I have plans for restoring a '69 Z-28 with the DZ302 small block. I have read and heard quite a bit about the lack of bottom end torque from the 302 and the great rush of top end power. Since camshaft technology has greatly advanced in the last 32 years, do anyone have an opinion on a replacement cam which could improve the low end of this motor and not sacrifice the high end? I'm planning on keeping the original 186 heads and the 11:1 compression (looking into piston coatings and other tricks to make it work on 92 octane!).

Thoughts?

Thanks in advance,

ICamaro

I am not sure if the 69 302 is a large journal block or not (never messed with them), but if it is, the easiest, best way in my opinion to gain a LOT of torque at lower speeds would be to swap in a crank from a 350. The short stroke crank and the cam specs are the 2 biggest reasons that 302's have no torque. Plus, the crank job would be totally hidden. That 30-30 cam sounds awesome in a 350! I would consider dropping the compression a bit for either engine...11-1 is possible with pump gas but thats really pushing it...you have to stay on top of the tune at all times, and you'll have little or no saftey margin for stuff like a tank of bad gas.

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375hp 78 Chevy truck
77 Chevy Nova
95 Chevy Lumina 3.4L
and building a 78 Nova

You must remember that a 30-30 cam was made for a 1964 vette. Thats over 35 years ago there are definately better designs on the market. Try calling the cam companys and see what they recommend.

My friend got Crower to do a custom cam for his 69 Z/28. It has a little more torque, but otherwise you would not know it was not a 30-30 cam.
It has plenty of top end too! http://www.camaros.net/forum/smile.gif
David

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Check my web page for First Gen Camaro suspension info:
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67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Chev 350 Can-Am Vintage Racer

I'm running a comp cams 294s in my 327 w/4speed it works well I think it would be a good replacement for the 30/30
MIKE

The 1970 LT1 cam would be a good solid choice!!

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...Dennis
'69 RS Convertible w/SS trim (http://www.camaroslimited.com/memberscars/den.htm)
'96 Z28SS #1679 of 2410 (http://www.camaroslimited.com/graphics/memcars/96ss.jpg)
"The Club" (http://camaroslimited.com)

Dennis,
That cam was designed to help the 302 build more low end. But it wound up in the LT1 when the 302 was discontinued.

I bought an LT1 with that cam and drove it for many miles.
I later changed to a mild Crower cam and it had a LOT more low end and better top end too.

The factory cams seem to "come on" at 4500 and up.
The Crower I used came in good at 2500 and just pulled and pulled all the way up to 7000 in my 350. I guess my point is, you can buy a better cam nowadays that will run better on a street engine.
David

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Check my web page for First Gen Camaro suspension info:
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67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Chev 350 Can-Am Vintage Racer

The DZ 302 has a large Journal Crank. If you wanna have a fun street car you need at least a 350 crank. You can get alot more Torque that way but it won't be able to wind as high. 95% of your fun is in using the torque anyway.

<BLOCKQUOTE>quote:</font><HR>Originally posted by davidpozzi:
Dennis,
That cam was designed to help the 302 build more low end. But it wound up in the LT1 when the 302 was discontinued.

I bought an LT1 with that cam and drove it for many miles.
I later changed to a mild Crower cam and it had a LOT more low end and better top end too.

The factory cams seem to "come on" at 4500 and up.
The Crower I used came in good at 2500 and just pulled and pulled all the way up to 7000 in my 350. I guess my point is, you can buy a better cam nowadays that will run better on a street engine.
David
<HR></BLOCKQUOTE>

Do you have the specs on the LT1 cam David? I know it's a dual pattern .465(I) .485(E) lift but is the duration about the same as the 30-30? In the 70 Z/28 the LT1 was rated 360hp and other than the cubic inches and cam I believe it was the same as the DZ...

My thinking was it would keep the DZ sound but make power sooner!!

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...Dennis
'69 RS Convertible w/SS trim (http://www.camaroslimited.com/memberscars/den.htm)
'96 Z28SS #1679 of 2410 (http://www.camaroslimited.com/graphics/memcars/96ss.jpg)
"The Club" (http://camaroslimited.com)

GM spent millions developing there cams and combinations. Most aftermartket cam companies will tell you to run headers with it. I run the original solid cam from GM in my LT-1, wouln't put a different one in for anything. With stock exhaust manifolds,2.25 pipes and the single crossflow the car has gone 13.22 and on BFG Drags high 12's. Put the stock one in! It was designed for that motor and trust me, you won't be disappointed!
Peter

