OK,
i know i'm a huge proponant of the OE cams, (mainly the30-30)
But i'm going to put headers and freeflowing exhaust on my 302 Z28.

it has the stock 186 heads with some decent bowl work, the stock aluminum intake, stock 780 holley,

60 over 302 with true 11 to 1 compression.
wide ratio muncie and 4.10 gears.

1 3/4 headers and 2.5 exhaust with crossover and Pypes racepro muffler.

i defenitaly want to keep it as a solid flat tappet, but wonder if anyone has found a cam that really does improve over the OE cam when using aftermarket exhaust.

only issue is that it has to be able to run the vac brakes, and should be streetable enough to enjoy from stoplight to stoplight, but have plenty of backpinning power when you mash the throttle.

thanks

aaron

My heads have been pocket ported, etc., and are not original to the car- so I felt compelled to do the same thing- with the idea of improving on the old Tech of the 30-30 cam with a modern profile. I am sure some may not like my choice, but I wanted to try something different...the car has not run since 1985, so I look forward to finding out real soon how it performs.

So, I just went with this CROWER 00322 cam:

Part Number/Work Order Number 00322
Engine Application 262-400 CHEVY
Grind Number 282SF

ADVERTISED CAMSHAFT SPECIFICATIONS:
INTAKE: Duration: 282º Lift: 0.504 Clearence Hot: 0.022
EXHAUST: Duration: 292º Lift: 0.528 Clearence Hot: 0.024

The specifications listed above are based on a rockerarm ratio of 1.5 IN
1.5 EX

RECOMMENDED VALVE SPRING INFORMATION:
Part # 68390-3 Single Dual X Triple
Approximate spring pressure: valve closed: 120/130 LBS.
valve open: 320/330 LBS.

16.0
BTDC 10.0
ATDC
ABDC
52.0 62.0
BBDC

The information below is for degreeing cam only. Correct only at .050" tappet lift.
INTAKE Opens: 16.0 BTDC
Closes: 52.0 ABDC
EXHAUST Opens: 62.0 BBDC
Closes: 10.0 ATDC

LOBE SEPERATION 112º

Duration at .050" Intake: 248
Exhaust: 252
LOBE LIFT Intake: 0.336
Exhaust: 0.352

If using "Lobe Center" method of degreeing, cam should be installed on an intake centerline of: 108º

Aaron,

Did you read me over at Big Brother??

UDHarold is the man!!

I honestly forget if 302 Z-28 cars had P/D/B's, but I do know they had front disc's.

So if the old 30-30 worked for P/D/B's back then look into a modern version that is approx. the same timing, but w/ a lot more lift!!

Harold can really fix you up here!!

I personally tend to be "old-school" so I would ask you to please consider Isky's old Z-30!! Nothing fancy at all...

290/250, 108/108, .485" gross lift and need's .030" lash on both sides!!

Where the old 30-30 is 346 per GM, 314 per WBR and 304 per Pat K./254, 114/112, .485" gross lift and also need's anywhere from .024" to .030" lash depending on who's running it?

Otherwise, you CAN'T go wrong w/ a UDHarold cam recomendation!!

pdq67

Another comment is regarding the distributor set up. Lots has been written here on ignition timing, so I went ahead and had Jerry MaC set mine up as well as the 4053 Carb. I look forward to hearing what you do, and how it works out.

Rob

1 3/4 headers and 2.5 exhaust with crossover and Pypes racepro muffler.



I wouldn't use 1-3/4" headers on a street 302, I'd use 1-5/8" max, about 36" long with a 2-1/2" x 18" collector.

I run a 30-30 in my 68 z/28 with a original 302. Have had some head work done, and run hooker 1 3/4(pn 2131) headers, with a 2 1/2 inch system with magna-flow mufflers. The car runs great. I'd try the cam with the exhaust, then change the cam if your not happy. There's no doubt a "new" style cam will help out the bottom end, but it won't have the "cackle" a 30-30 does. Remember that if you tighten the lobe centers too much, you'll lose some idle quality.

And Harry's right b/c there have been too many guy's that mess w/ the little engines and then don't like their sound b/c they've lost the sound of the good old 30-30 cam!!

pdq67

well... i had headers on it for a while (1 3/4 primary 1968 Z28 reproduction headers) and it ran great.

i might play around with the old offroad cam and see just how I like it.

you can't beat the sound... and i'd bet it runs alot better with headers and a free flowing exhaust, than the 30-30 does with manifolds and chambered exhaust. LOL

the car is geared to run right so i shoudl be ok....

if I don't like it, i'll pull the 302 and drop an L88 in it for some real fun LOL

Comp Cams has a 30-30 Nostalgia plus cam that should be good. Otherwise look at the Crower line and the Engle Cams line.

