I'm trying to finish upa 302 build and I have a problem, I'm hoping to get some ideas. After I started this rebuild on what was supposed to be the original 289, turns out it is a 69 302. Well, no problem, most things are the same except for the crank, connecting rods, and a few other things. However, I'm having a really tough time on the heads. They are marked as 302 heads, and I already sunk a BUNCH of money into getting them machined with new valves, and hardened seats. Here is where I'm struggling.... of course, my new Edelbrock cam came with new lifters and I ordered a stock set of new pushrods and roller rockers that were supposed to work on a stock setup (I posted about this a week or so ago). Anyway, the new stock pushrods were just slightly shorter than the orignals and the roller rockers would not work because the studs for the rockers were a smaller thread and Summit said they did NOT have a set that would work for those studs (they recommended I take them back off and have them refitted with new and/or larger threads - I already have so dang much into these heads and really don't want to take them back off unless I do not have any other options). So, I decided to use the old rockers, but the stock pushrods would not adjust - the nut would go all the way down to the bottom of the thread on the studs. Well, I took them all back off and put the original pushrods back in, they didn't look too bad. When I try to adjust them they do the same thing. The adjustment process is to index the engine to 3 different stops, TDC, BDC, and 90 out to get all of the valves. When I turn them to one of these stops and try to adjust the valves my book points out I bottom out on the threads before they are really tight. I simply don't think this is right but the book does not say what to do in this situation. Has anyone who has rebuilt engines help me here? What should I do? The valves that were put on the heads were supposed to be stock so I don't think they are the problem but I won't rule that option out. If the original pushrods are not long enough what do I do? Should I put a drill down into the oil pump to ensure the lifters are really full of oil? I did pump the lifters up with an oil can when I put them in but it took me almost a week to get to the pushrod/rocker part, they may have went down... I just have no idea what to do, I do want this engine to work though!
Any help or suggestions are GREATLY appreciated!
D

 

First of all, don't talk to the Summit techs, they're morons. Second, it sounds like you need longer pushrods. Try getting a pushrod length checker and follow the instructions, then you'll know what length pushrods you need. As far as the stud size for the roller rockers, what heads do you have? They could be a later model pedestal mount, if they're stud I think there may be 2 different stud sizes. You gotta get the right studs for the head, and the right rockers for the studs. Also, make sure you prime the engine once it's together, with the dizzy out and the valve covers off turn the oil pump with a drill until oil comes out of the rockers(then I'd keep priming a bit more just for good measure). That will prelube the oiling system so the engine ain't dry when it starts up. PRIME THE ENGINE! It'll last longer. Also, if it's a flat tappet cam, make sure you use a cam break in oil addative and follow the cam break in procedures, or your cam/lifters will eat each other up and go flat in a few thousand miles(or less possibly).

 

First of all I am going to assume that the stock rocker setup is the non-adjustable type. The second thing I am going to assume is that you are running hydraulic lifters.

If this is the case, when you tighten down your rocker arms, the pushrods should not get really tight, they should "center" the plunger (the inside part of the lifter) in the lifter. You will be able to "feel" the plunger move against the spring in the lifter as you tighten down the rocker arm.

You will need to be sure that when you tighten the rockers, that the pushrods are moving against the plunger/spring in the lifter. If this is the case, the "slack" will be removed once your new lifters fill with oil and "pump up".

If you are running new hyd. lifters and all of your pushrods get really tight, then your pushrods are too long. The pushrods that are being "lifted" by the cam should get tight. So in other words if the pushrod legnth is right, all of the pushrods should get tight and loose as you rotate the engine crankshaft twice. The plungers in the lifters neeed to be depressed at least some, all of the time, for the same two turns on the crankshaft.

The hydraulic lifters will take the "play" out of the valvetrain when they are working within theirrespective range of motion of the internal plunger. Ideally the plungers should be more or less centered in their bores when the rocker arms are tightened down and the camshaft for that particular lifter is in the "valve closed" position.

If you dont have the heads on, I think you can have the heads machined to accept bigger rocker arm studs, thereby allowing you to use your new stuff.

 

+1

An engine builder on this site (mustanglover66) advises using Rotella oil for the break in of your flat tappet cam as there is a lot of zinc in this oil. I have read this elsewhere as well. Rotella is an oil formulated for heavy duty diesel trucks, I for sure advise this as well.

 

Yeah, the engineoil companies stopped putting zinc in the oil after the manufacturers switched to roller cams, and man them flat tappets don't like breaking in without zinc. They do however like breaking without zinc [&:]

 

Thanks guys for all the good responses so far! Yes, these are stock hydraulic lifters and stock rocker arms (again, the roller rockers would not work because the studs that were included were for a larger tapped thread). I already bought a bunch of Rotella 15w-40, enough for a fill to start, a change after I run it for an hour during cam break-in, and then another to run it fora while after that. I have heard that it is a good oil, just never heard the part about zinc being added.
Ok, my guess is that I need longer push rods. What confuses me is that they came out of the engine in the first place, not sure why I would need longer ones. But, with the nuts taking the rocker arm all the way down to the bottom of the threads, the rockers aren't level and they don't depress the springs at all. The engine build book I have, How To Build Small-Block Ford Engines by Tom Monroe, indicates that I should just take the wobble out of the rocker, then go 3/4 of a turn more. I can't get the wobble out, I hit the bottom of the threads.
So, where can I get a pushrod length checker and hopefully this thing isn't too expensive. I'll do a couple of google searches after posting this to see if I can find something like this. Would some place like Checker Auto have one of these?
Thanks again!

 

Well, I found several references to a pushrod length checker. there are bunches of them out there for "The C Word Cars" but not for small block Fords, the one's that I found were about $75... well, I found one that is a univeral for about $10 which I ordered. Hopefully that is a good thing, if I need one specifically for Fords let me know!
D

 

If your stock rocker arms have a "cradel" that fits around the top of of the valve stem, this indicates that the valvetrain is non-adjustable, if so, the procedure that you got out of the book will not work. If you have the non-adjustable style you just torque the rocker nuts down to spec. If I am not mistaken, (I might be though), all stock 302s utilize non-adjustable rockers. If this is the case it is imperative that the pushrods be the right legnth.

You need to be sure what style rocker arms you have before buttoning down the valve covers.

The pushrods that came out of your engine should work, providing that the cam base circle is not reduced, the valves were not changed or shortened, and the lifters are the same height as the ones that came out of the "old" engine. Head gasket thickness may have some effect, but not enough to cause an issue.

If you have the non-adjustable rockers, and everything is right, the pushrods should not be real tight unless the valve is in some stage of opening.

 

Take a pic of your valvetrain and post it, then we can tell you for certain if you have adjustable or non adjustable

 

Im not convinced he has the lifters pumped up.I usually stand mine up in a pan of oil at least over-night.Then Ill use a pushrod to make sure their pumped up