RE: [Chrysler300] Manifolds and carbs

From: Rich Barber [mailto:c300@xxxxxxx]
Sent: Friday, January 31, 2014 12:28 PM
To: 'news4ge@xxxxxxx'; 'd.verity@xxxxxxx'; 'mmoore8425@xxxxxxx'; 'kmaniak@xxxxxxx'; 'jkg@xxxxxxxxxxxxxxxxx'
Cc: 'Chrysler300@xxxxxxxxxxxxxxx'
Subject: RE: [Chrysler300] Manifolds and carbs

I hadn’t thought much about blocking off the heat tubes and purchased a new set of same. Now, I’m thinking of just blinding off one of the two tubes on each side. That would allow some hot exhaust to rise from the exhaust header into the heat chamber. Natural cooling and convection. I think I also saw a note about putting in a restrictor. Is there any detail or opinion on that? Perhaps a little steel plate with a ¼” hole in it?

Operation in bitter cold is not an issue. Creeping along in stalled freeway traffic is more likely.

C300K’ly,

Rich Barber

From: news4ge@xxxxxxx [mailto:news4ge@xxxxxxx]
Sent: Friday, January 31, 2014 9:43 AM
To: c300@xxxxxxx; d.verity@xxxxxxx; mmoore8425@xxxxxxx; kmaniak@xxxxxxx; jkg@xxxxxxxxxxxxxxxxx
Cc: Chrysler300@xxxxxxxxxxxxxxx
Subject: Re: [Chrysler300] Manifolds and carbs

One more comment on J/K rams: When I was putting mine back together there was some discussion about whether or not to block off the heat tubes. Some of the club members had done that. I asked George Riehl about it and he said they absolutely should be blocked off. He said to block them off where they meet the intake. That's what I did, altho I wonder if it might have been better to block them at the header, to avoid eventually blowing out the tubes (and reducing back pressure). Maybe there's some value in having at least some exhaust heat reaching the intake. I reasoned that if George could run his J in Michigan, I could run my K in Florida.

Any thoughts?

George Clineman

-----Original Message-----
From: Rich Barber <c300@xxxxxxx>
To: 'Don Verity' <d.verity@xxxxxxx>; mmoore8425 <mmoore8425@xxxxxxx>; kmaniak <kmaniak@xxxxxxx>; 'John Grady' <jkg@xxxxxxxxxxxxxxxxx>
Cc: Chrysler300 <Chrysler300@xxxxxxxxxxxxxxx>
Sent: Fri, Jan 31, 2014 10:54 am
Subject: RE: [Chrysler300] Manifolds and carbs

In a final effort to disseminate information today, I’d add these notes on the ram J-K intake manifold heat issue. Just to describe the flow pattern of the hot exhaust gas used to heat the manifolds under the carbs. There is, of course, a baffle plate under the four holes that admit the fuel-air charge from the carburetors into the two single cross section passages of each intake manifold (and, the smaller equalizer tube connecting these chambers on each side). The lower section of each chamber has two down-facing flange-like surfaces, drilled and tapped for two bolts each. In order to achieve flow of hot exhaust gas into one of these ports and out the other, connections are made with flanged-end steel tubes to similarly-flanged ports at, apparently, high-pressure and low pressure areas of the huge cast iron exhaust manifolds. I’d expect that side flow to vary somewhat with volumetric flow of exhaust gas in the manifold, but the system seems to provide plenty of heat—uncontrollable and maybe sometimes just right or too much. Some of the heat would be expected to flow upward through the chamber tops and into the carbs. The whole idea is to vaporize the liquid fuel coming in through the carb jets before it hits the combustion chamber and before the plug fires. Although rather simple, the concept is brilliant and seems to work—probably quicker and hotter than heating the manifold with engine coolant.

My first car, a ’40 Ford, had a similar system for heating the passenger compartment. A fan blew cold air across a finned section of the exhaust pipe and the heated air was then re-introduced into the passenger compartment and to the windshield defroster system. It seemed to work well, but any exhaust leak in the system would introduce CO into the passenger compartment. And, there was no temperature control. In 1938-39, Nash invented and patented certain features of their Weather–Eye heater system that used hot coolant to heat outside air for the heater & defroster. I always heard that Nash then licensed their heaters to the Big Three or traded the rights for something they needed that was patented by the Big Three.. See: http://en.wikipedia.org/wiki/Weather_Eye

Th-th-that’s all folks,

C300K’ly,

Rich Barber

The “Other” Brentwood, CA (OJ and the Governator never even visited here—ornamental trees in full bloom)

From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On Behalf Of Don Verity
Sent: Thursday, January 30, 2014 4:07 PM
To: mmoore8425@xxxxxxx; kmaniak@xxxxxxx; John Grady
Cc: Chrysler300@xxxxxxxxxxxxxxx
Subject: Re: [Chrysler300] Manifolds and carbs

Hi,

Agree totally, Don,--- and was starting to doubt my sanity as I remember the F heat risers rattling or sure thought I did , distinctive noise of 60-61 idling. ...and getting them equal.

