Rebuild of an A series engine

[austina35]

Hello all, I'm going to be rebuilding an A series 1275 engine soon after having new liners fitted and new rings. The crank was in good order so didn't require any work.

I have 2 questions. When assembling, what lubricant should I use. Just 20W50 oil? The engine wont be fitted until the winter.

How should I run the engine in? Meaning how many miles does it need before I can use it correctly.

Thanks

[tapkaJohnD]

There will no doubt be a hiost of other suggestions, all the one and onky thing to use, but my choice is Graphogen for the main, big end and other white metal bearings. Cams need their proper lubricant as well.

[littleredrooster]

Back in the day, I used to use Wynns additive for the slidy-turny bits and some specialist stuff from (IIRC) Kent cams for the valvetrain bits.

[DVandrews]

When building A series engines many years ago I used 50/50 wynns/oil to coat bearings and on the rings, this reduces the tendency or the lubricant to drain away, use proper cam lube on followers and cam lobes. If you are storing the engine, make sure you rotate it by hand on a regular basis to ensure the rings don't rust to the bore.

Dave’s

[NMNeil]

Every time. Cheap insurance.
https://www.redlineoil.com/assembly-lube

[stevieturbo]

graphogen etc is fine...oil is fine.

As for running in....with correct bore finish pretty much none is really required. But there are so many variables and peoples versions of how, just do whatever way makes you happy.

[Lotobear]

For reasons I don't fully understand the A series has something of a reputation for poor bedding of new rings in freshly honed bores so I would take care not idle it and get straight out on the road to avoid risking a smoky engine. Do a few cycles of top gear acceleration runs from around 2k rpm to say 4.5k. The aim is to build good cylinder pressure to force the rings to bed in.

I followed this on a newly built Lotus TC and the results were amazing - you felt the engine getting stronger with each run and it was essentially run in within a hour and used no oil (except via the usual TC leaks!). It's counter intuitive but it works.

I'ts also recommended not over oil the bores - use a very light oil only and sparingly to reduce the chance of glazing the new bores. I've followed this advice as well and never had any problems.