Duntov 30-30 302 Camshaft [Archive] - Team Camaro Tech

: Duntov 30-30 302 Camshaft


dh302
Jan 18th, 06, 08:53 AM
Sealed Power makes a camshaft they advertise being the same as a GM #3849346 with the 254 duration @ .050" (intake & exhaust) but with .455 lift. If you take .485 lift minus the .030 tappet clearance you do get .455 lift. Does any one know if this is why they are advertising the lift as .455? I think the sealed power part number is CS118R or something like that. Thanks.

Doug

Larger Dave
Jan 18th, 06, 09:04 AM
In a word, yes.

If you want the "sound" of the Duntov 30-30 (which is getting long in the tooth) with a more modern cam profile look at CompCams N+30-30H grind number 12-672-4.

Larger Dave

Gary L
Jan 18th, 06, 11:37 AM
GM designers back in the day were able to use "grocery getter" valve springs and basic parts (except hardened rockers) to make a great running engine. I am never quite sure why people think that changing the 30-30 cam for something else is such a great idea. Be sure to read the CRG article on lashing a 30-30 cam if you go that way. The Comp 1.52 roller tip rockers are a real good upgrade idea.

If you go with another cam you probably need to look at the proper springs and parts to compliment that cam. What does a "more modern profile" do for you? Does it last longer, have less maintenance? Changing the power charecteristcs I understand if you want more low end torque.:confused:

zdld17
Jan 18th, 06, 12:05 PM
2 cents here, I think the modern approach is to grind in 4 or more degrees into the cam and still call it the old 30-30 ? Still not the same. Eveyone wants to here" potatoe , potatoe, potatoe, etc.

dh302
Jan 18th, 06, 02:33 PM
Thanks.

Doug

1FASTZ
Jan 18th, 06, 02:58 PM
I think comp cams makes a cam that's a duplicate of the original 30-30, might want to check with them if you really want the 30-30. I think it's in their musclecar line of cams. If I'm wrong about it being comp, then it might be crane. It's definitely one of the two. I remember seeing them advertised a year or two ago.

Neil B
Jan 18th, 06, 03:12 PM
Crane makes the 30-30 blueprint cam, but several companies offer a cam with the same specs (Comp, Lunati, Melling, etc.). I run the modern Comp Cams '30-30+' solid lifter grind (PN 12-673-4) in my DZ and it's one nasty-sounding sumbitch. This cam is more responsive on the low end and has a killer mid-range pull. I shift between 6,000 and 6,500rpm with it.

zdld17
Jan 18th, 06, 05:05 PM
Above article is what I was referring to when aftermarket ie, comp , crane etc, go produce a muscle car cam,,, the lift #'s are same but the advance grind the cam to make them more streetable. 30-30 in a 302 did not have bottom end unless you had steep gears but hit above 3k or so ,, better hang on . I am referring to the factory #346 , 140 & 154 grinds..

pdq67
Jan 18th, 06, 05:06 PM
Want more torque, then install a stock, LT-1, 330/360hp/350, -178 solid cam!!

242/254, 116/110, .435"/.455" net lift or something like that!

pdq67

zdld17
Jan 18th, 06, 05:10 PM
True,, # 178 was the second generation Z cam , yes, it does develop more bottom end. Ran one of those too... I really liked that cam over the #346 for the street.

CJP_69
Jan 18th, 06, 05:27 PM
My 302 has the Crane musclecar blueprint 30-30 also with stock internals. M-20 with 4.10's, headers and a Flowmaster American Thunder 2.5 exhaust with the polished tips. Under 4000rpm its a slug but at 7000 it sings like a chain saw.

pdq67
Jan 18th, 06, 07:14 PM
Too many guys have said that they haven't been able to duplicate the exhaust sound of the 30-30 solid cam in their 302" Z-28 motors!!

pdq67

Gary L
Jan 18th, 06, 07:24 PM
Above article is what I was referring to when aftermarket ie, comp , crane etc, go produce a muscle car cam,,, the lift #'s are same but the advance grind the cam to make them more streetable. 30-30 in a 302 did not have bottom end unless you had steep gears but hit above 3k or so ,, better hang on . I am referring to the factory #346 , 140 & 154 grinds..

