69 Z, Headers, VS Stock Manifold and Chambered

[COPO PETE]

I don't believe you will see that much of a gain with headers, but there will be some, nothing really seat of the pants. Sounds like it is geared wrong. What tranny you got???? If it's a M21, you'll need at least 4:88 gears. If it's a M20 4:11 minimum to 4:56. Maybe Mark will chime in on the crossram jetting???
Peter

[Keith Tedford]

Back in '69 Nurse Chev-Olds installed a track cam and cross ram setup on a Z/28. With the stock 3:73 gears there was absolutely nothing below 4000 rpm. 4:56 gears would be the minimum for this combination on the street. The M21 might have been the ticket on the road courses but it didn't do the street car any favours. Tony Pizzi showed what terrors these cars could be on the strip when set up properly. On the stock 780 Holley with power valves front and back #73 primary and #76 secondary jets would be a good start.

[NEW]

Me Again!

I am running M21, and 4,10 in the rear.

Its the 780 carb, but i∆m running 78 on the primary, and 80 on the secondary now.

What timing would be suggested? i∆ve read abt. people doing sometimes like 42 total.

I once had a L88 with stock manifoilds, and stock type exhaust, once i put headers and some less restrictive system on that engine it was like a diffrent engine.

It also have a tendency to get sligthly hot on the exhaust side, LH side.

Has anyone had any problems with the smog system leaking in, and making the engine backfire?,

NEW

thanks for the replys [img]/ubbthreads/images/icons/smile.gif[/img] [img]/ubbthreads/images/icons/smile.gif[/img] [img]/ubbthreads/images/icons/smile.gif[/img]

[COPO PETE]

Stick some 72's or 73's in the front, give it 42 degrees timing, put some 4:88 in it and call me in the morning [img]/ubbthreads/images/icons/smirk.gif[/img] L88 with headers will pick you up over 50 horse over manifolds, you will not see anywhere near that on a 302. Do run something like an ultraflow muffler on it.
Peter

[JoeC]

Also try the lightest springs you can find in the carb and dist.

[JohnF]

I am by no means an expert but I have been playing with different set-ups on my Z/28 for almost 24 years. Here is what has worked for me. I run 72 jets on the primary side and 76 secondary side; yellow secondary spring and 25 squirter. Headers do make a difference! I currently run the 1 3/4" Hooker Super Comps, 2 1/4" pipe to a cross flow muffler, and 2" tail pipes. The only muffler, other than stock, that performs better (and is not too loud) is a DynoMax cross flow that is listed for the Buick GN. It is a bit shorter than stock but looks good under the car and seems to flow quite well. As far as timing advance, I run 10 to 12 initial and 36 total, all in by about 2200 rpm. I have never felt that going over 38 did much to create any more power. These are not racing modifications but work very well for me on the street. I have tried everything over the years including the original manifolds, etc. With the quick timing advance you will need good gas. You may want to visit the Camaro.net site and do a search under the name JohnZ. He has studied the original 30/30 cam and gives very detailed instructions on how it should be adjusted. Again, just my opinion, but this works very well on the street.

[NEW]

Hi,,
Basically what you people are saying is ::

72/73 jets front, 76- secondary,
timing 38-42, light springs,
carb light springs.
I∆ll try sometime during christmas or slightly in to the new year..

But back to the Chambered, good, or acceptable or just nice sound?

Smog system, anyone had trouble with this?,


THANKS Great info......

NEWs [img]/ubbthreads/images/icons/smile.gif[/img] [img]/ubbthreads/images/icons/grin.gif[/img]

[Salvatore]

Tony Pizzi was great! That car flew. 11:68 with 7in. tires. NHRA kept factoring him to death, like they did to Bernie Agaman's 71 454 corvette. The both got out of stock and super stock racing because of that. Jenkins gets some credit for Pizzi running so well also.

[NEW]

Hi again,,

if you guys would like you could i think, if i do it right,
see the car here: www.newsgarage.com/inventory.html


NEWs
and again thanks [img]/ubbthreads/images/icons/smile.gif[/img]
And you know what, here in Norway we get 98 octane at the pump, so some additives easily gets us up to 102-104 octane