Decided to buy a "spare" 2001 AJ27 motor for $150 to rebuild over time figured I would just redo the top end and have a good runner.

I am planning to rebuild over the next 6 months, bit by bit. It looked like a good engine that had been overheated....but when I took the heads off and rotated the engine, one piston came up short. Looks like it has a bent rod from hydrolocking. (there was coolant in the cylinder for awhile, the valves showed wetness.)

SO- with the exception of a volkswagen, I have never done a full rebuild and I have questions.

Do I need to replace all of the connecting rod and main bearings? Should I have the crank turned? Should I have the block cleaned and stripped etc? Should put in all new rings? The cylinder walls have no "lip" and the hone marks are still clear and visible.

Can I get away with JUST replacing the bent rod and bearings without disturbing the crank etc? For reference it is the cylinder closest to the driver.

 

Depends . . .

. . . on what you want to accomplish.

You don't say how many miles so that is a serious consideration.

Changing the one rod and an inspection/service of the heads will probably give you a serviceable engine.

With no time constraints I might do a complete clean up but then I look for auto things to work on.

 

Tom's correct - do as little as possible. To fully refresh motors cost me £1500+ in parts alone, I can buy a car for that....

To check a crank I chopped the mains out of a spare bedplate to make dummy crank caps, these could confirm if the crank is good or fecked.

 

Ok- So I will avoid a full rebuild and stick to swapping the rod out. How would I check the crank without removing it? No ridge on the cylinder walls, os I am guessing relatively low miles?

 

You can replace just the one rod, but it may be a good idea to remove the main and rod bearing caps to see the condition of the bearings and journals.

If this is a Nikasil engine, it is best to leave the cylinder walls alone if there are no scoring or other marks. Depending on how much you want to spend, you can always install a new set of standard sized rings.

 

That sounds like a good idea- I am planning to replace the rings, it is a steel lined motor from 2001, so no nikasil- probably should hone as well.

So my parts list is a gasket set, one rod, tensioners and rings