FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: fryedaddy on May 05, 2017, 07:46:31 PM
-
can anyone explain this,at idle my harland sharp rockers have 60 psi cold and 30 hot,oil pressure that is. and my factory adjustables have 75 cold and 50 hot,why the lower oil pressure running the hs rockers,and would you rather have the extra oil pressure,or the roller rockers?nothing else was changed but the rockers,on the same engine on the same day.
-
More leakage with the HS rockers
-
maybe they arent shimmed correctly might be to loose
-
The aluminum HS rockers will expand more as they heat up than the stock cast iron rockers, but still, that seems like more difference than I would have expected. Just last week, we broke in the new flat tappet cam in my fresh 428 CJ that I will will be installing in my 59, on my buddys engine dyno. Although I do plan on using iron adjustable rocker arms on this 428, the pushrods I had on hand were too short, but when I installed the Erson roller rockers, there was enough adjustment, so I used the Ersons for the cam break in, and a few dyno pulls. Keep in mind, the Erson rockers have needle bearings on the fulcrums, I believe that the Harland Sharps do not, so I think the Ersons should bleed out more oil than most others. That said on the dyno, the 428s oil pressure stayed steady at 80 PSI hot above 3000 RPM, and had between 55-60 PSI at idle. Frankly the oil pressure was higher than I expected (I am using a 57HP oil pump), and I was using Joe Gibbs 15-50 BR break in oil. I am guessing when I switch to 10-30 Brad Penn oil, the oil pressure may drop down some. What oil are you using?
-
i shemed the rockers like the book said,they lined up good.my engine also has 75-80 psi over 3000 and over 50 hot at idle.the hs rockers are brand new.and i use valvoline 10w-30 conventional.but what about the trade off,roller rockers at 60-30 psi or iron rockers at 80-50?
-
What are the details on the rest of your engine? I have used OE Ford and Isky iron adjustable rocker arms, with shaft ends supports for many years, on solid flat tappet cams with well over .650" lift, with no rocker failures. The only reason I ever went with aluminum roller rockers, was to make life easier on the valve guides with the larger cams. (By the way, when I switched from the iron rockers to the Erson full roller rocker setup, I saw zero improvement on the ET slips). Unless you are running a solid roller cam, I think the iron rockers, with either thick walled shafts or end supports, are sturdy enough, I just like a roller tip with higher valve lifts. That said, since you already have the HS rockers, I imagine that you want to use them. I have had many FE engines that ran just fine and had no issues with a fair bit less oil pressure than yours does, even with the roller rockers. I agree the drop in oil pressure does seem like a lot, I would remove the roller rockers, measure the shaft OD and rocker ID, and check with Harland Sharp to see if the clearances are within their specs. Another thing to check, is to make sure the hold down bolts are not too long, which could prevent the rocker stands from seating solidly against the head, allowing oil to escape from between the stand and head, that would drop the oil pressure for sure. But otherwise, 30 PSI at hot idle with 10-30 oil would not bother me in the least, as long as it comes up with RPM.JMO
-
thank you Rory,great info,im sure my combo is mild enough to use the iron rockers,and i dont care which set i use as long as everything is ok.let me tell you my engine story,my uncle Roger was a racer a a big fe fan.i remember when he used to run hobby cars and the rules let chevy run up to 454 and dodge 440,but fords were limited to 390 ci.i watched my cousin in my uncles car many times got to the front with his 390s,even saw him start last and come to the front in less than 10 laps.my uncle promised to build me a strong fe,i have owned many fes but nothing over 450hp.i took my uncle a 66 428 and a set of cj heads and pi intake.he bored the block .030 over,the crank was good so he internal bal it,speed pro 10.7 to1 forged pistons, msd dist,coil,wires,arp studs in the rods and mains.he was going with a solid flat cam,but he got sick before finishing my engine and died.his wife told me i could come get my engine.i told her i owed roger for work and parts and machine work,but she said come get it,you owe nothing.so i picked it up and took it to the machine shop,who is also a fe fan.i told him my story and he finished my engine for 200 dollars.i had to put a hyd comp cam in it because me and roger never got around to getting the solid cam.the hyd comp cam is a mild.243 at .050,less than 600 lift.but anyway it runs great in my comet with 411 gears,c6 3500 stall.i put a set of bbm heads and rpm intake on it about a month ago.i just came in from the garage and found out why the low pressure.my hs end stands are hitting the top of my arp head bolts.i saw a dent on the edge of the end stand where it came in contact with the head bolt.i guess i need to tell hs rockers im sorry. could i grind some medal off the edge of the stands or head bolts?they are barely hitting the head bolts just enough to cause a tiny gap under the stand.
-
If you want to use those, just clearance the stands. Not a big deal.
-
those hs rockers were a Christmas present so i guess i will clearance them and use em.THANKS BRENT