JakeL

Seems like general knowledge is that about as big as you can go and still pass emissions on a 346 is with a 224/224 on 114 or thereabouts.

My question is, since a large motor, say, a 427, with that size a cam will idle like a stock car, if you threw in a ~230/230, which is still going to idle smoothly, would that have cleaner emissions, or is the quality/cleanliness of a car's emissions not directly related to its idle quality (I'm assuming there's efficiency of fuel burning or something issues related to bad idles because of big cams...etc etc)

Sorry if it's an unwittingly stupid question, or has been asked before. Friend of mine is building a blown 382 stroker, and doesn't want to go bigger than his 220/220 XE-R on 114 because he's worried about emissions tests (Colorado tailpipe sniffer), but he wants to hit 600whp, and we're not sure if he can do it with that cam? (I've seen folks run 220/226 ande 224/236 with good results on blower cars, but dont' kknow about the emissions implications)

Cheers!

-Jake

Colonel

Yes.

JakeL

Not a bad guess then

Any guesstimates on how much larger a cam one could run in a 382, versus a 346, and still expect to pass most emissions tests? If a 224/224 works, then perhaps something in the 226/226 or 228/228 range?

As a corollary question, how would a 220/226 compare on emissions to a 224/224. It is a question mostly of overlap?

-Jake

WhiteDiamond

Jake,

I know the TR224 cam on 114 degrees passes the Colorado test easily in a 346ci LS1. I think your friend should be able to go a small percentage bigger on the cam for a larger CI. Either way, it would be wise to get full overlap numbers for the cam before choosing.

Todd

Bowtieman4life

iTrader: (1)

From what I have read, its 6 degrees of duration for every 50ci but watch the overlap.

Reboot

iTrader: (5)

I would think a 228/228 114LSA would pass in a 382 or bigger. This cam has 0 overlap so it should pass.

JakeL

Todd - whereabouts in Colorado are you? Do you still have your TR224/114 cam? I'd love to take a listen if so - drop me a line

-J

WhiteDiamond

Jake,

I sold the WS6 with the MTI B1 cam a while back and went back to school. You couldn't tell I had a cam in the vehicle, though, as it idled very smooth at 900rpm(Steve Cole did the PCM tune on it). A buddy of mine down here has a WS6 with ARE heads and a bit bigger cam. You can tell his is cam'd. I'll have to ask him if he has tried emissions in it.

I know somebody that ran a emissions test on the TR224 cam and its numbers beat the Colorado sniffer specs. There is a guy in Denver that had the MTI 422 engine put in a C5 Vette and it also passed the sniffer test. I believe he had the R1 cam in that motor. Maybe you could "recommend" something along the lines of the 228 cam mentioned above. With little overlap and 114 degree, it should run nice with FI. Depending on the head flow numbers, your buddy could consider something with some more exhaust duration as well.

Todd