Thermo-Quad metering rod measures
- Thread starter Mecki
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Mecki
Active Member
Nothing on ebay at the moment.
I found this site: tgmotorsports.net. They have two 10-203 kits, both opened and with only 2 pairs of rods in each. The 10-203 should have 6 pairs and they are asking $450 for a kit.
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I paid $500 for my kit complete. The come up now and then you just need to be patient.
I have been using TQs since the late 70s. They do not seem too fussy about exact metering steps.
Not sure what engine you are working on, but even if it was all original, todays fuels are different & the original rods might not be ideal.
#9097 originally uses a 069/50 rod. There are some that are quite close:
- 2110 69/40
- 1938 71/40
- 2159 70/40
- 2211 715/40
Not sure what engine you are working on, but even if it was all original, todays fuels are different & the original rods might not be ideal.
#9097 originally uses a 069/50 rod. There are some that are quite close:
- 2110 69/40
- 1938 71/40
- 2159 70/40
- 2211 715/40
From the Carter carburetor parts catalog:
Carter 9097
Primary Jet 120-4099 - orifice size .099
Rod 75-2086 - dimensions are .069 x .061 x .040
There are many sources that show what came in the Carter 10-203 strip kits.
Carter 9097
Primary Jet 120-4099 - orifice size .099
Rod 75-2086 - dimensions are .069 x .061 x .040
There are many sources that show what came in the Carter 10-203 strip kits.
Mecki
Active Member
Thanks for your inputs. I'm planning to use it on a 440 with specs close to the 69-71 hi-perf version, nothing extreme. I took the rod # 75-1966 (.067/.052/.045) and primary jet # 120-4098 from the FSM for the first year a TQ was put on a 440 as a starting point. The jets I already have are 120-4098.
That's what I have heard and I was thinking that getting something close to what was used on a 440 and then change the primary jets if needed.
Mecki
Active Member
The 9097S came on a -76 400 LB so the original jetting might be off. The 10-203 kit would be perfect. But paying $450 for a incomplete kit not knowing what you get ?
Here is one of my strip kits still for sale.
www.forabodiesonly.com
[FOR SALE] - Thermo-Quad Strip Kit Partial 72 up Solid Fuel 10-203
Thermo-Quad Strip Kit Partial 72 up Solid Fuel 10-203. Some parts may be slightly used, not by me. Three pairs of rods are missing and the 120-5149 secondary jets. $120 OBO + shipping.
www.forabodiesonly.com
Mecki
Active Member
By the way. I was wondering why this TQ has this air pipe? The channel goes straight through the bowl and base plate and opens up to manifold vacuum. It looks like the pipe and the hole drilled in the base could have been added later. I don't get the purpose and was planning to block the holes in the cover and base.
Mecki
Active Member
Ok, thanks. Could you check and list what's remaining in the kit? Especially the rods.Here is one of my strip kits still for sale.
[FOR SALE] - Thermo-Quad Strip Kit Partial 72 up Solid Fuel 10-203
Thermo-Quad Strip Kit Partial 72 up Solid Fuel 10-203. Some parts may be slightly used, not by me. Three pairs of rods are missing and the 120-5149 secondary jets. $120 OBO + shipping.
The missing secondary jet 120-5149 is the biggest in the kit and probably not needed in my setup. The rod 75-1966 is not included in kit 10-203 but the rods included are all pretty close and all a bit richer (slightly smaller step diameters). Could be just what I need for tuning if I can get and start with the 75-1966.
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[1] Mecki, you are over thinking this.
[2] The tube in post #34 has probably been added. Some TQs used that port for a hot idle compensator. Somebody may have used that carb with a huge cam that needed a lot of bypass air, & used that hole for bypass air.
[3] I have only ever found two sizes used for the sec high speed air bleeds. Early carbs used 0.039" along with big jets [ like 0.149"]; some later carbs used 0.029" air bleeds with smaller jets [ some had 0.098" sec jets, smaller than the pri jets. Go figure! ]
[4] I enlarge the sec air bleed to 039 on all TQs & use the bigger jets.
[5] Some later TQs had 0.101" pri jets, buuuuut they also had larger air bleeds. not sure why, presumably for emissions.
[6] I would NOT be using AFB rods in TQs. first, you would want to check to see if the total travel of the rod is the same for the TQ & the AFB. Probably isn't. Also, the power step on AFB rods is usually longer than on the TQ rods, so a fundamental difference there.
