Do I Need my Drippers?

[Patrick N.]

Can someone educate me on the need for drippers on my valve covers? (68 L68). This is the first experience I had with drippers and wanted to know if they are a critical component? On the set I have the drippers have been cut down but the covers are very nice otherwise!

Should I begin my search for replacements or keep the set I have?

Thanks
Pat
68 427/400
88

[Joe L.]

Re: Do I Need my Drippers?

Can someone educate me on the need for drippers on my valve covers? (68 L68). This is the first experience I had with drippers and wanted to know if they are a critical component? On the set I have the drippers have been cut down but the covers are very nice otherwise!

Should I begin my search for replacements or keep the set I have?

Thanks
Pat
68 427/400
88

Patrick------


They're not critical, at all. In fact, many Chevrolet big blocks with hydraulic lifters never originally used dripper type covers.

[D S.]

Re: Do I Need my Drippers?

There has got to be a reason why some valve covers had drippers. I personally like them over the non-dripper valve covers especially if the vehicle came from the factory as equipped. I'm thinking of installing a pair of original ones on my '66 Impala SS396.

[Stuart F.]

Re: Do I Need my Drippers?

My understanding is that the drippers were primarily on solid lifter equipped engines for the expressed purpose of deflecting the oil squirted up through the push rod and hole in the rocker down onto the rocker pivot ball and valve tip. Otherwise, the oil under pressure would over shoot these critical areas, particularly if a short type adjusting nut is used. Applications using taller adjusting nuts did not need the drippers as the nut itself acts as a deflector. Made sense to me.

Stu Fox

[Bill M.]

Re: Do I Need my Drippers?

There has got to be a reason why some valve covers had drippers. I personally like them over the non-dripper valve covers especially if the vehicle came from the factory as equipped. I'm thinking of installing a pair of original ones on my '66 Impala SS396.

It's been a long time, but I remember we would occassionally burn a Mark IV rocker arm/ball on a hydraulic lifter engine running the durability test on the Tonawanda dyno. It was always the exhaust valve, and we would just move the intake set to the exhaust, install a new set on the intake and motor on without another problem. I don't specifically remember if those engines had drippers, but I'm assuming they didn't based on Joe's post.

In the case of an L88, the valve spring pressures are higher and the engine runs at higher RPM so it would have a much higher chance of a rocker ball burning, but I don't remember having a rocker arm/ball burn on an L88.

[Patrick N.]

Re: Do I Need my Drippers?

Otherwise, the oil under pressure would over shoot these critical areas, particularly if a short type adjusting nut is used.

Stu Fox

is the "over shooting" of oil constant at any RPM /changes in preassure- high rev vs. idle?

I would have to get my specs to clearly relay the cam I put in, but I have a cam with more lobe to it than orig and bored 0.60" over. Does the mods I made add any changes to the need for drippers and feeding oil to the pivot ball?

Thanks
Pat

[Jack H.]

Re: Do I Need my Drippers?

Yep, that's my recollection to, Stuart, (drippers for solid lifter)...

I also remember (sometimes you remember things that "ain't") the debut of the L78 back in '65 produced engines with slightly different states of tune + internal components and the Corvette version (exclusively solid lifter construction) being somewhat unique in that its crank featured a double journal to spritz oil onto the piston walls on BOTH the upstroke as well as the down stroke.

Plus, during shake down testing at Milford, Zora's staff discovered the need for dripers in the valve cover to 'focus' valve/push rod lubrication. I can't say which, if any, of these 'special' features (crank + valve covers) carried over to the other versions of the Mark IV, 396 motors...

[Jerry G.]

Re: Do I Need my Drippers?

How do you tell if a ball is burned. On the race car they turn blue but there is no gauling.? thoughts? Jerry

[Bill M.]

Re: Do I Need my Drippers?

How do you tell if a ball is burned. On the race car they turn blue but there is no gauling.? thoughts? Jerry

It's been 41 years, but I think they were squeaking (on the Tonawanda dyno engines).

[Ridge K.]

Re: Do I Need my Drippers?

I cannot address the issue on 1968 models, but I can on 1966, 1967, and 1969 big block hydraulic lifter Chevrolet engines.

I bought my first one in 1969 (SS396 Chevelle 350hp).
Since 1969, I have owned well over a dozen,

In my current collection, I own a 1966 Chevelle SS396 hardtop, still with it's assembly line installed 325 hp AIR engine. Built April 1966 at the Fremont plant, and having 48,000 miles today. It is 95% original with a no-hit body.

My second car is a 1967 Corvette convertible with it's assembly line installed L68 427. This car has 46,000 miles, as it sat in a barn from the late 1970s, until I purchased it in 2006. No-hit body, and 99% original.

Both of these hydraulic lifter big blocks have drippers on their original valve covers. The '66 Chevelle has it's original flash chromed covers. The L68 Corvette of course, ....orange painted covers.

My first big block from 1969 (Chevelle SS), likewise had drippers in it's factory flash chromed valve covers (350hp),.......known as I was the first one to pull them off at 40,000 miles.

I've also previously owned low horse-powered Impalas thru the years, equipped with big blocks ....and they did not have drippers.

[Stuart F.]

Re: Do I Need my Drippers?

Yes, bad fulcrum balls will chip, sometimes loud enough to locate by ear, but easier to pinpoint with a stethoscope. Gosh! I haven't used my scope in a long time. The squeak or chirp is much preferred to the clatter or engine miss brought on by one that was let go too long.

Stu Fox

[Clem Z.]

Re: Do I Need my Drippers?

to prevent "burned" rocker balls on new rebuilds use moly kote on them so you have not dry starts.