1970 472 tear down and rebuild. As cash comes in for it.

[Speach]

Ok so now I know what this motor is and have begun the teardown to see the condition. My plan is to do moderately build this engine up and put it into my 66 2dr Calais at some point. I would like to add some high performance mods. Cam, intake, etc. I have done significant work on my 68's 472 but I have never done a complete rebuild. I love these cars so much so Its time to know this motor inside and out. Any recommendations and insight is very very much appreciated. I want to build a tough motor but still be able to drive in stop and go traffic if I have to. This car will prob never be a daily driver but I still would like to be able to drive it anywhere without hassle. After opening the motor up I found the timing gears seriously worn, valve seals in the oil pan and pump screen. I was shocked when I saw the timing cover. It looks real good. The one on my 68 was almost rusted through. My 6th cylinder was dirty and looked like some water made it in there at some point. Cylinders are not very worn. Not much ridge. The drivers side exhaust manifold is cracked, possibly how water got in the 6th cylinder. Below is a photo of my 68's motor as well.

[EZ]

Have fun!!  The 472 is a great engine.  There are lots of aftermarket parts for the 472/500.  I'd get an Edelbrock intake,
probably use a #10 cam from MTS.  Freshen everything else up and you'll have a very reliable and sporty engine!

[Speach]

Yea I was on the  MTS website and saw they had a bracket and compressor to run with the edelbrock intake. Pretty cool. I got to study up on cams. I don't know to much about size differences and what they do.

[STDog]

After opening the motor up I found the timing gears seriously worn, valve seals in the oil pan and pump screen.

The timing gear isn't worn. The nylon coating cracked and fell off.
That's what's in the oil pickup screen, pieces of nylon from the timing set.

[Speach]

Ah. That makes sense. It seemed really worn. So that explains it. My 68s timing chain and gears must have been replaced before because it did not have that kind of timing gear, it was all metal and not really worn.

[The Tassie Devil (Bruce Reynolds)]

Sounds like the previous owner replaced the set, but failed to clean up the rubbish that collected in the Sump.

Bruce.

[STDog]

Sounds like the previous owner replaced the set, but failed to clean up the rubbish that collected in the Sump.

Come on Bruce, pay attention.

The gunk is in the '70 engine with the shot gears.
The good/replaced gears were in the '68 engine.


So he had not seen the nylon coated gear before.

[Speach]

Yup, I didn't deal with the nylon gears before when replacing the one on my 68. Here are a few photos of all of the fragmented pieces of the gear coating that came out of my oil pick up. I cant imagine that all of that crap helped the oil circulate. As you can see from how loose the chain is that the nylon coating made up a good bit of the gear prior to it deteriorating. I was told that this motor only had 60,000 miles on it. That could be true but it,s still an old motor. I am so glad that I am going through it like this. The other photo is of me pulling off the crank end with a puller that came with a steering and tie rod puller set that I found on the clearance rack at Harbor freight. It worked extremely well unlike the crappy three prong pullers that tend to move as you tighten them. I will probably have the timing cover blasted. Any recommendations on what to do with the block once I get everything off of it?   

[blue68deville]

Man, I need to pull my distributor and take a look. I bet my gear looks the same.

Nice progress!

[STDog]

Yup, I didn't deal with the nylon gears before when replacing the one on my 68

You got lucky then. Someone must have been in it befroe you.

I was told that this motor only had 60,000 miles on it. That could be true but it,s still an old motor.

Age and lack of use are the bane of those nylon coated gears. The dry out and get hard. Then the nylon cracks and falls off.
Lack of use exacerbates it as there's no oil moving around.

Back in '88 I bought a low mile '69 SDV. It had sat unused  for a few years.
Ran great for a few months then the timing gear fell apart like that one.

Meanwhile, the much higher mileage '70 CDV I bought in 2000 had been used regularly. The timing gear was still good when I rebuilt it (oil pump issue)

with a puller that came with a steering and tie rod puller set that I found on the clearance rack at Harbor freight. It worked extremely well unlike the crappy three prong pullers that tend to move as you tighten them. I will probably have the timing cover blasted. Any recommendations on what to do with the block once I get everything off of it?   

I'm really surprised that puller worked. The jaws usually aren't strong enough.

The "3 prong pullers" should have 4, and you use the 2 that are 180^o apart on these hubs.


Hot tank the block at least. If you can find an acid bath even better.  Check the bores and see if a hone will clean them up or if you'll need to/can bore it.

Then use brushes and solvents to clean the water jacket. The current cleaners used by the shops just won't get the rust out.


Get it cleaned good. Then fix the cylinder bores and new freeze plugs. That's all she needs.

[STDog]

Man, I need to pull my distributor and take a look. I bet my gear looks the same.

I doubt it. If you're driving it and it's like that it'll jump real easy.
So, a bad gear and you'd know about it by now.

Still worth a look. If it's still nylon you can gauge it's condition (look for cracks and chips).
Then make plans to replaces it soon. If it's cracked pan to do it sooner.

I wouldn't drive one that I knew had cracks in the nylon.

[guidematic]

 The more I see this, the more concerned I am about the state of the gears on my '70. I have heard of 472/500's tossing a rod, and I suspect that the timing gear remnants are plugging up the oil pickup causing oil starvation.

 I'd like to pull the engine and give it a freshening It has 120,000 on it now. It still runs very good and is church mouse quiet, but there may be demons lurking inside.

 Mike

[STDog]

The more I see this, the more concerned I am about the state of the gears on my '70.

Has the timing set be changed? Did you do it?

I'd at least inspect the cam gear. If it was replaced by someone else, I'd pull the oil pan and inspect the pickup tube.
You can pull the tube and clean it if needed.

[Speach]

Yea and if you pull the oil pan be sure to clean it out as well. Mine had all kind of pieces in it along with the pick up tube.

[Speach]

I got to work on the motor a bit tonight. Pulled the pistons and cam. I gave the pistons a quick soak and cleaning in gasoline. As you can see the crack from the exhaust manifold let in moisture and created some rust and corrosion to the #6 valves, and piston head. I am letting that piston head soak in gasoline. Anyone know what the best way to clean the carbon residue off of the pistons? I used a broken piece of a ring to clean a few of the ring grooves. I dont want to use anything to abrasive, green scotch brite pad? My cylinders have pretty much no ridge at all. I know I need to measure them to see how worn they really are. Most of the pieces seem to have little wear. Can anyone gauge what condition this cam is in based on the photo? Also what can I reuse and what do I deffinitely not want to reuse. I will post more photos of the cylinders and bearings with measurements later.