TomP

I was reading the PAW catalog last night, and noticed the Compucam has the <3> emissions label next to it. That means it's an off-road-only cam, as far as emissions legality! I thought the cam was emissions friendly... no?

Would there be any way to compare the Crane Compucam's specs to the stock specs, and determine if the aftermarket one would pass emissions?


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
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RenoLB8

Everyone seems to have them, (heck, I thoguht you did, Tom), and noone's complained about emmissions yet, just don't put a Crane stiocker under your hood, and they shouldn't know the difference.

I'd be curious too as to what our stock specs are...

-Reno

Jason E

I'm glad you brought that up, because a Crane cam was gonna be the heart of my rebuild ARGH!!!!

I had a feeling it might not be legal, even though I too thought Crane guaranteed them legal!!! Although, with emissions standards giving you a fair amount of fudge room (assuming your car is in fine shape and tune), you can probably pull it off anyways. I mean, my car registers BARELY above 0 on both emissions requirements.

With my luck though, I'd have the engine rebuilt, I'd put it in and the damn emissions would go through the roof

3.1 firebird

I cant pass emissions! I;ve tried twice now! I went to the muffler shop yester day and had a tube welded to my headers so my SMOG pump is functional again,,,, maybe that will help?? I also plan on doing a tune-up oil change/PVC/clean air filter/ and retarding my advanced timing/ adding some pass emisions to the gas and praying it passes this time.

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Modified 3.4 Pacesetter headers,Crane 2020 cam,K&N cone, cat-back ,shift kit,pulleys,3.73's(openrear)
16.18@85.6 and 16.09@83.7

TomP

Ouch! Dude that blows.. do you have to run your car on the dyno, or do they just do the sniff test when your car's idling?

Here's what I did to pass the dyno-test this past January 2000; keep in mind the car gets a major tuneup every year...

Mid-December 1999:
Bought a new $7 K-mart air filter

End-December 1999:
1. Replaced my computer's ADS Street Chip with the original GM chip.
2. Replaced my 160 degree thermostat with a 195 degree one.

Mid-January 2000 :
1. Carefully removed all the carbon tracking that had built up on the
terminals inside my distributor cap. I used a small, fine-tooth metal file
for the initial scraping, and followed that up with a very light sanding
with 400 grit paper.
2. Sprayed a half-can of "throttle body and intake cleaner" (from my tuneup
page) into the engine.
3. Covered 1/3 of my radiator with a piece of cardboard to help the engine
run a bit hotter.

Weekend before going for the test:
1. Dump a bottle of "Guaranteed to Pass (your emissions test)" into the gas.

I passed so well my mechanic was amazed at how low my numbers were! I should asked him for the printout, dammit, but I was so happy to get back in my car and get the heck outta there!

The smog pump might help you pass; it shoves clean air into your exhaust pipe, which dilutes the emissions a bit. Did the place tell you how far you were off by?


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
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TomP

Oh and Jason that's what I was worried about: Rebuilding the whole engine with this cam, and finding out I can't pass emissions!

I'm hoping my GM service book gives some cam specs; but I doubt it will. I've looked in that 2.8 section a few times to see specs, and they've been missing. Funny thing too, those cams at that "GM Performance Parts" website ( http://www.spoperformanceparts.com I think? ) are made by Crane. I bet they're the same grinds as the Compucams... I should check the specs.

There's also the thought that my 208k mile motor would benefit from a new factory cam. I'm sure the lobes have worn down a bit- but as I recall your motor's not scratching 70k miles yet; your original cam's probably in great shape.

Sigh...


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
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CC_HotRod

Tom the cam specs that my chilton give for an '86 are:
Jurnal Diameter (in.): 1.8678-
1.8697
Lobe Lift:
Intake: 0.263
Exhaust:0.273

Bearing Clearance (in.): 0.0010-
0.0040

TomP

Part of the mystery's solved... the Summit catalog shows a big 'ol "50 state legal" next to all the Crane Compucams. At the bottom of the part listing, it says "these have earned CARB E.O. #'s blah blah blah"- I checked up on those #'s at the list of EO #'s at http://www.arb.ca.gov/msprog/aftermkt/aftermkt.htm - seems a "few" of the Compucams have earned #'s, mainly dealing with the Ford & GM v8 motors. (sigh) I'll try to dig up some cam comparisons over the weekend...


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
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TomP

Well, here's another oddity.

The FAQ at thirdgen.org on Camshafts says that the higher the # for lobe separation, the better the vacuum/idle and driveability.

The Crane cams have low lobe sep#'s! The first one, the 2020 grind (#254112), has 104 degree sep. The second one (2030 grind #254122), has 109 degree lobe separation.

