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ive got a 78 bronco with a 351 modified i just put new plugs, wires ,cap on. my question is what would cause the exhaust to be hotter on one side? there is a pretty good temp. difference from one side to the other thanks for any help mike
Last edited by 78 stepside; Nov 6, 2006 at 12:48 PM.
Need some more information. Assuming you are running dual exhaust, the typical installation was down the right side of the vehicle. This would make the left exhaust about 4 feet longer and give it more time to cool down. Does the Bronco run good? If this is the case with the exhaust have a little "H" pipe built to equalize everything and your temps will equal out. If you have a nice cam in it and like the sound, and it runs good, then leave it alone.
Start with the plugs.. is there a difference in color from the cold side to the hot? This is a carb'd motor so stuck metering rod or clogged jet could lean out 1 or several lungs causing the overall higher temp on 1 side of the motor.
Stock exhaust manifolds? There's a damper built in to the drivers side manifold to force exhaust through the intake manifold to the right side. This could be stuck closed.
yes the truck has duels, and manifolds. it runs pretty good, its a little sluggish, but overall it runs ok. when i pulled the plugs there wasnt any difference. the drivers side runs hotter than the passenger side. it has a stock cam as far as i know. i am going to take a look at the carb as soon as i get a chance. a guy at work said maybe a sticky valve??? if more info is needed let me know. i will post any progress. thanks for your help mike
It would be interesting to hear exactly how you have determined it is running hotter on one side. I can't see any way to really know this unless you have EGT probes in each manifold collector.
Stock exhaust manifolds? There's a damper built in to the drivers side manifold to force exhaust through the intake manifold to the right side. This could be stuck closed.
It is hotter at the tail pipe. I haven't checked at the manifold. The carburator is brand new. I can tell it's hotter by putting my hand up to the tail pipe. There's a huge difference between the two. There's no cats on the exhaust.
i dont believe there is a functioning air pump. is that an emmisions thing? we dont have to have all that stuff here. we dont have to have vehicle inspections. so im not really up on the emmisions stuff. i will go and cheack the heat riser right now. i really appreciate all the help and advice, thanks mike
well i looked for the heat riser, and i dint find it or its not on there. would it be where the exhaust bolts to the manifold? the exhaust looks new and proffesionaly done. could they have taken it off or am i not looking in the right spot? thanks mike