Boomyal??? FORD Rocker Arm Studs and Lifter Questions

[qaztwo]

Re: Boomyal??? FORD Rocker Arm Studs and Lifter Questions

I also believe the 302ho has the 351 firing order. When tightening the rocker arms, just went throught this process, rotate the crank untill the intake or exhaust starts to open then tighten the other one to 18-23 foot pounds.

 

[kwoolard]

Re: Boomyal??? FORD Rocker Arm Studs and Lifter Questions

Thanks for the advice guys. <br /><br />I would have to double check the casting numbers on my heads and block to absolutely be sure about what I have. I do know that the heads are stamped 302, and that my intake has the 302 firing order, and she ran great. Just had a little overheating problem. <br /><br />Anyway, I'll just torque them down to 20 ft-lbs and go. <br /><br />Boomyal, the valve stems were grind down as well so that is good. However, the shop also had to mill the heads a little. They said the heads were warped about 15-18 mils. How much would that affect the valve clearance? Should I even worry about it, and just bolt the rockers down and go?

 

[Boomyal]

Re: Boomyal??? FORD Rocker Arm Studs and Lifter Questions

There is a fair amount of latitude in the the valve lash for hydraulic lifters. I don't think that .015-.018 would make a difference but if it does it would require you to use shorter pushrods. <br /><br />Once again I would call the machinist and ask him. They should have all those SBF numbers in their heads.<br /><br />You have to look at valve train geometry from two different perspectives. One is the relationship of the rocker to the cam, the other is the relationship of the rocker to the valve. One of course is in the head the other is in the block. Often there are three adjustments that can be made. Pushrod length, rocker height, valve stem length. Any adustment has to take into account the end result of how the rocker contacts the valve (side load against valve guide) and the designed opening dimension of the valve plus the required rocker valve clearance.<br /><br />In your case, because the rocker is fixed you are only concerned with two possible adjustments. Because both dimensions have been altered (cam to rocker and valve stem length to rocker) you need to be sure that the lash is within the allowable parameters.<br /><br />You've already determined that the valve stem to rocker relationship has been compensated for, now you need to inquire if the .015-.018 reduction in distance between the rocker and the cam keeps you within the allowable range of lash.<br /><br />Whew! In short, call the machinist.

 

[kwoolard]

Re: Boomyal??? FORD Rocker Arm Studs and Lifter Questions

Take a deep breath!<br /><br />Talked to machinist, he said I shouldn't have a problem. <br /><br />Thanks for all your help. I'll let you know how it turns out, should be running the engine on sunday.

 

[kwoolard]

Re: Boomyal??? FORD Rocker Arm Studs and Lifter Questions

I got my motor back together and running this weekend. When adjusting the valves I noticed that to reach 20ft-lbs of torque it started collapsing the lifter quite a bit. So I called a mechanic/friend over and he informed me that they were adjustable and to adjust them to 1/2 turn past zero lash. Did that and the motor cranked right up and purred like a kitten.<br /><br />Now I am wondering what is the difference in appearance between an adjustable and non-adjustable lifter? <br /><br />If mine are adjustable as you guys claim, would I notice any rough running or valve slapping? Because the engine runs great now.

 

[Boomyal]

Re: Boomyal??? FORD Rocker Arm Studs and Lifter Questions

I would like to know also kwoolard. All small block Fords of that era had stamped steel, non adjustable press in stud mounted rocker arms that you just torqued down and walked away from. This, as mentioned before, assumed that you had the proper length valve stems and pushrods. Maybe somene changed them or changed the heads. You don't have any pictures do you? <br /><br />If they are stock I'm suspicious that your adjustment won't stay put. If you had to back the nut off to compensate for PR length or Valve stem length, the nuts won't hold their position.<br /><br />Maybe Mercury Fords were different but I don't think so.

 

[kwoolard]

Re: Boomyal??? FORD Rocker Arm Studs and Lifter Questions

I don't have any pictures, wish I did. Do the studs on Chevy's look any different than the studs on Fords? It would seem to me that you would have to have a shoulder for the fulcrum to sit on..this would give you a positive stop for the nut to torque to. Other than that I don't know, I know that I could keep cranking the nut down the stud until the fulcrum wedged up against the stud where the threads stopped. I thought that was my positive stop, however it the rocker started compressing the lifter way before I reached that point.<br /><br />The previous owner was a Chevy man and a damn good mechanic...maybe he changed them over???

 

[qaztwo]

Re: Boomyal??? FORD Rocker Arm Studs and Lifter Questions

I've included a link to some of my pics, the last two show the rocker arms on the studs. There are also several others that show just the studs. Just to let you know there's about a hundred pics on there so it may take a sec.<br /><br /> http://photos.yahoo.com/qaztoo

 

[kwoolard]

Re: Boomyal??? FORD Rocker Arm Studs and Lifter Questions

The pictures shown are identical to my setup. The engine starts and runs great both at idle and full throttle. So I'm not sure if I need to go back and recheck the nuts or not. Like I said, 20ft-lbs would have taken a lot of nut turning passed zero lash. The lifters should self-adjust anyway right?

 

[Haut Medoc]

Re: Boomyal??? FORD Rocker Arm Studs and Lifter Questions

Kwoolard, I looked at pics, & couldn't see the detail on the studs, but they sure look like mine. Mine are not adjustible...How did you find zero lash? Even on a Chevy, you have to be at TDC in the #1 & #6 position and tighen the appropriate valves....Has Ford changed to a similar set-up? But if they did wouldn't you have to go through some sort of Chevy type process for adjusting the valves....By going 1/2 turns past zero lash, you are still putting some torque value on those nuts....My point is maybe some of those lifters were supposed to be compressed becuse of the part of the stroke they were on. Have you run under load yet? Qaztwo had pics, but he didn't say what he did to adjust his valves. This one of the things that make Ford a pain in the a$$ They change firing orders, heads, cams and who knows what else.... Don't get me wrong the Fords are hardy engines, I just wish they were a little easier to work on. I'm really suprised that no one on this forum has a definitive answer to this question.....You might want to search on some of the auto forums...There are a lot more cars powered by Ford than boats...I would like to get to the bottom of this too...I'm glad that it is running well, but keep your ears open for any clattering.......J

 

[Boomyal]

Re: Boomyal??? FORD Rocker Arm Studs and Lifter Questions

My point is maybe some of those lifters were supposed to be compressed becuse of the part of the stroke they were on.

That's true kwoolard. I just assumed that your rotated each cylinder to top dead center before you tried to seat your rockers. I wouldn't be running your engine much until this is settled.

 

[kwoolard]

Re: Boomyal??? FORD Rocker Arm Studs and Lifter Questions

My procedure for adjusting the valves was as follows:<br /><br />Adjust each cylinder at a time.<br />Turn each cylinder to TDC.<br />Turn the nut down on that particular cylinder until the push rod has some resistance while turning. <br />Checked to be sure that was zero lash by checking to see if I had any play between the rocker arm and the valve stem.<br />Then turned the nut 1/2 turn more.<br /><br />Performed this procedure for each cylinder. The boat runs great, actually quieter and better than it has before at both idle and while on plane at 3500 rpms.....just still have to overcome my overheating problem.....but that is another open topic...."cooling question: diagnosis".