For the second time I've had a rocker seize on the shaft. I've got a 1965 200 cubic inch block with a 1980 granada 250 cubic inch head. Stock bottom end, and a early model 144- 170 cubic inch adjustable valve train. The head has been modified to accept a 350 CFM Holley carburetor. This is a street driven combination that is used for car shows. Has anyone else experienced this situation. It first happened on #1 Cylinder, second rocker, causing a backfire that blew the plug out of the front end of the intake log, and bent that pushrod. Disassembled, cleaned, filed, honed a reassembled. It ran for about a year, and unfortunately happened again a few days ago. This time it was a different rocker, #4 push rod once again off the rocker, but not bent. Had to use a puller combination to disassemble the rocker. I run a quart of Lucas additive and 15 w 50 Mobil one oil ( the same combination I run in my 1956 Ford pickup with a 455 Olds engine ). Any one else experiencing this situation.
Rocker Arm Seizing to the Rocker Shaft
- Thread starter 1965Pony6
- Start date
When you were ready to install the later head, did you mill it .070". If so you should have enlarged the egg shaped area leading to the oil passage to the rocker arms. Without doing this you starved the transfer of oil to the head from the oil supply at the left side rear of the block.
Are you using the early forward pedestal with the top cover? The one that dumps oil to the distributor gear through a hole on it's underside? If so, that can't be helping, replace it with a regular pedestal. Get a new shaft, deburr all the oiling holes, ensure an 1/8" drill bit will pass through the oil passages on the rocker arms. If not, drill all rocker arms to 1/8". Ensure there is no excessive wear on the rocker bores and that their oiling grooves are clean and clear.
I did have the head milled .065, and I did enlarge the egg shape hole leading to the oil passage. I ordered the complete adjustable valve assembly from Vintage inlines as well as the appropriate proper length pushrods. At this point I am going to have my machine shop take a look at rocker arm assembly,. I do thank you for your responses, and I will keep you updated on the eventual outcome. Incidentally it does run much better, and I have installed power front disc brakes as well.
is it #11 or 13 that is shaved for oil passage? That help here?
"...It ran for about a year, and unfortunately happened again..."
@ the hr/mi U use it, that is "almost immediate" so there's that too.
Pretty late, addled brain here. Hafta read again. Like the pedistal idea as swapin can substitue incorrect there...
"...It ran for about a year, and unfortunately happened again..."
@ the hr/mi U use it, that is "almost immediate" so there's that too.
Pretty late, addled brain here. Hafta read again. Like the pedistal idea as swapin can substitue incorrect there...
If you are not getting oil to the rocker shaft & you did state you enlarged the egg shaped access for oil to the rockers.
That being said, you will have to pull the engine & you will probably find your problem at the rear camshaft bearing. The groove in the rear journal of the cam transfers oil via passages in the block via the rear camshaft bearing. Either the bearing has spun blocking the one or both oil passages or one or both are blocked in that area.
Oil is sent via a passage in the rear main bearing to to the rear cam bearing & the groove in the camshaft then to the passage that exits at the LR of the block.
Good luck.
That being said, you will have to pull the engine & you will probably find your problem at the rear camshaft bearing. The groove in the rear journal of the cam transfers oil via passages in the block via the rear camshaft bearing. Either the bearing has spun blocking the one or both oil passages or one or both are blocked in that area.
Oil is sent via a passage in the rear main bearing to to the rear cam bearing & the groove in the camshaft then to the passage that exits at the LR of the block.
Good luck.
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You should be running 10W-30 oil with zzdp additives. What you are running is too thick, that could be also part of your problem.
Hello, My reference to Vintage Inlines was returned by Matt, he provided the info to Gary at Rocker Arms Unlimited in Redding California. Gary wanted me to send my assembly for evaluation. Bill at B&B here in Mesa wants me to reassemble my rocker arm assembly and check for coil bind on the valve springs, which I believe I'll do. I have also noted that 5 of the hold down bolts have reduced midpoint diameters, but one of the bolts does not. I also want to point out that each time I have checked, I do have oil coming from the oil supply points on the rocker shaft. I have cleaned up the rocker arms, and will be assembling my original shaft with the adjustable rocker arms. A fresh oil pump has been ordered, and before I refire the engine it will be with fresh oil, 6 proper hold down bolts thru the appropriate stands. I will keep you updated
Can anyone in the Phoenix area provide some info on these hold down bolts. Are there suppose to be six matching bolts or is their one that is different, the reason I ask, is one of mine does not have the shaft reduction the others have. Perhaps that is the cause of my oil restriction. Most bolts in this application reduce to 5/16 about 7/8 below the head and come back to 3/8 course thread at the end. One of these bolts is a standard 3 1/4 long 3/8 course bolt. I can see that it would limit oil flow. Incidentally I have found the Zinc formula from Lucas and will be adding it as well as a new Melling oil pump
The rear bolt is the only bolt that needs to be necked down..You can see on the head, the oil hole.
Thanks to all of you who are following along, given I was working with a mismatched set of hold down bolts, I contacted ARP, the folks who provided my head stud kit. After talking with several of their personnel, they pointed me back to original equipment. I contacted a salvage yard, with positive results for the bolts, and was able to return with a complete rocker arm assembly. The rocker arm assembly is reassembled with engine assembly lube, 1/8 holes for oiling, six grade 8 reduced shank hold down bolts torqued to 35 FT#. I still plan to replace the oil pump and refill the crankcase with fresh oil and the Zink additive, and hopefully that will be the end of my sticking rocker arms, I will keep you apprised. And I will also be providing info to my machine shop on the spring coil bind issue, but with a stock cam I do not think that will be the problem
Hello again, while waiting for my timing gears to arrive, I began assembly of my Kool flow water pump and ran into a situation. My new pump would not turn, I checked and found that the ARP stud in the front right position extended into the water jacket and was in conflict with the pumps impeller. I know that because the original pump with a stamped steel impeller was marked by the bolt and bent (limiting the pump capacity). When I installed the new pump with the machined impeller, it would not turn (luckily I did not tighten it). The solution, stud removal and 4 threads removed and reinstalled. New oil and water pumps installed, Rocker shaft installed, waiting for the arrival of the timing gears. If you are using ARP studs check that those water pumps are free, because those stamped impeller water pumps will deform and you will not know it until you take them apart. Also wonder what others have done about radiators, I have a three row aluminum unit that will not allow the use of an electric fan due to space limitations, I can modify the mount but I was trying to avoid that. But if no other solution is available I will remount the radiator.
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If you are getting the adjustable roller timing set, do not use the oil slinger if you have one, it is not needed and will hit.
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