Hello, just finished my 3rd DZ motor, and i went all stock this time. Carb to pan, manifolds w/smog etc. Concours engine cpt.

I'm tired of the 30/30 cam. I made the decision to use it months ago, but am really not happy with it. I want to keep the solids, and keep the engine a high rev-er, but I know the 30/30 was considered a terrible design.

Anyone have luck with the offroad in a motor w/manifolds, or should I go aftermarket, and if so which cam?

Ultimately, when the motor idles, I don't want people guess that it isn't a real Z motor, but when you get into it, it should be plainly obvious. I've been thinking about going roller, but want to try another solid cam,before I rip the heads and all off.

Any suggestions???

Thanks

Sorry,

I forgot one thing. I wouldn't care if the motor idles as if it had the 140 cam in it, I think that is out of this world actually.

Perhaps something like 240/245 @.050 on a 110 or 112. Perhaps 510-530 lift?

What do you think? Still needs to make vaccuum for the Pbrakes.

How about the Comp Cams Nostalgia Plus grind N+30-30S part number 12-673-4? The description in the Comp catalog is "SOLID-Outstanding power & modern tight lash with the exhaust note of the 30-30 cam."

Specs are: 284/291 duration, 247/254 duration @ .050, .504/.498 lift, 112* LSA.

Advertised duration numbers are shortened up quite a bit from factory specs, .050 duration is a bit shorter too, so hopefully it would be more manageable on the street. Never used this cam personally though.

Eric,
I know of that cam, and even COMP doesn't reccommend it as the best, but i'm not sure those guys are really all that knowledgable on 302 chevys.

What cam do you have in your 383?

Thanks

Aaron

I run the 12-673-4 cam that Eric68 talks about. It has a nasty-sounding idle, makes good mid-range torque, and makes peak power around 6,000rpm. I get 7" vacuum at 950 rpm idle. Comp makes Ovate wire valvesprings for it that fit the 186 heads with no machine work.

The Comp tech line liked the 282S for my DZ. I went with the 30-30+ cam because I wanted to get as close as possible to the original sound.

Neil,


Can you say how it performs over the 30/30 Duntov cam?

My car had been restored with the -178 cam instead of the 30-30. I modified the engine with cam, aluminum heads, headers, and 2.5" exhaust all at once. My seat of the pants tells me I now have 50 to 75 more HP. It dynoed at 283 hp at the rear wheels two weeks ago (equivalent to a modern, roller-cammed 5.0 Ford with good heads). I was amazed at how streetable this cam is. It's still soft below 3,000rpm, but very driveable.

I don't think you'd like the 140 with factory manifolds. Also remember GM suggests a minimum of 12:1 compression with that camshaft. It is less prone to detonation than the 30/30. I last used it in a 331 with 12.15:1 and 1 3/4 headers and a Yunick crossram. Engine pulled 7" of vacum at idle, (1200 rpm) and quickly comes up above that, but I can't help you on the power brakes, I never run them, but I wouldn't expect them to work too well either.

SY1

how did you like the 140 cam, in that combo?

The -178 LT-1 cam is an excelent choice especialy with cast iron manifolds. One of the best all-around solid lifter factory cams. It has similar exhaust timing as the factory "30-30" but a little less intake timing so it pumps up the power over the factory 302 cam anywhere below 6000 RPM while still sounding "correct" out the exhaust. It has Torque/HP peaks about 500 RPM lower than the original cam. That is what I would run if I ever decide to pull the "30-30" cam out of my 302. smile.gif

-Mark.

I don't know why Comp would "not recommend" that cam for a DZ motor when they label it in their catalog specifically for this application. I still think it would be a reasonable choice - lobes are more agressive @ .050 than the 282s but advertised duration is still right in that ballpark.

