355tpipickup

iTrader: (5)

hi im lookin for the specs of the cam from a 69 z28 350 camaro, also specs on the heads, my father has a 74 camaro with the 69 cam and heads on a built 327, we need to know the cam specs to get her runnin better!! can anyone help me out? thanks

RB83L69

A 69 Camaro with a 350 would have been the standard 4-barrel model, possibly with double-hump heads.

929 cam, 186 heads.

That cam is dung, if that's what it is (stock 69 Camaro 350 cam). It's the same cam as was used in just about everything else from the mid 60s up until the early 80s. It's best remembered and loved for its contribution to the 165 HP 350s of the mid-late 70s.

I don't know how "built" a motor could be considered, if it has a 929 in it. I guess it might be more "built" than "disassembled", FWIW.

ede

FYI the 69 z/28 came with a 302 not a 350 as did all z/28s before that

355tpipickup

iTrader: (5)

alright well i was just guessin about the 350 motor, i have no clue what motor the cam was in all i know is that the cam came from a 69 z28 as did the heads, dad said the heads have a 1.94 vavle i think thats what he said, were just tryin to get her runnin better and he said if he know the cam specs it would help out!!

Crusin' 1980's

you could also get a 69 camaro with a 350 or a 396 from the factory...maybe not a z/28, but those engines were available

RB83L69

Sounds to me like basically a bunch of drivel.

As said, 69 Z28s didn't come with 350s; they came with 302s. However the "base model" SS did come with a 350; it was as I described.

You don't have the cam "for a 69 Z28 350", because there is no such thing.

None of us here can accept responsibility for what you were told. All we can do, is give you the facts. If what you were told dosen't agree with reality, we'll just have to leave it up to you to draw your own conclusions.

Get some head casting numbers, and use a dial indicator and degree wheel to find out what the cam is.

1.94" is the usual and customary stock 350 intake valve size. Nothing special at all.

If you want to get it running better, start with tune-up type things, set the timing for best mph in the 1320, and work on carb jetting and the like. Then if that's not enough, find out what you've actually already got, and then it will be possible to make an intelligent decision as to how to improve on it.

Did I mention, get the head casting numbers. All else is just a wild guess without that piece of info.

Cams are cheap. Even an expensive one (which doesn't include ANY stock replica), I personally have no qualms whatsoever about throwing in the trash, if it isn't right for the combo. I wouldn't worry so much about what that is.

Black Bomber

Glad to see some of the old bastards around. I found, when I was younger, that the police didn't frown down on a cam sitting in the back seat as opposed to a baseball bat. There RB and ede, is a good use for that cam!!

If all holds true, you'll get an honest to *** opinion form RB on the heads... you may not like it, but it'll be honest.

Black Bomber

*** is banned now? WTF?!? So now I live in a *** fearing nation? Geez...

355tpipickup

iTrader: (5)

ok well i talked to him more and he siad its a flat tappet cam and its often called a mushroom cam, i dont know maybe this will help!??

five7kid

iTrader: (14)

Mushroom cam? Not from the factory.

If it is a factory '69 Z28 cam, it is a flat-tappet, mechanical (solid) lifter cam. Very marginal from a streetabililty standpoint.

Also not that great power-wise compared to currently available cams.

35+ years have gone buy since that car came off the line. Who knows what's been put in it during that time? That chance of it having a factory cam after all those years is next to nil.

Pass on it and get a known quantity.

355tpipickup

iTrader: (5)

My dad is the one with the car, he built the motor, this is not a car that I am trying to buy!!! I am just trying to find the soecs for a 1969 Z 28 flat tappet "mushroom" cam!

five7kid

iTrader: (14)

Okay, I'll have to admit I skimmed through the thread a little too quickly and missed one small detail: It's in the 327 and you're trying to get it running better.

If it is the 69 Z28 cam, it's also known as the "Duntov cam". Here's a site about valve adjustment, if that helps any. http://65corvette.nonethewiser.net/t...AdjArticle.pdf

355tpipickup

iTrader: (5)

ok so its a solid lift cam, he got it new "back in the day" from a parts shop, its a gm cam, called the mushroom cam, i guess it was used in the 302 z28s, he said its not the base cam its more of a street cam, so im not sure if it will help or not.

rustybluebird

Yahoo is an amazing thing
http://www.rpmoutlet.com/camfac.htm
about a quater of the way down.

five7kid

iTrader: (14)

That explains what a mushroom cam is (you have to install the lifters from the bottom, before the cam goes in), but it doesn't explain what a GM Z28 mushroom cam is.

