Breaking in New Engine, Leaks...crankcase pressure? Options

[BeatNavy]

The last week or so I've been breaking in a new engine I built last winter and finally manage to install a couple of weeks ago. I'm pretty happy with how it pulls, and after a LOT of fiddling with the MPS and timing I think I've got it where it will start right up, idle cold (barely), idle nicely when warm, and run with nice cool head temps. I do seem to have a slight bit of ping/detonation under load around 2800 to 3000 RPM, so I guess I need to play with timing a bit more.

I am much less happy with the oil leaks. I know building a leak-free Type IV is a challenge, and given this is my first effort, I didn't expect perfection. But right now it's leaking pretty badly in a couple of places: out of the transmission weep hole (probably RMS, I guess), somewhere around oil filter console and/or pressure relief valve, and, surprisingly, what seems to be sort of spraying out and around oil filler neck.

Here I need help from the World; I see a combination of three possible causes for this many leaks (when I otherwise took my time and tried to follow guidelines, using Jake's recommended sealants):

1. My own inexperience
2. Too much crankcase pressure from rings not seating yet
3. Too much crankcase pressure from no head venting.

Here are some details on build:

2056 with 9950 Cam using D-Jet
Brand new AA Heads built by HAM, and Len sealed up the vents
96mm KB Pistons with Hastings Rings
8.6 CR

A couple of notes: I didn't gap the rings per Jake's philosophy that crankcase pressure is what causes oil leaks, and the rings come properly gapped. Also, Len (and Jake) don't like head venting for oil flow (so my heads had vent plugged). If I understand him correctly, Len told me the stock PCV vale should provide enough crankcase pressure relief on a street car. RMS is the Sabo brand (the "good" one).

Any thoughts on 1, 2 or 3 above? I'm willing to pull the engine and reseal, but I wanted to see if 2 or 3 are possibilities that I need to address. Is the stock PCV valve (which I am sure is not clogged) enough pressure relief?

Thanks for any help.

[Olympic 914]

Just sticking this in here..

More ring gap stuff,

http://www.914world.com/bbs2/index.php?sho...=232536&hl=

[BeatNavy]

Just sticking this in here..

More ring gap stuff,

http://www.914world.com/bbs2/index.php?sho...=232536&hl=

Tom, good stuff. I recall reading that article that's linked there.

Interesting, in your thread, you say instructions weren't included with the KB pistons. I don't think mine were either. To be fair (to me), I generally DO read instructions (if they are included). To be fair (to them), I have to believe one or both rings probably broke during initial install - my own lack of experience. If that's the biggest and really only mistake I made on my first T4 build, I'll be happy. It didn't require splitting the case.

[Superhawk996]

To be fair (to them), I have to believe one or both rings probably broke during initial install - my own lack of experience. If that's the biggest and really only mistake I made on my first T4 build, I'll be happy. It didn't require splitting the case.

What did you use for a ring compressor? Really should be little risk of breaking a ring on install. Shouldn't take much effort at all to slide the piston into the cylider. If it hangs up for any reason, stop.

I've had terrible luck with those U shaped compressors. Junk in my opinion.

I use a Lisle spring steel compressor that encompasses the whole piston. I've never had any issues using this type.

https://www.lislecorp.com/specialty-tools/ring-compressor-79

Use lots of oil, lube the ID of the spring compressor, and the piston should slide right in with only light taps from the wooden end of a mallet on the cylinder and/or a slight twisting motion (hard to get on VW's on the stud (IMG:style_emoticons/default/sad.gif) ) My compressor has 3 or four little nubs on the bottom side to sit on the top/bottom (for VW's) of the cylinder and keep the compressor from moving into the cylinder as you tap. A bit trickier with VW's going in from the bottom. They also offer a slick VW style "Take Apart" version. I just make do with mine and take it uncoil it to a large OD that will slip over the cylinder after the piston is in. A bit of a PITA but it works.

I might just buy one of the Lisle take aparts this next trip around given the cost isn't that high but somehow I've always made do with the other one both for VW's, for the Norton, for an old Honda motorcycle engines, etc.

https://www.lislecorp.com/specialty-tools/t...ring-compressor

The other trick that works in a pinch on small OD pistons is a very thin aluminum sheet (i.e. pop can) and a hose clamp. I believe the trick is to get complete encirclement of the ring so there is nothing to catch the cylinder lip as the piston/ring enters the bore. That is what the U shapped compressors lack.