[7] Since you have the carb apart, you may want to do the mods I listed in a thread in this section in Oct 2023. Those mods will make a veeeeeery noticeable performance improvement. On a 440 that I built for a 68 Charger, 5 speed man, TQ modified as above, it spins the wheels in 3rd gear when the secondaries open....
[2] The tube in post #34 has probably been added. Some TQs used that port for a hot idle compensator. Somebody may have used that carb with a huge cam that needed a lot of bypass air, & used that hole for bypass air.
[3] I have only ever found two sizes used for the sec high speed air bleeds. Early carbs used 0.039" along with big jets [ like 0.149"]; some later carbs used 0.029" air bleeds with smaller jets [ some had 0.098" sec jets, smaller than the pri jets. Go figure! ]
[4] I enlarge the sec air bleed to 039 on all TQs & use the bigger jets.
[5] Some later TQs had 0.101" pri jets, buuuuut they also had larger air bleeds. not sure why, presumably for emissions.
[6] I would NOT be using AFB rods in TQs. first, you would want to check to see if the total travel of the rod is the same for the TQ & the AFB. Probably isn't. Also, the power step on AFB rods is usually longer than on the TQ rods, so a fundamental difference there.
[7] Since you have the carb apart, you may want to do the mods I listed in a thread in this section in Oct 2023. Those mods will make a veeeeeery noticeable performance improvement. On a 440 that I built for a 68 Charger, 5 speed man, TQ modified as above, it spins the wheels in 3rd gear when the secondaries open....
Mecki
Active Member
Yes, I probably do over think this (as I often do).
That's a reasonable explanation for that tube. It would probably do more harm leaving it open on a relatively stock 440 with A/T or?
Ok, thanks for that information. Luckily it looks like the rod problem is going to be solved.
I suppose that 440 was nothing but stock. I will look for that thread.
Thanks
Just be aware that the AFB/AVS rods are thicker than the TQ rods so you’ll ether have to have the ends turned down to fit the TQ tree or remake the TQ rod holder.
Mecki
Active Member
Thanks for that info. I start to think that instead of trying to modify some existing rod easier would be to start with a straight 2,0mm (=.079) brazing rod. That diameter is already close to the first step. The holes in the holder (the one I have) are 2,2mm (=.087) so that would be a perfect fit when the rod is bent. The steps could be made in D-shape with a fine file with the uncut rod supported in a 2,0mm hole drilled in a piece of wood shaped so that it's partly exposed in the middle. Finally cut and bend. Some simple math in a excel table to compare the round and D-shape areas to know how much to file off the rod.
Lets see first how getting the original TQ rods works out. That's a much easier road to take.
The tube clearly has not been added. It has its own bosses on the casting. It was cast with that tube as is.
Mecki
Active Member
The cover casting clearly has a provision for something (hot idle compensator, two-way bowl vent) that has not been installed. The tube looks homemade, same sharp edge on both ends as when you cut with a hand tool. The base plate doesn't have the canister vent tube for two-way bowl vent installed, if it was the hole through the base plate would connect it directly to manifold vacuum.
I'm not sure about that tube, I don't see the purpose of having it there. The hole drilled through the base plate makes no sense other than what Bewy suggested.
In other words, it's just like the other tubes on it. None of them were works of art. Maybe it was added. It certainly doesn't look like it.
Mecki
Active Member
You are right. It's hard to tell just by looking at the finish. I'm more concerned about that hole in the base. I'll just put a rubber cap on the tube and it's blocked.
Mecki
Active Member
I saw some other models with that same cover casting have the hot idle compensator fixed with two screws in that place.
I've never seen a HIC on a thermoquad. Mostly on AFBs and AVS.
TQ with HIC. There is a hole of about 7/32" under the HIC, goes through to the carb base. When I am going to use a TQ on an engine with a big cam, I use that hole for bypass air. I make a plate that screws into the adjacent boss that I can swivel over the hole to vary the amount of air.
![DSCN0268[1].JPG](https://www.forabodiesonly.com/mopar/attachments/dscn0268-1-jpg.1716317893/ "DSCN0268[1].JPG")
I had a suspicion they may have been, I've just never seen one.
The Ford TQ used a HIC as shown above. Not sure MOPAR ever did.
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