To Rebuild or Not to Rebuild?????

[cwmcobra]

I won't bore you with a Shakespearean pun......

I'm about to pull the engine from my 4-speed convertible and get started on the body work part of the restoration.  Before pulling it, I did a compression check, but probably not the conventional way.  No fuel, no ignition switch, so wasn't able to start and warm the engine before the test.  Didn't open the throttle blades on the carb(s) either.  PSI ranges from 140 on two cylinders to 160-170 PSI on the rest.  Using the acceptable range table from the GS manual, this is acceptable, within the 75% of max. compression rule.  It was running very well before disassembling the car and has about 60,000 miles on it. 

Should I rebuild it just because it will be out of the vehicle or should I put a few new gaskets on, paint it and run it?  What's the consensus?  I'm torn; on one hand I hate to tear it down if not necessary as these are expensive engines to rebuild.  On the other hand, if I stick it back in the way it is and it fails in the near future, I'll be kicking myself for not rebuilding it.  Also, my Steve Shuman car has over 100K on the engine and, except for being a bit noisy, it runs quite well, one possible argument for leaving it alone.

Guess I should start a poll.....to rebuild or not to rebuild?  I'll appreciate your thoughts and experiences.

Cheers!

Chuck

[GreatScat1965]

Chuck, With 60K street driven miles I don't see the need for a rebuild. And once you open the motor you are committed. That can get expensive fast with those motors. I personally would put a neoprene rear main seal, fresh oil pump, any other suspect gaskets and A fresh set of valve springs and Viton seals. There is nothing like a fresh set valve springs to wake up a older motor. Paint and detail it and you are ready to go.

But that's just my opinion based on my history with these cars, I don't personally know your car; so in the end you have to make the call. I vote: NO

Jerry

[schlepcar]

I agree,
Sometimes fixing things that are not broke can be very frustrating. New pump,thoroughly clean pan,and check for anything out of the ordinary. Be sure to prime new pump before restart. Most machine shops have to go "all the way" in order to insure their work. If it ever needs that,it is the way to go. With the compression you are talking,and assuming is has good oil pressure,I would run it like it is.

[Mister T]

I'm with the leave the internals alone camp as well. Clean, prime, paint and reinstall. 

[WkillGS]

I'd suggest replacing the timing chain and gears as part of the 'clean it and run it' going over. The original gears have nylon teeth and they don't age well.

[Fun401]

   I gotta think all of us go through this exact dilemma. I have a numbers matching 4 speed '65 with about 96k on it (changes as I drive it). It runs pretty good, I don't drive it very hard, but I will rebuild it,if it ever comes out. Just when, is the question. My thought is to pull it & the T10, spray it with a preservative, bag it, and store it in a corner of the garage until I can rebuild it the way I want, about a $7-9K project, with me doing all work except machine shop procedures.
   In the mean time, a crate engine or build up of a Big Block Chevy will be installed with 6 speed or 5 speed tranny behind it(yes, I know, that's a $15k project on its own). I like the idea of being able to beat the Chevy engine like a rented mule, and not hurting the value should I lunch it. I'll keep the 401 preserved and safe for the next owner/cork sniffer. When the time comes, swap the Buford back in, drive it nicely, and save the Big Block Chevy setup for another car. At that point it'll probably get sold as a well restored '65 GS. I have tubular control arms front and rear and upgraded suspension, but have all the original crap. Paint will be the stock color, interior will be original, etc.
   If you pull an engine, you need to at least change the timing set, check the cam, check the heads/valves, check the lower end rod & main bearings, check the distributor, replace the water pump, oil pump, and all gaskets. Radiator needs to be checked out, all hoses, belts etc. replaced. It's usually a small thing that begins the cascade of a catastrophic failure. I say all this because my biggest fear is lunching an original block, and ruining the car's value with it(hence, the BBC plan).
   Good luck with your project...
   

[dsags]

Chuck,

My advice is worth what you're paying for it. That being said 60K miles doesn't seem like a lot for a nailhead that has been used on a pretty regular basis. If they sit for long periods there can be problems. Not sure about your engine. If it was not using an abnormal amount of oil then it seems that a rebuild would not be required. Some of the items others have suggested may be in order. Can vouch for the 'they get expensive' part of rebuilding an engine.

Lots of luck with the project.

Dan

[35chevcoupe]

Chuck ,
Even though  the engine will be out I wouldn,t do completely tear it down . Maybe just freshen it up a little bit on the top end
LOL

[cwmcobra]

Thanks to you all for your comments.  It seems that the consensus is unanimous to just do a few basics and not tear it down for a full rebuild.  It did sit for a lot of years without running, but once I got the proper carbs on it and put a Carmen Faso distributer in, it was running very well.  So I will definitely take Walt's advice and change the timing set, probably to a double roller.  And take the pan off, replace the oil pump, etc.  A few new gaskets, a fresh coat of paint and away we go. 

Going to pick up a parts car today that will provide most of the needed parts to retrofit factory A/C into this restoration, as discussed in another thread. 

Thanks again for your shared knowledge!

Cheers!

Chuck

[Brian]

Replace the head gaskets with a new set of the factory-type steel shim gaskets.  They are notorious for leaking oil, plus the areas of them that block coolant flow in certain areas rust through over time and you don't get proper coolant flow throughout the engine.   Spray the new gaskets with blue Hylomar before installation to prevent them from weeping oil.  DO NOT install the replacement composite head gaskets like you can buy at the autoparts store.  They are much thicker and you will lose a substantial amout of compression and degrade engine performance. 

[cwmcobra]

Thanks for the heads up, Brian.  Great tip that I will follow!

Chuck

[cwmcobra]

Well, fast forward six months and I've decided to do a complete teardown of my engine.  Everything else with this restoration is being done in a very particular way, so I decided to not take a chance on the engine.  If you like, you can follow progress in my restoration thread:  http://65gs.com/board/index.php?topic=2075.0

 

Chuck

[telriv]

If you are NOT boring for NEW pistons & using the old ones. Look very closely at the pistons especially in the area of the pins & skirts. They have a tendency to crack in these areas. I torn down a '66/401 that had two cracked pistons with only 70K or so on it.


Tom T.