Originally Posted by AMC
I am wondering if anyone has any ideas on cooling my exhaust manifold down.
I have a 1987 33' fleetwood with a 454. I think I got a good deal from a guy who bought it pretty cheap but couldn't get it pass Ca smog.
When I got the MH it had two burnt wires; they looked deep fried. They where new and replaced less than 500 miles, but they where missing heat sheilds. I could not find the OEM tin heat shields any where so I purchased a set of soft ones. I then ran a can of sea foam through the tank, regassed and took it to smog the next day. It had lower hydrocarbons but still way to high and I could tell it had a miss. The problem was a melted wire.
Also failed for poor idle only 450 rpm and bad timing was like 20 BTDC.
I reset the idle and warm it up to check the timing. The dam thing is so hot you cant get your hands near the exhaust manifolds. Every thing is so cramped under the dog house the manifolds are cooking everything, including my timing light!
The MH has two little electric fans on the radiator with what I am guessing is the tranny cooler in front of them.
In summary. I would love to know if anyone knows the Part # for original heat shields. What kind of wires and plugs are best to use to tolerate the heat. Is there an aftermarket fix to cool under the dog house?
First of all where and how did you measure the timing?..(What cylinder)
The metal shields that cover the plug wires are hard to find (not at the "Chebby dealor") so it's off to a salvage yard for you...
Is the original mechanical fan in place along with the shroud?....
Those 2 electrical fans plus the trannie cooler may be blocking the cool air but I would need a picture to confirm it......
My old 87 (now sold) had soooo much ~stuff~ blocking the air flow PLUS the open space (front & below) the radiator would NOT allow e'nuf air through the radiator for cooling and blowing the air over the engine & plug wires.....
If a "Straight boot" plug wire will (and should) fit straight in I use "Borg warner "Select" plug wires purchased from of all places "Pep boys" for around $50.00 and have plenty of miles & years on them......
Only 2 reasons for blistering cherry red manifolds to exist and they are (1) lean carb (extremely doubtfull) and (2) retarded timing.....So my first question (Timing measurement) is critical..