Has anybody else had problems with these? broke the second one this season today. They are splitting right around the shaft. Are there any aluminum shaft rockers that will handle high horsepower? What do you guys think?
what 496 dart said
did you get them new (complete assembly-shafts and rockers) and what kind of spring pressures are you running.
what RPM do you shift at?
i know a lab in Atlanta that can tell you about metal fatigue issues---stress,material,crack,etc..for a fee of course.
Harland Sharps are usually pretty tough. I won't tell ya that they are indestructable, tho! I'm also wondering if maybe there's another problem in the mix? I have seen valve retainers get into the back side of the rockers and wreak all sort of havoc. Friends Super Stock Dart had lots of cussing thrown at it, for that!
Yeh I always thought they were good to an have never had any problems in the past. The rockers are not hitting the springs. I know the angle on these is terrible so I have been going through the valves after every run. This is a 392 stroker moter with w2 heads. I got 651 horses on the desk top dyno but that is just a guess. I am running a 630 lift cam with quite a bit of spring pressure. I am running it in a sprintboat. I turn it 6500 for about 60 seconds. Am I expecting to much? Is there a better rocker out there?
Never had an issue with mine. I was told not to surpass 600 spring press. though. At that point better ones were suggested. Aluminum does have it's shortend work history also.
I think the geomety is about as good as you can make it on a small block mopar. Nothing is hitting or binding as far as I can tell. When I broke the first the new ones I ordered were alot meatyer than the originals. That leads me to believe they know there was a problem. I will check the exact spring pressure because I dont remember off the top of my head. Hate to spend that kind of money on a different set up but if I keep snapping these its going to add up to that quickly.
The ones I am snapping are exzaust. the wider ones on the intake I havent had any problems with. Using solid roller lifters. Did not get a chance to check spring pressure today but will tomorrow
I would say you have other problems, maybe ex/valve hitting pistons. I run a 422 small block with w5 heads and the same rockers as you it is also a roller with 640 lift, and shift at 7,000 have had for about 5 years with no rockers problems.. do you have race heads, or econ heads.
Do you have one thread on adjuster showing on push rod side? only other thing i can think of is hitting retainer on rocker are you bending push rods? I had same problem on my w2 using mopar alm rockers,,
This time I did bend the push rod. The first time got it shut down before I hurt anything. You would be able to see if they were hitting the rocker? Was it a continuing problem on the mopar rockers?
Checked the spring pressure this morning Got 532 open. I would think these should hold that eazy. Could it be the amount of time I am holding the motor wide open?
532#'s open is well within the range of Harland's. You either have a float problem or bind, I'd think. I've not done much with A engines, so I don't know sustained rpm effects the 59* valvetrain. I know harmonics is a big issue with the NASCAR teams and we all know they manage to go 600 miles, @ 9000 plus revs with flat tappet stuff!
Have you checked for coil bind at max lift. what is the spring hight should be around 1.90 to 2.00 on race long valve w2. If you bent push rod I would say you have a bind some where.
The bent pushrod was the next one over when the piece got stuck under it. No bent valves.Checked coil bind this morning when I checked the spring pressure. The springs were new this spring an havent got over 25 passes on them. I always back them off between races to since our races are 3 weeks apart. Never seen these do this before is why I am so baffled. Could it just be fatige from 6500rpm for 60 seconds? Looks like about 2 threads on the bottom side
I too run Harland Sharps and must say that I haven't had any trouble with the rockers. Now I have had some of the adjusters break off but I think they were used from another set that I had long ago. Got a new set and had no more problems. I run race W2s with the long valves and have over 600 lbs open pressure. Cam is almost .700 lift. If you have close piston to valve clearances and depending on the way you have your cam degreed, there may be an issue there. Also if there is slack in your timing chain/gear then your cam will tend to retard which will tend to decrease your exhaust valve to piston clearances. In this instance though you should have seen this on top of the piston. The only way you can bend a pushrod is if there was interference there mainly with the piston. Hope you find it! Wedgehead1
Talked to the tech at harlon sharp today. Said about 10 years ago they went to a beefyer rocker an mine happen to be the early ones. Said to send them all in an he would send out the new ones for $100. Glad to see there was a problem an they stand behind there product.