Both the GM High-Po (made by Crane!) cams at http://www.spoperformance.com have higher lobe #'s. They both list as 114 degrees.

I found a place called Accelerated Motion, in Canada. They have their own 2.8 camshafts, but what's great is, they list what I think is the stock cam spec! Here's the link: http://www.amotion.com/amcams.html#19661 (Remember to use the HO cam specs; HO = MPFI injection. Stock = 2bbl carb'd.) If these are really the stock cam specs, then stock for our computers has a 108 Lobe Separation.

So, it would seem as if the Crane 2020/2030 aren't far from the "stock" separation. BUT! Why the heck are the GM Hi-po ones listed at 114 degree sep?

Could it be the stock one at Accelerated Motion is a Canadian export cam's specs, different from "normal" United States cams? Although, if it's different than US cams, why are the lift figures the same as what CC_HotRod listed?

(Oh, to turn CC_HotRod's lift #'s into useable #s, multiply them by 1.5- that's the ratio of the rocker arms. So the 0.273" exhaust lift turns into 0.410" of "final" lift.)

Anybody have any thoughts? Or, does anyone know where to dig up another set of specs for the "stock" GM Cam? (Remember, look at the "H.O" cam at that Accerlated Motion site, HO = MPFI injection!)

Man what a pain in the *** this is; I'm considering getting a stock GM cam and 1.60 radio rockers for the rebuild!


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
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Jason E

You may just want to consider doing that...a stock cam should certainly feel better than a 208k mile one!!

Yeah, I have only 87k on my car, so needless to say other than the somewhat-leaky valve seals that contribute to using 2 quarts in 3k miles, it runs perfect! You'd probably be surprised Tom how much your cam is worn...my friend replaced the cam in his '82 267 Impala, and the lobes were gone with 135k miles! That's why I'm always shocked by the 1/4s you run with a 208k mile engine!! How your pistons don't end up sitting in the oil pan, I still don't know...lol.

3.1, did you bring it back yet? I gotta think hooking the smog pump back up will help. Was it way outta whack the 1st time?

3.1 firebird

I havent taken it back in yet. The only thing it failed was hydro carbons.

Someone told me to get something called dry gas....have you heard of this?

Jason E

Hehe...you ain't from up north are ya??

Dry gas is an additive that's supposed to take the water out of gasoline, and nothing else. Someone else can better tell you what the composition of dry gas is, but I know when someone is concerned about condensation getting in their gas tank in the winter, they throw dry gas in after they fill up. I've never had a problem with my car hesitating in the winter, so the only time my car has ever had it were those WONDERFUL winters where it was under wraps for 4 months.

Jason E

2 corrections to the last post

1) You add dry gas (its a liquid BTW) BEFORE you fill up so that the stuff mixes throughout the gasoline as you fill the tank up.

2) It will do NOTHING for your emissions...tell the guy that said that to you that a freezing pain in the a*s from MA said he's full of it

All dry gas does is take water out of your gas and keeps your car from running rough with bad gas. It will not clean anything to help your emissions!

TomP

I figure I'll find out how much my cam's worn when I pull this 2.8 out... I plan to buy one of those dial-indicator gauges (specifically http://www.penntoolco.com/catalog/te...milyID=P25441J ), and I'll check out my cam's lift with the motor out.

I think this cam issue is going to have me calling a few of the companies. I checked out the "Cam Spec Card" at cranecams.com for the 254122; and it lists two different lobe centerlines (of course) for intake & exhaust. It makes me wonder how they got the lobe separation #! Maybe I shouldn't concentrate on the seperation angle, and just worry about the centerlines? Argh. Oh here's the spec card: http://www.cranecams.com/cgi-bin/spe....htm&id=254122

The bottom right, there's two numbers, one on top of another. You read the two lines as the top one's for intake, bottom is exhaust. Intake's 105, Exhaust is 113. Now I'm not sure if these equate to anything regarding lobes... hm. And this was supposed to be an easy choice!!


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
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Jason E

Well, I'm eager to find out what you can come up with!! I'll be honest...I know little about cams. Good luck with what you find out.

I hope someone can get a 2030 to pass a sniffer before I do a rebuild in another 2 years or so. If no one has passed the sniffer by that point, I'd be better off going with a stock cam

TomP

If only we had carbeurated v8's; a cam swap would be cake. I wonder if it'd be smarter to get a stock cam, and then get 1.52 or 1.60 rockers? Gross valve lift would increase... for our stock cams, lobe/1.50/1.52/1.60 gross valve lift would be:

Intake: 0.263 lobe, 0.395/0.400/0.421
Exhaust: 0.273 lobe, 0.410/0.415/0.437

Of course the 1.52's probably don't increase emissions, but I'm sure the 1.60's do... and who knows about the driveability of the 1.60's...


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
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