Being from Arizona we still have to deal with emissions! I wiped a lobe on my cam in my 402 bbc and want to go larger but don't know what to try? I know I can get a Crane H-272-2 through (it wiped the lobe) I really like the response here on the Lunati 280/288 but I know I will be pushing it. I am allowed 450 parts for the hydrocarbons. Has anyone had to try this or have any input? Parts that may need to be mentioned.....MSD digital 6, MSD billet distributer, 10.25 cr, air gap intake, edelbrock 750 for the street, headers, 2600 stall, etc. Motor is in great shape, not daily driven, want the lope, power,etc. but still need to be able to tune for emissions. Help Please!

Go with the 276/284 .515 lift on the intake/exhaust..221/230 @ .050 its a smaller version of the 280/288

I'm running a 454 with a Crane hyd 550/570 lift,296/306 adv duration, 236/246 @ .050, lsa 114. It has a very noticeable rumpity idle. My first emission test with this engine was remarkably clean. I ran a 750 vac with .090 holes in the primary throttle plates to allow me to close them a bit more giving more control to the mixture screws. I ran 68 jets and a 45 pv and 12 deg timing. Car actually runs reasonable well and gets decent gas mileage like this. Here are my results from this engine with about 50 miles on it.

idle 240ppm HC - 1.17% CO
cruise 74ppm HC - 0.77% CO

standards are 450 HC - 5.0% CO

I tuned this without the benefit of an exhaust analyzer. Had I used one I could probably improve this.

Bill70 I was wondering what you are running for a transmission. I know the manual/auto choice makes quite a difference with testing for emmisions. If you are running a auto what type of stall do you have and how "loose" is it at an idle. That is a pretty large cam and I am assuming the 114 lsa is what is allowing it to pass. Also do you like the power it makes (i.e would you put the same cam back in it?) Any help would be appreciated.

70ss
does arizona have classic vehicle plates or classic rod plates??like we do in nevada,if so you might want to check.i'm in vegas and just got classic rod plates.no yearly smog!!!!!!! only bad thing is you cant go over 2500 miles a year,and they had to do a one time inspection(smog)
have no idea how i'll get passed that 2500 mile thing. ;)
shane

I run a TH350 with a B&M 2400 converter. The cam was a recommendation from the machine shop. They build engine packages and this is the cam they use in their 'Pro Street" 454. The dyno results he showed me had a peak of 530 HP and about the same torque. They were using their shop prepped 781 heads. I'm using Edelbrock 6045 heads. The idle sounds mean while it's warming up. I think it smooths out a bit at full temp. It pulls from off idle to an accidental run up to 6500rpm. It's a pretty old design and to read some of the things I see here it would not be a popular grind. It has wide lsa and a not very agressive lobe. It would probably make a great nitrous or blower cam. I gotta tell ya I've been able to spin the rear 265/50/15 tires after going full throttle at 50 mph. I run a 3:55 with posi. If it had more torque I don't know what I would do with it. BTW, I do have historic plates on it but that doesn't mean much in AZ.

Yeah, but Bill, my old L88 motor was pretty tore up inside and a Crane solid was the cam used. It was mint. Could run it again. Bearings were shot, crank was cracked, etc etc.

So those 'old' grinds have very, very good durability IMHO. And that cam saw 7400 ** I think **.

For someone not chasing a certain performance goal, those gentle lobe , wide lsa cams are very street-friendly.

My car 'shakes' more at idle. OK ALOT more, with a modern hot quick ramp cam vs the old 114/LS6 type cam. Great balls of fire to be sure, but it's starting to feel too much like a racecar at idle. Don't like that.

I passed a 450ppm test just barely with a 12-1 468, 850dp w/80 jets square, torker single plane, 288/288 110lsa Erson solid cam lashed real tight.

I'd try the 280/288 if that's what you want for a cam. The 276 lunati should run well too, but may not have enough lobe for you. The H-272-2 has a 112 lsa btw..


Sounds like Bill70 has a BRE motor.