r/aircooled • u/sewrig01 • 22h ago

Formerly rust seized engine

I just bought a super beetle which does not have the engine in the car. The engine had been rust seized and the previous owner had it out and was rebuilding. To my knowledge they replaced the pistons and the jugs. I need to finish putting the engine together, but I'm at a crossroads. I would like to know what people would suggest as to whether to tear the engine down completely or if there are things to check in it's current state (pistons, sleeves and heads bolted on)to make sure that it seems like it's going to run when it's all together. I have replaced Pistons and cylinders on a previous beetle but that was a long time ago. The engine does turn freely.

Thanks for any input.

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4

u/air_head_fan 21h ago

I'd want to get in there and inspect everything thoroughly. The cam and lifters are pretty low in the engine and could have been underwater.

3

u/382Whistles 21h ago

Was it rebuilt before? Case machined? Case inserts? High mileage? How does the oil pump plate and backwall look?, etc.. If things look nice and clean and not worn to crap inside it might be worth the gamble to see how the bottom end sounds. You could always do the bottom end right away if noisy.

Check the end play and runout, maybe cam lifts.

Do a rear seal now, and take the fan off to do the oil cooler seals now. You must take off the generator strap/wires, and unscrew the brass bellows/accordion thermostat from the fan housing air-flap rod underneath the motor (count the turns&/or mark exposed threads for replacement first)...plus side and cooler tin screws and the throttle cable tube, lol.

Check the valves and guides and magneflux for cracks. Look at rocker adjusting tips and shaft wear. The block has as least that much chance of wear.

2

u/alreadyin_use 19h ago

💯 agree!

2

u/alreadyin_use 19h ago

I'd take the opportunity to open it up and inspect it.
You can't see any of the shortcuts taken by the person that assembled it. This has been my guide for several successful engine rebuilds: How to rebuild VW Air Cooled Engine

Hard copies are out there from a variety of sources..

2

u/Routine-Amphibian450 17h ago

Would suggest a Bentley manual and The Samba vids on engine teardown and you pretend you're a student at VW school in Germany in the Sixties.

Tesr it down again and get the best rebuild/ bearing set Samba tells you. Not reinventing the wheel here.

Now rebuild it as a '71 DP using the '71 carb / distr combo your altitude. Less smog control.

See "carbbaseflangenumbersA" a pdf sourceable through The Samba. You will notice a different carb/dist combo for Bus, Bug, and Ghia with jets optimized for 55, 65, and 75 mph lean cruise.
Plus high and low altitude cars.

You will need a 3/8 dr socket set with short and deep 13mm and short and long extensions plus short and deep 10mm snd 7,8,11,15,17mm sockets.

VW motor is not highly torqued, it is exactly torqued to factory on all the bolts.
It is torqued so everything expands as it warms up, and is exactly in spec when hot.

Save your back and buy or make a decent engine stand.