Well, as most of you know, I've been putting my 302 together, cam, gear drive, etc. It's all together. I got the valves adjusted and wanted to start her up. Just keeps cranking. I heard a snap sound a few times. Went to check the valve rockers and found a few loose. Tightened them up and tried to start it again. Nothing. Same snap sound. Again, a few loose rocker arms. I noticed that it appears that the stud is pulling out of the head? Has anyone heard of this? So, now totally frustrated and at the point of having an ulcer, I need some advice on how to fix this or recommendation. You guys have pulled through for me before. Thanks guys. Miller sounds real good right now! ( I posted on the 302 guys also)

 

Cam and crank out of time? If you rebuilt, did you put in new timing chain and new gears. If so did you line up the timing marks correctly? Sounds like the valves might be down when the pistons are coming up.

I hope I'm wrong

Good luck

Bubba

 

Are you running a high lift cam? Sometimes rocker arms will bind or valve springs will bottom out from excessive lift. Some cam grinds need roller rockers to avoid binding. Pure guessory on my part since I don't know what cam you are running. In any event the heads are coming back off if the studs are pulling. I wouldn't try to start it anymore. Wish I could be more cheerful.

 

why don't u pull the tappet covers and turn by hand, see what is happening, are the springs binding?, how did u adjust the clearance manually?, if the heads are reco or new i would speak with the dealer before something major happens, we could probably figure it out eventually but with so many possables this may be quicker and cheaper.good luck
cya..gary

 

BTW when in dought always go back to basics

 

To follow up on what fenders has said it might be good to look at the lift of the cam and the type of rockers you have. If you have deviated from stock the oval cut in the rocker that allows for the pivoting of the rock may too short and is causing it to bind and ultimately cause the studs to pull out. If the studs are pulling out there are at least two things you can do. You could take the heads into the machine shop and have theaded type studs installed or you could get the old studs pressed back in and then install pins in each of the stud bosses and studs. I know a gentleman that drilled a hole through the boss and stud and drove a drill bit slightly larger than the hole and then broke them off. It cured the pulling problem. I am not aware of the 302 being an interfearance type engine but if the lift is greater than normal it may be possible that the pistons are hitting the valves and forcing them shut. How radical is the cam? I worked on a 65 mustang in the late 70's with my student and we had an awful time starting the engine. Matter of fact it wound up going down the to local garage where they finally got it started and when it did it would barely idle. It sure came alive after 2,500 rpm. Come to find out the local parts house had given us a full race cam instead of the one ordered. The family that owned the car had the cam replaced so they could at least drive the car from time to time.
Good luck.

Gear Up

 

You guys, thanks. Here's some info that may help. The cam is an Elgin hydraulic cam. It suppose to be 470 lift with a duration of about 272. It's not a radical cam. The engine ran fine with the old cam. The old cam that came out did have several flat spots and needed replacing. It was the stock cam that came out. A buddy of mine who builds hot rods, manually adjusted the valves with me to zero lash and than a quarter turn. I installed the gear drive. The old chain timing marks were lined up TDC when I took it apart and I put the gear drive exactly the same way without changing the rotating the engine. I'm not sure if putting screw in studs will solve this problem? I guess the hard part is I've spent hours of late nights working on this thing and now this has to happen. Makes me sick! I guess it's all part of the fun, right? I have to check the distributor to see if my buddy put it in 180 off. It's not backfiring or cranking hard. It just wouldn't turn over as if it wasn't getting any spark. Just don't know what to do at this point. I know I'm not starting it!!!!!! Thanks again guys. I really appreciate your advise. It helps.

 

It sure sounds like you did it the right way and all. If you Adjusted the valve with each cylinder on its respective TDC you would have to have them in the ballpark. If your friend had checked to make sure the number one cylinder was on TDC or a few degrees before your distributor placement has to be correct also. Do you have the wires on the cap in the right order and set for the proper rotation? If you took a dwell meter and hooked it up with the distributor and turned it over you would be able to see if the points and coil are functioning also. The 272 cam will give you a nice throaty idle and good power on the low end. Had that in several of the Mustangs my son put together and it responded well for him. Good luck.

Gear Up

 

Well, I'm tearing the engine apart again. This time the heads are coming off. I was suspecting the springs may be bottoming out? That doesn't appear to be happening. I'm going to check the lifters, maybe they are different size than the original. Anyways, while the heads off, I'm just going to go through them and do seals, etc. Do the screw in studs and go from there. Now my next question is, "where do I find the time to do all this?" LOL.... I'll let you guys know what I find.

 

push rods could be the wrong length when we rebuild an engine we use a push rod measuring device from rhoads lifters i think .have seen alot of people with this problem

 

f600, I'm using the same pushrods that was on the engine? It shouldn't matter I would think because the cam is not that high of a lift to were it make a difference. Maybe I'm wrong.?

 

Did you check thta you had spark and fuel, lioke our friend from Australia said, sometimes it pays to get back to the basics....I know it bit me on lthe dark side this week!

GW

 

No that was actually a very good call from F600. If you used your old ones you should be fine, but a pushrod from a slightly different application has caused this sort of problems many times. It completely slipped my mind. It's one of the very few engine parts where you can install the wrong one and it isn't pretty obvious you did.

 

was the cam a new billet or a reground old one?if the latter and the pushrods are too short maybe when adjusting things the nuts were thread bound, this could explain not firing but not the studs pulling. some clevelands are a bugger for it, u have too crank the motor some before it pumps the lifters to let in the charge, the quality of lifter really plays a big part. did u pre bleed the lifters?, even though i beleive hydrolic lifters only have 60 thou float, with enough parts out a little this would leave the valves open, and pull studs, u should feel the air coming back through the carb if it were the case ( not backfiring )
did'nt meen to babble, but the causes are numorous.
cya...gary

 

Today I'm going to pull the heads off. The heads are going in for screw in studs and may as well do a valve job on them, seals, check the valves, surface, guides etc. I've spoke to several people at a car show I went to yesterday. They said its common for pressed in studs to simply pull out because of a new higher lift cam being installed. Some don't some do. I am going to check the spring pressure, length of push rods, the lifters appear OK and they were all pumped up, etc. I may need to get a new distributor. I have the mallory dual point which I have had problems with in the past not getting spark from the coil. I may go with the stock distributor and put the pertronix ignition on it. Heard they work well. Guess I have some work to do on this. Thanks for the suggestions again. I'll be posting progress as I go.