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]

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Well the good news is that the internals are clean and the cam barely has wiped off the parkerized coating.

My first order of business would be to try to understand why there is so much crank end play. Typically it is about 1mm without shims. You seem to have about 50% more play than that. Is there anything mis-machined at the crank end that interfaces with the thrust bearings. It may all be OK and can be shimmed - now is the time to look to see if you can understand root cause.

Good to see they did use a double thrust cam bearing.

Good stuff in there.

Hopefully just as simple as confirming, operational clearance between case and moving components, bearing clearances (rod and mains), rod end play, and balance (highly recommended). Then, clean and reassemble.

Am I correct in remembering that you didn’t have any issues spinning the crank when the heads were removed?