old 30-30 cam valve lash [Archive] - Chevelle Tech

: old 30-30 cam valve lash


548chevelle
Aug 19th, 07, 1:01 PM
My friend has a 64 Vette that has the 30-30 cam. I was wondering why that cam has so much valve lash (.030")? I had an earlier fuelie it only neede .012 and .018" lash. I know the later cam had more duration but its not really that much. I have a 540 big block in my '69 Chevelle and the cam with 255 degrees duration at .050" lift only needs .016 and .018 lash.

The Devil's advocate
Aug 19th, 07, 1:10 PM
As the "30-30" cam identification says...intake, .030, exhaust, .030.

Yes, there were early cams for 283 that used .012/.028, and others as well, like the 327 off road service package "098" ID cam, which used .018/.018.

pdq67
Aug 19th, 07, 4:03 PM
.012" and .018" lash is for the great old little-bitty Duntov, -097 solid lifter cam!!

Imho, it is onna the BEST little motor solid cams ever made!!

I had one I pulled out of a junk engine and coffee-canned it's lifters in my old junk301 and I loved it!!

pdq67

von
Aug 19th, 07, 8:40 PM
The reason for the .030/.030 lash in one cam and .012/.018 in another had to be in the way the lobes were designed. Back in HS I put an 097 Duntov in my 265 4 bbl '56 Chevy. It ran like stink for a stock 265.

461RAT
Aug 19th, 07, 9:17 PM
Hey 548CHEVELLE,whats up man?You wouldnt by any chance go to the Chatterbox on Saturday nights?If so,is that your 69 with the blower?

548chevelle
Aug 20th, 07, 9:54 AM
Yeah, I go to the Chatterbox, but I have a red '69, no blower. I think the one you have in mind is blue.

Jerry70
Aug 20th, 07, 12:29 PM
GM's original AMA lash specs for L-76 @ L-84 (the original applications of the "30/30" cam) were .025. This was changed to .030 in production to help low end torque.

Keith Tedford
Aug 20th, 07, 12:42 PM
It's surprising at how much bottom end torque you can pick up with looser lash. In our L72 engine I could actually feel the difference between 20-24 and 24-28 lash.

Jesse66Original
Aug 20th, 07, 4:08 PM
097 Duntov's how sweet they were in my time in 283's,292's and oh yes 301's. And the price was right over the Chevy parts counter. If my memory serves me rright they had a green painted band next to the distributor gear, been a long time ago.

Jesse

OLDED
Aug 22nd, 07, 3:44 PM
Still have one in my old 59 Vette. It really is a musical sound to us old timers of the "day". It needs adjusting about every 10 years or so. It really is a great cam for those little mice size motors. Olded

Jesse66Original
Aug 22nd, 07, 8:21 PM
Olded, I can very much appreciate your 59 Vette, since I finished High School in 1960, That was my time for sure and the 283 270 H.P. two fours has a place in my heart, and yes that combo hit a nice sweet lick that I still enjoy hearing. I am a cam nut that loves to hear on hit a good lick.

Jesse

TXCR13
Aug 22nd, 07, 8:42 PM
Dudes-
It's all about that "clicking" sound the solids made back in the day. I liked the exhaust note as well, but to me, it was that great solid lifter click that sounded so cool, especially when the hood was up!
TXCR13
'66 Chevelle 300 2dr with a LONG way to go!

pdq67
Aug 22nd, 07, 10:26 PM
Here's one for the book's!

Back when I was divorced and batchin' w/ my Buddy Doc, he had a '70 Duster w/ the old 225 slant-6 banger in it and one Sat. morning we were changing oil and whatever and the old Duster was justa sewing-machining along and I asked Doc, when the last time was that he lashed his slant-6??

He looked at me kinda funny so I told him that solid lifter engines should be lashed every so often and he replied never in the 175,000 miles that he'd driven it!!

He, He!! the little sucker just clicked away so beautiful to my ears back then..

pdq67