Carbon on valves

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brian6pac

brian6pac

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Last night I took apart my 71 360 and the carbon on the valves were like nothing I had never seen before, the port is almost blocked off ! Has anyone seen them this bad ?

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Not quite that bad, but almost.
Pull the rockers n knock it out with a flat head then vacuum it out..

New valve seals and slap it back together.
 
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They are the worst I have seen, They will get pulled at some point and get 2.02 valves, bronze guides, and a good cleaning.
 
Old school treatment done back in the day,,Rev engine to about 3,000 rpm and slowly dump (small amount at a time) a full glass of water in the carb to break up the buildup.In the 60's we did it at the Dodge Dealership, it was common for the people that didn't drive much or far.Good practice ? I don't know but it was what they taught back then.
 
It could be a number of things adding up over the years contributing to this. Camshaft over lap, ignition less than perfect, vale seals leaking, and that doesn’t take much at all! A teeny tiny coating over time will grow like a cave stalactite.
 
This engine came out of a 71 Newport Royal, a slow boat to nowhere.
It probably did just putt around most of it's life.
 
running cold or heat exchanger?
mopars make better Marine motors than chevy
ask me how many bbc my customer destroyed in his Cigarette boat
 
They just about liter the place!
Wyrmrider said:
running cold or heat exchanger?
mopars make better Marine motors than chevy
ask me how many bbc my customer destroyed in his Cigarette boat
Click to expand...
 
needed lot"s of brooms
over speeding biggest problem
well not exactly
come out of the water and hit the rev limiter(after they realized the were not quick enough on the throttle- (macho problem)
the coming down is hard on the whole of the drivetrain
like coming out of the burnout box and hitting dry track
think about what that does to a torqueflyte if you don' lift first
 
Darter6 said:
Old school treatment done back in the day,,Rev engine to about 3,000 rpm and slowly dump (small amount at a time) a full glass of water in the carb to break up the buildup.In the 60's we did it at the Dodge Dealership, it was common for the people that didn't drive much or far.Good practice ? I don't know but it was what they taught back then.
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Yep, works like a charm. Just don't pour too much in at a time. I remember in the late eighties my buddy had a water injection system on his '71 Roadrunner 383.
 
Direct injection engines get this a lot. Even more with a turbo. So much that one engine had typical manifold type fuel injectors that ran at idle to clean the intake tract. Frequently, rev them up high for about half-minute to “excite” the valves and produce a lot of heat to wick any carbon buildup.

Do you use ethanol fuel?
 
I healed a few interference motors with the steam clean. Did it through a vacuum port.
 
T56MaxTorq said:
Direct injection engines get this a lot. Even more with a turbo. So much that one engine had typical manifold type fuel injectors that ran at idle to clean the intake tract. Frequently, rev them up high for about half-minute to “excite” the valves and produce a lot of heat to wick any carbon buildup.

Do you use ethanol fuel?
Click to expand...

I'm sure it used a lot of ethanol fuel :rofl:
 
T56MaxTorq said:
Direct injection engines get this a lot. Even more with a turbo. So much that one engine had typical manifold type fuel injectors that ran at idle to clean the intake tract. Frequently, rev them up high for about half-minute to “excite” the valves and produce a lot of heat to wick any carbon buildup.

Do you use ethanol fuel?
Click to expand...

I heard Toyota added port fuel injectors to their GDI engines at some point to keep the valves clean.

That engine looks like it was driven very slowly probably never more than 1/2-throttle. Also probably ran rich (I'd bet from an improperly-working choke) and/or had oil leaking down the stems and I wouldn't be surprised if the thermostat failed at some point but they just kept driving it and it never got up to full operating temp. Lots of drivers out their think it's bad for your engine to go WOT and without idiot lights most people don't even know what the temp gauge means or they think as long as it doesn't overheat everything is fine.

I know when I drive my brother's TDI (diesel) VW after my bros have been driving it a lot it seems just a tad down on power until I get it warmed up and floor it for 5+ seconds to burn out the carbon then it runs better lol. Neither of my brothers are gearheads or into cars at all so they have no interest in going faster than they need to whereas I'm a total leadfoot lmao.
 
I used to see heads like that quite a bit....... not so much anymore.

I had a DOHC Neon a few years back that I ended up re-ringing....... and even on that thing the intake valves all had a big tee-pee of carbon built up on them.
However...... the ports themselves were still pretty clean.

On the Neon head, that stuff on the intake valves was really quite hard and baked on.

On the old v8 stuff, it was often softer...... more like very thick dry sludge.
 
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