jong1821 Posted July 29, 2022 Share Posted July 29, 2022 I'm wondering what purpose this flapper serves. Will it function properly if I remove it or should I try to repair it. The weight was rusted in place and the weld to the plate is broken. Quote Link to comment Share on other sites More sharing options...
TheFarmallKid Posted July 29, 2022 Share Posted July 29, 2022 I just did a manifold like that on a 656. The flapper directs exhaust heat into a cavity that surrounds the intake manifold, preheating the gas/air mix coming from the carburetor. When the engine warms up, the spring loses its tension and the weight pulls the flapper closed, blocking off the hot air. I'm thinking probably try to replace that. there is a kit that comes with all the parts necessary. On the 656 I think the flap was rusted closed which was blocking of hot air all the time (it did run fine). I guess I don't know what would happen with the flap open all the time. 1 Quote Link to comment Share on other sites More sharing options...
jong1821 Posted July 29, 2022 Author Share Posted July 29, 2022 Ordered a new spring. I can only find one place that has a shaft and it's 225$ so I'm going to get this one freed up and weld the plate back in place. When I get it together I'm thinking the flap should be open then the heat will close it. Is that correct? Quote Link to comment Share on other sites More sharing options...
TheFarmallKid Posted July 29, 2022 Share Posted July 29, 2022 Yes when the engine is cold the flap will be open. The drawing shows how we did it on the 656 and it seems to work well. the stop cast into the exhaust manifold holds the flap up and when the engine warms up the weight pulls it down. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.