Got a question for you guys. I recently got a 78 Bronco that has a 460 beefed up. I do not know what kind of heads it has in it and dont really want to pull the motor to find out. i bought it from a guy who knew absolutely nothing about engines but i did run into the guy that built it and got most of the basics about it from him.i know that nothing in the motor is stock, and i did the typical things that you would do when getting a new toy from someone who didnt kow anything about it. drained and flushed the radiator, changed the oil, tranny fluid, fuel, the usual. changed the plugs and have only ran it about 3 hours since picking it up, and it is running like crap. blowing smoke (thick) so i pulled the plugs out to see what i could find out. the plugs already have carbon on them. the first thing i checked was the radiator to make sure i wasnt loosing any fluid into the cylinders and it was fine. i put 10w30 oil in it (which could be my problem). do you think my oil is to thin and its getting passed the valves and burning up in the motor? maybe the plugs arent burning hot enough? any help would be appreciated.

 

the head casting number is between the valve cover and exhaust manifold, just look if you want to know. no youre not running too thin of oil. what color smoke comes out of the exhaust? if its blue youre burning oil, if its black youre running rich, and if its white youve got problems. what id do is try jetting down the carb, and make sure the timing is set right.

 

thick white-blue smoke, carb is brand new and timing is perfect. i sent 2 hours adjusting the timing to see what i could do to get it as perfect as possible. i know that the heads that originally came in the block are not the heads that are in in now. was just trying to see if there was something i hadnt thought about that could be wrong.

 

Thick blue white smoke is usually oil.

I would run a compression check. I don't know the specs of your engine but a general ballpark might be about 150+ psi per cylinder. I would be more concerned with any single cylinder with say 20% less compression, or two cylinders next to each other with low compression. The single is probably a bad ring set or valve guide. The double is probably a blown head gasket.

Usually if you have an oil problem the plug on that cylinder will be oily black wet. If it is fluffy dry black then I would suspect running too rich or wrong heat range plugs.

If the engine is in decent shape the oil weight should not be a problem. If it is a bad ring you might be able to bandaid it with say 20W50 oil. If you have a bad head gasket nothing will help except pulling the head.

Good Luck,

Jim henderson

 

i think i am going to pull the heads off anyway and see what the valves look like. i do not think they are seating fully. plus i wnt to replace the gaskets, they arent leaking or anything but i do think they are old and it would make me feel better to change them.

 

oh yeah, and they are all oily black. that was why i am thinking i am running to thin oil.

 

Before pulling the heads, run a compression check. This will help tell you if the cylinders are bad or the heads or maybe the plugs are too cold for your engine.

If the compression is even and normal, there is no need to pull the heads, the problem is more likely the plugs or something else sucking oil into the engine.

Good Luck,

Jim Henderson

 

This guy needs to come to my house I have a bunch of stuff that he could pull apart. Like I know my 460 needs the heads pulled. The valve guides & seals are leaking.

 

hell if you are willing to let me pull it apart i will be more than happy to. putting it back together though is going to cost you. lol. i will run the compression check and see what its looking like. oh and one more thing. when i shut it off it is spitting smoke back through the carb and out of the air cleaner.

 

I'm thinking you should pull the top off the carb, replace and set level on the float, new needle and seat, set the timing, change the oil to 20-50, clean the plugs, and try again....you may be surprised.

 

i hope i dont have to do that to the carb. i just put on a brand new edelbrock 800. i am going to change the oil to 20w-50 and run the compression check just to be sure. i think i am going to order some better plugs as well. the ones i put in it were the auto-zone specials (was anxcious to get it running) so i think the are to cold for it. thanks for all of your help.

 

Before you go pulling the engine apart how is your PCV hooked up?

 

pcv is ran from the drivers side valve cover to the carb.

 

Is this really carbon build up on the plugs or is it oil deposits? If the engine is running normally, proper fuel/air mixture, then any carbon should be white to light brown on the plugs. Oil deposits will always stay black. Plugs too cool will cause these kind of things too.

 

If that Edelbrock is an 800 it is way to big for that 460 unless you have a major big cam and big stroker kit in it with a lot of cubes. I doubt your oil is too thin I run 10/30 in mine with no problem. Valve seals are the major source of oil smoke I would suspect this before anything else.