The 282s would probably work well too (definately milder) - except from a performance standpoint it is a single pattern which in theory would not perform as well with weak factory exhaust ports as a dual pattern would. I have used the 282s in my 383 (too much TQ) and in a friends 327. It is a very nice all around street cam for the 327 engine --- although our project has aftermarket heads with a very good exhaust port.

The "Concours restoration" part of this particular combo has me wanting to suggest a cam that would sound pretty similar to the factory grind. Its hard to say for sure . . . maybe a call to Comp or Crane would be in order.

Currently I use the Comp 294s in my 383 with 1.6 rockers. It has a pretty nasty idle and makes only about 7" vacuum in gear at 850-900 RPM.

PS Neil - 283 HP at the rear wheels is awesome IMO, much better than any street 5.0's I've seen. A 302 will always be soft below 3000 RPM anyway, so I think your cam choice is a good one. I bet it DOES have a WICKED idle :D

Thanks Eric. I'm happy with the combo, but my goal is 300hp at the tires. I thought I was going to get there through tuning, but it's going to take some hard parts. I use the Ford 5.0 tech articles as a guide because it's the only modern 302 tech available. Muscle Mustangs and Fast Fords has a great series of articles on cylinder heads starting this month. I highly recommend it. It's always good to know your competition. : )

Aaron,

I agree with what everyone else has said here. If you are looking for a concourse car, I'd stay away from this cam. It is a nasty sounding cam, even at 1200 rpm idle it is pretty rough. Nobody is going to mistake it for a 30/30 cam. I used 1.6 rockers and it put the lift at .526 Iand .539 E. Crane makes a single valve spring and damper design that is good to .580" valve lift and fits the factory valve spring pockets.

I have always felt the 302 motors I've had with 30/30 cams were soft below 4000 rpm, but pulled real hard 4500 to 8000. I love the 140 cam, but it was my brother and a couple other guys I met who all ran it before me and they all said they'd never run another 30/30. A concourse car is pretty nice to have, but once you start getting bit by the performance bug, it can bite hard and pretty soon you're replacing one thing after another until you've bullet proofed the entire drive train. I've seen this happen repeatedly.

It's your car, but sit back take a breath and really think about what you want. With the 140 I'd run at least 4:10 gears, stronger valve springs, the BEST hardened push rods you can get (this is the only thing I've ever broken on a 302 turning them to 8500 a lot), Trick flows are a nice choice, a little grinding on the heads, ARP screw in studs and guideplates, 1.6 rockers, a new true roller timing chain and gear, an 830 Holley double pump carb and some good super comp headers. Aside from the headers it still appears concourse. But you see how quickly things start to get of hand. You don't need all these things, but to take advantage of the next level of performance you're seeking I'd consider most of them.

On the other hand you can just slap the 140 in there and see how you like it. Maybe it'll be okay, I just don't know anyone who hasn't run headers with it. You might get away with just a change to headers at a later date and possibly a set of springs.

THanks guys for all the help.

After all this reading, i'm definately considering the 140 cam, although as you all seem to agree, not with manifolds. I do have 4.10 gears, though.

I guess, so long as I am going to goin the direction of the 140, do you think that the CC294s would out perform the 140? At this point i'm not worried about idle as anything more than the 30/30 is wicked as hell.

I've driven in a car with the 140, but it had headders, and only a 3.73,and under 11 to 1. It was dead down low but took off like a mother above 3500, and with it being on a 112, it seems more responsive than the 30/30. I'm not sure that the difference between the 3.73 in that car, and 4.10 in mine will make up for the headders or not, but my motor does have higher compression.
SO having said all that, anyone comment on the 140 vs. CCs 294s ? SY1 what do you think of that idea?
Right now, I"m convinced that the 30/30 is out and I do want something more. I know that 7 in HG will work PBrakes, not much though, but enough.

The car might not stay concours appearance for ever but for now she is. I really like the look of that, and understand that the combo is a little messed up with castiron manifolds, but down the road when I put the headders on and such, I want the cam to be right.

