I have a 69 camaro with a 350, stock cast iron heads. I have an issue with oil build up on the intake valves. I had the heads rebuilt 2 years ago they have about 4000 miles on them. The #2, #6 plugs had a lot of oil buildup are were fouling out. I've attached a picture of the heads and the cyclinders. I did a compression check on all 8 cyclenders. Each cylinder held 140-150 psi for 10 mins with no leak down. I don't really know where to go with this.If I get the heads rebuilt again I'm concerned this is just going to happen all over again. Any suggestions would be apprciated.

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Do you see smoke when you first start the engine? Also, it looks as though none of the cylinders are burning properly. First, if there is smoke at startup, it may be bad valve guide seals. If the rebuilder used OE style o-ring seals then replace them with Teflon seals, they are much more reliable. CAUTION: If the guides were replaced they might be too tall for this and it will require trimming the guide height. If you do not the seal will get crunched between the spring cap and guide. This is especially true when running a high lift cam. (Did you cam the engine and NOT let the head builder know your lift?) Since all cylinders look dirty, how about mixture and plugs? Get the carb mix correct and check it by reading the spark plugs. A rich mixture will leave unburned fuel in the cylinder and accelerate fouling. Check the entire ignition, make sure you are getting all the spark to the plugs. As a last resort you can step up to a hotter set of plugs.

 

I didn't notice smoke on start up. I did give the cam specs to the head builder. The cam is .488 intake .510 exhaust.

Maybe I doneed hotter plugs but first I need to figure out what to do with the heads and the block. I'm running a Mallaroy ignition.

 

what are you driving habits, do you take the car out and drive it intell it warms up and do you putt around or do you drive it like it you stole,you could have a lot of carbon do to not letting the motor warm up enough when you drive it,and every motor needs to have the crap ran out of it every once in a while to clean the all crap out of it. oh and what kind of oil do you use you might want to find a oil that helps get rid of build up and all so what brand of gas do you use.

 

Well, you probably have a good point there. I probably drive it like grandma most of the time. I use Valvoline oil. I gues atthis point I should have the heads cleaned up before it gets put back together.

Is the only way to tell if the carb is not too rich to check the plugs after driving it for awhile? The engine starts up very easily, idles well and was running good unitl I notices a little miss one daythen I pulled the plugs

Attached is a picture of the #2 plug.

 

wow there is no way thats from driving it like a grandma, that is a very oil fouled plug,you should go talk to the guy that did you heads and ask him what the hell cuased that and see if it was his fault by not building them right or if it is something more serious. wow i just cant beleave how fouled that plug is.

 

That is one nasty looking spark plug!
One more question I have. The original post says oil build up on intakes. Did you take an intake valve out and look at the backside of it? Oil buildup there is a sure sign the seals are leaking.
Back to the spark plugs. The picture looks as though you are running .035 gap and the plug really does look like it is a range too cool. With the mallory ignition did you get a hotter coil? With a good coil you should run .045 gap.

 

That was the worse plug #2 The #6 was pretty bad too the otehrs look clean with a slight grey color to them.

I pulled the intake to look in the intake ports for build up. I can see the build up starting on all of the intake valves at the base of the stem. I had the heads rebuilt before and this was the issue then. I think the gap of the plugs is .035. The coil was in the car when I bought it a few years ago. It is a Mallory Promaster Classic series. Any suggestion on what plugs I should run. I calculate the compression to be close to 10:1.

Here are the specs.




Part Number:
MAA-29440

CoilWireAttachment:
Male/HEI

CoilStyle:
Canister

PrimaryResistance:
0.600 ohms

CoilInternalConstruction:
Oil-filled

MaximumVoltage:
55,000 V

TurnsRatio:
105:1

SecondaryResistance:
12.3K ohms

Inductance:
7.3 mH

PeakCurrent:
100 mA

SparkDuration:
500 uS

MountingBracketIncluded:
Yes

CoilWireIncluded:
No

BallastResistorIncluded:
Yes

CoilColor:
Black

CoilShape:
Square

Height(in):
5.297 in.

Length(in):
3.706 in.

Width(in):
3.846 in.

 

First offI think Jr72rs is correct. Valve seals is the most likely issue. There are a lot of option out there to try, You can switch to an umbrella type seal.

The only think I could add issome questions, There is no type of EGR valve on this engine? Or a PCV valve? Somthing that could be dumping crap into the intake. How does the car idle is it loading up all the time?

 

I do have a PCV valve,a new onewas installed when I head the head rebuilt. I didn't build the heads. I need to find a shop to do this work for me. The car idles fine. What do you mean by loading up?