aaronz28

Ok, i'm not looking for cam recommendations specifically -
but my otherwise all stock 64 L84 has the 097 in it -
i've always loved the 30-30 which i'm 100% certain i'll swap too sooner or later -

but for the time being - i just pulled the valve covers off to adjust lash - and found that they are REALLY loose - like some opened as far as .045 -
(no wonder the car really wasn't all that impressive winding out) especially on tight lash cam like the Duntov

but i've decided to switch to poly locks since I no longer trust the lock nuts and since its a pain in *** to get the drivers side valve cover off with FI - and wondering - as long as all 16 rocker nuts are coming off - should I throw 1.6 rockers on to help out that cam some? or leave it along until i go to the 30-30 (probably sometime this fall)

I have zero experience with the 097 cam - and have had the 30-30 and LT1 cam in several cars so I know what to expect performance wise.

i've read that the 097 is about as good a vintage old school street cam that you can get - without the lopey idle of the 30-30 or LT1.

any thoughts on the rocker conundrum?

Cheers

Aaron

MikeM

Set the lash at 8-18 using NEW OEM type lock nuts. Forget the rockers and forget the polylocks. You won't need them until you adjust the valves 5-6 times. How long will that take?

aaronz28

sounds good - weren't you the guy who recommended 1.6s on the intake?

MikeM

No! But there is a guy here that has one of those desk top dynos, a gas pedal screwed to the floor under his desk and a broom stick beside his chair so he can shift gears while he's getting the max performance out of his latest program.

I like the durability of stock OEM parts.

aaronz28

I do to, but the OE rockers are more like 1.3 according to swcduke and john h's article. So at the very least- a good set of 1.5s are required. And poly locks are just added insurance from having to take the damn FI throttle body off

MikeM

That was old news in 1955 if you remember or ever read any old camshaft ads. Chevy engineers knew what the actual rocker ratio was when they designed the camshaft but you can do as you like.

You asked for opinions of those who have run the cam and I've run several of them over the years along with the OEM rocker nuts and no hi lift rockers.

aaronz28

Absolutely. Ive never run the 097 and even now- until i get it lashed right, and the correct timing on this motor i cant comment on how i like it. Will keep er stock- get it right-and go from there! Cheers

Gene jockey

You might look at the rocker studs, even though it involves undoing some of the FI plumbing. I had a problem that sounds like yours. I had a hard time keeping valve lash on my FI engine. It turned out to be loose rocker studs, not bad rocker nuts. Replacing the rocker studs seems to have cured the problem.

65tripleblack

I'm the guy with the gas pedal screwed to the floor with the desktop dyno, and I have a finished 327 engine that makes close to 500 HP with tons of bottom end torque, to prove that I can design and build 'em.

Some other dopes here are stuck in the past and have heads like concrete blocks.

I'm the guy who recommends 1.6 rockers (both sides) when using an 097 cam with 2.02/1.60 heads. I like the Duntov better than the 30-30 in many regards because of the tight lash (smaller clearance ramps). If you do this, be sure to increase lash on both sides in proportion to rocker ratio increase, and make sure that you have enough clearance in the pushrod (you will, but check it anyway) slots. It would be cheaper to pin your rocker studs as insurance rather than spend a lot of money on machining for studs. You can pin them yourself without removing the heads. There are at least 2 guys here that can comment on this upgrade.

If you want to change camshafts, and want an OEM cam, then use the LT1 instead of the 30-30 (because you have FI). Better still, upgrade to a hydraulic roller.

65tripleblack

That cam is too small for "big valve" heads.

It was OK for the 283 with 1.94/1.5 valves. It's a great cam, but needs more lift to use the full potential of the later heads.

BTW: the actual rocker ratio is 1.37:1 @ POML.

ohiovet

Any thoughts about a L79 cam? GM 151.
Lots of vacuum and no solid lifters, although I like the solid lifter sound.

65tripleblack

Not a "real" SHP cam, but it would work perfectly with the OP's application.
I like solids because they rev higher, although guys that zero lash their hydraulics get an extra 500 RPM or so with theirs. Of course, the higher revs are only needed if your engine is still making good enough power on the top end.

aaronz28

The L79 is great cam but i wouldn't use it in an original solid lifter motor.

as for 1.6s on the 097 -
my only concern is that i don't have guide plates or screw in studs - - which the aftermarket manufactures recommend for use

i'll double check to see if the studs have been pinned yet or not - I've done it before myself. cheers

Donny Brass

Aaron,

I have a really nice set of gently used roller tip rockers you can try out

they are a true 1.52:1

aaronz28

Donny - thanks - but i actually have a set of those myself on my 302 (which is now on the engine cradle) I was thinking of borrow them lol

i do think the 1.6s are the route to go for the short term - until i get the bigger brother in that FI motor - but until then i think i'll resist blowing money - and put the 1.52 roller tips i have on

Cheers
A

MikeM

I ran a L 79 cam in an otherwise stock 327/375. It works great as well. Running great defind by smooth, torquey and powerful. RPM limit was 6000 with stock springs. You don't need to run that cam any faster than that anyway.