The LT-1 cam is a good replacement - not as peaky, makes better torque down low, still screams at higher rpm. Put a 350 crank and pistons in it as well and you've got an LT-1 that only you know about http://www.camaros.net/forum/smile.gif

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JohnZ
'69 Z28 Fathom Green

<BLOCKQUOTE>quote:</font><HR>Originally posted by ICamaro:
I have plans for restoring a '69 Z-28 with the DZ302 small block. I have read and heard quite a bit about the lack of bottom end torque from the 302 and the great rush of top end power. Since camshaft technology has greatly advanced in the last 32 years, do anyone have an opinion on a replacement cam which could improve the low end of this motor and not sacrifice the high end? I'm planning on keeping the original 186 heads and the 11:1 compression (looking into piston coatings and other tricks to make it work on 92 octane!).

Thoughts?

Thanks in advance,

ICamaro<HR></BLOCKQUOTE>
with 3.73,s and a stick, i wouldn,t worry much about bottom end.

LT1 cam, #3972178
Specs are at .050" lift.
IN LIFT .452
EX LIFT .455
IN DUR 229
EX DUR 227
this was a pretty good cam in my 67 with LT1. I ran a 12.88 quarter with poor traction off the line.
But I put in a super mild Crower rated at 2500 to 6500, and had much better low end and it pulled an 800 Holley DP carb on top end where the LT1 cam would not take it.
I never ran the drags again but would estimate it was at least a half second quicker with the second cam.
The cam I used was a short track grind made for a wide rpm band.

With the 302 you gotta watch out or if you get too much cam, the bottom end will go away.
I distinctly remember driving a stock Z/28 and it coming on at around 4500 and the ignition would typically break up around 6000.
With good points and tune it would rev higher, but it was difficult to keep running well with the point ignition. The points seemed to go away quickly. I know the Z/28 had a different profile breaker cam and that might have caused some of the short point life. Also most engines didn't rev that high to where the problem would show up.
I used to buy the D-112P point sets and they came in the little cardboard container with tin top and bottom, you pull the string to tear all around the center to open them.
Later they came in a foil box. I've still got some of each. Anyone know if they are still available?
David


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Check my web page for First Gen Camaro suspension info:
David's Motorsports page (http://ourworld.compuserve.com/homepages/David_Pozzi/)
First Gen Suspension Page (http://ourworld.compuserve.com/homepages/David_Pozzi/first_gen_suspension.htm)
67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Chev 350 Can-Am Vintage Racer

[This message has been edited by davidpozzi (edited 07-25-2001).]

[This message has been edited by davidpozzi (edited 07-25-2001).]

Oh, and pocket port those heads! It will make a big difference in power.
David

------------------
Check my web page for First Gen Camaro suspension info:
David's Motorsports page (http://ourworld.compuserve.com/homepages/David_Pozzi/)
First Gen Suspension Page (http://ourworld.compuserve.com/homepages/David_Pozzi/first_gen_suspension.htm)
67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Chev 350 Can-Am Vintage Racer

Man, if you have the 302 for your Z/28, install the old 30-30 and 3:73 or better yet 4:10,s and just go out and rev http://www.camaros.net/forum/smile.gif like I say "I don,t need no stinkin'low end"

Leave an original DZ302 alone!!
Pull it out and set it in the corner and install a 383 stroker. Just my $.02 .

<BLOCKQUOTE>quote:</font><HR>Originally posted by TJS69:
Leave an original DZ302 alone!!
Pull it out and set it in the corner and install a 383 stroker. Just my $.02 .<HR></BLOCKQUOTE>
chevrolet engineering:
take a small high winding,high output engine,mate it to a slick shifting 4-speed transmission,throw in a dose of high performance chassis components and top it off with stiff rear axle gearing.then go out and blow the doors off anything that comes near you.

Leave in the 30-30 cam! I have run both in my 302(original bore/stroke), the LT-1 by accident. The GM dealership gave me the wrong part when I went to replace it years ago. The engine showed only minimal improvements down low but lost a lot above 5000rpm. Remember - you are never going to be below 4500rpms if you intend to play with it. The LT-1 is a great cam, but I think you need the cubes for the torque thing to work out. Plus...the 30-30 cam sounds better idling.

Sorry guys, what I should have said is that an original 302 DZ has both collector and originality value. There is no doubt that it is a good motor. For all around fun and driveability I'd still take a 383.

My friends are the same with my 69 Z. I have been building a 427 engine, and thats what they want me to use for a host for the engine.

I told them "nah, I am going to rebuild the 302 that originaly goes in it". They say do this and that, but I humble them when I tell them its a Z.

A Z with a big block? Alot of people would be scratching their heads, but then some people would'nt know the difference.