2.7L Rebuild thread, Sad findings Options

[Cfletch]

Wanted to share an update and also use this thread as way in holding myself accountable and give you guys updates regarding a 2.7L rebuild.

Backstory:
In 2014 or so I had purchased a 2.7L that had been rebuilt and was removed from a running car. The engine then sat for roughly 10 years or so and after coming back from college and a few years of lack of interest in the conversion project I finally got some interest back in the car and wanted to finish what I had started. I ended up getting the engine in as well as my other conversion parts and the car ran and I was so excited thinking that I would be able to more or less have a running project I would be able to drive on the weekends and also tinker on to fix things that bothered me that I found while driving it. I never thought to give it a good ol compression test because when it was purchased, it was sold with good leak down numbers and I had trusted them since it came from a well known shop. Whoops! After waiting about 7 months or so for an appointment at a local indy Porsche shop, I had them do a proper alignment and just check over the car to be sure its safe. One thing they did was a compression test which led to a leak down test. Cylinder #4 has 25 compression and about 80% leak down which was a big bummer to hear. The other Cylinders apparently were more 'okay'. The numbers were as follows for compression: 125,140,145,25,140,130. They mentioned the air was escaping into the crank implying that the rings on #4 were shot or something else that I won't know until I get into it.

Plan of action:
I cannot afford a shop to do a rebuild, and welcome the task of learning to rebuild the engine. I'm still concerned about cost and it might turn into a slightly longer rebuild than I would like because of the cost. My plan is to ditch the CIS pistons and go with the Mahle 90mm 8.5:1 Euro RS P/C set and probably go with some Solex style cams or E. The engine has Carbs already. Main goal here on the piston change is to allow for a more aggressive cam than the CIS cams that are currently in it.

Based on my reading from the engine rebuild book. 1974 could either have cylinders that could be honed, or not and there is not a recommendation to just replace the rings on the other cylinders as it runs the chance of just eating the walls alive shortly after install.

Another point of concern is I don't really want to split the case, but think I should. Assuming I have case savers, which I am not certain I do, that might end up being the reason why I end up splitting it.

If anyone has any video recommendations that go through the whole process of disassembly and reassembly of an engine in depth, please feel free to send me the links!

I only care to post this here at 914 World as the community is more tight knit than at the Bird!

[mepstein]

If you split it, you will need to send out the case to get line bored. They always need it on a mag case. Then have the machine shop do the case savers. Grab your wallet because there’s no way to rebuild an engine for penny’s.

Are you sure it’s not just a slightly stuck valve from a bit of carbon. That happens all the time. Especially if the engine has been sitting.

[Cfletch]

If you split it, you will need to send out the case to get line bored. They always need it on a mag case. Then have the machine shop do the case savers. Grab your wallet because there’s no way to rebuild an engine for penny’s.

Are you sure it’s not just a slightly stuck valve from a bit of carbon. That happens all the time. Especially if the engine has been sitting.

Based on what the shop said, where the air was leaking into the case, seems more like rings- they also mentioned bore was scored a bit so I'm inclined to believe them.