'69 1600 Loss of Power

[Hippie]

'69 bus, stock 1600 single port.
The other day on the interstate it lost power. Couldn't keep up to 55 mph when I had been going 70.
So's I pull over on the shoulder, leaving the engine idleing, and see there is a ton of smoke from the tailpipe. It was gasoline smoke...light and gassy smelling...coming out in regular pulses.
The engine felt hot.

I figured that since the newish spark plug wires are not reliable (I've had them pop off enough to lose a cylinder before) so I wiggled and pushed down all the plug boots, but I couldn't tell if it was running rougher or smoother. I took off gently, still smoking from the tailpipe when I got in the driver's seat. I was thinking better get some fan speed to cool off, slow acceleration, low load. After a minute, I tried full throttle and it was back to normal and able to pull full speed the rest of the 25 miles home, but I kept the speed down a bit. My oil pressure was only 18 PSI at 60-65 MPH in fourth gear, of course. (10W-40).
It had been higher before this incident.

So now it sound noisy....rattly, maybe like loose valves. I don't know. Possibly my imagination?
I don't trust it on the highway commute right now.

So, if this was your situation, what/how would you test to see if it is OK? What should I look at or look for?
I have kind of been out of "mechanic mode" for a while and my mind and time is/are full of other, new bullshit from college, so I am at a loss here, for now.

Thanks in advance.
-Rob

[hambone]

Timing, or a bad condenser? Sounds like ignition issues but I may b wayyyy off. A good place to start lookin'.

[ruckman101]

A condenser could do that. It can be intermittent.


neal

[Hippie]

Thanks for tips. I have a spare, I think. Also, it runs at real high idle when hot. Didn't do that 2 weeks ago.

[RSorak 71Westy]

Sounds to me like a temp. fuel issue. Has the filter been checked changed redently?

[Amskeptic]

'69 bus, stock 1600 single port lost power.
smoke from the tailpipe. gasoline smoke... engine felt hot.

took off gently, still smoking from the tailpipe
After a minute tried full throttle back to normal and able to pull full speed the rest of the 25 miles home,
oil pressure was only 18 PSI at 60-65 MPH had been higher before this incident.

now it sound noisy....rattly, maybe like loose valves. I don't know.

Hippie, this needs to be treated as Bad News.
Start with an oil change.
Valve adjustment + actuate each rocker with your valve adjusting 13mm wrench to check for loose valve guides. Check rocker stand nuts for tightness.
I would do a compression test and check plugs for equal color/condition.

Carburetor may have stuck the needle valve open and diluted your oil.

Listen closely for looseness mechanical clatteriness/knockyness both cold and hot. See if oil pressure recovers after oil change.
Colin

[Hippie]

OK.
A stethescope on the valve covers sounds like #1 area is clattery with the engine idling. I haven't opened it up yet.

[vdubyah73]

x 2 on what colin said. the smoke and clattery sounds are not to be ignored or slowly analyzed while toodling down the road.
get in there, it may be as simple as loose rocker shaft blocks or the spring clip that holds all of it on the shaft may have busted. don't run it any more til you've had the valve covers off.

[ruckman101]

Yeah, thinking back on it, a failing, intermittent condenser or coil fails all the way until things cool off. So either, run, or no run. No inbetweens.


neal

[Hippie]

I'll look into it tomorrow, barring rain. Been driving my pickup.

[Hippie]

Darn. It's bad news, guys.
Looks like number 3 cylinder's exhaust valve seat is so sunk into the head that it can't be adjusted.
The adjuster screw is backed all the way out and the valve stem is sticking out so it is only a few thousandths inch from the rocker.

Considering the bearings are probably shot because of the low oil pressure it has, maybe time for an overhaul. The engine has to come out and be pretty much stripped to do the heads anyway, you know? Maybe go ahead and overhaul it?

I got to figure how to get some money set aside for this. We can, I think, but it will take a little time.

[sped372]

Bummer man... at least it's the end of the nice weather season around here.

[Hippie]

Ya. I was hoping to drive it until just before the weather got snowy-salt-on-the-roads-ish.
I guess it's parked for a while. I want to get a long-block or a rebuild kit.

[ruckman101]

Bogus. Time marches on.


neal

[Hippie]

So now I got a few decisions/questions for you all...
Do I order a rebuild kit and chance that my engine case is good? It was new out of the box (AS41) seven years and ~45,000 miles ago. Should I pull it apart before ordering anything?
Should I just order a long-block because of severe time constraints? From who?
Mofoco has one that is mostly new parts...not the cheapest but has new crank, camshaft and lifters, new case, new connecting rods, pistons and cylinders, and rebuilt heads. (The heads are single port, so hard to find new.)
I don't know about Mofoco's reputation though.

Also, I thought about getting a 1776 for more power, but then it would automatically be a dual port. I could get new heads that way, but then I almost have to buy a turnkey motor which is expensive. None of my engine tin would fit a dual port. The intake manifold is all different, of course, too.

If I try to make time to do a piece by piece rebuild (looking doubtful) then could I measure the case myself to see it the bearing saddles aren't pounded out? There's not any VW machine shops around anymore.

I'm lost at the moment.