What To Do With A 72

[Dan A.]

About a year and a half ago I bought a 29,000 mile Ontario Orange base motor/auto coupe. It is in excellent original condition with original glass, headlights, and interior. It has the original engine with all "born with" parts like carb, distributor, alternator and distributor. The paint appears to be mostly original and still looks very nice. The frame and birdcage are rust free. The car runs and drives great and the A/C is very cold, but there are a few problem that the previous owner "forgot" to mention - the motor smokes a little upon start up, which I attribute to valve seals and is not a big concern, and when the engine first starts it sometimes sounds like it has some bearing knock for a second until the oil pressure builds. The oil pressure appears normal at all speeds and it uses no appreciable amount of oil. I have a lot of repair receipts dating back 30 years that includes a new oil pump a few years ago, which maybe should have been a clue.

Here is the real issue - I would like to sell the car and buy a 71-72 LT1, but unlike the previous owner I would not attempt to sell the car without disclosing these things, even though the car runs extremely well. If I have had more time I would rebuild the engine but I don't see that happening for awhile. So, how much of a hit in value would the car take in everyone's opinion assuming it needs an engine rebuild?

Thanks.

[Paul H.]

Re: What To Do With A 72

I would say the amount would be about the cost to re-build the motor. That varies quite a bit depending on who does it.

[Edward J.]

Re: What To Do With A 72

Dan, I don't think the motor would need a total rebuild if your only talking a rod type bearing noise, the engine can be removed and the crankshaft machined and new bearings, and while its out do the valve seals. I think the engine should not need a rebuild, And if it were my car this would be my plan of attack. As far as the value as the car sits I would think a few thousand dollars. The car sounds like a bowtie car so dissay and reassy should be done carefully leaving the paint as it is if has never been touched, and not tampering with bolts that don't need to be removed.

[Roy V.]

Re: What To Do With A 72

If you find the engine does need to be rebuilt, make sure the original engine block is not "decked", it's seldom necessary, and you might loose the important stamp pad numbers

[Jack H.]

Re: What To Do With A 72

Corvettes are somewhat unique in that you can easily drop the pan and access the bottom end of the engine without pulling it. Not saying this is ideal, but I freshened up a similar '73 I owned long ago by replacing rod & main bearings, rings, rear main seal which was leaking, etc all with a lift and accessing thru the dropped oil pan all without pulling the engine. Didn't really find anything obviously wrong/bad, but it provided peace of mind, and saved me the time/hassle of pulling the engine. I've also successfully replaced valve seals, springs, retainers, keepers, etc. using the air hold adapters in the spark plug holes to keep the valves in place, i.e. only removing the valve covers. Maybe this provides an easier solution without having to pull the engine or removing the heads in order to address your concerns.

To answer your question regarding value, I think it depends on the buyer. A buyer who is comfortable with mechanical work might see it as a good match to his/her abilities with only a "cost of parts" discount. I've often been drawn to those kind of cars personally, as I'm less comfortable/capable to do body/paint work. The other extreme as Paul suggested would be the complete cost of a professional rebuild, which I couldn't even guess being more of a DIY'er myself.

BTW, I applaud your outlook and honesty. Wish there were more that shared your attitude.

[Dan A.]

Re: What To Do With A 72

Thanks to all that have replied. I hadn't thought about freshening up the engine without pulling it but that might be a reasonable option in this case. I don't want to disturb anything I don't have to.

[Patrick H.]

Re: What To Do With A 72

I have found that a similar knock after sitting is not uncommon in these motors. You might want to try (just a suggestion; keep the flames down boys) different weight oil that is a bit heavier and see if it makes any difference. With the low mileage on the car it would seem unusual to actually have bearings worn to the point of knocking.

[Dan A.]

Re: What To Do With A 72

Patrick,

I have actually experimented a little with that as well as with different oil filters. The latest oil I have tried actually seems to have made it a little worse so your point is well taken. I agree it seems odd given the mileage, and it might run like this forever, especially with the ample oil pressure, even at idle - at least according to the gauge.

[Patrick H.]

Re: What To Do With A 72

Dan,

I'd tell you that at least 2 of the 72s that come through here do the same thing. Honestly, if it were my car I wouldn't touch it.

I will see if I can update you tomorrow after I move one of the cars.

Patrick

[Dan A.]

Re: What To Do With A 72

Patrick,
That would be a big help. Thank you very much.

[Michael F.]

Re: What To Do With A 72

I go with dropping pan and replacing bearing and replacing valve seals as well....I would feel comfortable doing this and selling and you could tell buyer you did so....good luck on finding the LT-1 you seek, 70 best for performance and less made, 72 if you desire airco is way I would go.

[Russ S.]

Re: What To Do With A 72

The only thing this engine should need by your description of it is valve seals. They can be replaced with out disassemble of any thing other than valve covers and spark plugs. Maybe loosen up air compressor to make room to work.

[Patrick H.]

Re: What To Do With A 72

My car didn't make one bit of noise this morning when I started it, but it has only been 3 days since I last started it. I do know that it made a bit of noise on Saturday when I started it but it had been about 22 months since I last started it. It has made a slight noise in the past when it sits for months, but I so rarely start it that I can't say with any regularity how much time has to pass for a noise to occur. Of note, one of the other 72 I work on does make occasional noise, but I haven't tried to see how often that happens either. Regarding your car if it were me I'd fix the valve stem seals, use 15W-40 CJ-4, and call it good.

[Dan A.]

Re: What To Do With A 72

Thanks, Patrick. I think that's the plan for now.

[Duke W.]

Re: What To Do With A 72

Are you sure the noise is from a bearing? How about a sticky lifter? Or it could be cold piston slap. You should take it for some drives with fresh CJ-4. Get it up to operating temperature for awhile.

If it indeed has no significant oil use, don't worry about the valve seals. A little smoke at startup after sitting for days... or years is not abnormal.

Change the coolant, transmission and axle oil, flush the brake system, and just be honest with potential buyers that is has some minor issues. A 40+ year old car - even with such low miles - is bound to have issues, and if a buyer expects a "perfect" car he's in la-la land.

Duke