I love your description of the hillbilly repair style Your are right - if two rear injectors do in fact output significantly less, hillbilly with just two new pistons will be in the same boat fairly soon, blaming the failure on poor engine design. I'm definitely going to address the injectors. The shop can flow test them and they can ultrasonicly clean them too. If injectors are too far out if spec - I'll replace the entire set. I'm considering installing all new injectors anyway, but the final decision will be based on the flow rate test. Plus I just need to know if that's what happened.

I think it's reasonable to expect rear injectors to go bad before the rest of them. They are working in the hottest area of the engine, tucked away under the intake plenum in the back. They easily get the most severe duty there.

I doubt you can "tweak" output of the individual injector. If all injectors on one bank get same length of the OPEN dwell time, the only way to vary the output is to install injectors with higher output rate on the back (more fuel flow per second at the same pressure). Unfortunately, the difference in the output step up might be in large enough interval to starve the front cylinders of fuel by the time computer calculates average dwell time based on O2 signal. Definitely more deep dive and reading required.

 

Hunter......I just checked the prices of injectors on Rock Auto.....they have remanufactured ones for about $25, and new ones for $150. Not sure what it will cost to flow test the old ones.....but it sure would be good to verify that they were the problem.

Makes sense what you said about the injectors not being "tweekable"......sure would be awful to increase the flow rate on the rear ones, and then have super lean squirts on the front cylinders......and then have Nos. 1 & 2 go belly-up.

This Hillbillie is learning alot from your ordeal.

 

Hunter........Any progress on the injectors and your project?

 

No progress so far. The local shop that could do injector testing said their machine is broken. They can ultrasonically clean injectors, but not flow test them. I want to flow test first, so I'm waiting for them to fix machine.
The engine builder/machinist told me that he was pretty backed up with work. He did say he will get to it towards the end of February. I was just going to call him tomorrow to check on the status.

 

Gotta wait for them to fix tha machine.........hopefully the spare parts are not coming from Shynna, as it seems they have not shipped any container boats in months. I just saw a video of the ports in California, and boy.....they are empty.....no fresh containers stacked up like usual, just a bunch of empties.

 

Yeah, fun times. With such level of inter-dependency all is well as long as everything works like a clock. Unfortunately now it feels like riding a bike and getting a fat branch stuck through your front spokes...

 

Back to my Monty. Talked to the machinist today. He's been working a little on the engine. He said all 4 valves on #5 piston were busted up significantly, so he is going to replace them. He said one of the valve guides on that cylinder was cracked too. I guess that metal piece did good enough damage there. Couple of guides on other exhaust valves are worn to the specification limit, so he is going to replace them too. He is lining up the rest of the parts for the rebuild. We definitely going to replace rod bearings.

 

Sounds like she will be running like a new one when all is done.....hopefully he keeps the cost as low as possible for you.

 

keeping my fingers crossed

 

Well folks, it looks like Christmas came early this year. Look what Santa brought from his workshop to mine 😁😁😁

My machinist did an amazing job. He did have to bore pistons 0.050 oversize. The scratch from the blown piston was a little too deep. Got all new pistons/rings, main and rod bearings. He also cleaned/reconditioned the heads. When he worked on the heads he found that on the blown cylinder all 4 valves were slightly bent. You can't see it with the naked eye, except when you micro them. If you line them up just right you kind of sort of can see it. Not sure if photo shows it well enough. One valve guide was cracked and couple guides on the heads were worn past the specs, so those got replaced.
When I dropped off the engine, I talked to the guy that I will do the final asemby myself in order to save some cost. He was totally ok with that. Since I like to do things by the book and not half a**, I was honestly starting to stress out if I can do good quality engine assembly under conditions I hand with tools I have. I tried to educate myself by reading FSM, reading a hundred online posts on how to do engine assembly the right way, binge watched too many videos from the channels I trust on how to do good work on engine assembly... I was ready, but with butterflies in my stomach. On top of that I had a page full of questions for the guy, to make sure I got assembly/break in done right according to his quality parameters. I get to the shop, the block gets lifted on the hoist... and I don't see light shining thought the cylinders... Instead I see pistons in every cylinder hole 😲 The guy says - "I wanted to make sure it all spec'd well after assembly and my micrometers are probably (haha) better that what you got at home, so I just put it all together... No extra charge."
What relief...
So... I got a short block and heads, nearly ready to reassemble. I'm waiting for the results of testing/cleaning fuel injectors. I had to send them out, since my local shop said their tester is broken and not going to be repaired any time soon with this COVID-19 situation. I'll update you when I hear back about that.
I have to order new seals for cams and I'm going to throw on a new oil pump. This way I figure I truly will have an engine with zero miles on it. It's going to be a fun couple weekends 😁


My new block. Looks much better than when I got it apart.

These look as good as they did on the day they were made ...

I hope this shows the slight deviation. I definitely would have missed it on my own.