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3/21/16 7:17pm - Original Message: 'Camshaft'
tb2k82ce Lifetime Member
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Lemon Grove, CA - USA

Vette(s):
1982 C3 Collectors Edition 44000 miles, sat in the sun most of it's life, My wife purchased it for me for fathers day in 2007 from her girl friend that had it for 19 years. It is on the road again. I'm retired but it is now my daily driver.

Joined: 10/17/2007
Posts: 2007
Found my 82 has a crate engine therefore as the wrong camshaft in it as the manufactures do not distinguish from a standard engine and a high performance Corvette engine.  If you can call a 205 hp engine high performance. This is causing me some California smog and some other issues according to a number of local corvette specialty repair shops in the area.
 
A repair shop I have all my other cars repaired at has made me an offer that if I bring my corvette in on April 10 he will replace the camshaft and lifters for me and all I have to do is pay what he pays his mechanics for about 10 hours of work.  Acually it is a better deal than that as he told me I could pay whatever I wanted.  Anyway between April 10 and April 15 is his really slow time normally. 
 
Ok I'm not an engine guy but I found through NCRS I found specifications for a GM# 14044613 camshaft:
intake lift= 0.410"
exhaust lift= 0.424"
intake duration= 316 degrees
exhaust duration= 320 degrees
 
Another corvette article provided this information:
1.      9.0:1 compression ratio.
2.      L83 had a high-performance camshaft which had: 
Lobe lift intake = .269"
Lobe lift exhaust = .276"
Valve lift intake = .403"
Valve lift exhaust = .415"
Duration of 202 degrees (intake)/206 degrees (exhaust)
Lobe displacement angle of 115 degrees
 
These are both close to each other and GM over 5 years listed 3 different camshafts that worked on this engine so the minor differences (I think they are minor) are understandable.
 
Now here is the problem I talked to a couple of people one was Northern Auto Parts and they said I needed a CS766 camshaft.  I was about to order it when I looked up the specifications  which are:
Cam Lift intake = .269"
Cam Lift Exhaust = .276"
Valve Lift Intake = .403'
Valve Lift Exhaust = .414
Lobe intake centerline = 115
Lobe exhaust centerline = 114
Separation angel = 114.5
 
Two questions, is the CS766 a replacement? And what difference will the intake and exhaust durations make as the NCRS specifications are different than the other article and from the recommended CS766 campshaft.
 


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3/22/16 12:02pm - Reply: 'Re: Camshaft'
Adams' Apple Lifetime Member
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Duncanville, TX - USA

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#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

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You dint list the cam duration nums for the last cam, so it's a little hard to compare with the OE stuff. I notice the info on the OE cam you found was from Joe Lucia over at NCRS. He is THE GM Parts guy, so his info can be taken as gospel...and usually is. However....the duration #s for the OE cam you listed(GM# 14044613) seem a bit high, imo. That's a pretty healthy spec for an L83 Crossfire engine. Normally, duration #s around 310-320 tend to create a pretty good "lope" at idle, and don't help create much idle vacuum.
Now then...if this is not a stock L83, and it apparently is not, then things change. IF....IF the cam you have in your engine now IS the one with those higher duration #s, then that can very well be why you're having trouble with the Smog cops.

What kind/brand of "crate" engine do you have, anyway? Is it supposed to be a stock replacement for the Crossfire, or is it something else?

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3/22/16 8:34pm - Reply: 'Re: Camshaft'
tb2k82ce Lifetime Member
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Lemon Grove, CA - USA

Vette(s):
1982 C3 Collectors Edition 44000 miles, sat in the sun most of it's life, My wife purchased it for me for fathers day in 2007 from her girl friend that had it for 19 years. It is on the road again. I'm retired but it is now my daily driver.

Joined: 10/17/2007
Posts: 2007
It was purchased by VIN number so it was suppose to be for a Corvette but after lots of people trying to make it work correctly one shop discovered it was not the correct camshaft. Do not ask me how they discovered that I have no idea. 
 
They also said they could get it to work they thought.  They did get it to smog.  Not trusting them I took it to a friend's shop and he came up with close to the same smog numbers they did.  So I know it was a good smog. 
 
