Tear Down and Reassemble Unstarted 1.7 built to 2270, 1.7 to 2270 Unstarted 10 Year Old Build Options

[Robroe]

Moved from topic of first start of 10 year old build to tear down, inspect and reassemble. The 10 year old build is from a 73 1.7 to a 2270. Stroked to 78 mm and 96 mm cylinder diameter. Heads are Ham/RAT with 36 mm exhaust and 44 mm intake. Both are nicely ported.

Have torn it down to the case and checking crank end play before I split the case and pull the cam and crank. So far, everything is new and looks in good order. I'm concerned about oil passages being blocked with old assembly lube so a complete tear down and reassemble is happening. Discovered stacked cylinder spacers (4) totaling .150". So looking to replace those with single spacers. So far I can only find .160" spacers from type 4 store and may just use them as impact on compression appears minimal. Was shocked to discover crank end play is .450"! Sure glad I didn't try to start this thing. Will check again in the morning to make sure I'm checking it correctly, but I'm doing the same thing on the videos such as Ian Carrs YouTube engine builds so pretty sure I'm checking it correctly. Now to figure out what to do about that huge end play.

Any thoughts about what to watch out for?

[Superhawk996]

It’s just another oil drain back passage at a lower point 6 o’clock position rather than the OEM oil drain to prevent oil from pooling up behind the RMS. As ninja stated, the 12 o’clock position is an air breather to enhance drainback.

It can be be done easily with a mill by a competent machinist. Hand filing it will take a little while but isn’t out of the question.

If it’s not for you, that’s OK too. It’s just a mod to help reduce the tendency for RMS to leak.

It goes right along with the risk of having an RMS fail because it was pounded in with a hammer and having the garter spring pop off the seal vs. pressing the seal in using a press tool that seats the RMS slowly and uniformly.

Shade trees have been banging seals in with a hammer for decades. There are also a lot of RMS leakers out there.

Personally, I do everything I can to avoid RMS leaks since they aren’t fun to fix and are so messy.