I never recommend hot rod stuff for the reasons you state above and for the simple reason the OEM stuff is reliable. I've spent a lot of time working on cars in the past, now I just like to ride and not be concerned about breaking something.

I've heard conflicting reports on whether or not the high lift rockers will do little if anything for a SBC with stock heads. Your call.

aaronz28

I too am a big proponent of factory OE parts - but that isn't to say that there haven't been some improvements that are just as rock solid in terms of durability. For instance - the new roller tip rockers with grooved rocker bearings are indeed a drastic improvement over the oe stuff - that isn't to say that the OE stuff is junk - just that the roller tip indeed reduces friction - and it actually helps in aligning the rocker flat on the valve stem - not to mention consistent ratios.

Somewhere I read that a study was done on OE rocker arms and that the actual ratios (while supposed to be 1.5) were all over the map 1.2 to 1.4 and everywhere in between - how much real world power that equates to, I don't know - I suspect however that there is a reason that GM dropped the 097 cam shortly after they increased cubic inch to 327 and specifically when they opened up the valve sizes to 2.02/1.6

The rockers on my 327 are not the originals, but i can't be certain what manufacture they are.

I too have seen conflicting results on the 1.5 vs 1.6 rockers - but those examples were all on considerably larger camshaft in larger engines on aftermarket heads.... it certainly stands to reason that a .400 lift cam would benefit on an engine larger than it was originally designed for with heads (also larger than the cam was designed for) which are capable of flowing well up to .500

nevertheless - there is no real reason to debate this further.

I'm gonna throw the 1.52 roller tips and poly locks on for now - and revisit this when i do the cam swap down the road! Maybe the LT1 with 1.6 on the intake and 1.5 on the exhaust - i have a version of the LT1 cam that is essentially an OE blueprint - except the lobes were phased 1 degree closer to put it on a 115LSA instead of the factory 116

My last 64 - which was an L76 - had the LT1 cam in it when I got it - i later swapped it for the 30-30 which I preferred - but i also had a hot rodded Holley on it...

ramblings ramblings ramblings - sorry!

cheers
A

jerry gollnick

I run a Rochester FI on my road race car. i've spent a fair amount of time on the flow bench figuring out how to get more usable power out of the 461 heads and the essentially stock cam combination. i don't think the 1:6 rockers will do much. More lift is not the problem and the stress it puts on the stamped rockers and studs doesn't seem worth it. i got the best improvement by relieving the heads around the intake side of the combustion chamber and then going with more duration not more lift. These old heads shroud the intake valve pretty badly so for bang for the buck i would start there.

65tripleblack

"I've heard conflicting reports on whether or not the high lift rockers will do little if anything for a SBC with stock heads. Your call."

Now there's a remark proving that the person who made it knows nothing about designing and building engines that make torque and power. He should think outside the box some time. Maybe even get himself one of those gas pedal and broomstick contraptions that attach to the computer. On second thought, fuhgeddaboudit.....he wouldn't have a clue as to how to use it.

The fact is, is that one cannot simply make a blanket statement like that, because it doesn't apply IN THIS CASE. Explanation:

The 097 cam is a great cam but has very low lift. It was designed for the "small" valve heads. If someone wants to use the 097 with "big valve" heads, then the engine will positively respond to the added lift provided with the 1.6:1 rocker arms. THE PRIMARY REASON FOR USING HIGHER THAN STOCK RATIO ROCKER ARMS IS IF YOUR VALVE LIFT IS NOT FULLY EXPLOITING YOUR VALVE DIAMETER.

MikeM

[QUOTE=jerry gollnick;1589839015]I run a Rochester FI on my road race car. i've spent a fair amount of time on the flow bench figuring out how to get more usable power out of the 461 heads and the essentially stock cam combination. i don't think the 1:6 rockers will do much. More lift is not the problem and the stress it puts on the stamped rockers and studs doesn't seem worth it.


Looks like a conflict between "hands on" and "desktop dyno" baloney.

Nobody asked but I could build a real good big inch SB short block for a lot less money than what it costs to put a roller cam in an engine that wasn't designed for it to start with. That's the biggest bang for the buck!