I noticed a leak on a few of my tubes, and with the engine running I could see them wobble in a pretty even pattern. The other six aren't leaking, although with the engine running I can definintely feel some clicking on those too. It appears that the push rods are banging them around. This is a '75 1.8 that has been modified with FAT heads and stroker crank, along with all of the other goodies that go with that package. I was told that the tubes are billet FAT parts as well, longer than stock to accomodate the taller cylinders. Any ideas on what might be going wrong?

here's what it looks like:
http://youtu.be/xyOfRSoRwvg

Are you positive that those tubes even have seals on them? Best to pull them out for a look!

I was told that they are new seals, although I already have a new set of Viton seals on the way to me. Apparently FAT says that the correct method to seal their billet tubes is by having a pristine surface on the head and case, and applying red hi-temp silicone sealant on each surface before inserting the tubes with new seals on them....

when I get it apart I'll know more. Apparently there is some sort of slot on the end of the tube for the pushrod to pass through, my theory is that the tube might have to be aligned a certain way for the motion of the pushrod to clear it. I'm not familair with how much horizontal pushrod movement there is normally on this engine, although I intend to find out!

"Horizontal pushrod movement" isn't normal whatsoever. There is a retainer clip inside the valve cover below the rockers that holds them properly in place. Does each side have one? They're there for a reason!

Make sure the wire is in place to hold in the oil tubes ,they should seat against the oil tubes.

That is just odd. I wonder why it is not leaking all over?

I don't know the FAT ones your using.
but normally the pushrod oring is not supposed to be siliconed in. it should have the ability to rotate and still seal against its o ring....

most o'ring applications frown upon rtv silicone
(we use silicone o'ring paste... common with plumbers.. on orings. It does not "Glue" the oring in instead moistens it and helps keep it from drying out so it can work like an Oring)

I think its called "dow corning 111" but I'll have to double check that.

brant

My guess is cheap or wrong O-ring seals.
When I assembled mine with the O-rings that came with the engine gasket kit, the tubes were loose feeling. I never ran it cause I didn't like the way they felt. I replaced them with ones that were pushrod tube seals from Pelican I think. They were thicker and when installed the tubes were considerably tighter. I'm sure I'll get flamed. But I did use High temp silicone, and I have zero leaks.

I have a set of Viton seals on the way to me from FAT, we'll see how they compare to what's installed...

What's bothering me is that when I hold the tube while the engine is running there is definitely something moving the tube back and forth a slight amount. regarding oil leakage, I took the video with the rear wheels on ramps and the leakage was minimal. With the car on level ground the two loose tubes give up a drop about every 5 seconds and the heat exchanger gets soaked.

When I mentioned "horizontal movement" I was referring to the geometry of the rocker arms and the possibility that the pushrods are brushing up against the inside of the tube. When I get it apart we'll see how they look on the inside.

thanks for all of the ideas, I'll know more once it's opened up

I would definitely look and make sure the retaining wire is installed correctly, sound like the tubes are touching the rods. Inspect the tubes when pulled to make sure that are not bent

Using red (or ANY) RTV on pushrod tube seals is a guaranteed leak.

The Cap'n

Click to view attachment

It looks like I found the problem, as you can see in the near valve the rocker is at about a right angle to the valve, and the cam is at max lift for that valve. Looks like the rocker stands need shimming..

By the way, the guys at FAT say that their method to seal the tubes is use red RTV and let it dry before final assembly. I can tell from looking at my setup that the guys at AA inserted the tubes while the RTV was still wet. It probably still would have worked except for the push rods banging against the tubes. I'll probably use the teflon paste, if anything, along with the new Viton seals.

I get the case and the heads CLEAN. Put a small amount of grease on the outer surface of the Viton seals to ease installation and push them in place. Never, ever use any type of sealent.

I'd appreciate any suggestions on how to set the tips on the new pushrods. I have 'em cut to within .002" of each other, now need to clean them and finish the job. No wonder this engine sounded like a sewing machine, look at the scuff marks on the aluminum push rod that was too short and rubbing against the FAT billet tubes...eventually it would have worn through, and probably had a big oil fire on the exhaust.

I own a large mallet with a nylon head on it, my thoughts were to tap the tips on with the other end of the push rod on a 2x4, thoughts? These are Manton rods from Raby's, and I dont have any old lifters to use on each end to set the tips as they suggest.

You may also want to check that the tubes are compatable with the case,....just a thought.

No shims? Seems to me you would need shims or longer push rod tubes. I had shims on my 2270 motor and I am using longer "stroker" push rod tubes that Mark at Original Customs sourced on the 2432...

The tubes fit tight, and are part of the package from FAT, I now have some of their Viton seals that will be installed. There were two leaking pretty bad, although with the pushrod banging on them it made them move back and forth on the head. I originally thought that I needed shims, although after reading Jakes geo article, I realized that the pushrods were too short, luckily I tore them out and saw the rod damage and the need for thinner steel rods. All eight of the pushrods were scuffed and scored. In my first pic you can see that at max lobe lift I was only perpindicular to the valve instead of perpindicular at half lift as it should be. After running the geometry tests with an adjustable pushrod I found the best length was 27.1cm (about right in the middle of Jake's sverage range). If I can get the tips on correctly I'll heat up the garage and get this all straightened out. Then I get to learn how to set the lash as my next assignment...

I'm trying to contact one of the prior owners to see what parts are on the engine from FAT. I was told it has a big bore kit, although I'm not sure how big, and FAT changed their computer system a year ago and they don't have the hsitory for me.

Thanks for the ideas

I have built +- 15 engines in the last couple of years and have never used RTV on the O rings and have never had a leak. The gasket rebuild kits usually contain two sizes of O rings. Very early TY4s had a smaller diameter hole in the heads and required a push rod tube with one end smaller. FAT may have used this smaller O ring on the larger tube , it is very tight and will be loose in the head.

That 27.1 number is for reference only.. It is what we see with my very mild 9550 cam grind.. Just because your numbers may be close to that it doesn't mean they are right.
We have a full1.5Cm of range for our engine combos in relation the pushrods length. If your pushrods are hitting the tubes, you have a significant goofed up valve train geometry.

It makes sense then that after running through your geometry procedure that I yielded the best results with a length in the range of a mild cam. I was told that this engine has a stock FI cam grind. My induction is a stock L-jet system .

The tube/rod problem is now being corrected with proper length pushrods. I'll know in a few days how the O-rings fit, although I ordered them directly from FAT, so I'm confident they will seal correctly with their billet tubes.