Just to try to share info with the group, I had a soft cylinder at my last annual, through disassembly found a bolt head in the oil pan, turned out to be a 1/4 inch bolt from the impulse coupled mag drive gear in the accessory case. Should have had an AD/SB done on it to the larger 3/8 bolt, when that bolt fails it damages the block, which then needs an expensive repair, etc, etc. Soon, the soft cylinder turned into majoring the engine. Long, sordid story I will spare you.
Enter the majored engine, used a reputable builder, color matched the engine block to the plane, chrome valve covers, polished push rod tubes, intake tubes chromed etc, etc. Looks like a jewel! Proud papa does the ground runs and discovers what looks like a copious front crank seal leak, has 3 aircraft mechanics look at it, consult with the engine builder, and am told these front seal leaks happen from time to time, just replace it.
Replace the Superior one piece seal with another, it leaks, replace that one with a Lycoming seal, break it trying to get it on, replace that Lycoming seal with another one piece Lycoming seal, it leaks. Get a special one piece Lycoming seal with a molded in spring from the engine builder, it leaks. Pull the engine, send it back to the builder, at which point I am told that the 4 screw holes made to hold the old style metal seal plates in the front of the block are actually leaking, not any of the crank seals we replaced. Simple 5 min fix with Loctite 550 and 4 small screws. Why on earth did no one I talked to, and nothing I found on the net mention this? Just one of those things I guess.
My plane has been down for a year now due to doing the work myself with the assistance of an AME I know, who helps me for next to nothing on his days off, very grateful for that. But this experience has been somewhat of a nightmare and I just wanted to let the Vans group know something that I had never been able to find searching front seal leaks, nor the 3 experienced AME's I talked to, nor the experienced engine builder. Everyone said, oh, yeah, never thought of that.... So, in closing, if you have what appers to be a front seal leak on your engine, and a new style seal, and four little holes in the front of your block around the seal area, maybe put four little screws in there and save yourself much grief and time and money. Now I expect to get numerous posts saying, well duh, I knew that! ...well, I didn't
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