But it still did ran poorly at idle.  I contacted the people that the engine was purchased from and they would not give me a build sheet for the engine.  They finally told me that they build the engine to fit in the "Standard" Chevy and it was not a Corvette specific engine.  I asked why they wanted the VIN and they failed to provide a good answer except that the vacuum was a little low and that was my issue if I took care of that everything would be great.  They also told me not to call back they were done discussing the issue.  
 
That leaves court but they have the engineers that will tell the judge that the engine would work and of course they will state they have been doing this for a long time and I'm the first complaint.   I know the routine I have been on both sided of court actions.  It is who has the best expert and the cost is not great enough none of the local corvette shops are interested. And besides I cannot really prove until I pull the cam if it is the correct one or not.  I'm also not sure changing the camshaft will answer my issues.

I know that the heads are most likely a little different not sure what issues this will cause.

I may not have any choice but to go to court.  I do have until May before the year is up and I can no longer go to court.

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3/23/16 12:33pm - Reply: 'Re: Camshaft'
Adams' Apple Lifetime Member
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Duncanville, TX - USA

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#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

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Otaaaay......that's a little more info! Most engine rebuild/reman places don't build engines for "specific"applications like that. They usually just build them pretty much all the same. They will tell you it will fit and work, but that doesn't mean it will work as well as the "correct" engine would. Since you have the Crossfire set-up(I assume you still do?), that kinda opens a new can-o-werms. Vacuum leaks are fairly common on those things, with the intake being the most likely to cause a problem.
The only way to know for sure what cam it has, or the specs on it, is to use a degree wheel, a dial indicator, and a piston stop(to find TDC). It's a big pita to do, even with an engine on a stand outside of the car. I would bet the people that did the engine buy cams in bulk, and use the same one on prolly all small block builds that use a flat tappet cam, with few exceptions. There is a major reman facility here in Dallas that I have been to many times, and I've seen how they work. It's possible(and very likely in most cases) that you could get a reman engine that has heads with the same casting numbers, but with two different valve sizes. I've gotten them like that before, so I know it's possible. It's also possible that the valve guides are shot...or at least one or two. The engine I bought for my 'Burban is a perfect example of that. With less than 600 miles on it, it started having a miss. By the time I finally got around to actually checking it out, it had a completely dead cylinder. The problem was a valve guide that was so messed up that you could actually move the valve around in the head(still assembled in the head) with your fingers. There was so much exhaust blowing past the guide that it literally melted the valve springs for that valve. It's a dang miracle the friggin valve keepers dint fall off, and drop the valve into the cylinder. By that time, my warranty had already expired, so I was stuck with having to fix it on my own dime.
 My point being, "new" don't mean diddly. Hope you can come to a conclusion on WHAT the actual problem is....that will be the only way to hold your own in court, if it comes to that. You'll have to be able to PROVE it was a faulty part/assembly on their part.

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Joel Adams
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3/23/16 2:35pm - Reply: 'Re: Camshaft'
F4Gary Gold Member
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Grapevine, TX - USA

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Joined: 8/26/2006
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I would think that someone like Comp Cams would have a nice CARB legal cam that would go in that engine and maybe even get a little more power out of it.

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3/27/16 6:50pm - Reply: 'Re: Camshaft'
tb2k82ce Lifetime Member
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Lemon Grove, CA - USA

Vette(s):
1982 C3 Collectors Edition 44000 miles, sat in the sun most of it's life, My wife purchased it for me for fathers day in 2007 from her girl friend that had it for 19 years. It is on the road again. I'm retired but it is now my daily driver.

Joined: 10/17/2007
Posts: 2007
From when I talked to the guy I'm sure it was just a stock engine that runs on the vast majority of Chevy small block.  That would include the heads.  My understanding is the Heads were also a little different.

So my question is replacing the cam with stock head is that going to help?

As far as the vacuum leak goes the shop has offered to smoke test my vacuum system for me. (by the way this would be a freebee.  I will take it down to them this coming week and get that done.  I will know where and if I have a vacuum leak in the system.  They did not have a smoke test system when I had my engine worked on it is something he purchased for checking BMW which have lots of vacuum leak cased problems also.

Again not being much of an engine guy would replacing the cam with the correct cam even with stock heads help or not?  A little help would be ok I just would not want to make it worse.


