Author Topic: Can't ID my no tag 2100 (Read 10793 times)

SNOWMAGEDDON · « **on:** January 03, 2012, 04:23:00 PM »

Hi
I have what appears to be a late 2100 motorcraft 1.08 venturi carb
I can't precisely ID it because whomever rebuilt it (whenever) didn't put the tag back on
there are definitely a number of numbers and letters
What stands out most is
Motorcraft
a giant raised "13"
1.08
8FGA9 beneath the 1.08
an FA stamp
on the wings of the bolt holes there is an H on one wing a 2 on another and a 3 on a 3rd
any help will be appreciated
Jerry

GRONK · « **Reply #1 on:** January 03, 2012, 05:16:16 PM »

Jerry, Why do you need to identify it? Unless it's going back on it's intended application, a 2100 1.08 kit is a 2100 1.08 kit.

If you post some pics I can probably tell you everything you need to know about it.

carnuck · « **Reply #2 on:** January 06, 2012, 01:14:10 PM »

Just make sure it doesn't have a vacuum line to the powervalve under the front of the carb. That would be a 2150 which needs to be hooked up (vacuum lines) differently to work.

GRONK · « **Reply #3 on:** January 06, 2012, 02:45:21 PM »

It's a simple fix for the externally sourced power valves, you can drill them to pull internally, then put on the proper cover or cap the external port.

carnuck · « **Reply #4 on:** January 07, 2012, 10:27:24 AM »

Quote from: GRONK on January 06, 2012, 02:45:21 PM

It's a simple fix for the externally sourced power valves, you can drill them to pull internally, them put on the proper cover or cap the external port.

Not so simple if you didn't know that though. (which I didn't back when I was young)

doc65 · « **Reply #5 on:** January 31, 2012, 06:04:35 PM »

How about some help with appropriat jet size, got an 85 wagon with the carter still on it, but came with a 2100 that has the likage adapter etc. But the guy I got the car from said he thought it was intended for a 258 CJ, AND the car came from VA to UT so I'm guessing the jet size may be wrong, anyway, the Alt. here is about 4500 MSL

GRONK · « **Reply #6 on:** January 31, 2012, 09:05:54 PM »

1.08 Motorcraft/Autolite 2100 gets #46 Jets at 4500' elevation. I recommend TFI/HEI distributor and you will set your timing at 12-13deg.

Did that help?

doc65 · « **Reply #7 on:** February 01, 2012, 01:46:10 AM »

It does, I'll have to check what jets it has in it, interestingly it looks a lot like one of your, at least based on the bracketry. Which is best TFI/HEI. I like the less wires on the HEI I think, really wish there was a small cap HEI option...

Doc

carnuck · « **Reply #8 on:** February 01, 2012, 01:55:09 AM »

If you want small cap HEI, go with a '77 Chev Nova 250 6 cyl with external coil.

doc65 · « **Reply #9 on:** February 01, 2012, 02:34:31 AM »

Gronk,

Interestingly I have one 45 & one 46 jet in it right now... Any thoughts???

Thanks,

Doc

GRONK · « **Reply #10 on:** February 01, 2012, 08:26:40 AM »

1 #45 and 1 #46 you are still good to go. I was about to write 1 #45 and 1#46 but get tired of explaining why it's OK on a common plenum carburetor/intake to mix jet sizes. That will allow you to run between 4500-5500' elevation with no issues.

doc65 · « **Reply #11 on:** February 01, 2012, 08:59:38 AM »

Thanks, I actually realized that it was a common plenum manifold & figured that someone had done a little "fine tuning". I just meant I found it interesting that the car came with it, and was jetted right for the alt here but came from VA, guess it's possible that the owners that pulled it out here bought the carb after getting here...

I suppose that does mean that if I ever drive it out to visit the Fam. in western OR i'd better take jets & a could screwdrivers as the alt in Eugene is like 350 ft.

Or just make sure it's after I do the 4.0/4.6HO FI swap out...

Any thoughts o the other question of which do you recommend, the TFI or HEI, also any thoughts on the other comment about the small cap HEI? Also what's pricing like on the two (I think) options that you offer?

Doc

GRONK · « **Reply #12 on:** February 01, 2012, 10:16:06 AM »

TFI is the better choice IMO unless you are replacing an old points distributor. The TFI (Duraspark II) ICM is great and will last a very long time. The cap and rotor are readily available and inexpensive to maintain and it installs in no time.

The HEI is best for replacing the points ignition but is a little more indepth to install. If I were gonig HEI, I recommend the large cap style as the contact points are spaced further apart. The small cap HEI has more clearance (not a problem in the 258)

carnuck · « **Reply #13 on:** February 02, 2012, 02:42:00 PM »

The mixed jets are often done to compensate for PCV and brake booster vacuum "leaks"

GRONK · « **Reply #14 on:** February 03, 2012, 10:46:45 AM »

Not so in this case. You decrease jet size 1% for every 1000' increase in elevation. Baseline is #48 at sea level so for every 1000' elevation increase -1% means you go down 1 jet size on 1 jet for 1000'. Go down 1 jet size on 2 jets for 2000', etc.

doc65 · « **Reply #15 on:** February 03, 2012, 01:54:42 PM »

That's great info Gronk, thanks. I spent a few hours trying to ID this carb last night & this am. I want to think that they got it from someone sold as a replacement for a carter based on the linkage. There is also writing on it in pik/faded red that says PCV/4x4/Dist/Vent etc. it's got a long throw accel pump, and the taller power valve. From the engineering stamps I am at a loss to figure what it is though....

