Just outta curiousity, what are some of the bigger cams that have passed emission testing. Not asking what is the biggest emission cam, just what has been passed even though they wasn't technically legal emission cams.

Reason for my asking is I have a 383 with AFR 190 heads, a Comp 218/224 112LSA hyd roller and all emission stuff still intact (dual aftermarket cats included). I have the TPIS Big Mouth base and will soon be going to a SuperRam plenum/runner (because it's the only aftermarket setup that retains egr).

I don't have to pass emission testing where I live but everyone around here automatically rips out the pollution stuff and I'd like to show them you can have a strong car and still be "emission legal" (spirit of the law). OK, so maybe it's not a "legal cam" but it still passes.

Anybody snuck a bigger that legal cam through testing and still passed?

Doug Gulley

 

LT4 Hotcam clocks in at 218/228 duration.

Live in NW IN so its a version of IM-240 on the dyno.

With a good tune I got it too pass emissions better than my next to factory stock 91 GTA :-)

Only item not on car was the egr because I do my own tuning and its pia to route to the vortec setup. I didnt want to cut and weld to the headers and fight something else in the engine bay.

later
Jeremy

 

Thanks for sharing that info. I was wondering if a cam of about 224/230 duration and 112/110 LSA could pass. I know the state of tune has a lot to do with it but I am still running the EGR valve, air tubes in the headers, and dual cats with the air tubes.

If your cam, which is about the same as the one I have now, passes that easily then it stands to reason that the 224/230 should pass even if "just barely".

Thanks again for the info Jeremy.

 

Well my opinion of cams is something I measure in the fact that I used to put 300+ miles a week on a hotcammed 350 vortec setup.

Also you begin to realize that when u are honest with yourself on what application the car will actually be used in :-)

I would imagine that your 224/230 choice will still idle very nicely in a 383 and should help the Superram out a little in the upper range when u swap it on.

The tune, the tune, the tune, will make it liveable or miserable, check out the prom board and learn what your doing :-)

My cam in my 383 is 216/222 w/ around .500 lift w/ 1.6 rr :-)

My compression is also a whopping 8.67 to one. This engine was built with boost in its future and cammed/rings/compression were set accordingly now, rather than later.

Im still betting on the fact I can get it into the 12's hooking well and running what toher people consider a small sissy cam here.

Before you laugh at what I am saying think about the 300 mile a week mark in I-80 traffic near Chicago and about the current price of gasoline and get back to me.

later
Jeremy

 

Good points. What you'd gain in horsepower wound't be worth the torque, drivability, and fuel mileage loss.

I have everything from Craig Moates to do my tuning/burning. I'll just make do with what I have now which isn't no slouch to begin with. With me being a truck driver learning how to tune this will take some time having only one day a week if that much. I'll get there someday.

 

My cam passed in California. Look at my sig. The 224-230 Comp Cam is close to mine. It will pass also. I heard the 230-242 Comp Cam pass in Cali too in a LT1 car. You just have to tune it with all the emission equipment hook up.

 

VincentZ28 that sounds like an awesome combo! Very simular to the same direction I'm headed except mine is a 383. Do you have any fuel mileage figures since I'm assuming this is a fairly streetable setup? Drivability?

I may take that one step jump in cams afterall.

 

About 280-300 MPG

 

wow i wish i got 280 mpg!!!

lol

 

Hey Vincent those are good time for your combo. Hehehe. Allen

 

Mine has a lobe of 114, 235/235, with 480/480 lift. I passed with flying colours first try. Didn't think that would happen, but not complaining.

 

My 383 SuperRam, with 10.5 compression and a custom Comp hyd roller (218/224 duration, 495/502 list @050, 112 LSA) just barely passed the dyno test here in TX. My proble item was the CO level - I was at the EXACT limit. Another .01 and I would have failed. My EGR appeared to be hooked up, but my heads aren't currently drilled for EGR. I suspect an AIR flow problem with that high of CO, but I'm no expert on this part of things....

 

It would be interesting to know what Vincent and vernw are running for the LSA on their cams.

 

It was 112LSA. I had Lunati to reground to 113LSA

 

Hopefully

 

Look again - it's a 112 LSA. Sorry I didn't make it clearer....

 

Yup vernw you're correct. I sure did over look it......sorry.

Doug

 

Hey, no problem, Doug! Hope I didn't come across harsh with that comment, sure didn't mean to!!!

 

No problem here, I appreciate the info

Doug

 

It all depends on your tune. I've passed in MI and TN with no cats on mild set-ups. 230-236 .604-.608 114lsa passed here in TN with cat and so did the LPE 219.

I have a 242-254 110 lsa cam that I need to tune with a 4 gas analyzer to pass because of the overlap. A 224 cam on a 110 lsa doesn't have alot of overlap, so it should pass with cats and a tune and with no cats with 'tricks'.