Crower did a custom cam for my friend who has a 69 Z/28. He wanted similar to stock power but better torque if possible. David Crower worked up something custom for him and it worked pretty well, but it's probably not enough HP for your needs.

The CROWER cam I listed above ( which is now in my 302) was supposed to do just that- a whole lot more lift which I understand boosts torque- a little less duration ( 248/ 252 @ .050 vs 254 on the 30-30) and a slightly tighter lobe center @ 112* (which should actually make it sound raspier)... should increase usable/ sensible street performance. The guy at CROWER seemed to know what he was talking about, not just reading notes or whatever out of a book- so I went with it. PN 00322.

Desk Top Dyno may be all wet, but when you plug in the numbers between this CROWER cam and the 30-30, it flat kicks its butt up to the point where they both max out at the same HP. I certainly dont believe the raw numbers, but the tendency to provide power in a usable range is impressive- again without compromising the ultimate peak HP. Note that the 30-30 Nostalgia Plus from CC does the same thing- it puts the power where you can use it. It would seem to me to be a bit disappointing if they couldnt improve upon the 30-30 at least a bit after almost 40 years of Tech!!!

I tried Lunati, they wanted to sell me something not even remotely similar, and CC wanted me to use the 282S,( althougth I mentioned the 30-30+) which again is a far bit from being equal to the factory piece. ISKY recommended the Z27, which looked very good on paper as well. I guess if the CROWER cam is a dog I can try something different ( like the 30-30!!!). I suppose my feeling is we know what the factory cam is and does- so I wanted to try something different. To be clear, the factory 302 cam is just that, and has been making 302's haul #%% for a long time- so my intention is not to diss it.

I think the advantage with the newer cam would be that while the duration at .050 may be similar, the modern profile will by much shorter in the seat and as a result will help build cylinder pressure and low end TQ. In addition, the duration at higher lifts will generally be longer than the 30-30 which will create more area under the curve, more flow, and more HP.

Not knocking the 30-30 . . . it was great in its day.

Remember that the little-bitty Duntov -097 solid lifter cam was used in the 340 and 360hp/327's!

And it's only like 287/228/287/230,110.5/108, .385"(?) net lift using .012" and .018" lash on the intake and exhaust!!

I ran it in my old junk301 as my daily driver years and years ago and really liked it!

It would rpm up to 7,500 rpm w/ new plugs and points!!

pdq67

I think the advantage with the newer cam would be that while the duration at .050 may be similar, the modern profile will by much shorter in the seat and as a result will help build cylinder pressure and low end TQ. In addition, the duration at higher lifts will generally be longer than the 30-30 which will create more area under the curve, more flow, and more HP.

Not knocking the 30-30 . . . it was great in its day.

Thats the premise I am working on- should know in a few weeks, or at least this Fall.

Cheers-

Rob

If you look closely at the old Duntov, you will find that even tho it is like 45 years old or so, that it is a modern, tight-lash and a close LCA/ICA design and I figure that it is really like a 272 cam!! Vs Gm's 287/287!!

It's just too low a lift cam nowadays, but all in all, the little-bitty bugger will get right up there and go!!

And fwiw, I've been meaning to bug UDHarold again by asking him to come up w/ a modern 302 Z-28 use Duntov cam for the guys that want rpm's but alot more midrange grunt than the old 30-30 b/c I figure there is a market for just such a stick!

Harold came up w/ a dandy of a BB solid cam for my 496 that is 278/249, 110/106, .600" net lift w/ .018" lash on both sides! It is "ULTRADYNE" aggressive to say the least!! And I'm figuring at least 75 to maybe a 100hp over my CC 282S if I dial in my combination??????

And I figure that Harold can do the same magic for the 302 cam!!

Harold!! Are you out there????????????????

pdq67

I have wanted to see what Harold could come up with, but dont know him so did not want to bother him- I am not sure how or where he is now.

So, as ussual PDQ I enjoy your comments and advocacy for the little engines. If I am ever in your part of the world I would love to see the balls to the wall driving first hand!!!

For alternatives to a 30-30, look at short track solid lifter cams. Cams in the 2500 - 6000 range.