Is it just me? When I get to drive mine I am never very far from 3000 rpm. I have no complaints with the 30-30 for the street, even with my 3.73's. Of course I have never owned a BB.

zdld17
Jan 19th, 06, 04:42 AM
Must be you unless you are growing soft or have a Od trans. When I had the 4 speed with 3:73, I was just under 3, but if I found a side street for on ramp, rpm was always on the other side. Depends on whats in front of you and who is around.

As for the sound of a stock 30-30 cam,, Remember now that the distinct sound was produced at 900 rpm and stock low restrictive transverse mufflers.
It was some of the first balanced or both side connected muffler systems.
Today we run two mufflers and connected way up front.
My flowmaster transverse (17104K) with some up front flow thru glass packs almost produces that raspy super car sound.

pdq67
Jan 19th, 06, 06:49 PM
Gary,

Imho, if you aren't thumping on your motor up at least to 6500 rpm, then you just aren't letting the little bugger run like it was meant to run!!

Heck, I used to take my old homemade, unbalanced, junk301 above 7,000 alot with just the -097 Duntov solid cam!!

Hit her and hold on until my points bounced up around 7 to 7,500 rpm or so, she'd miss, I'd back off AND nail her again up ta 7,500 and shift!!

WoW what fun!!

pdq67

kirkwoodken
Jan 19th, 06, 11:15 PM
I advanced my 30-30 about 8 degrees and lossened the tappets to .035". That car had 3.73 gears and 1 7/8" headers, and yes, they were too big. Still the car pulled pretty good, much better than it came from the factory. I believe I put 72 or 73 jets in the front of the DZ carb along with jet extenders and changed to a 180 thermostat. Dist. was also recurved to something faster advancing but not as much. Probably about 16 initial with 40total. Those early heads seemed to need more advance than what's being made today. Isky double valve springs would give about 140 lbs. seat load and that would allow the 30-30's lazy lobes to spin 8 g's with something like a dual coil ignition. For those who can't remember, a well tuned z-28 would run in the mid 12's; still compares well to a new N/A Mustang. Old 375 HP 327's would also run 12's. The memory of their sound makes "my heart soar like a hawk." And 110 octane gas was 35 cents a gallon!

Quality was really a crap shoot with older high performance cars. Some ran good, some were dogs even though they were identical. Cars are built MUCH better today.

By the way, the DZ car was stolen with 3700 miles on it, and when found was totaled by insurance company. It had not been wrecked, but was without drive train.

pdq67
Jan 20th, 06, 07:15 PM
My -097 cammed, junk301 sounded great up about 7,000+ rpm as did my Long Gone Crippled Buddy's, Z-30 cammed 375hp/327 FI motor at 7,200 with his 2.5" dumps off right under it!!

I am really afraid that the kids of today just can't imagine this!!

Solid lifter cammed, short stroke, SB motor's that you hold down until YOU decide to shift!!

pdq67

Gary L
Jan 21st, 06, 12:02 PM
Potatoes are one of my favorite foods.:D

8178
Jul 13th, 08, 04:06 PM
This discussion sure takes me back to the good old days in 65 when I was building an engine for my car. Back then you could go to your local GM dealer parts department and pick up the 375 HP FI cam (30 30) and the lifter set for around $65 or so. The cams were very popular and most dealers had them in stock. My engine build included an aluminum high rise Corvette intake, Carter AFB (the one with air bleed idle speed adjuster that made the slight whistle sound like FI), light aluminum flywheel, Headmen headers, Mallory Rev Pole, aluminum bellhousing and an all aluminum case BW T-10 close ratio. Used a friend’s P&G valve gapper to set the lash. What a great tool! That was one bad sounding engine that pulled revs like crazy!! Used Chevron high octane for $.48 gal! There is just something about the radical 30 30 idle and valve lash sound combination that is beautiful music. My brother bought the car from me a few years later and replace the flywheel with a stock one and it never sounded quite same.

berkeleyite
Oct 7th, 11, 08:29 PM
I made the mistake of getting a 30 30 for my chev v8-its for high end road racing. slow on take off, easy to mess up push rods-the 8 18 is the way to go-wish I had.

berkeleyite
Oct 7th, 11, 08:30 PM
I made the mistake of getting a 30 30 for my chev v8-its for high end road racing. slow on take off, easy to mess up push rods-the 8 18 is the way to go-wish I had. Oh well