Thread: still fouling plugs

Tweet

Opps I meant positive seals not positive stop.My bad..

I think the oil problem has been found,77 I had asked what type Fuel pump not carb type,If it's mechanical may not be supplying sufficiant fuel on big end cousing your lean condition conferm this first then look at jetting.may have to switcth to electric pump with regulator.If this is the case then you can play with jets,what size carb spacer plate do you run the thicker the plate the leaner the signal 1in 2in ETC.Do you run A hood scoop with out A air pan?

Henry Rifle asked what carb I had.As far as the pump its a holley blue set at 6.5 psi what quickfuel recommended.And I have a 2" spacer made of aluminum.
As for the guides and oil problem will a leak down test confirm the leak through the guides?

Leak down test checks the valve seats and piston rings . Tell us more about these heads . Are they factory assembled . You may only have to change the seal that lifted . And the only ones that can suck oil are on the intake side . I think even if the seals lifted they still would act like umbrella seal that just move around on the valves . The old Chevy heads had just an O ring at the top of the valve . When the guides are new oil contral is not a problum . You need some oil so you do not burn up the valve stems .

Originally Posted by DennyW

That's pretty much it Tango, but when he shuts the car off, and it sits, any oil that can run down the guides, it will run down which ever guide it can, exhaust or intake. That's why with worn guides, when you start it, you get the cloud of smoke, and then it goes away.

ps: It sounds like he has a not so good a set of new heads to me.

On a worn out older engine yes not on a new set of heads . Get rid of that PCV valve first . And a little smoke on start up on a race engine is normal . Carefully push the seals back down and run a slightly hotter plug . Make some more passes with this car then see how it is .

IF you don't need the 2" spacer for clearence issues try A 1" see if that gits rid of the lean condition.Remember adding A spacer to your intake increases the distsance between the carb and the floor of the plenum.This will weaken the "signal" which in turn requires a larger jet for compensation.Is your spacer open or 4-Hole,Both need increased rejeting but not as much with the 4-hole just trying to see if your over jeting it.

FIDO did you buy that welder yet ? COOL

If the heads are as bad as Denny thinks they are . Pull them off and send them back !

Tango,I haven't got the welder yet playing the waiting game,won't to see if it go's on sale closer to christmas or see if I can get A % off.IM getting the pro-mig 140t.

Originally Posted by FIDO

Tango,I haven't got the welder yet playing the waiting game,won't to see if it go's on sale closer to christmas or see if I can get A % off.IM getting the pro-mig 140t.

You will like it when you get it . I welded a chair the other day . I boxed it and now its stronger then when it was new .

If I take these heads off and there is something wrong with the guides can I myself be able to tell someway?There should be oil coming down the valve stem into the chamber right?I live in texas and got the heads from a shop in arizona.I may just take them to one of the many local Dallas head shops and have them checked out and maybe ported.How much does a usuall port job cost?
I learned something thats for sure.I could have spent a little more money and used someone local and been able to take them back easier,but now I have to go through the trouble of shipping and only talking over the phone or e-mail not face to face.Another thing that points to the heads is I have had this problem since the first startup of the motor.

Camaro77

We deal with problems like yours quite often and most times it comes from the customer buying something online at a better price than the prices available from an Dart dealer---often times, someone will buy heads bare and then put in cheaper components to complete a package, valves,seals,springs, retainers,etc

Most likely you have gotten some heads that have undersized stems(too much clearance) or more likely the wrong seals( a .531 seal on a .500 guide) and the seal won't stay on the guide boss.

If you have the capability to use air and remove the springs, release the air, and see if the stems have a lot of wiggle---
Measure the guide top for sizing and use the correct positive seal---

If the stems have a lot of wiggle---remove the heads and return them
If it is the wrong seals, just change them on the engine without removing the heads

As a note---We have seen head packages bought on line that had .006 -.010 guide clearance and they did much of the same thing that you are describing

There seems to be many valve stem sizes out there today that vary several thousands( maybe inch/metric conversions?)


Jerry

Thanks for everyones advice.So do all of you think the oil is causing the fouled plugs?How can every plug be black with oil only getting in a few cylinders?It may be getting in every cylinder I dont know yet but I am going to check soon.I will try what Tango said and pul the pcv valve out and put in new plugs and let it run a while and check the plugs to see if they still turn black then Ill go from there.

77 if you just let the car set and run at idle,then pull plugs thay will be Black with carbon build up that's normol.now if the car is missing poping out the exhaust one side or both then you have a fouled plug.plug may be wet with gas or wet oil soacked,the method I mentiond earlyer is the only way I know how to do a true check on what the plugs are doing.just driving around the pits or block the plugs will still be Black if you pull them,Test hamer down full power run threw the gears shut engine off then pull plugs.dissregard this test if locking steering colum is the only shut down method for your car.

I read back threw all your threads---you have stated a idle vacume reading that would let the power valve be open running very rich

As far as plugs on one side of the engine being more oily than the others--where does the vacume line/pcv go into the manifold---it could be effecting only one side