I inherited a 316 pontiac. I started taking it apart to see what I had. It appears that someone in the past put in screw in studs in the heads. I have read that these heads get oil through the studs instead of the lifter/pushrods. I have a broken stud, a few mushroomed valve stems, and a few rocker arms that the pushrods ate into. What are my options for getting this right? Switch to diferent rockers, change studs, or ??? Thanks.
My 55 287 gets oil through the pushrods and splash lubricates the rocker ball and end of the valve stem.I would assume the 56 engine does the same.Sounds like someone over-revved the engine a couple times.It doesn't take much to bend a pushrod or put one through the rocker arm or pull out a press-in stud;these engines really don't like a lot of rpm.I'd drill out the stud and replace it and when you get it back together go easy with the right foot.
Thanks, safariknut. I thought I read that the 55' valvetrain was a one year only. Does your rocker arms have a hole for the oil to go through at the pushrod end? Mine don't. I don't have the stock press-in studs. These are screw-in studs that someone added.
Yes they do have a small hole in them.If the rocker arms have been changed it is possible that someone may have substituted rocker arms designed for a solid lifter engine.Does your engine have hydraulic lifters in it?Easy enough to tell;just press down on the pushrod end of the rocker arm and the lifter should depress slightly.I would check this after the engine has set for awhile. Possibly the reason that screw-in studs were installed is that high lift rocker arms may have been used.I think the standard rockers have a 1.6 to 1 ratio and the high lift ones are 1.75 to 1.These can sometimes cause problems such as coil bind in the valve springs and even holes in the rocker arms and bent or even broken push rods.Many times high lift rockers can cause studs to pull out. Just some ideas to ponder.
No, my rocker arms do not have holes in them. Yes I have hydraulic lifters. My father-in-law bought this a few years ago and left it outside for a few months before it got put in a barn with a tarp over it. I started tearing it apart to see if it was useable. From the looks of things, this engine had a pretty fresh rebuild. I have found fresh freeze plugs, hardly any carbon on the pistons, and the cam and con-rod bearings look like new. I have'nt checked the mains yet. It also has a new cloyes timing chain. I can also see the cross hatch on the cylinders after I cleaned them up. I'm guessing they starved the valvetrain of oil pretty quick and pulled it for something else.
I had a factory high performance in a late '56 and it was a really strong engine. It came with a different set of heads and valve train. I'd suggest you talk to someone on the Pontiac website about that engine. They used to be a sought after block by restorers and performance people too. When in the Quarter Mile Drags they made a good accounting. Lots of racers saw '56 HP 317 tail lights at the finish line. Mine came with 3:90 rear end gears, dual quads and an improved exhaust manifold setup too. Normbc9
You will need later rockers with the hole in the push rod cup if the studs are solid. That's how you will oil the rocker ball. If someone had put a bigger cam in it in the past and revved it up too much, then it pulled the studs up, hence the screw in ones were installed. 99.9 % of Pontiacs have 1.5 rockers ..Only the RA IV and Super Duty had 1.65's...and that's why they were offered as a replacement part.
You are right, the 316 was a one year only engine - 1956. It came in two forms, a 227 HP model with 8.9 to 1 compression ratio and a 205HP version with 7.9 to 1 compression ratio. The lower compression model can be identified by the letter "L" with a circle inscribed around it, stamped alongside the engine number. All '56 316's used hydraulic lifters from the factory and oiled through the pushrods. Starting in '56, all Pontiac V-8 hydraulic lifters were adjusted by tightening down the rocker adjusting nut until it bottomed out and then torquing it to 15-25 ft. lbs. The factory studs had a shoulder on it which was precisioned machined to give the correct clearance. Given that the studs have been replaced with screw-in (probably during the rebuild) to either accommodate a aftermarket cam or as a hi-po upgrade. Either way, the valve train damage could have been caused by the valves being improperly adjusted along with oil starvation due to the lack of oiling holes in your rocker arms.
