Time attack beetle

[Humble]

Finally got the motor out and found a lot of good news and some weirdness. I quickly found the source of the noise which turned out to be from the retainer on the rocker shaft backing out. No harm done *big sigh of relief* but where is my lack of power coming from? I kept digging to find 3 out of 4 pistons sooted up with carbon but #1 was clean as a whistle. the 3-4 head was tight as a drum no leaks, but the 1-2 head wasn't as tight and #2 was leaking slightly. Also found the source of a couple persistent oil leaks, the turbo drain pipe (which was loose) and the 3-4 lower head studs. The case sealed up great and there were no seam related leaks. The galley plug in the back of the block had started seeping so I'll have to find a better way to seal it up. Cylinders looked great, bearings looked great and in some places the dry molydisulfide (MoS2) film coating I applied during assembly was still in place. I did find a slight wear pattern in the intake lobe for 1 and 3 and patterns on the lifters for the same but not high enough to feel with a finger nail scrape.

Some bad news now... I went to pick up the spare block on friday only to find a bunch of issues. The order was to deck it by 2mm each side and I confirmed this but they did more. They removed the case savers and drilled out every stud hole. Then they pressed in some kind of insert threaded for a 10mm stud except for the deep stud in #3 which they drilled out but never replaced. On monday the block goes back for a deep stud insert and hopefully I'll find out what the inserts are made of. If worse comes to worse they will have to fill every hole with weld, re-drill, and install new case savers.

Now on to the good stuff...

Here's one of the leak culprits, the threaded pipe for the turbo drain was loose


This is what all of the plugs looked like


the 3-4 head, exhaust valves got toasty


The other big leak I couldn't fix, the 3-4 lower head studs


I'm not sure if it's normal for untreated cylinders to bronze like this


3-4 pistons, lots of carbon


pulled the 1-2 valve cover to find this




Some weirdness here, I think there may have been some fuel starvation here so I'm going to double check the #1 fuel injector




some scoring on the bottom of all the pistons, not sure if that's normal for big bore/stroke combos

[Humble]

lifters now, you can see the circle patterns in the intake lifters for 1-3








here's the best shots I could get of the cam wear, this pattern is on both sides of the lobe




crank and cam gears got the same dry film coating and you can see the wear patterns in them


Bearings

















Now that's it's apart, I think lack of compression and fuel in #1 were responsible for my low dyno numbers. Once I get the spare case back I'll build the motor back up but I don't know if the cam is fine or not. Also now would be the time to grab a better cam since the case is split.

[volkdent]

I don't think #1 was running at all!!! That would explain the weird running sound on the video AND the low power!!! So really you're getting pretty good numbers for a 3 cylinder!!!

Have you pulled each injector and watch it squirt? I'll make you a small bet the #1 injector has issues or the wiring to it has issues.

Jason

[Humble]

I had to pull the injectors off to pull the motor but I'll probably put just the fuel system back on and fab up a test rig. the injectors were all brand new, balanced and tested from rc engineering. But since everything on the engine was new something could be in there blocking the flow. I'll double check the wiring but 1-2 fire together and since 2 was working I'm thinking the wiring is fine. I'm also not ruling out a spark issue... actually now that I'm thinking about it we were trying to time the engine on the dyno and a couple timing lights wouldn't work. A third finally did but it was spotty, so timing could definitely be part of it.

In other news I got the spare block back, turns out the didn't clean the case after machining and there was aluminum build up over the case savers. The deep stud hole by #3 was also filled with shavings. I still got to clean the case up more but re-assembly should happen soon.

[volkdent]

I'm hating crappy craftsmanship more and more as time goes on...

Jason

[Wally]

Just back from holiday and am very happy your engine issues are actually quite minor and don't cost much to mend
I agree with Jason about the no. 1 cylinder: it may just be a blocked injector due to some crap that was in your fuel system (tank, lines, who knows?)
If the spark was at fault, wouldnt the plug show a totally different color?

[Humble]

Damn I feel like and idiot now. No harm done and not much money lost (a wasted trip to the machinist) but I found the source of my problems. Turns out a bad measurement was made and that effected everything. I measured the plate for checking deck height incorrectly, or rather must have read the dial calipers wrong. Probably due to assembling the motor at 2-3am the first time around because I was excited :P

Well I found the mistake today when I double checked the plate thickness. My measurement was off .100" so I had an actual deck height of .171" instead of .071" or a total compression of 6.5:1. So If you're curious as to what kind of power a 2165cc, very low compression motor, running on 3 cylinders makes on 13lbs of boost, it's about 107hp. The low compression explains the hard starting problems and low power so I'm relieved about that. I'm going to tear the short block back down and have both cases machined a total of 4mm (4mm on one block and an additional 2mm on the other). In hindsight, I would have caught this problem early on if I did a compression test, so maybe it's time I got a compression tester.

So going from 6.5:1 to 8.5:1 should be a real kick in the pants with or without boost I'll probably be re-re-assembling next weekend and hopefully driving again a week from today.