Cam Options?

[DEEJAY]

I was told recently By previous owner of my car that there were 2 different cams
available in 1969 302 (street & offroad).Is there any truth to this?
2nd question....I pulled valve pan off passenger side of my 302 and found a couple
of casting #s(464669 &464670).Since I have a CEB block I wondered if these numbers
would help with proper identification?

[sam]

I don't believe that the off road cam was available other than over the counter.

[GaryL]

Remember, the 302 was built as a race engine from the factory. All the parts needed to be factory and available to qualify for Trans Am racing.

Per John Z as posted over at Team Camaro:

Standard 302 (30-30) cam, P/N 3849346
Casting #3849347
254 duration @ .050" (intake & exhaust)
.485" lift (with 1.5 rockers)
114 deg. lobe separation
Exhaust Max lift @ 116 deg. BTDC
Intake Max lift @ 112 deg. ATDC

First Design Off-Road cam, P/N 3927140
Casting #3927141
Intake 257 duration @ .050" (333 advertised)
Exh. 269 duration @ .050" (346 advertised)
Lift: .493" intake, .512" exhaust
Intake Max lift @ 108 deg. ATDC
Exhaust Max lift @ 116 deg. BTDC

2nd Design Off-Road cam, P/N 3965754
Casting #3965751
Intake 248 duration (324 advertised)
Exh. 267 duration (334 advertised)
Lift: .512" intake, .535" exhaust

(Thanks to Mark C.)

------------------
JohnZ

DEEJAY, are you saying the casting numbers are the heads? The casting numbers should end in 186 for a 1969 302 engine. And are you saying the engine assembly date suffix is CEB? Should be DZ.

[Jerry@CHP]

All of the factory built 302's that were installed in Z28s received the "346" camshaft.  There were actually two upgrade versions, but they had to be purchsed over the counter.

Jerry

[RamAirDave]

I think I found the same post last night in which you quoted, Gary.

I was doing some searching on TC about it since the Z Im finishing now has an NOS 140 cam in it.  Probably no good for regular driving, but has a wicked sound at idle, especially through the Gardner

[hotrod68]

The "30-30" solid cam was factory. The "140" cam was over-the-counter and a lot more radical, and it sounded TOUGH. There was the 2nd-design 140 cam that Gary posted. That's what we called 'em.

[Jerry@CHP]

Sometimes you can get the same sound out of the 346 cam if you tighten the valves down to about .022".  What we've found in our dyno testing research is that you lose cylinder pressure when installing a higher lift camshaft such as the 140 so there are trade offs.  Bigger is not necessarily better all the time.  The 140 uses a lot of fuel on the street too.

Jerry     

[JohnZ]

In order to identify your engine, we need:

Block casting number on driver's side rear flange
Block casting date code on pass. side rear flange
Stampings on the machined pad in front of the pass. side cylinder head

I don't recognize the 464669 and 464670 numbers - the head casting numbers and casting dates should be centered on the heads, and the format will look like the photo below (Corvette head, not Camaro):

[GaryL]

I think I found the same post last night in which you quoted, Gary.

I was doing some searching on TC about it since the Z Im finishing now has an NOS 140 cam in it.  Probably no good for regular driving, but has a wicked sound at idle, especially through the Gardner

Been following that one. How did you get 800 rpm idle? With full manifold vacuum advance I can not get that low because the vacuum drops and I lose the advance. Any chance of getting a sound clip?

I am changing my repro chambered system for the transverse system. I think it should sound a little crisper.

[DEEJAY]

Head casting # is399492(inverted)
Block casting (driver rear)  3970010
Block casting date (passenger rear)  D241
Front machined head pad   CEB1244
The 464669 numbers I gave are on the interior upper section of the factory alum. valvepans.
       Thanks for replys

[DEEJAY]

Oh and by the way engine idles at 1300rpm.SWEET!

[Jerry@CHP]

Once the distrubutor is set up with a short curve and light spring set on a Sun distrubutor machine, you're good to go.  Read the customer feedback on distributors on my website, www.z28camaro.com.

Jerry

[RamAirDave]

Been following that one. How did you get 800 rpm idle? With full manifold vacuum advance I can not get that low because the vacuum drops and I lose the advance. Any chance of getting a sound clip?

Good question...

When I was dealing with the idle/timing issue, I was able to get it settled in in the 800s according to the timing light.  I dont know exactly where its at right now, but doesnt sound to be too far away from that.

Considering that it doesnt feel like the brakes are getting much vac assist at idle, I would doubt that the vac advance (connected to the port on the carb base) is doing too much either.  Then again, I dont think it should be doing much, if anything, at that rpm anyway.

Idle sounds good, total timing is at 34*, so I figure I'll just leave well enough alone for now.

For a sound clip, I'll try to work something out.  It will have to be a short vid clip.  I'll see what I can do.

[GaryL]

This is what I did.

http://www.camaros.net/showroom/showphoto.php?photo=1204&cat=500&ppuser=11189

[RamAirDave]

Here's a 10 sec idle clip.  Timing light was showing around 750RPM.


http://s20.photobucket.com/albums/b217/RamAirDave/GoldZ/?action=view&current=GoldZIdle.flv