The Jalopy Journal
Discussion in 'The Hokey Ass Message Board' started by THE FRENCHTOWN FLYER, Jun 5, 2012.
Last night my hoodlum Loose Screw buddies came over to help me prep this engine to go on the engine test stand. All I wanted to do was install the roller rocker arms, fill it with oil and prime the system with oil pressure. I noticed one of the roller arms looked cock-eyed when we screwed it on. Upon close examination I noticed one of the studs was bent about 1/16". You may be asking yourself why I was using pressed in studs in the first place. This was an intentional experiment to see if the use of roller rocker arms would eliminate the sideways rocking motion on the rocker arms and thus keep them tight in the head, in spite of the increased lift and ramp rate of this performance cam.
[THOUGHT EXPERIMENT: Pound a tent stake in the ground. Now try to remove it without inducing a rocking motion on the stake. Much harder than rocking it back and forth while pulling on it. Now try pounding a nail partway in a piece of wood. Again, if you don't rock the nail back and forth it is very difficult to remove the nail.]
Roller rockers eliminate the rocking action applied to the stud. Anyhow, I tried to remove the stud and ended up breaking the head casting. THE HEAD IS RUINED. I have to build another. All that time and money wasted - there went a couple of weeks of my life I'll not get back.
So now that I've had 12 hours to mourn the loss of my head I realize its just stuff. It is not like a real heartbreak - like a terminal illness or the loss of a loved one. So I'm off to search out another head. I think this was my last usable small chamber early 240 head. I may have to go with a less desirable 300 head. Live and learn.
That's a shame! Just curious, did you jack it out with a stack of washers or rocker balls? If so, it was probably cracked before. Can you cut all the bosses down and use screw in studs, maybe with hardened washers underneath. I'd hate to give up on it having all that time and money invested.
Yup, I put a sleeve over it and put a nut on it and pulled it, adding washers under the nut as necessary to maintain threads under the nut. I'm afraid the fact that the stud was bent must have introduced side loading on the cast boss and cracked it. Maybe it cracked when somebody bent it in its' previous life. Bummer
Well I got another head - this time a 300, not a 240 - with 76 cc's vs the 68 cc's of the old one. At least it should run on regular pump gas with the bigger combustion chambers. I will check all the studs for straightness and looseness prior to the long rebuild process. Since I have documented the other head build with pics I'll skip that unless there is something particularly salient about this head build, but I doubt it.
"The King is dead. Long live the King"
"...Meet the New Boss - same as the Old Boss..."
"One of these things is not like the other."
There is one thing I could throw in here and I do this particularly if somebody else out there is planning a build-up of one of these sixes. If you are going to use a later model head that has holes in the roof of the exhaust ports to affix air injection for emissions control and you want to eliminate this "feature" you will have to plug up the holes. Ford sells special pipe plugs to do this but they are pricey - about $6 each if you can find them - so here is another solution. Little plugs I turned. They look like the heads from little LEGO people.
Measure the hole size. This varies depending on the model year. Some had 1/4" holes. For those I just use 1/4" rod Locktited and driven in place. For the larger diameter holes like this later model one I decided to turn plugs. The holes in my head varied in size from .322" to .328" so I decided to turn each plug uniquely for a .001 interference fit on every hole. There is less than a quarter inch of engagement and the plugs needed a lip so I did not drive them in too deep. Here are some pics to explain. Enjoy.
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