What cam would you run in a day 2 69 Z28
 

Title says it all
Stock 302,
Headers,
Wide ratio and 3.73


Do not wanna loose the Z28 character

I have the 140 in the car now - its too much for a driver

70 LT-1 camshaft

Everything sounds good to me. Just put in a 4.56 rear gear and you are golden. No worries. car will run great and much easier to drive.

So - Howards Cams has a Lt1 lobe which they spec at 316 adv, 242 @.050 and 144 at .200
.459 lift


I was thinking of having them grind me a smallblock version od the L78/l72 cam

316/316 - 242/242 on a 112

Or go with a 112LSA Lt1 cam 316/336 - 242/254

Or do you think messing with or trying to redesign GM cams is a bad idea?

I like the 140 cams but your never going to get much grunt out of that 302 from light to light. Either throw a set of gears into it like Sam suggested, or maybe go back to a 30/30 grind. The newer 12-673-4 nostalgia cam has the best of both worlds in a solid lifter. Sounds old school and has better bottom end performance out of the hole.

The car I just bought has the Comp 12-107-3 Muscle Car Cam which is a direct replacement for the 3849346 cam and it works really well in the 302. What else are you doing for the Day 2 finish?

Headers, ignition, a dbl pumper instead of the 4053 Holley,
A good free flowing 2.5” exhaust,
A set of torque thrust d or minilites and radials!

Thats it

Sounds great. You'll have to post some pictures of the car when you get it where you want it. I'm going to put a few day II bolt on parts onto mine. Original set of Cragar headers, Lakewood bars, TT Wheels, Wide Oval Radials and maybe a Sun tach.

great info on this thread-
I ran the stock solid LT1 350 cam in my Z/28 in early 80's after rebuilding the 302. Bought it at Chevy dealer that sold the car originally back in '69. I was happy with it.
I've been collecting parts for a vintage themed SBC build, going with 355 short block and picked a Crane copy of the 140 Cam, plus this Isky 505T Solid grind from a recommendation from an experienced old-timer who picked it over the 140. Its a period cam with 254 Duration at .050/108/505 Lift. I was thinking 1.6 roller rockers to bump lift a bit. Haven't tried it yet- but food for thought.
Cheers!

If it's a 69Z it needs to have good cam in it for sure. The old school people know what they sound like you don't want them thinking its not a 302 car! Just my opinion because I love cars with cams.

No need to be to technical. Put the 140 cam in with a set of gears or even the stock cam will do. Small blocks with high rev cams need gears or your defeating your purpose. Have the carb done and the distributor done along with a good exhaust and you will run great. Hopefully you have the forged pistons in that motor too, or your "old school" sound will not be there. Its all about the combo. Good luck!

Ask (67 Nova Boy Dave) what Comp Cams he is using in his 302. That car sounds great!

I really loved my old school GK C1M-308R. I went from the 140 cam to this in my LT-1 and it was noticeably stronger in the mid range. It was hard on the valvetrain though. It also barely had enough vacuum for the brakes but man what a rush at 3500. This was with stock heads and the dual plane manifold. 4:10 gears and the M-21.

Are your planning to leave the rest of the valve train stock? It seems like a good idea to update the rockers, maybe like these Comp Cam rollers. It wont keep me up at night without the O stamped originals on there.

The press in studs do create some anxiety though. They are original and cool but it seems worth the 'loss' to keep my original 302 in one piece. Am I worrying about nothing here??

I'm likely going with the Comp Cam 12-107-3 (3849346 replacement). My '69 has an M21 and 4.10 gears. Both of these have updated internals.

:wink:

I'm in the same boat with the car I have now. I was thinking about roller rockers but then it usually mushrooms into removing the heads, doing a set of screw in studs, guides and likely more when I get to that stage.

I'm not planning to buzz my stock 302 beyond 6500 when hammering it through a few gears, and it's not like I'll be doing it that often so I then relented to leaving the stock valve train alone. Just my 2 bits...and just so you know, that 12-107-3 cam choice makes "excellent" vacuum for the brakes. Mine are fantastic right down to 900 idle and brakes work awesome.

For the studs you can always do the old trick of pinning them. It's hard to see once done and keeps them from backing out.

The best running BBC's I've owned for the street, always had three things in common: 4:56-4:88 gears, high compression, and high performance GM cam (l-88 ZL1).
Can't say if it's the same for sbc, but I agree with Sam.

I'm a huge fan of the LT-1 cam. I've used it in a few different 327's. 11:1 and 9:1 pistons. Still makes good vacuum to run the brakes and easier to tune. I have one in a 62 F.I. Corvette right now and it runs HARD.

Hell, I'd put that cam in my garden tractor if I thought I could get it to fit!

Here is Tim's garden tractor come next summer...:3gears:

https://i.pinimg.com/originals/e4/6c...2e644c6c69.jpg

I have these 492 heads also but currently into the Day 1 thing. They do have screw in studs already though :) Would a cam choice here be any different or perhaps make the 140 happier?


Attachment 149498

I went with a Comp Cams grind selection that was based on my engine displacement, compression, and rear ratio. When done with modifications roller rockers , headers and bored 40 over, the engine put out 409hp @ 7050rpm and 373lb-ft of torque. It's a flat tappet cam. The modern dual pattern and aggressive ramp cam allow for both HP & Torque. I have the grind card and will send it to you. It has a nice lope but I could care less about the idle sound, the drivability & performance is what I care about.

