Here is what's left of the non-functional Heat Riser on my 55 F-100. If I understand correctly, this is in the open position. Being in Florida where it's warm 10 mos out of the year, would I be better off to try and close it to avoid additional heat rising from the exhaust to the carb? Appreciate any tips.
To free it up & make it operable would be the best solution. Even in hot climate, they work well as designed. If you close the flap, it'll boil the fuel. Either pull it & repair or make sure it's wide open. There's a Fenton header for sale in the classifieds ... the truck probably cost you less than the seller is asking.
I realize this has been a few months and appreciate your reply however not sure if I understand. If the valve was closed, it would block prevent the exhaust heat from rising into the carb therefore the fuel shouldn't boil. It may take a little longer to warm-up the engine but again, this is not an issue most of the time in Florida.
When the valve is closed it directs some exhaust to the bottom of the intake manifold. When it is open the flow is directed out the exhaust pipe. Sent from my iPhone using The H.A.M.B. mobile app
Which ever way you decide to call closed, that position which DoesNot direct exhaust flow toward the intake is the one to choose. Been running with no intake heat in central NY till late November with no issuesfor twelve years.
Blocked the riser from opening with a simple bolt, washer and nut. Was no longer operational, and with TX heat I was having heat issues when starting. Problem fixed for about a buck!
I usually remove the shaft and butterfly completely and weld the holes why restrict the exhaust in Texas? Or remove the whole assy.
On the straight 6 when stuck in the open position heat would pour up into the intake once the engine was shut down. The effect was similar to vapor lock and made re-starting the engine difficult after a few minutes. Keeping it closed has no restrictive effect, as that is the normal operating temperature position on a warmed-up straight 6. Considering headers and a dual pot manifold, in which case the whole assembly goes away anyway.
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