560 heaT riser importance

[roadkingrich]

Hey Guys. I'm getting ready to install a new exhaust manifold due to cracking. How important is the heat riser? I would think my 60 year old 560 it probably isn't functioning yet it runs fine. Takes a few extra seconds to warm up, but no big deal. Does anyone know without a doubt if I'll be okay not replacing the heat riser?

TIA

 

[BarnyardEngineering]

If you got it apart you may as well replace it.

 

[naedlaen]

You do not need to fix it if you like reaching for the choke when you ask for power or rpms. I have limped by on the 460 (same setup) and until it is quite warm, the choke is often deployed. I recently replaced the missing spring, and it is less fussy now. The spring winds counterclockwise from the inside out, so that the weight is held vertically when cold.

 

[roadkingrich]

(quoted from post at 12:21:56 08/29/22) You do not need to fix it if you like reaching for the choke when you ask for power or rpms. I have limped by on the 460 (same setup) and until it is quite warm, the choke is often deployed. I recently replaced the missing spring, and it is less fussy now. The spring winds counterclockwise from the inside out, so that the weight is held vertically when cold.

Thank you. Maybe my old one still works as it doesn't take very long for me to get going and rarely have to pull the choke at all to get fired up. I'm at work now and can't picture it but if I only pull the exhaust and not the intake, maybe it will stay in tact or is it part of the exhaust? I just can't picture it as I respond to your message. I'm hoping to get away with just replacing the exhaust manifold and gasket.

 

[naedlaen]

The heat riser is part of the intake manifold. The two manifolds join together around the heat valve. You can find photo in the items the YT has for parts. Farmall, 560, exhaust, intake manifold.

YT does not have the heat valve plate, but I have seen it on other parts sites.

Normal default is that the valve allows for the exhaust to bypass the loop through the intake (weight forward). The spring forces the exhaust to flow through the passage in the intake manifold to heat the intake (weight up) until the spring relaxes and allows the valve to shut off the loop through the intake manifold.

I just bought a 656 where the weight goes past vertical, so the plate is gone. I plan to move the manifold from a parts tractor so that it works as designed.

 

[wore out]

Instructions, FWIW...

https://i.imgur.com/4mn9D0R.jpg