Oil leak lr cylinder head to block with yella-terra 1.65

This is the second time an oil leak has developed at the left rear of the cylinder head to block area using the full roller 1.65 yella-terra rocker arms.

The oiling on this rocker arm design is thru the lifters via the pushrod to the rockers just like the small block fords & chevys.

The mounting plate for the rockers blocks the oil hole supply at the rear rocker shaft pedastal pad.

This leaves full oil line pressure to be present at the sealing area of the head gasket at the left rear of the engine.



I did a temporary fix by just installing the 1.6 rockers which use the oil supply for rocker arm oiling. Doing this lowered the full line oil pressure considerably at that sealing point. Now that stopped the seepage of oil.
Yes this requires a special pushrod.
I also can feel a slight loss of power & the idle is smoother cause the duration @ .050 is less with the 1.6 rocker.

The point is has anyone using the 1.65 yella-terra rockers had this oil leak problem???

The oil seeps down the left side of the engine bellhousing area & finally drips out the converter-flywheel area.

The correct fix which i will do in the future is to tap that oil supply orifice on the block with a 3/8-16 tap & install a set screw which will act as a plug to keep line oil pressure out of that area & not reach the headgasket seal area.

The fel-pro seeps worse than the previous victor head gasket.

Just letting the forum know of this problem & wondering if anyone else has mistaken this leak for the rear main oil seal.
Does anyone else have the leak problem with this setup????
Bill

How about enlarging the hole in the gasket to fit a suitable sized .060 O-ring. or a suitable sized copper gromet, or a thin brass or copper washer (.010) inch around the hole to increase pressure at that point.

Bill,
Very simple fix......
Tap the block and install a plug in the passage. Works great! I've done it on two of Kelly's blocks and we've never had a leak.

I can take a pic of two and send them to ya if needed. It's real easy to do. However you do need to be careful about the metal shavings that comes from the tapping.
If the motor is on a stand and you already have the cam/crankshaft installed, then flip the motor over so gravity will keep the shavings from falling into the bearings. Use some grease o the tap to help retain them also. Inspect the hole and the cam bearing for any shavings. Clean out as necessary.
If the motor is still in the car, then fill the hole with a bunch of grease. Tap the hole, then suck out the grease/shavings with a shop vacuum.

Later,
Will

On the crossflow hybrid I also tapped the block and inserted a plug to seal that passage. No issues, just make sure the plug is flush or below the deck.

This kind of info should be included with installation instructions, don't you think?

Will & Jack, already have my spare engine fixed with a plug in the oil galley in the block.

Gene, yes this should be included upon purchase of the 1.65 yella-terra rocker arms.

The old story of some aftermarket parts, the user has to do the engineering work that should come with the product.

Mike of classic inlines was never aware of this problem, so you can't blame him.

The bigest dissapointment was the loss of power with the 1.6 roller rockers vs. the 1.65 rockers.

The engine just sounds different when driving & full throttle acceration. The exhaust sound does not have that throaty roar it did with the 1.65 rockers & the idle feels like a way smaller cam was installed.

Sound like if i continue to use the 1.6 rockers i will need a more aggressive camshaft to make up the difference between the two.

You guys with 1.6 rockers, you will see a drastic improvement just by going to the 1.65 rockers. Bill

I'm aware of it now.

Guess I need to make up a sheet to go with them, but also think I need to mention it in the product description. If one of you guys could e-mail a couple pics, I would appreciate it. Thanks

I've always been sceptical about the benefits of high ratio rockers, but after doing the dyno test on Gene's motor and hearing comments from guys that have installed them has finally convinced me. I was really surprised by the average HP gains we got when we tested them on Gene's. Definitely an eye opener.

No problem Mike! I'll send a couple of pics of two different blocks (grenaded and new)

Later,
Will