Also, where does one get an 830cfm Holley? Is that new, or did you mean 850 dbl pmper.

THanks again gang.

I'm with Mark - the LT-1 was the ultimate development of Chevy solid-lifter cams, and has better low-end torque than the 30-30, gives up very little at the top end; sounds the same, nobody would know the difference. It also has the distinct advantage of using all stock GM valvetrain components, so it's stone-reliable.
graemlins/beers.gif

The carb is an 830 Pro-series Holley. The part number is HLY-0_80511-1 with annular boosters or 509-1 with downleg boosters. It's a mechanical secondary carb with 1.75" bores, four corner idle and high flow power valves (picture window power valves some call them). I know it works well on the 302 especially with a Team G intake it was much more responsive than a tunnel ram with twin predators. The second set up was probably a bad idea from the start! I'm sure though that you'd also be happy with a 750 mechanical Holley, especially considering the price difference. I'd just set the vacum secondary DZ carb aside for now.

I'd really listen to Mark, Eric and John on this, they know their stuff. I haven't used the 294 cam, so I can't really pass judgement on it. Looking at Eric's times I'd say it is working really well for him, but he is running a 383 and the 302 doesn't offer the huge torque band the 383 does. If you're still not satisfied maybe pdq67 will jump in here with some solid cam choices, he's run a lot of them.

I know people who have run the 140 on 11:1 motors and it worked well, I have never run it with less than 12:1s. I'm really concerned how it would work with the manifolds, but like you said it's an easy upgrade later. I'd make sure to change valve springs and install screw in studs before I'd use that cam especially if you are using higher than 1.5 rockers. If you go this route don't even consider GM screw in studs, ARP's are the only choice, not just for the name. They offer the widest overall length of usable rolled threads, GM is the worst behind Dormans and Summit. I was able to mill less material from my heads which resulted in the studs sitting a little higher, but placed the rocker arm quite low on the stud. I think this results in less possiblity for the stud to flew and loads it further down towards the hex base where the stud is stronger. I could not have done this with the GM or any other manufacturers stud. I'm not recomending you do this, but just wanted to pass along there are vast differences in screw in studs, I've compared the top 4 brands and they're all different. ARP is also the strongest in my opinion. Without matching every aspect of your combination it will still sound wicked, and pull hard up high, but may run slower than the 30/30, unless you build it around this cam profile. Just keep that in mind.

By the way I agree with you on the engine compartment look. I haven't got any use for shiny aftermarket parts in my engine compartments. I like the factory look or at least a performance look without going nuts on the chrome. I like to keep it simple.

Thx, SY1 for the vote of confidence but I haven't run all that many cams, but have been around them by running guy's and riding with guy's that have in my mis-spent youth...

I gotta say that the operative here is COMPRESSION, COMPRESSION, COMPRESSION!!!

Th3 reason any of the cams worked from the factory from the great old fashioned -151 hy-, -178, "30-30" and finally the -140 is b/c the engines were all up to at least 10.75 to 1 or above in compression, period!!! Even the great little -097 Duntov was in this range in both motors, (283 and 327)..

Your motor isn't going to be a Z-motor unless it has the complete Z- package in it !!!!

And that means true 11 to 1 slugs, the old 30-30 cam, the 780 carb., (at least I think it was a 780??), and double hump, big valve heads!!

I personally would build a 10 to 1 motor, use modern, 170cc heads, a stock high rise or a Holley 300-36 and said carb. and stick on a cheap set of 1.625" four tube long headers!

Then install a cam spec'ed like maybe 278/235 or so, 110/106 and not so max. lift for halfway decent life!! As you can see, I am going more for max. grunt like I usually recommend for a street motor!! I know the little sucker will go 8,000 easy but why do it to her when she will go just fine with some more midrange grunt?????

To heck with the sound b/c without the stuff in it that makes the sound, it won't sound the same!!