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3/27/16 9:18pm - Reply: 'Re: Camshaft'
Adams' Apple Lifetime Member
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Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

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Stock spec cam, or even one a little more aggressive, with stock heads should work fin. A lot of folks will use an RV type cam, to get a little more low end torque, without effecting emissions.

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Joel Adams
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4/1/16 10:04am - Reply: 'Re: Camshaft'
tb2k82ce Lifetime Member
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Lemon Grove, CA - USA

Vette(s):
1982 C3 Collectors Edition 44000 miles, sat in the sun most of it's life, My wife purchased it for me for fathers day in 2007 from her girl friend that had it for 19 years. It is on the road again. I'm retired but it is now my daily driver.

Joined: 10/17/2007
Posts: 2007
So the first thing I will do is get the vacuum smoke test done next week if no vacuum leaks are found work on getting a Cam shaft replaced if there are leaks get them fixed and see how it runs see if it passes smog. 
 




|UPDATED|4/1/2016 8:04:59 AM (AZT)|/UPDATED|


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3/28/16 5:43am - Reply: 'Re: Camshaft'
Sarge81 Lifetime Member
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WEST SENECA, NY - USA

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1981 Blue Ice Met. w/pearl ghost flames TKO500 5speed. LS1 Swap 3.45 Dana 44.

Joined: 12/3/2001
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A RV cam like Joel mentioned would be better for low end power. 
No matter what heads or more aggressive cam you put in a Cross Fire engine isn't really going to help a bunch. There are 2 things that work against you. 
One is the ECM. Non programmable one time burn "chip" in it. 
Two is the intake manifold. The ports around about 1/2 the normal size of a regular small block intake. That is why the engine drops power after 4000 rpm's. 

Too bad Turbo City in California wasn't around anymore. I remember many years ago they did a '82 Cross Fire build that was supposedly emission friendly. The car ran great and put out around 270 hp. 


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3/28/16 11:35am - Reply: 'Re: Camshaft'
Adams' Apple Lifetime Member
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Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Joined: 11/8/2003
Posts: 19457
Sarge81 said...The ports around about 1/2 the normal size of a regular small block intake.


Yup...biggest issue there is on the Crossfire....half the dang intake port is covered up on the heads. The Crossfire was an interim set-up to begin with....it was never intended to be used more than the couple of years it was. Once the TPI was released, the Crossfire was a dead issue for GM. The aftermarket is the only place that supports it at all, and the market is getting smaller every day.
So...considering the limited RPM range of the intake, I think an RV style cam would be a good choice...unless you do something about the intake to get more air into the engine.


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Joel Adams
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3/28/16 12:23pm - Reply: 'Re: Camshaft'
tb2k82ce Lifetime Member
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Lemon Grove, CA - USA

Vette(s):
1982 C3 Collectors Edition 44000 miles, sat in the sun most of it's life, My wife purchased it for me for fathers day in 2007 from her girl friend that had it for 19 years. It is on the road again. I'm retired but it is now my daily driver.

Joined: 10/17/2007
Posts: 2007
Again not an engine guy is the  CS766 an RV cam? Specs are at the bottom of my first post.  

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3/28/16 9:40pm - Reply: 'Re: Camshaft'
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Duncanville, TX - USA

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#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Joined: 11/8/2003
Posts: 19457
The Sealed Power CS766 cam is basically a "stock" replacement cam for 350 Chev engines in the 82-86 year model range...including the L83 Crossfire. It will work otay in your engine, assuming the rest of the engine is close to stock specs.

If you're interested, here's a really good article on Cam Specs, and what they mean. Thumbs Up


|UPDATED|3/28/2016 7:40:33 PM (AZT)|/UPDATED|


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Joel Adams
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3/30/16 1:05pm - Reply: 'Re: Camshaft'
tb2k82ce Lifetime Member
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Lemon Grove, CA - USA

Vette(s):
1982 C3 Collectors Edition 44000 miles, sat in the sun most of it's life, My wife purchased it for me for fathers day in 2007 from her girl friend that had it for 19 years. It is on the road again. I'm retired but it is now my daily driver.