so if newer rocker arms with holes. any 1,5 pontiac?he can use skrew in studs and plug oil hole in heads. on my 57 engine i have problem with adjusting it with 15-25ft,lbs. engine started but when i shut it of lifters where pumped up with oil.and valves where opend.so it would not start again.so lift on my new installed cam was to high for rocker arms. i boughth a cam sold as standard aftermarket 4 barrel 55-79 when i rebuild engine. i adjusted as a chevy small block with looking nuts (same size thread) it started and did a new adjustment warm and i have been like that sinse 8000miles
I have read on another forum that I can use stock sbc rocker arms on the 55-60 pontiac heads. Can anyone verify this? If so I think that would be the easiest solution to my problem......Thanks
I would recommend being in touch with someone who KNOWS. Lots of ideas floating around here... I had an oiling issue with my 57 and was under the assumption these engines NEED the oil from the rocker studs to lube the rocker pivot. The oiling systems on the early Pontiac v8s were unique in the stud oiling system. I would recommend a phone call to Butler Performance, http://www.jbp-pontiac.com/ When I had my issues they helped me A TON!!! I emailed my questions and received a phone call from Jim Butler, the owner, who gave me as much advice as I could handle. I never spent any money with them. Just a nice guy, helping someone out. He spent about 30 minutes walking me through my issues and helping me troubleshoot over the phone. Just my thoughts, but you need good advice right now so you can fix whatever issues you have. Nothing worse than a bunch of bad advice that ends up costing lots of time and money to repair.
Thanks bryan6902. I'll keep that in mind further on down the road when I get a little closer to actually doing something. I hate to bother a vendor when I haven't purchased anything from them. Besides, that's what this board is for, to share ideas and information. I did play around with a chevy rocker arm last night. It looks like it might work. It fits the ball and stud and it appears to hit the valve right. I'll have to experiment more when I get the block back together. Thanks
No problem. Although this is a great resource, sometimes even the best intentions or advice can be incorrect. I'm guilty of dispensing bad info too.... Plus we need as many of these old Pontiacs back rolling as posssible!!!
I'd check to see if the new rocker studs have the hollow centers for rocker oiling. With all the valve stem mushrooming and holes in your rocker arms. it may be due to no oiling because of incorrect studs. They need to have a hole drilled in them from the bottom of the stud with another hole drilled from the side to allow oil flow to the rocker balls.
when i put my 347 engine together i had 32 rockers and balls to chose from and even pushrods where damaged from bad oiling chanel in heads where full of dirt .my opinion is that old stuff have better material so i did not buy new im planning to put the other engine together with threded studs and weld oil dripping shelds from newer engine in valve cover
here is some pictures explaining what i ment in last post this 1957 valve cover is going on my 65 389 and engine is for my 1958 gmc i will put a 700 od trans also. is there any who knows what year the oil dripping valve cover is from. in the 1980 i had a cal custum with same dripping notces cast in alunimum. hope every on the east cost is ok aftrer the storm. ken sweden
If I recall a historical blurb I read many years ago, the cupped rocker/stud/pushrod lube setup for sbc was actually invented by a guy at Pontiac.
My '62 Motor's Manual shows the '55 motor had oil galys in the heads and required adjusting of the valves. The '56 316" motor started the "tighten against the shoulder" valve sequence. Compression ratio's are shown as; 8.90 for all but the 2 4's motor which had 10:1 and 285 horses.
Just had the same thing happen to my 1960 389 engine. It was a recent rebuild that had small chevrolet repair studs installed with out oiling holes. I got the engine running not knowing this and drove it 500mi one weekend. It ran great the first half of the way there then started running real rough. I kept adjusting the rockers as the valves got shorter and shorter but I made it home. I have since rebuilt the heads with stainless valves, and it is my understaning that if you use leter rocker arms with the holes on the pushrod end as well as hollow pushrods everything should be just fine. Good luck, Pontiac's are fun engines...
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