Re the pad, Heat flows upward in gas except radiant heat, which is surface area related and pan top IS hot ; exhaust passage is small part of manifold underside compared to pan, (as you note about A block baffling ) and a pad might reasonably be acting as a thermal insulator and a silencer too ; whether air blowing through is better is up for grabs, but drag guys wrap manifold in wet rags etc .

Yes, the valley pan will be hot, but not as hot as the exhaust passage. Just look at any V-8 Mopar with the passage open and you will see burned paint where the passage goes through. Drag guys have the heat blocked off, don’t run on the street, and only run 1/4 mile at a time. The wet rags, cool cans, etc. are to keep the fuel air charge as cool as possible.

The pad would help hot soak, no question. but I never had use for one. Pick your poison on that. It is wrapped in aluminum , like present thermal/acoustic products for sound insulation..which also do both.

Re Fact 2,all we need is Don to set them up; That F in Maine was the real deal...reality...surrounded by smart ram experienced club guys. And Don knows not to flood it in the first place .

But a soccer mom may not.... fact remains the Plymouth wagon lost its rams when new, probably due to bumbling at dealer, but also due to having to know how to drive/start these cars. And it was brand new.

Soccer moms were not invented when the letter cars were new. They would not be driving such an impractical car even if they were. I remember the car in Maine. It was a pure show car if I remember right. The plugs were probably partially fouled.

I flooded mine, not often, but I did. It is easy to do, and frustrating . And when I did I had to remove air cleaners, open choke to get air into it ...vs kill battery trying to make a point (in the short term ) to start it. If not flooded no problem; I bought a G one time in 70’s off a used car lot in Reno and drove it back to Boston , some snow in Utah, (old Route 50!) with a small tool box, and it never gave me any start problems , but it was in Spring ,sort of ,--- but I hear you. It is not guys in 300 club who have problems ----but even they do sometimes.

Remember that the flooding was probably from a no-start condition in the first place. Or it was real cold out. I’m sure a lot of no-start, or slow start episodes can be traced to an ignition system problem. Those ram carbs never really warm up in cold weather. I drove my G up to northern Vermont once to look at a D. It was in the single digits up there, and it snowed some on the way home. When I got home and popped the hood, the carbs were ice cold.

Setup for start involves choke setup, mainly ....one assumes mixture idle etc has all been well set. All auto chokes a little dicey, depending on skill of mechanic , or they would not need WOT unloaders, at all, right?

Right. Flooding does occur. You can read about it in the owners manuals.

Are 300E carbs AFB? Most dual quads work just as you say. . Aftermarket progressive linkage same thing.

The does have AFB’s. I noticed when I was looking at mine that the connector link was in the upper hole on the front carb when it should be on the bottom. The linkage would jam near wide open throttle, and the front carb would never open all the way. Could be one reason why it blew up in the 60’s. To lean.

Interesting exchange....really.

Yes it is,

Don

From: Don Verity [mailto:d.verity@xxxxxxx]
Sent: Thursday, January 30, 2014 3:56 PM
To: mmoore8425@xxxxxxx; jkg@xxxxxxxxxxxxxxxxx; kmaniak@xxxxxxx
Cc: Chrysler300@xxxxxxxxxxxxxxx
Subject: Re: [Chrysler300] Manifolds and carbs

I guess I have to clear up a few facts about these cars.

Fact 1. The foil wrapped pad under the intake is not there to insulate anything. It’s a silencer pad to mask some valve train noise. The valley pan certainly does not need to be insulated from cross-over heat. It would be cooler without the pad and air flow going through it. Small block Mopars have oil from the lifter valley splashing directly on the bottom of the intake, except for one piece of tin directly under the crossover passage. Check the parts book and it calls the pad a silencer.

Fact 2. 60-61 Ram cars have a heat riser valve in both manifolds. 62-64 short ram cars with headers just have tubes with a restrictor on one of them. I drove a G for over 20 years and thousands of miles, and never flooded it. When set up properly, the ram system is quite reliable. They were no more troublesome than any other brand with multiple carbs, probably less in some cases. They were also never sold in anything coming close to large quantities, and the original owners likely knew what they were getting into. The big problem is lack of mechanics qualified to work on them, back then and now.

Fact 3. I don’t have an H so I can’t vouch for how those carbs are set up, but I do have an E (the intake and carbs are on my kitchen table), and both carbs have an idle circuit, and idle air screw. Only one has a choke though. The linkage opens in stages with the front barrels of the rear carb working first, then the front barrels of the front carb, then at wide open all eight. They do not go from 2 to 8. Ram cars are 4 all the time and 8 at full throttle. My C also has idle circuits on both carbs and won’t run right on only the rear carb. I found that out when the connecting fuel line went and I tried to run it on the rear carb only. It ran but idled rough.

That’s my rant for now. Did I miss anything?

Don Verity

C(2), E, F, J