Oppo opinions wanted

"lone_liberal" (token-liberal)
08/09/2020 at 22:12 • Filed to: None

Unlike Reese’s these are not two great tastes that taste great together.

For those who don’t subject themselves to pushrod engines that is coolant sitting on a rocker arm. There should not be coolant on a rocker arm. I started digging in to this thinking that the intake gaskets were leaking but once I pulled the intake manifold I couldn’t see any evidence of that. The damage here was from me starting to scrape it off. I then thought maybe the head gaskets and did a compression test. The high was 160 the low 140 with the rest being 150 or 155 so that seemed ok. That leaves a few options.

1. Just do the intake gaskets as originally planned.

2. Do the head gaskets since I’m most of the way to that point anyway.

3. Use this as a rationalization to buy a set of aftermarket heads since the heads could have a crack in a coolant passage causing the problem.

I’m leaning toward #2 but #3 is a very close second.

DISCUSSION (24)

shop-teacher > lone_liberal
08/09/2020 at 22:34

You probably have a crack in the head then. Take it to a machine shop to get it checked ... or just use it as an excuse to buy aftermarket heads!

Don’t just do gaskets and button it back up though. That’s asking for trouble.

If only EssExTee could be so grossly incandescent > lone_liberal
08/09/2020 at 22:36

If you have good compression then yeah, there must be a crack in the block somewhere. Just hope it's not a cylinder water jacket.

pip bip - choose Corrour > lone_liberal
08/09/2020 at 22:39

I’m inclined to say get the heads checked out and go from there

PyroHoltz f@h Oppo 261120 > lone_liberal
08/09/2020 at 22:41

#3....or #2, do not settle at #1

VincentMalamute-Kim > lone_liberal
08/09/2020 at 22:47

That’s a problem. I v ote #3.

Dr. Zoidberg - RIP Oppo > lone_liberal
08/09/2020 at 22:47

I don't know shit about cars, but that is not the correct color you should see in there

Brighammer > lone_liberal
08/09/2020 at 22:47

Man... I feel you on this...

After my motor died, and I ordered up a new short block and head from AliExpress, I decided to order brand new inject ors. Because why not. Then I took the fuel injection pump to be rebuilt. Them I decided I'm gonna get a new turbo too. Because why not? I've already spent $3000 so far!

lone_liberal > If only EssExTee could be so grossly incandescent
08/09/2020 at 22:53

A cracked block is the evil we do not name. I really, really hope it’s the heads.

lone_liberal > shop-teacher
08/09/2020 at 22:57

And really it would be a waste of time and effort. Right now, after thinking it over, unless I find obvious signs of a blown gasket I’m going new heads.

lone_liberal > Dr. Zoidberg - RIP Oppo
08/09/2020 at 22:59

It is not.

MM54 > lone_liberal
08/09/2020 at 23:01

Were the heads/block pressure tested or magnafluxed when the engine was rebuilt (this was just rebuilt recently right?)? What is the history of these parts?

If the intake was leaking from the water crossover into the lifter valley I suspect you’d be able to see quite a bit sitting in the valley since it’d have been leaking after you last shut it off.

Those compression numbers are... fine. If there’s no signs of water also making it into the cylinder (such as steam-clean spark plugs or visible coolant when you pull one) it’s probably not the head gaskets, but that’s hard to rule out without pulling the heads.

Demon-Xanth knows how to operate a street. > lone_liberal
08/09/2020 at 23:08

If the coolant came into the valley the lifters would pump it directly into that area via the pushrods.

lone_liberal > MM54
08/09/2020 at 23:10

The engine is not fresh. It was actually in a previous car of mine which was wrecked then it sat for a few years before being put into this car. It has low miles but a fair number of years on it. The lifter valley has some coolant but not a large amount. I’m reluctant to take these heads to be checked since they are late 70s smog heads and not worth putting much money into, but that might be the best thing to do.

lone_liberal > Demon-Xanth knows how to operate a street.
08/09/2020 at 23:13

That’s a good point. So intake gasket is still possible, though there wasn’t a lot of coolant in the valley. However there was some so still very possible.

shop-teacher > lone_liberal
08/09/2020 at 23:29

I think that makes sense.

Highlander-Datsuns are Forever > lone_liberal
08/09/2020 at 23:31

Do you have milkshake oil yet? I’d do the head gaskets at least.

camaroboy68ss > lone_liberal
08/09/2020 at 23:35

For coolant to be sitting in the rocker and over multiple rockers, the heads are more than likely fine as the leak is getting into the valley to pump up into the pushrod, buy the lack of chocolate milkshake (oil and coolant) is odd as well. I would not be expecting very green coolant on something coming up the push rod. Looking like a cracked block or head gasket. As water is pushing into the oil galley that runs along the cam to send oil up the push rods. Was this coolant on both sides of the block?

lone_liberal > camaroboy68ss
08/09/2020 at 23:55

Thanks for clueing in to things that I didn’t specify but were bothering me. The green color instead of a milkshake really struck me as odd. The coolant is on both heads but I’m starting to wonder if it’s just coming from a leaky intake gasket into the lifter galley and then going up to the heads via the push rods? At this point what I know for sure is that I’m pulling the heads and then taking it from there. To be honest, a cracked block was the first thing my dad mentioned when I called to pick his brain on it. Sigh. At least this isn’t an engine that has a lot of dollars invested in it.

camaroboy68ss > lone_liberal
08/10/2020 at 00:05

That amount of coolant would indicate practically no gasket. but the lack of milkshake is very odd as well. Was there milkshake in the pan? it would end up there if that much coolant was dripping down from the top of the motor. Because if there is a lack of milkshake there, then you could then also be looking at plugged oil galleys as well. That would explain the lack of mix at the top end. What year is the block? I know early small blocks required a oil grove at the back of the cam, I think 55-59 blocks and then everything else after that didnt need it and should not have that groove.

lone_liberal > camaroboy68ss
08/10/2020 at 00:18

The block is a ‘77 truck block according to the VIN. The dipstick doesn’t really show the milkshake like you’d expect more like thinned out oil. It does read high and the radiator is low so the coolant is in the pan but no cafe au lait. I’m going to drain the pan tomorrow before pulling the heads so I’ll have a better idea then.

Rusty Vandura - www.tinyurl.com/keepoppo > lone_liberal
08/10/2020 at 00:46

I’d hate to buy nice aftermarket heads and find out the block is cracked. I’d be considering Option 4: chuck the entire smoggy ‘77 engine and look for something else.

lone_liberal > Rusty Vandura - www.tinyurl.com/keepoppo
08/10/2020 at 01:08

But those heads can always be moved to a new short block. I'm just reluctant to shell out $4k for a shiny new engine with the economy in the shits even if I can afford it right now.

Rusty Vandura - www.tinyurl.com/keepoppo > lone_liberal
08/10/2020 at 01:36

Valid point. I suggest you look closely at what all else they fit before you buy them. But Option 3 would’ve been my first choice. Does pulling the heads keep you from performing some test for cracked coolant passages or something? Maybe hold off for a minute before you crack those head bolts? Also, what about blowing out the bottom end with the new heads? That’s a mighty old engine.

MM54 > lone_liberal
08/10/2020 at 12:18

Oh, I don’t know why I thought it was a recent rebuild... I’m easily confused these days.

I’d considering getting performance heads if (and only if) you plan on keeping the same bottom end even if the block is bad - i.e. if you buy heads and put it together and find out there’s a crack or pinhole leak in the block, would you get another shortblock you can use your existing heads on? If not, I’d get your current heads checked and if they’re good, time for a full tear-down.