It really depends on what your looking for. I purchased a 71 Z It was all original but indy cylinders heads built the engine, stroked it to 383 and used a Hydraulic :( XE 268H 224-230 110 cam. it had super strong low and midrange with 373 gears and the Four speed. but at 10.5 to 1 and California fuel. Boy did she rattle. So to bleed off cylinder pressure and get back to solid lifters. I installed the Nostalgia Pluss 12-673-4 247-254 112 .012Lash.. Best Sounding cam Ever.. Lost all its torque and dead on the top. And this was a 383.. I figured it would hate the stock exhaust.. But no more knocking.. I installed shorty headers and a low restriction transverse system. Now she had Killer mid and top end power.

When I was building my 69 Z engine I was planning on Dropping the compression to 10to1 and using this Comp XS 274S-10 236 242 110 .500 This would of made that little engine run much better than its high compression big cam factory setup. And been pump gas friendly, still sound great. But after tearing down the engine and seeing every factory part still there, I didn't have the heart to change it. and rebuilt it all original.

Use the Manley (stock type) Rockers cause they will not go bad and change the rear gear. No matter what cam a 302 Chevy runs it needs a stiffer gear or change the trans gears to have a lower first gear for easy light to light driving. Re do the distributor curve and have Eric tune/go over your carb. Then go have fun.

lmao

With the M-20 trans and the 3.73 rear gear, you're already equivalent to an M-21 or M-22 with a 4.27 rear gear. Running a 4.56 rear with the M-20 would be equivalent to a 5.22 rear with a close ratio trans. First gear would be a screamer.

Love my M20 with the 4.56 gear in my Z.

I wound up ordering a custom ground Bullit cam -

can't wait to install it - I have a set of roller tip comp 1.52 rockers, heads already have screw in studs and guide plates - and I will be installing stiffer springs to compensate -

the cam is thus!
CHS 278/282-F12+5
Duration @ .050 = 248/252
Lift with 1.5 rocker = .530/.540
Valve lash (hot) = .016/.016
Lobe separation = 112
Intake centerline = 107

so kinda like a tight lobe LT1 with much more aggressive ramps.

I'll be running a set of 1 3/4 Kustom clone Z28 Headers -
I ordered a Flowmaster American Thunder exhaust setup = but I won't be running he Super 44 mufflers, but rather (either) the Dynomax Ultraflow SS or a Set of Borla XR-1 mufflers -
I like this system because the tail pipes (while larger at 2.5") exit in the stock location with a 45" cut like the original tailpipes.

keeping the m20, and 3.73s

Also will be installing a set of BFGoodrich or Coker WideOval Radials on a set of vintage Minilite wheels -

CAN NOT WAIT!!!

I have the Borla XR-1's on one of mine, a little loud but I like it.
Sorry for the crappy cell phone vid.

Sounds like a good combo Aaron. Keep us in the loop.

I am sure you have already considered this, but if you wanting more aggressive than an LT-1 camshaft, using "stiffer springs" you are risking lobe failure. You can combat to some extent by using edm lifters, and making sure you use a good high zinc oil.

Still, if I were going stiffer than stock springs, I think I would just go with a roller cam package. Just my .02 cents. Wish you luck either way.

Yes I have - and actually - almost had a catostrophic failure with the LT1 cam due to TOO MUCH ZDDP.

I had foolishly assumed that if one bottle of ZDDP+ was good, then a bottle and a 1/2 would be better insurance -

BOY was I wrong - after 800 miles, the lifters had spalling - but not obvious damage to the cam lobes and it mic-ed out correctly

I do however have more spring pressure than the stock Z28 springs - but not 130-140lbs like the current solid flat tappets want

Do you get a highway drone in the car?

I am either ordering the XR1 or Dynomax Welded Ultraflows

No drone, but I only go about 60mph when on the highway.
I have the Dynomax on a Camaro, which replaced the Flowmaster 40's, it was
a huge improvement.

Which Are louder
Dynomax or Borla and is it a significant dif?

For 10 years now I've been using Hooker Aero Chambers. Best muffler I have ever heard. Quite but measurable at idle and low rpm cruise, and they wake right up when you get on it but its a smooth deep sound like no other. And at highway speeds you can actually have a conversation w/o much of any drone. They flat out rock and I just ordered another set of them.

I had flow-masters on my black nova and there was a heavy drone at any highway speed. Hooker's are way better all the way around. I'm loading a video for you and will post it in a few minutes here.

https://i.ibb.co/nMSyPp6/IMG-0119.jpg

The Borla's are louder, the Dynomax also have a deeper tone.

Here's the Hooker Aero Chambers at idle. Hydraulic roller 355ci motor at 550" lift 236/240 duration. I'll load another cruise video here in a few minutes.

Down shifts start at 00:29 and up shifts start at 1:20. This will give you a great idea of the sound on the Hookers. That's my shameless muffler plug. lol

Alot louder?
The XR1dont come in Center/Offset which might present an issue for a 69 Camaro.

Your car sounds great!

Two things bother me with Aerochambers, 1) my system is 409 stainless which isnt the end of the world but I was hoping to keep it all 304 or 409

And 2). I read about alot of issues with Aerochambers rattling from something inside coming loose. Do you know of any issues or has Holley solved this defect? Seems like the threads in them were a few years old.

Never had anything rattle or loosen in any of mine and have never actually heard that. I have ordered 3 pairs of them in the past 6 years or so and also have a pair on my run stand exhaust to quieten things up when running in new motors. Those one are about 10-12 years old now and are still sound great with no rattles.

They do have these in stainless as well. Had the polished stainless 3" Aero Chambers on my 55

https://i.ibb.co/THnFc5p/55-Chev-Exhaust.jpg

Stainless doesn't appear to be available any longer