If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You must be an NCRS member
before you can post: click the Join NCRS link above to join. To start viewing messages,
select the forum that you want to visit from the selection below.
Hi, everytime I see a reference to big block repro valve covers they are either with or without "drippers". First, what are they and, second, are they required for a non-judged car. Anyone with a smattering of technical ability could probably fake his way through a cursory explanation (I'm thinking of me in that regard). What I want to know is the nitty gritty... Thanks in advance.
Mike
aka "never had a big block before"
1977 L-82 M-21 Two-Time Top Flight
1976 L-48 M-38 nothing is correct
1973 Triumph Bonneville 750 T140V
they're small metal tabs spot welded on the inside of the valve covers on big blocks. one can see the spot weld scars on the exposed surface of the valve cover so if ya have a 67 435, the judges will want to see the scars. the drippers enhance lubrication of the valve train, albiet a small contribution for a street engine. mike
i thought it came from unprotected sex. they are in the covers to prevent the oil spray from overshooting the rocker ball pivot point. some hyd lifter BBC covers did not have them
If you are concerned about judging, it is my understanding that the repro's can be seen from a mile away. I have heard they look very nice, too nice. Originals will have wrinkles and such in the corners and waves across the face where the drippers are tack welded. I would gladly take your originals off your hands Terry
Sorry Terry, I don't have any originals. I'm building a "driver" LS-5 engine from scratch and I simply wanted to know if the drippers were necessary. It will never be judged, I simply like the chrome of the '70 vintage LS-5 motor and the price on the repros w/o drippers is much nicer than the exact copies.
Mike
1977 L-82 M-21 Two-Time Top Flight
1976 L-48 M-38 nothing is correct
1973 Triumph Bonneville 750 T140V
You are right about the valve covers and the prices are very reasonable. I would think the drippers would be a benifit for you. I have taken apart too many big blocks only to find their rocker arms badly gaulded especially the one's that didn't have drippers. The other consideration is if you plan to do any modifications to the cylinder head valve train. In that case there may be an issue of clearance.
cut some leather from the ball pockets to trim out some new washers to stop the dripping. I guess that explains why after awhile the balls would fall through the pockets and hit the floor.
on race engines where we had to use the stock rocker ball and rocker arm and we used heavier valve springs because of the cam we used we welded a piece of sheet metal over the pushrod side of the rocker arm so all the oil would be trapped in the rocker arm pivot point. this worked well when we used edge orifice lifters to keep the oil in the oil pan because the piddle valve BBC lifters put 15/20% more oil upstairs and cause a drain back problem and the pan would got low and the oil pressure would start to drop.
Over the past 20 years, I have had multiple big blocks both with and without the drippers. For a street driven engine with reasonable spring rates and the stock type piddle valve lifters, it really doesn't matter. Case in point, look at the thousands of one ton trucks built in the past 20 years - no drippers! In fact, a lot of the trucks don't even have a grooved pivot ball.
By the way, you can even use steel roller rockers under the stock or repro covers without the drippers if you use the Fel-Pro thick gasket, but the stud girdle won't fit - had a sleeper or two with a roller cam.
I currently have a set of the e-bay $30 dollar covers on my driver 1970 454. They won't ever fool an NCRS judge, but they look nice when you pop the hood at a local cruise night.
it may be the case that high RPM of solid lifter engines need them. i can not believe the general would spend the extra money to put them in certain engines if they were not required.
There were many parts on the solid lifter engines that weren't necessary for street use but were added to make the parts "legal" for "stock" racing classes.
Forged cranks are a very expensive example of this, I've run many big blocks to 6500 RPM with a cast crank and over 500 HP but the factory knew that in sports car and circle track racing the forged crank would be necessary.
I would bet that in motors used for long times in a high load, high RPM application, the stock rocker arm balls would gall and wear out, especially with higher than stock spring rates - so the factory added the drippers. It also explains why many racers would use the Ford Boss 302 stamped rocker arms with the needle bearing trunnions instead to avoid the galling.
That logic may well apply to the aluminum SB valve covers introduced in '69; my '69 Z/28 has its original valve covers, and they have no drippers. The exact same valve cover was used in '70 for solid-lifter Z/28's and Corvette LT-1's, and drippers were added to the castings for '70. Didn't matter for Trans-Am racing in '67-'68-'69, as Traco used their own valve covers on the factory engines.
We use cookies to deliver our services, and to analyze site activity. We do not share or sell any personal information about our users. For additional details, refer to our Privacy Policy.
By clicking "I AGREE" below, you agree to our Privacy Policy and our personal data processing and cookie practices as described therein. You also acknowledge that this forum may be hosted outside your country and you consent to the collection, storage, and processing of your data in the country where this forum is hosted.
Tweet
Comment