I just got done putting a cam and gear drive on my 289 Ford. I got everything together and adjusted the valves. Tried to start the engine and it wouldn't start. Periodically it made a snap sound. Concerned, I checked the rocker arms again. A couple were loose. I adjusted them again. and a few others were loose. I could see the threads on stud were getting longer at the adjustment nut, and it appears as if the studs are pulling out of the heads? (They are pressed in studs not screwed in). Has this every happened to anyone? and is this a common thing with 289 heads? Besides pulling the whole engine apart again. What can I do to fix this problem. Really frustrated at this point and would appreciate some advice. Thanks guys.

 

With the press in studs used on alot of the ealier small blocks it can be a common problem. Your best bet would be to pull the heads, take them to a shop and have them cut for guide plates.
Sorry, no cheap and easy fix that I know of. What kind of cam are you running?
Clint

 

It's a Elgin cams, it has a 470 lift with a 272 duration. It's a hydraulic cam and lifters. The lift and duration doesn't seem to be that radical enough to do this to the studs. But then again, the engine has some miles on it too. I just hate pulling the heads. A buddy of mine suggested pulling the studs out. and replacing them with screw in studs.

 

Your buddy was right. Pull the heads and have them machined for screw in studs.

 

There is an old trick of installing rool pins in the side of the studs casting boss to hold the studs in place but since you already have studs pulling out it would be best to have screw-in studs installed as mentioned.

if you have early style 289 heads with the rectangle push rod hole then you do not need guide plates.

 

Have the heads drilled and tapped for studs. Usually what causes this problem is stiff springs and high lift cam.

 

I'm not sure if the springs are stiff. They may be original by the looks of the engine. The new cam definitely has more lift than the one that came out. I'm taking the heads off to do this right. I guess I'll see whats going on when they come off. For sure I'm going with the screw in studs. RTM, they are early 289 heads and the push rod holds are squared. One good thing I guess. I'll let you guys know what I find out. Thanks everyone for the advice and info.

 

The springs should match the cam.

 

Question? How to know if the springs match the cam? The cam does not come with springs? The springs appear to be original unless someone did a valve job prior and replaced the springs with heavier springs? I also remember putting 351 W springs on a 302 which stiffened the spring for higher revs (valves did float). I never had a problem with the studs pulling out and I've ran cams with the same lift in other ford engines? The problem here, and it's weird,is the whole engine is pretty much stock with no modifications that would cause this to happen. All I'm doing is putting a higher lift and duration cam in and lifters. The pushrods are the same, rocker arms, etc. No heads have been milled, etc. I'm guessing and hoping that the studs are just pulling up from the high lift and pressure. But then again, I need to make sure!. I don't want to go through putting screw in studs in and the bending pushrods or valves, or something. This is a tough one. I'm sure someone else has gone through this. Hope no one else does.

 

Screw in studs are the way to go. Pulling the heads is a forgone conclusion for any drilling into your heads of any sort. Call your cam manufactuer and buy the recommended springs and retainers that go with your cam. If you can't, get a Crane or Comp Cams catalog and pick out a cam with similar lift and duration specs and use their springs and retainers.

 

As mentioned before for the studs to pull out you must have heavier springs and of course a bigger than stock cam. Just because you got away with it before doesn't mean you will always get away with it. You are on the edge of what may or may not work.

I've removed the press in studs before on my own and it doesn't take much to get them out so you can see how a larger cam and springs could easily work the studs out. My buddy had the same problem as you. Car ran fine before he bought it but after he started to drive the car and he did drive hard, the studs started to pull out. I think he had his pinned to save money, not sure. Even if you pin the studs you stand a chance of them breaking off next.

The rest of the motor has no bearing on the rocker arm studs. The only thing that does it what you are installing or have installed, bigger cam and springs.

To find out if the springs have the correct number of lbs a machine shop can pressure check them and compare the readings they get from your springs to the required spring rate by the cam manufacture.

Springs do wear out and I am not sure if 351W factory springs are heavier then factory 302 springs but my guess is they are more than likely the same since the cams could be the same in each motor from the factory and factory cams didn't vary much as far as specs go. Point is the springs you installed in the other motor just may not have broken down yet or they were just in better shape than the 302 springs you had. This proves the point of the need for the springs to match the cam. When things are correct they will either perform less than expected or cause cam failure. Kind of like a heavier load needs heavier springs. Well you have a heavier load with a higher lift cam.

Installing screw in studs will not cause any troubles for your motor like you mentioned. You should run hardened push rods with the cam up grade no questions asked. Screw in studs are needed as you know. As for bending valves, that can only happen if they hit the piston or get hot and warp. Screw in studs will not cause the valve to bend nor will the springs. With a lift of under .500 you should have way more than enough valve to piston clearence for your cam.

While you have the heads off you may as well do a little porting work on the exhaust side to help the new cam breath.

It may be cheaper to find a set of used heads already set up with screw in studs and maybe some port work? It's worth looking into. Compare the cost of used heads to what the shop will charge and go from there, if you have the time to shop around. plus a shop will give you good advice and if you are unsure of them just ask here to see if the shop is doing right.

 

Wow! Thanks for the informative information. Sounds like you have experience with this one. A friend of mine has a hotrod shop and states he'll do the screw in studs for me and while he's at it will do the valves, a little porting etc. I think your right in everything you stated. As for the 351 W springs, I did do some research on them before using them. The springs are virtually identical however the specs stated that the 351 W had more pounds per sq inch spring pressure. (can't remember the actual numbers off hand) That's why we went with the 351W springs. It eliminated our valve float that occurred at about 5500 RPM. I'm sticking with the 289 springs on this one. However I will check the spring pressure on these versus what the cam manufacturer recommends. I truly appreciate this information from you. I hope I can return the favor one day. I'll let you guys know my findings. Thank you again.

 

believe it or not, I have actually done a set of these heads on the engine. The guy that owns the machine shop where I go and do my work talked me into it. It worked fine. He showed me a trick for keeping the shavings out of the engine. He is not a shade tree. He builds 760 horse small block dirt trac engines.

 

I hope you get running soon and glad I was of some help.

 

ga, I know what your saying. My friend has a set up where you can pull the stud, tap it and put a screw in stud in while the heads are on the engine. I think you wrap the area and use a vacuum cleaner and magnet to get the chips, etc. It's a little more risky I think. I'm gonna pull head and go through them anyways. Thanks again.