If it ever existed, this is the first I've heard of it.

RB83L69

It didn't exist.

The mushroom cams came out in the late 70s IIRC, as strictly race-only parts. They were NEVER put into production engines of any kind.

355, basically, you don't have enough information to identify your cam. All you have is a non-existent description containing lots of romantic-sounding buzzwords. Either you have a 350 cam; or you have a 69 Z28 cam; or you have a mushroom cam. Those 3 attributes are mutually exclusive. It cannot be any 2 of them simultaneously, let alone all 3. Or, of course, it could be none of the above, and it could all just be monkey-spank. I'm betting that's closer to the truth.

Bottom line is, you need a part number, because nothing else will do, if you want to identify it. Or, you just need to pull it out and put in something that you know what it is and you pick it for what it needs to do, and not worry about the buzzword situation.

But, this is a supposedly 71-back motor with supposedly 69 parts in a 74 car, so it's not thirdgen-related anyway; so I don't see how there's much more we can do for you here.

zNucleaRz

From GM PArts Direct

12364052 Camshaft Kit, Mechanical

Blueprinted replacement for factory P/N 3849346 with 290 hp and 302 cu. in. 228 camshaft, auto with 4000 converter.

Technical Notes: Basic rpm range is 4000 - 6800; and compression ratio is 11.0 - 12.5. The duration at .050 lift (intake/exhaust) is 254/254 degrees, and the valve lift is .485"/.485". Lobe centerline is 114. This camshaft kit is designed and manufactured by Crane Cam Co.®. It contains one camshaft and 16 tappets.

EDIT: Anyone read the part on http://www.rpmoutlet.com/camfac.htm that said

So does that mean they don’t exist or just became extinct? Also mushroom refers to more of the lifters not the type of cam? Seems to be a regular flat tappet with mushroom lifters. Also when I search for mushroom cams/lifters I get a lot of banned things from racetracks.

F-BIRD'88

GM performance parts did sell a "mushroom cam" and lifters for their Z28 "off road racing program" way back when.

It required spotfacing the underside of the lifter bores to clear the wide foot of the mushroom lifters.

Don;t remember the exact specs but it was more radical than any of the other SB factory racing cams of the day.
Z28 off road 1st design 257-269 @.050 and Z28 off road 2nd design
263-272 @.050"

it had near .600" valve lift.

If you have one of these cams you cannot use it with standard .842" lifters. It is a very radical high rpm cam requireing a very high compression ratio to work.

Its very unlikely you have this cam in your motor.

Do you know if the cam in your motor is a hydraulic or a solid cam?

If you were to measure the cam lobe lift with a dial indicator off the top of one of the pushrods you may be able to id the cam u have based on the valve lift.

SBC factory cams from the day had lifts ranging from
Hydraulics

.390-.410" stock 327-350 hyd "929 cam" 275-300hp cam

.447"-.447" 327 "325 and 350hp" L79 hyd
.450"-.460" 350 hp "350 horse" L-46 350-350
Also used in the low compression 350 L-82

Solid cams
.455"-.485" 1971-72 350 LT-1 solid
.485-.485" 327 365-375hp fuelie cam (dontov cam)
also used in the 68-69 302 Z-28 and early 1970 350 LT-1 with manual trans.

.493-.512" Z28 1st design off road (not factory installed.)

zNucleaRz

Arent these know as the DZ-302 cams? Not mushroom

RB83L69

No.

The "Duntov" aka "DZ 302" cam was a flat-tappet; 324°/324° advertised, 254°/254°@ .050", .485"/.485" lift, IIRC. It adjusted to .030"/.030" lash. It's been about 25 years since I last had one, so my memory could be a little foggy. After all, they do say that as you get older, your memory is the 2nd thing you lose. Trouble is, I can't remember what the first one was supposed to be.

