Author Topic: Cam Options?  (Read 8569 times)

DEEJAY

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Cam Options?
« on: December 30, 2006, 04:34:13 PM »
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

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Re: Cam Options?
« Reply #1 on: December 30, 2006, 05:08:54 PM »
I don't believe that the off road cam was available other than over the counter.

GaryL

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Re: Cam Options?
« Reply #2 on: December 31, 2006, 03:34:46 AM »
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.
« Last Edit: December 31, 2006, 03:44:30 AM by GaryL »
Gary

Lemans Blue X33. DZ, M20, manual steering. Only BU code rear end is original.

Jerry@CHP

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Re: Cam Options?
« Reply #3 on: December 31, 2006, 04:43:22 AM »
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

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Re: Cam Options?
« Reply #4 on: December 31, 2006, 06:39:10 AM »
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 :)
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hotrod68

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Re: Cam Options?
« Reply #5 on: December 31, 2006, 06:39:10 AM »
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.
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Jerry@CHP

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Re: Cam Options?
« Reply #6 on: December 31, 2006, 04:22:29 PM »
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

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Re: Cam Options?
« Reply #7 on: December 31, 2006, 04:22:41 PM »
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):

'69 Z/28
Fathom Green
CRG

GaryL

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Re: Cam Options?
« Reply #8 on: December 31, 2006, 07:55:13 PM »
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.
« Last Edit: December 31, 2006, 08:08:15 PM by GaryL »
Gary

Lemans Blue X33. DZ, M20, manual steering. Only BU code rear end is original.

DEEJAY

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Re: Cam Options?
« Reply #9 on: December 31, 2006, 08:28:03 PM »
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

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Re: Cam Options?
« Reply #10 on: December 31, 2006, 08:30:39 PM »
Oh and by the way engine idles at 1300rpm.SWEET!

Jerry@CHP

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Re: Cam Options?
« Reply #11 on: January 01, 2007, 12:30:08 AM »
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

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Re: Cam Options?
« Reply #12 on: January 01, 2007, 06:25:19 AM »
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.
« Last Edit: January 01, 2007, 06:27:42 AM by RamAirDave »
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GaryL

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Re: Cam Options?
« Reply #13 on: January 01, 2007, 05:52:06 PM »
Gary

Lemans Blue X33. DZ, M20, manual steering. Only BU code rear end is original.

RamAirDave

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Re: Cam Options?
« Reply #14 on: January 01, 2007, 06:27:23 PM »
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
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JohnZ

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Re: Cam Options?
« Reply #15 on: January 01, 2007, 08:48:06 PM »
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

That's a 350 block, cast April 24, 1971, most likely furnished originally as a warranty replacement short block. Are you sure the heads aren't 3991492 (not 399942)?
'69 Z/28
Fathom Green
CRG

GaryL

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Re: Cam Options?
« Reply #16 on: January 01, 2007, 08:57:33 PM »
That sounds nasty. What SCR did you use? I have camshaft envy. ;)
« Last Edit: January 01, 2007, 10:52:52 PM by GaryL »
Gary

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RamAirDave

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Re: Cam Options?
« Reply #17 on: January 02, 2007, 12:27:48 AM »
Im guessing by SCR youre talking about static compression ratio  ???

Its built back all stock (except cam  ;) ) with the 11:1
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DEEJAY

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Re: Cam Options?
« Reply #18 on: January 06, 2007, 02:57:36 AM »
Will  pull pans on 1/6 and post correct #.Thanks for reply JohnZ.
                    DEEJAY

DEEJAY

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Re: Cam Options?
« Reply #19 on: January 07, 2007, 08:33:50 PM »
JohnZ......Pulled valve covers & you are correct.Heads are 3991492.
              Are you sure block is 350  with 3970010 casting?

JohnZ

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Re: Cam Options?
« Reply #20 on: January 08, 2007, 12:14:47 AM »
JohnZ......Pulled valve covers & you are correct.Heads are 3991492.
              Are you sure block is 350  with 3970010 casting?

Yes - that was its only volume usage (also used with a 3" crank for 302's).
'69 Z/28
Fathom Green
CRG

Flowjoe

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Re: Cam Options?
« Reply #21 on: January 11, 2007, 12:27:36 AM »
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    
When I first got my Z back in '84 I read about the offroad cam and when I rebuilt the motor in '85 I bought the Crane Blueprint version of the "140" cam and stuck it in (well , had the machine shop stick it in)...more lift, more duration..had to be better right?  With stock compression, stock exhaust manifolds and the stock intake and carb it sounded wicked at idle (everyone thought I was running headers)and at full throttle.  But boy oh boy did it suck fuel (jsut like Jerry said) and off the line it couldn't get out of it's own way (didn't help that the car had 3.07:1 gearing either)...and abolutely no vacuum at idle.  In '98 I changed the gearing to 3.55:1 and that made it more enjoyable to drive around.  In 2003 (after years of procrastination) I decided to crossram it...and read Wayne Guinn's books.  The crossram in combination with Stahl headers final made that cam wake up (Just as Guinn said...it is a package deal, it was all meant to work together)...now it runs very hard, is more enjoable to drive (except when cold) but still sucks fuel like nobody's business ;-)