Joined: 10/17/2007
Posts: 2007
Thanks I will read that article.  I did a smoke test on my engine vacuum system and that is a wonderful process.  We found some vacuum leaks that need to be fixed before I do anything else. 

I have to identify a switch and I will make a new post for that and I have to order a couple of parts and replace them.  Then we will re-due the smoke test and see where we are.

Thanks again for all of your help and this is one of the reasons this is the best forum on the web.


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3/31/16 1:22pm - Reply: 'Re: Camshaft'
F4Gary Gold Member
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Grapevine, TX - USA

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tb2k82ce said: Thanks I will read that article.  I did a smoke test on my engine vacuum system and that is a wonderful process.  We found some vacuum leaks that need to be fixed before I do anything else. 

I have to identify a switch and I will make a new post for that and I have to order a couple of parts and replace them.  Then we will re-due the smoke test and see where we are.

Thanks again for all of your help and this is one of the reasons this is the best forum on the web.


What is this smoke test you speak of?


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3/31/16 1:54pm - Reply: 'Re: Camshaft'
tb2k82ce Lifetime Member
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Lemon Grove, CA - USA

Vette(s):
1982 C3 Collectors Edition 44000 miles, sat in the sun most of it's life, My wife purchased it for me for fathers day in 2007 from her girl friend that had it for 19 years. It is on the road again. I'm retired but it is now my daily driver.

Joined: 10/17/2007
Posts: 2007
Smoke test is the greatest thing I have witnessed to find vacuum leaks. 

What is done is they plug this machine into the vacuum port on the intake manifold.  It pumps smoke into the engine that then goes throughout the system. Anyplace that there is a vacuum leak you see smoke even pinhole leaks are visible.

You have to block off the carb or in my case the two TBI's along with any place that normally air is sucked into the engine because a lot of smoke will come out of those area.  

I should have bypassed my check valve so it could have checked the complete vacuum system including the lights, wipers, etc.   I did not and will next time I do it.  The best part is it was free.  But even if it was not if someone is chasing down vacuum leaks or just want to make sure their system has no leaks then this would be a great test.

But I would prepare for it better.  One I would make sure I brought with me items to block of carb or TBI.  They used a rag.  I'm thinking a soft foam ball cut in half to push into the TBI's also the plugs I use to block the IAC intakes.  I would also make something to bypass the check valve so the complete system could be checked.

In my case I found:
the IAC leaked around the shafts really bad
A vacuum hose had a pin hole in it. 
Also the cruise control relay was open  (Not sure if this is suppose to be that way or not yet will have to find out.  I know that it opens up when you press on the break to disengage the cruise control)

The independent shop I have been taking my cars for over 15 years has one of these he purchased because he does a lot of BMW and Mercedes work.   He purchased this machine that does more than just smoke to help him troubleshoot them.  Those two manufactures have put vacuum systems in their cars that cause lots of trouble once the car is 6 or 7 years old.

Hope this helps explain it. 

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4/1/16 11:29am - Reply: 'Re: Camshaft'
Adams' Apple Lifetime Member
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Duncanville, TX - USA

Vette(s):
#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Joined: 11/8/2003
Posts: 19457
Smoke machines were developed to aiding finding leaks in Evap systems, but their uses are varied. They work well in finding water leaks around windows and such, too.
It's basically a container with a heating element, and small air pump. We use baby oil as the solution to heat, and create the smoke. The air pump pumps the  smoke under low pressure(usually less than 10psi) into whatever system is being tested for leaks. Pumped into the intake, the smoke will find it's way to even the smallest leak, and you can visually follow the smoke to the leak. Some oils have dyes to make the smoke more visible, but the normal color is white...fairly easy to see, in most cases. They can find a leaky gas cap quickly.
Good smoke machines will also have flow meters that tell how much of a leak is there. They're super critical in finding leaks in evap systems, where the manufacturer(and the EPA) can specify that a leak in the system not be greater than 1 psi per hour, or per WEEK....think aboot that.
You can find smoke machines on ebay for around $100....but those things look, and prolly are, dangerous. A real machine will set you back over $1000...which is why not a lot of places have them. We have two here at the shop....they get used regularly.

|UPDATED|4/1/2016 9:29:47 AM (AZT)|/UPDATED|


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Joel Adams
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
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