Heat Riser

[Droptop 500]

Hello all,
While I have managed to find about 95% of the parts I need but the one thing I have been having trouble finding is a heat riser, So I am turning to you all to see if anyone has any good leads or did you just remove it completely. I have searched the webs but I feel that I have to be missing something cause I can't believe someone ain't making these. So without rambling on(I know to late) thanx in advance for any and all info given.

 

[jct]

what year and engine

 

[CBODY67]

Is your heat riser seized? There are two brass/bronze bushings that are driven into the hold in the manifold. That's what the heat riser shaft goes through, not the bare cast iron of the manifold.

You can find heat risers every so often on eBay.

When I got the one in my '66 Newport replaced back in the '70s, initially, the shaft was "tight" in the two bushings. Which meant it would seize as the existing one did, in a short while. SO . . . we got out an air-powered drill and put a reamer bit into it, after finding out which one was needed. A light reaming of the bushings gave the shaft a smooth/loose fit, so it worked MUCH longer than if it'd just been installed "as is". No exhaust leaks, either.

You can probably disassemble your existing valve and drive it out of the manifold, gently. If the bushings come out with the shaft, you can measure them and look for replacements as that's what causes the valve to seize anyway. Most of the valves, from what I've seen, on normally-driven cars stick at the 1/2 open orientation.

In our North Texas climate, which can get below freezing every so often, I could tell no difference in how the car ran with the heat riser 1/2 open or with the new one that was "clearanced". You experiences might be different.

If you put some aluminum heads on with no heat riser port, you don't need a heat riser valve anyway.

CBODY67

 

[Davea Lux]

Hello all,
While I have managed to find about 95% of the parts I need but the one thing I have been having trouble finding is a heat riser, So I am turning to you all to see if anyone has any good leads or did you just remove it completely. I have searched the webs but I feel that I have to be missing something cause I can't believe someone ain't making these. So without rambling on(I know to late) thanx in advance for any and all info given.

www.megapartsusa.com has some of the more common big block repair kits.

Dave

 

[FURYGT]

Jamie and the folks at Mega Parts are great to deal with.

 

[Droptop 500]

1968 440HP and the only problem I am having is the heat spring coil as it is toast but the valve moves freely. If I can't find one by the time I reassemble the engine I will just wire it open as I wont ever drive it in the winter but will start it once in a while over the winter months thanks again for all the info

 

[69bfan]

Google Dynamic Renovations as they are the manufacture of the heat risers that everyone sells.

 

[Droptop 500]

Google Dynamic Renovations as they are the manufacture of the heat risers that everyone sells.

Thanks a bunch already placed my order, easy people to deal with

 

[rapidtrans]

1968 440HP and the only problem I am having is the heat spring coil as it is toast but the valve moves freely. If I can't find one by the time I reassemble the engine I will just wire it open as I wont ever drive it in the winter but will start it once in a while over the winter months thanks again for all the info

Me too.
Broken spring on my 383 but valve moves fine. Bent the spring enough to hold valve permanently open.

 

[Droptop 500]

go to dynamic renovations, super people to deal with

 

[BillGrissom]

Modern engines don't have an exhaust "heat riser" (actually a throttle plate). Nor do they have an exhaust cross-over in the intake manifold (to heat underneath the carburetor). Thus, if you plan to change to electronic fuel control (TBI or MPFI), none of that contraption should be needed. Most cross-over ports in V-8's are probably blocked w/ carbon anyway. EFI is getting very affordable, w/ some "ready-to-run" TBI kits <$1000. Saves gas, less emissions, smoother cold start and idle, forget about chokes, heat risers, ... Those that say "modern engines are too complicated, can't work on them" know little and/or are nancy-boys looking for an excuse. My 1996 & 2002 minivan engine controls are quite simple. MPFI is easier to diagnose than a carburetor. They don't even have EGR, since minivans are "trucks" that can pollute more.

 

[Droptop 500]

Thanks for all the info but my mechanic and I decided to just remove it completely since I wont be driving it in the winter that much. Also I want to try and keep it as much original as possible (within my budget) I am not building a show car or anything just a nice driver on the weekends and such

 

[Davea Lux]

You may have to convert to a manual choke or an electric choke as the automatic one your car came with is dependent on the heat riser to function. Heat going thru the passage under the carb causes the auto choke to open up as the engine warms up.

Dave