 1.6's. since i'm in CA i just wanted to make sure the new engine would pass our emissions laws. i would hate to get it all together just to find out it wont smog and i have to change stuff out.
