Engine 89 5.0 pushrods rubbing on guide plates

plout99 · Oct 8, 2021

I am looking for some suggestions for why the pushrods would be rubbing. The engine is supposed to be a stroked 5.0 it has aluminum heads with stud mounted 1.6 rockers on it with guide plates, hydraulic lifters with the e303 Ford cam. This is according to the guy that my wife’s uncle bought the car from several years ago. There is wear on about half of the rods on both banks of the engine and on exhaust and intake sides. I have done valve train work before but it’s always been on pedestal rockers and with oem parts. I would think the builder would have used hardened rods but maybe not? I used my caliper on the rod in the picture and it’s 6.195 and some others are 6.200. I have bought a pushrod length checker just need to watch a few videos since I have never used one before. The only numbers on the rod are pr1473.

manicmechanic007 · Oct 9, 2021

That sure looks like real heavy wear
How old is that pushrod?
I am surprised the end is still round
I think you have interference somewhere
Possibly they did not mill enough off the pedestals when the machine shop drilled and tapped for screw in studs?
That will cause excessive wear and bent pushrods
Inspect the bottom of each rocker arm for witness marks of interference against the screw in stud

Monkeybutt2000 · Oct 9, 2021

Wow,never seen that before. Are they 1 piece or 2 piece guideplates? At any rate,there are some very good videos on Youtube they go over setting up guideplates.

plout99 · Oct 9, 2021

I pulled all the rockers pushrods and guide plates and there are no witness marks on the rockers where the studs would rub. All the pushrods show some to significant wear. There are marks where it looks like the rockers are rubbing the valve spring cap on all of the rockers. Picture of number 5 exhaust rocker.

The engine has at least 1200 miles the car was bought in Florida and driven back to Ohio mileage beyond that is unknown. The guide plates are one piece. I’m guessing here but wouldn’t a pushrod that’s to short allow the rocker to rub against the valve spring cap since it wouldn’t be setting level/parallel enough in relation to the valve spring?

manicmechanic007 · Oct 9, 2021

You found your interference
Fix that and the pushrods will last
Great job

Monkeybutt2000 · Oct 9, 2021

What heads?

plout99 · Oct 9, 2021

Not sure who made them, they are aluminum so there not oem. From pictures I have looked at the aluminum Ford heads have the Ford logo stamped in the head under the valve cover. Are Ford trick flow and Edelbrock the only aluminum head manufacturers for the 5.0?

Monkeybutt2000 · Oct 10, 2021

plout99 said:
Not sure who made them, they are aluminum so there not oem. From pictures I have looked at the aluminum Ford heads have the Ford logo stamped in the head under the valve cover. Are Ford trick flow and Edelbrock the only aluminum head manufacturers for the 5.0?

No,there's several more.

plout99 · Oct 10, 2021

Is Trick Flow the only manufacturer that have the valves and rocker studs at a slight angle? Looking at some pictures I am leaning towards them being from Trick Flow.

Monkeybutt2000 · Oct 10, 2021

plout99 said:
Is Trick Flow the only manufacturer that have the valves and rocker studs at a slight angle? Looking at some pictures I am leaning towards them being from Trick Flow.

I believe so,they require quite a bit longer pushrod ( around 6.700) than most others. My AFR's I was able to reuse stock length rockers. Did you note where the rocker tip was on the valve?

plout99 · Oct 15, 2021

So I made a hydraulic lifter into a solid lifter and got a pushrod length checker. I am getting a good narrow line in the middle 1/3rd of the valve tip. My concern is the length is about 6.325 average longer than the stock rods in the head now but everything I read tells me with trickflow heads I should need a pushrod around 6.700 in length. I do not know if the block was decked or the heads milled. If they were could that be enough to account for needing shorter pushrods?

Monkeybutt2000 · Oct 16, 2021

plout99 said:
So I made a hydraulic lifter into a solid lifter and got a pushrod length checker. I am getting a good narrow line in the middle 1/3rd of the valve tip. My concern is the length is about 6.325 average longer than the stock rods in the head now but everything I read tells me with trickflow heads I should need a pushrod around 6.700 in length. I do not know if the block was decked or the heads milled. If they were could that be enough to account for needing shorter pushrods?

That's approx. 3/8 of an inch,no way.

plout99 · Oct 16, 2021

Here is a top view of the cylinder head. With everything being angled I am guessing they are TF heads. So far I can’t find any markings to identify them. The pushrod numbers would make more sense if they aren’t TF heads.

Monkeybutt2000 · Oct 16, 2021

They appear to be. I believe the early casting's didn't have any markings on the outside. There should be a number in there somewhere though?

plout99 · Oct 20, 2021

So I used the mid lift method from the Straub video to check for pushrod length and ended up with 6.698 average so I ordered the 6:650 trick flow pushrod. This length makes more sense than 6.325 I had previously just hoping this does not create any other issues I an unawares of. I am thinking about piston to valve clearance possibl.

vrm71 · Oct 31, 2021

why would you not get a 6.7 pushrod?

manicmechanic007 · Oct 31, 2021

I agree go longer not shorter and 6.7 is what I would try
Really ought to check rocker arm geometry and determine the length needed that way
It may be more than 6.7 with the guide plates, screw in studs and roller rockers
The piston to valve clearance will not change with different pushrod lengths
The rocker arm geometry will as will the clearance with the stud
Go a tad longer and get the roller rocker away from the stud
Like to see you use good tapered ones if you have to pay big money for them and do not go with the adjustable ones

plout99 · Nov 4, 2021

So the 6.698 is a typo the average was 6.648 so I went to 6.650 and the trick flow push rods ended up ranging from 6.655 to 6.7005. I did expect more consistency in the length of the new pushrod. Anyhow I rotated the engine with everything installed and using my borescope everything appears to clear and the geometry looks good, as close to 90 degrees as I can tell at mid lift. I know 6.7 is what trick flow suggests however I do not know if the block was decked or the heads milled since I didn’t build the engine and that should shorten the length if they were.

manicmechanic007 · Nov 4, 2021

All you can do is try it
It should work
You did not need much additional clearance anyway
As long as the new pushrods are longer they should give you the clearance you need

plout99 · Nov 5, 2021

Hopefully it will be fired up this weekend. Finally got the wonderful bbk fuel rails to stop puking gas everywhere. I pulled the thermostat housing off since I had the lower intake off and found no thermostat . Easy fix I just don’t understand why you would run without a thermostat. Hopefully the previous owner wasn’t trying to correct a overheating problem. The car was free and it’s rust free so throwing some dollars at it if needed is fine.

Engine 89 5.0 pushrods rubbing on guide plates

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