When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
'87 F250, 351 w. So, most of the emission control stuff has been removed. Heat Riser Valve was originally controlled by a vacuum line. Well that ain't happening anymore and now the darned bushing has blown out of the butterfly axis on the engine side. I kinda need the valve up here in the Great White North during the winter but would like to replace the vacuum set up with the old bi-metal, heat activated spring and counter weight.
Question: Anyone know of an interchangeable part that will do the job? How about if I were to use a manual choke cable on the existing rod to manually activate the heat riser valve? (Just thinkin' out loud)
Just remove the butterfly and its rod then braze its bushing holes over so no exhaust leaks from them.
Unless you want the heat riser, don't really need it though.
You don't actually have to remove the butterfly, we only did that if had the pipe or the manifold off already. If system is otherwise fully intact don't wanna take it apart to remove it, just make sure its in its full open position before brazing sealing up the pivot bushings locking it in place in the process.
Thanks danr1. Thought of something along those lines but the way this engine runs cold I kinda suspect that the added heat under the carb might help things run more smoothly. "...don't really need it though", If we didn't get minus freezing temps here I wouldn't bother but during the winter it can freeze the carrot off a snowman.
Thanks danr1. Thought of something along those lines but the way this engine runs cold I kinda suspect that the added heat under the carb might help things run more smoothly. "...don't really need it though", If we didn't get minus freezing temps here I wouldn't bother but during the winter it can freeze the carrot off a snowman.
Yea gets that cold here too never had trouble getting by without, eliminate system no one would even realize it was gone no longer functioning.
Butterfly restricts exhaust gas flow out of manifold, manifold get hotter faster because of it, breather box heatriser tube connected to medal housing enclosing over and around that manifold, air box draws that heated air created by it in aids in warming up engine faster.
Engine gets warm faster people inside vehicle get warm air little quicker. The engine itself doesn't need that warm air. Has choke for rich mixture cold all it requires until up to running temp.
Often (around here) that metal housing would rot away long before any other part of the system fails, without that housing the remainder is useless does nothing but limit exhaust flow out of that manifold.