The mushroom cams never were very popular. They were quite expensive, and as noted, required block modifications; so as cheap and easy as it is (and as it was at the time) to use rollers for more aggressive cam profiles which DON'T require block machining, nobody in the aftermarket was interested. GM couldn't get the racing sanctioning bodies (NASCAR specifically) to approve them either, so they just kind of withered and died.

F-BIRD'88

No "DZ" refers to the 1969 z28 302 engine block serial number prefix 1968 was "MO"

both the 1968 and 1969 302 Z28 motors came with the same
.485-.485" 254-254@.050" 114LSA solid cam
The valve lash was .030"-.030"

This same cam was used in the 1964 327-365(carbed) and 375hp fuel injected corvette motor.

the "mushroom cam" was a much more radical competition only cam. You had to buy it from the parts dept along with the special lifters and valvesprigns and install it yourself.

five7kid

iTrader: (14)

FWIW, the cam lobes and lifters have to be intended for each other, as always. The mushroom lifters had to be used with a cam with lobes intended for them.

tom3

Well to answer your question. Set the valves at .030 on exhaust and intakes, this was called the "thirty across" cam after all. The heads should be 64 CC chambers with 2.02 intakes and 1.6 inch exhaust, probably screw in studs and guides. Farily radical cam, not the best for this engine, too much duration and overlap and not so much lift. Decent heads but the unleaded gas will get to them in time. Set the timing pretty well advanced, at least 12 degrees intitial.

355tpipickup

iTrader: (5)

ok sounds like were gettin somewere, asked more questions and i got kinda mixxed up with things......my bad.....ok this is what he just told me--the block is a 1964 super sport impalla 300hp 327 stock motor, with the 1974 350 camaro heads,he thinks there 1.94 intake vales"reworked and milled" he was goin to use the 69 heads but he didnt want to drill and tap for the alt and they wouldnt work long with the new unleaded gas, the cam came from a gm parts store, solid lift cam, supost to be an option in a 1969 z28 302. he thought he read that it was a mushroom cam but i have told him what you all have said and he told me the cam has a lope to it but he dosnt think its as big as what you say the mushroom cams are! so i think this will clear it up a bit!!! sorry about the mix up!!

RB83L69

You're right, now you're getting somewhere.

The 74 heads are trash.

That's why the motor is weak.

You have a cam designed for 11:1 or higher compression, and a motor with about 7.8:1 compression. That's why it's SO LAZY off the line, and never has any punch at all. No cylinder pressure ever at any RPM.

The block does not care what sheet metal is had been wrapped on at one time. All the magic is gone out of it. A rebuilt 327 is a rebuilt 327, based on what it was rebuilt with, independent of whether it came out of Grandpa's sled, or an Impala SS. The cast iron has long ago forgotten all of that.

You'd get better results out of a set of 305 heads and ALOT less cam.

How heavy is this third gen Camaro/Firebird vehicle that this thing is in?

Air_Adam

Real '69 heads should have accessory holes in them already. That was the first year GM used them. If the holes aren't there, then the heads are '55-68 castings. They can have hardened valve seats installed, which would let you use unleaded fuel. If the holes aren't there though, you can't drill and tap them. Don't try to.

'74 heads suck. Period.

F-BIRD'88

The "optional cam for a 69 302 would be the 1st design off road cam. This cam is pretty big for a street car needing at least 10:1 compression, a 3500 stall converter and 4.10's.

The valve lash for this cam is .024"-.026"

It's a high rpm cam. What is the head casting ###'s?

The only way you're going to tune in this motor is to stop guessing and relying on your Dad's memory from 25 years ago. If you do have typical 1974 heads on a 327 the compression ratio is going to be too low even if the heads were milled a bit. They are 76-80cc's and can be milled to 69 to72cc's. Some of the 1974 heads are just not worth using.

If you have such a cam in a relativly mild combination other wise ( converter, rear gearing, intake manifold) you'd be much better off with a milder modern hydraulic cam.

The only way to id the cam while its in the motor is to measure the valve lift.

355tpipickup

iTrader: (5)

well i do know the 1974 camaro was made vary late in the year , the dash dosnt match the seat and carpet color, and he said somthin about the motor havin mixxed parts on it, he said they were just tryin to get it put together and sold!! ill have to take a look and find some #S