I have a '93 LT1 black on black 6-speed coupe that I've been working on. Engine runs real rough, sounded like timing was off, or the 'race cam' the guy I bought the car from installed was too radical. Smelled very rich also. I also checked the codes, there were a couple, but none that were engine related. Car is stock except the engine was overhauled 8,000 miles ago. It was overbored some (not sure how much) and an aftermarket cam installed. Also has a K&N filter setup.

I've got the engine pulled out, car had been sitting for about 2 years, engine bay was very dirty and had all kinds of leaves and junk in there. It will get a good cleaning!

I checked the timing, it is right on. Some of the plugs were very oily, which I knew was a bad sign Then I looked in the exhaust ports and noticed that some of them had lots of oil leaking from around the valve stem. The sparkplugs that are oily, match up with the valve seals that are leaking badly. I think that is what is making my engine run so rough. The oil soaked plugs probably aren't firing very well. Looks like some of the intake valve seals are leaking too, but its harder to tell on those.

I pulled the camshaft out and got some numbers from it, but can't find any info on it, there is no brand name on it. Here are the numbers I found: E40768(is on the oil pump end of the cam) and 773.CPC.BC.15(is in the front part of the cam, in front of the first lobe)

Does anyone recognize these numbers? How can I find out what type of cam this is (brand, specs, etc)?

Since I have the engine out and all apart, I plan to put in an LT4 Hotcam kit, and an MSD Optispark. I'm also installing a new clutch, the one that's in there is worn out. Unfortunately since I live in California, I can't install long tube headers , which I know would compliment the Hotcam kit well.

Any help would be very appreciated!

 

Do you know if a custom tune was done after the cam change? That could be a problem. When you install the HC kit you will need a tune so not a big deal. On a LT car longtubes aren't that big a deal, the exhaust is pretty good. Just make sure your cats are OK. A crappy tune can mess them up.

 

You can take to cam to a shop that has a computerized cam checker. They'd be able to give you many of the specs you'd need to ID it. It'll probably cost about $25 or so.

It then becomes the task of checking the camshaft company sites to see if any of their offerings match up.

Even if you can't find which company ground it, you'd be able to have all of it's characteristics to make comparisons with similar cams.

Jake

 

it looks like a gm cam number.. the last 3 of the part number are the first three in your first number ie. 773. so if it were a gm 847 that would be the first three numbers. at least that would how it was explained to me once. i tried searching but only found a cam that didn't show any specs. does theat cam look machined between the lobes or rough cast?

 

If it were a GM cam, wouldn't it have 'GM' stamped on it? If its a stock cam, then the guy I bought the car from lied to me. But it can't be the original cam, no way it has 120k+ (my odo says 123xxx) miles on it, looks hardly worn.

Here are some close-ups of my cam:

 

bump

 

I had a ZZ9 checked at a local machine shop. They did it while I watched and waited.

I highly recommend you have it checked. You really need to know what you're dealing with as a starting point. Say, down the road, you're considering a swap. Not knowing what you now have won't let you know which way to go in selecting a new one.

Money well spent.

Jake

 

For those that may also come across this and wonder what the answer is:

It can be found on:
http://www.thirdgen.org/techboard/te...disproved.html

305 G92 5spd / 350 AT
10111773*
.413 .428
202 207
114.5 (116/-116)

It is called a Peanut cam and is the stock standard GM cam for certain models, around 1990.

Hope it helps somebody.

Henk