And I dearly love the sound a them "Cop-calling " glasspacks too if you just gotta have a REAL, nostalgic sound!!!

Kinda like trying to duplicate the GREAT exhaust note of the '69 or '70 BOSS Mustangs that to me had the greatest mild sounding exhaust of all times!! Kinda like in the league of the sound of a MOPAR gear starter turning over a 440!!

You could hear the Pony's sound in the movie "Bullitt" as Steve McQueen ran her through the gears!! And I'm not even sure it had the little motor in the car now that I think of it?? Maybe the 390???

pdq67

pulled the 30 30 cam out when i changed the heads
and headers. i put in comp cams muscle car replacement 284 s better idle,same sound and a rocket after 3000. no one knows the difference. good vac 12-15. changed the 780 to a 650 with 72 jets and it helped the throttle responce under 3000.

Yeah, I was just glancing throught the COMP Catalog and I like the way the 284s appears. Plus it is on a 110 c/l which should make it a ton more responsive than either of the 30/30s or the 140 cam.

THe nostalgia plus looks cool too as it is a smaller dual patern cam than the 140 but on a 110 c/l also.

I was checking out COMPs XS2822 which is an extreme energy cam which specs at 244/252 @.050 an .520/.540 lift also on a 110. THat cam is probably a brute as well above 3000.

My compression is at least 11.00. We used wiesco racing pistons which were 11 to one assuming 64cc heads like the 186 Z heads. But I had them cut slightly (cleanup) and am using steel shim head gaskets so I'm certainly above 11.00, probably 11.5 is more realistic. Also, I have manifolds on the car, but it has the chambered exhaust. The sound is fabulous.

The last idea I am actually considering most right now, is a completely different direction but would probbaly do the trick. Comp makes some new street solid rollers that look dynamite.

The 1st is their XR280R which is 242/248 @50 and .570/.576 on a 110

or even a little bigger, 248/254 @50 and .576/.582 on a 110

Both should make 10in HG which is enough to run the Pbrakes and should skyrocket above 3000. I can always put the headers on later, and I know that the magnum roller rockers will fit under my valve covers as I"m running them now. Id have the change the springs but I've got the clearance to do so and I alreaddy have the ARP screw in studs, so some of the perf. upgrades have been done on the inside, but the appearance is 100% stock. That's what I'm going for.

Any of these cams that I've mentioned, probably would not sound as mean as the 140 does, but they would certianly outperform it I would think, especially on the street.

With regard to the full Z package, I understand completely and do not want to change the idea of what a Z/28 was, a small motor that revs like a b1tch and pulls hard above 3500, but when that 3500 comes, I want that baby to pull like crazy.

Thanks again for all the great input and if anyone has anything to offer regarding any of the cams I've mentioned, I would greatly appreciate it.

Thanks

69z28boy,

Back again, imho, try to build the compression in your motor with true flat-tops, longer rods and as small a chamber as you can buy and then plane her down more to get where you want to be along with steel shim headgaskets...

I mention this b/c it seems that our engines like this combination to fight detonation with respect to running pump gas and any CR. approaching 11 to 1 AND slightly above!!

AND I am talking hi CR. AND 87 octane gas engine theory here!!

Guy's are even running quench down in the .035" range and even lower IF they don't have to worry about piston rock due to running tight expansion clearance forged pistons b/c of the "better/lower expanding" piston alloys out nowadays..

pdq67

I think the 294s would be way too big in a DZ motor - It's bigger than the other cam I was suggesting at .050 and way bigger on the seat. I'm not a DZ 302 guru, so pls don't place any extra weight on my opinion here . . . but I will say that seat duration should be considered because it is part of the whole overlap equation. The longer it is the more cylinder pressure you bleed off and the softer low end gets. .050 numbers will also have a big effect too. With a 302 I would keep the seat duration as short as you can to help maximixe the low end while taking full advantage of moderm agressive lobe designs. Just my opinion.