I have a friend and a customer who own a set. One is on a 455 Pontiac the other set is on a 360 Mopar. Both are exibiting the same problems at about the same mileage. The Poncho started it first, oil fouling the rear four cylinders badly. The problem was minimized by drilling and tapping exernal oil return lines on the back of the heads. The Mopar just started doing the same oil fouling trick this week. Both cars are having heating problems that were not there before the head swap. The Mopar did pick up a point in compression with his swap but his overheating problem isn't as severe as the Poncho's. The Poncho has been together for two years now. Has a radiator almost 4 sq/ft, shrould and aggresive engine mounted fan. We have enough airflow to hold a gauntleted heavy welding glove to the condenser core! In the past it overheating was marginal but this year it starts getting warm right after start up and doesn't stop climbing untill you shut it down. We replace the water pump, thermostat and had the radiator checked for blockages. We are starting to think there are problems with these heads, anyone else?
Obvious questions first. Running a thermostat in either motor ? Is the filler neck higher than the cylinder heads ?
Running a thermostat in either motor ? Yes high flow rotary types in boths. Is the filler neck higher than the cylinder heads ? No, top tank is a good 8" higher in the Poncho and 6" in the Mopar. I have been solving overheating problems for years. In both of these cars we can get a 23-30 degree drop in water temp across the radiator at idle. Both cars have great air flow and did not overheat untill these heads were a year or so old. Brand new problem without making changes. I am just wondering if the guides are **** and expand after 20k worth of use to cause the oil fouling problems or something related like poor choice of alloy to cast the heads from, porosity, warping etc. Neither of these cars has boiled over. But both have run in excess of 230 degrees!
I'm not sure about the guides......but what if the rocker geometry is off with the edelbrocks causing premature guide wear? Maybe the pushrod length? Just a guess though......
I have this picture in my mind of galvanic corrosion product clogging p***ages in the heads restricting coolant flow (cause of over heating) which causes the valves to get too hot which causes premature guide wear and oil comsuption. But what do I know.... Al
Rocker geometry off by that much in both cars? One I could give you but both seems too much of a coincidence. If Edelbrock relocated the valves and thus requires different pushrods, they should mention it in thier literature. And I don't belive this is the case. I didn't install either set and the Poncho was built by a reputable Pontiac high performance guy here in town. As to the galvanic corrosions theory, interesting. If these heads have small steam ports this may be a reason to the time frame. The Mopar has an aluminum radiator, heads, intake and water pump. Same for the Poncho except for a br*** copper radiator. I know for sure the Mopar runs distilled water and anti-freeze in it, can't say for sure on the Poncho. hmm.
This probally doesn't help, but I have had the Edelbrock aluminum Pontiac heads on my Model A for three years with NO problems at all. My Poncho is 10 to 1 comp, 296 degree cam, 1.62 full roller rocker. (have also used 1.5 ratio), stock length pushrods, fel-pro head gaskets, Autolite 3926 plugs, MSD 6 box, 36 degrees of total timing, 15 degrees initial. 3 core 32 Ford radiator, 160 thermostat, about a 50/50 water antifreeze mix..runs no more than 190 in heavy traffic. About the only thing I can offer that you haven't already addressed is make SURE you are running the correct spark plug. The Edelbrock Poncho heads take Autolite 3926s only. Regular Pontiac plugs are waaaay too short as far as gettin the electrode into the combustion chamber.. Good luck and please keep me posted. See you at the Drags?? -Abone.
I put Edelbrock Performer heads on my wife's 5.0L Mustang coupe. I did notice it runs hotter. In her car, it's not a problem, it does not overheat, but it will run somewhat hotter for the same situation than it did with the stock iron heads. I attributed that to the increase in comression the heads gave us. Second, within 20k miles, I started to see signs of valve guide issues. Upon start up, there would be that puff of blue smoke which made me think of worn guides, or at least bad stem seals. It pissed me off, the heads cost 900 bucks. They are "okay" I guess, but if I were in the market for another set, I'd look more closely at other brands. I've always bought Edelbrock stuff pretty readily because it's always been good stuff, this was dissapointing though. All of this is on a low mile Ford Motorsport 302 crate short block with E303 cam with Crane aluminum full roller rockers and lots of external goodies, like injectors, throttle body, big m*** air meter, and Cobra intake.
I have read ( internet ) that Edelbrock had problems with castings and maching on the aluminum heads. The rocker studs not being in straight and off position.....and wearing out the guides. Had a friend with a set on a SBC.......ran warmer....too much so......he pulled them off and got a set of Brodix......with even slightly higher compression.....NO heating issues...... I figured it was a isolated deal because Edelbrock has always been good stuff. Then I keep hearing about these issues....
I have ran the small blk Chrysler heads the last 5 seasons on my Dodge Daytona super street car and with no problems.I run pretty much 2 twice a week except this year.Only thing I have ever changed have been the valve springs as the orig were not stong enough for my cam selection.I have a few friends who run them on the street and no problems as of late...... shoe
Hell yeah I'm gonna be at the Drags! Thanks for the info on the plugs too, I will p*** it on and see if it makes a difference.
I have always had to get new pushrods for eddie heads. I have also noticed that the original guides are real soft and unless the rocker geometry is prefect, they will start consuming oil pretty bad after a while. Had a set on my 340 in my Dart. Sold the motor after having the heads redone. It was a millimeter away from dropping several exhaust seats also. They fell out when the bare heads were flipped on the bench.
Now that I think about it....Summit talked me into +.010 pushrods when I bought a set a few years back. Really should check the length to be sure on any build. Still doesn't cover the overheating though....or was that covered and I missed it?
I think the oil consumption and overheating are unrelated. I talked to Chip with the Mopar, he does have the longer pushrods as recomended by Edelbrock. He is out on the road, up near the Canadian border in Washington with the car. I hope it doens't get to bad for him to make the return trip. You guys up there might catch him. Its a beat to hell 48 Plymouth coupe. Two tone black and rusty gray primer with American Saltflats wheels on it.
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