Fluid heat riser

[Degnol]

I've seen heat risers for headers, but I've also heard of but never seen a "fluid heat riser". I'm a newbie so go easy on me, but if I were to install a header, I'd need someway of heating the intake. Like tonight it's going down to 7 degrees. So do they work? I've heard yes and no. Should I forget a header? Everything is working just fine, so why screw it up, eh?
Thanks,
Ed Long

 

[IDave]

Unless you are a purist, and don't like the idea of changing your stock cruiser in any way, headers will by nature give you more power and perhaps a little (up to 10%) better fuel milage. Most headers get in the way of your oil lines and PTO if you have one, so that is a consideration, too, and some kinds of headers are not "street legal" in some juristictions. That said, I have headers in my rig and have the fluid heatriser you mention. I think the heatriser makes a real difference. If you live in a high humidity cold environment, it can prevent carburetor icing. I find that I have substantially better cold starts and faster warmups with it than I did without. But for those who, unlike you and I, live where it rarely drops below 40 and/or have low humidity, it won't make much difference.

 

[Guest]

The downey headers (at least the C.A.R.B. approved ones) have an exhaust heat riser on them already.

 

[Degnol]

So Dave, who's headers are you running and is the fluid heat riser part of it or an add on. Are the headers ceramic coated?
My '40 is a '66 with a 74 F motor so the oil lines are not a problem. And it is desmogged by PO, so I don't need emissions type headers. Is this a case of the more you spend the better the header? Where did you get yours?
Lotsa questions, sorry.
Ed Long

 

[jprissel]

I desmogged my 84 fj-60 last sept. and don't run any heat riser. i put a 9" by 2" mr. gasket air cleaner on top my stock carb w/ stock manifolds. I live in west central WI & @ 18 below 0, still no problems, in fact the colder it gets the better it runs. I guess i don't know why your trying to use a heat riser.

 

[Degnol]

Well, to put it simply, your stock manifolds are joined together right under your carb. Hot gasses from the exhaust warm the intake manifold which helps to atomize the fuel/air mixture. With a header, there is no joining of the manifolds therefore, no warming of the intake by the exhaust. This is of little consequence if you live in an area where it never gets very cold, but it is like 10 degrees here now and that would make for very long warm-ups without some way of warming the intake manifold. You are thinking of that little hose to the intake that takes warm air off the manifold, eh? Well the heat riser warms the intake directly, not the air going into the carb. Clear as mud?

 

[Chef]

the fluid heat riser ties into your heater lines, and uses antifreeze to warm the intake. It works well, and you can make one yourself from 1/4 aluminum plate by using the gasket as a template. Drill the holes, the drill and tap for 2 1/2"npt barb fittings, and tie into the heater hose at the back of the head...Alan in tornadoalley

 

[Degnol]

So the aluminum plate just covers the place on the intake where it joined with the exhaust. Then you would come off the back side of the head for flow to the heatriser and flow from the heatriser would go on over to the cab heater. Cool.
Thanks,I see the light
Ed Long

 

[IDave]

Ed,
I am using the MAF fluid heatriser which is exactly what is described by Alan above.
I have been running SOR's 2 piece headers for about 6 months with no problems.  I chose those because 2 piece headers loosen less than 1 piece headers, and they were relatively inexpensive.  I am, however, about to replace them with a 6>1 header from MAF.  The only reason I am doing that is because I've gotten ahold of a PTO winch setup, and it is not compatable with any headers I can find except the MAF 6>1s.  Even that has to be modified slightly by notching the bracket between the headers and the header exhaust to accept the PTO driveline. (No, the MAFs are not ceramic coated headers and neither are the SORs).

I think heatrisers help substantially, and the main reason I went to headers is that the stock heatriser on my exhaust had rusted away (like most of them from my vintage of '40).  There are other great reasons to use headers, and I really like the way my '40 runs with them.  I would bet that the reason jprissel's stock manifold setup runs so well cold is that his stock heatriser is functioning.  I don't have experience, but I would bet that a stock exhaust gas heatriser works better than a fluid heatriser, because the temp would rise faster.

The danger of an old stock heatriser is that if it gets stuck in the on position, you'll boil your gas and burn your head/valves/engine.

Someone else will have to speak to the value of ceramic and/or tuned headers.  I'd be interested in an independent view on that.

Anyway, I'll have a cheap, barely-used set of SOR 2-piece headers available soon if somebody wants them.

 

[Degnol]

Dave,
What do you want for them, and would it include the collector? The 2 into1 "Y" pipe? Everything is working well, so I hate to dick with it, but I've got an extra intake, so I could work out the split washer deal and the fluid heat riser and have everything ready to go ahead of time. &nbspoes your header have the same flange thickness as the intake. If not did you have the intake milled or use the split washer? Also most guys seem to swear by using 2 gaskets and NOT the Kevlar one SOR touts.
Let me know, and thanks for the reply
Ed Long

 

[Man Jerk]

2nd in line.

I PM'd Ya.

 

[jprissel]

;DRe: Fluid heat riser

crystal, once again, i spoke before thinking. thanks to all,for i now know exactly what i'll need when i make my header w/ non-usa carb and dist. swap complete.

 

[Degnol]

Easy to confuse, I've heard the warm air intake with the bimetal spring referred to a a heat riser, and I suppose technically it is.
I've decided to make my fluid riser as the earlier post suggests. I'd like to find a pair of 90deg 1/2" barb connectors to get the hoses away from the header heat.
Good Luck on your upgrades,
Ed Long

 

[Lane]

There was a write-up with drawings in TT a few years ago on the fluid heat riser. Had all the dimensions etc. needed for the do-it yourselfer.

 

[Mavric1298]

I say even if it doesnt do alot, just make it anyway, its a cheap and easy thing to do, so hell, why not!?!?

 

[Degnol]

I'm going to make the heat riser (fluid), think I get it but if anyone has the Toyota Trails article, I'd appreciate it.
I've got an extra intake so I can fab the Fluid HR in advance. Is there any feedback on the 1 piece vs 2 piece header? &nbspoes one have a better flange design than another? Gimme a brand name.
Anyway thanks for all the comments and input.
Ed Long

 

[IDave]

Ed,
The SOR 2 piece fit with my intake manifold just fine with no milling needed. I did their kevlar gasket and have never had a leak. &nbspidn't have any need to double gasket either. Hope I don't need to do anything to the MAF. Also, the stock studs were just fine with that gasket.

 

[Straylight]

? on the fluid heat riser. The stock one "shuts off" as the spring heats up and flips the butterfly valve to the shunt position. The fluid version (I assume) doesn't do that, it is on all the time. &nbspoes this present a problem when the ambient air is hot, like in the summer? Or does the fluid only run when the heater is turned on?

 

[IDave]

I suppose you wouldn't have to, but I have mine in line with the heater, so it goes off if I shut the valve. It is only the temperature of the engine water, so it is not likely to cause problems even if it gets hot. The exhaust heatriser is much hotter, and therefore more effective, but potentially dangerous.