carnuck · « **Reply #16 on:** February 03, 2012, 03:00:44 PM »

got a pic? There was a Holley replacement for a couple years of the BBD, but I thought only Dodge used them.

doc65 · « **Reply #17 on:** February 03, 2012, 03:37:27 PM »

I'll get a couple pics, but it's definitely a MC2100(Motorcraft not autolite as Motorcraft is cast in the top cover), just not sure which variety or vintage...

doc65 · « **Reply #18 on:** February 14, 2012, 05:12:56 PM »

GRONK · « **Reply #19 on:** February 14, 2012, 08:46:02 PM »

That is a Motorcraft 2150. Very late 70's, probably early 80's. Has a fixed state venturis cluster and a 2 stage accelerator pump. Would have come on a 302.

carnuck · « **Reply #20 on:** February 15, 2012, 11:06:35 AM »

What's the jet size? (pic 1 behind the spring)

GRONK · « **Reply #21 on:** February 15, 2012, 11:50:57 AM »

Behind the spring would id the venturis size, not the jet size. The jets are in the fuel bowl unde the float.

Looks like a 1.08 venturis carb (287 CFM) Perfect size for the 258.

doc65 · « **Reply #22 on:** February 15, 2012, 11:54:22 AM »

Carnuck,

You mean the venturi size right, the raised cast in number on the side, it's a 1.08? The jets on the other hand, you have to be read off the jets themselves down inside the float bowl, they are a 45 & a 46...

Doc

GRONK · « **Reply #23 on:** February 15, 2012, 11:55:28 AM »

That's jetted for 5000' elevation if it has #45 and #46 jets

doc65 · « **Reply #24 on:** February 15, 2012, 12:07:49 PM »

Yeah, we "talked" about that a week or two ago, the floor of the Salt Lake valley is about 4500 MSL, but going up into the "hills" could easilly gain you 1000 MSL. My biggest issue right now is that it just totally falls on it's face when accelerating at all(VERY light ) just driving it around the block to test. The PCV is new, the 4x4 labeled port is capped still, and the ported vac goes direct to the dizzy. Idles pretty nice though...

PS, I just had the thought that once I get the falling on face issue sorted I might jet down one on that 46 to lean it out for emissions sniffer test, then swap back out after... THoughts???

carnuck · « **Reply #25 on:** February 15, 2012, 12:35:11 PM »

Errr.... yeah, I meant venturis (where's that smiley guy slapping himself?) With the motor not running, look down the throat and move the throttle to see if you are getting a squirt of fuel right away. If not, the check valve in the Accelerator pump may bad or the nozzle may be clogged. You can fix both by just removing the accelerator pump housing and diaphragm. Replace the rubber valve by wiggling it out and pushing a new one in and spraying GOOD quality carb cleaner (I like 3M) through the opening to see if it squirts in the carb throat.
At high altitude you may have to advance your timing even more.

GRONK · « **Reply #26 on:** February 15, 2012, 01:38:08 PM »

Mke sure your vacuum advance is properly advancing when ported vacuum is applied and that your timing is properly set. Your timing should be about 12-13deg at 650 RPM when at 4500' elevation.

doc65 · « **Reply #27 on:** February 15, 2012, 05:13:49 PM »

I think it's about 13* right now, I intend to pull the timing light back out along with a vacume pump and manually apply vac to the vac adv to see whether the adv changes, I was also told that it could be caused by a bad/dried out & ruptured power valve, thoughts? seperately I also don't have the vac choke pull off on this, should I add one? seems that opens the choke plate(some) as soon as the engine is running & making vac.

carnuck · « **Reply #28 on:** February 15, 2012, 05:59:11 PM »

Ruptured vacuum advance would do that too

GRONK · « **Reply #29 on:** February 16, 2012, 12:25:07 PM »

You can check the vacuum advance bu sucking on the vacuum line to the dist and you can watch it advance. If you need a new vac advance diaphram it's cheaper to go HEI than to replace the stock dist.

You could have a bad power valve.

doc65 · « **Reply #30 on:** February 16, 2012, 02:21:24 PM »

Gronk,

I kinda like that idea for the clealiness aspect, but that'd suck(pun intended) given I have a brand new Pertronix coil & the cap/rotor/adapter combo to install already on hand.

Doc

GRONK · « **Reply #31 on:** February 16, 2012, 02:37:17 PM »

Replacing the diaphram on the advance costs more than replacing the whole thing though. Just sayin' from experience. I keep several HEI's on hand in the shop so when i work on customers Jeeps andfind a blown diaphram I can jst swap the whole think over quickly and inexpensively. Never had a customer complain once I showed them what they gained and what they saved.

You could package those extra parts and make someone a heck of a deal on the Nest and be that much closer to the HEY as well.

doc65 · « **Reply #32 on:** February 16, 2012, 07:19:25 PM »

Well it doesn't seem to be the vac adv diaphragm as I can squeeze the handle on my vac pump and get about 6 inchs and it seems to hold that, and while doing so I can watch the timing with a timing light and it changes like 4* or so. Found several minor vac leaks, fixed those, I think, still got a serious flat spot on mild acceleration I do have that long accelerator pump, and am wondering about that, but it definitly does squirt. I'm leaning toward the power valve...

kajsdf · « **Reply #33 on:** February 19, 2012, 01:57:54 AM »

saw the other thread, figured i'd post here too just to be sure

i had the same problem after i did my conversion -- it is probably your vacuum advance to distributor. inside the port on the distributor is a little allen set screw that needs to be adjusted. my issue was that the vacuum advance was basically fully on at idle. i forget which direction does what, you can properly set when your vac advance kicks in. took a lot of trial and error to get it right.