Autolite 2100 & stock 200 six

[s_montgomery]

I have a few questions that I could not find a definite answer to.

I pulled an autolite carb with the 1.21 venturis from a junkyard. Seems to be in great shape, the carb had gas in it and looked like the boat it came out of was running when it was brought there. I did'nt realize at the time that I should be looking for any particular 2 barrel.

That being said, it looks like it flows 351 cfm. I noticed on classic inline 2bbl dyno #6 a holley 350cfm was used (with a 1 bbl adapter) on a modded 200 and they did not mention anything about drivability being bad.

I am going to be mounting it right on the log. Im in the process of hollowing it out, flattening, building up a couple areas with JB weld while the head is on the car.

So is a 1.21 too much carb to direct mount on a stock 200? If so my back-up plan is to swap it with the autolite 1.08 289cfm on a 302 we have.

Also, I'm a young guy and am not familiar with carbs; I assume I definitly need to rejet the carb for the 200 since its from a 351 or a 302 (depending on which I use), but what about if I put the 1.21 on the 302? I could not find anything on what size jets for the 2bbls are typically needed on a i6, anyone know sizes to try?

 

[early ford fan]

how are you getting the metal filings out of the intake?

 

[rommaster2]

I run a stock holley 2 barrel off my sisters 289 mustang on my stock internals falcon and have not had any driveability issues in fact my car runs better. The old one barrel (wasn't that old, was a pony carb too, way too much money spent on that POS) would always get really bad issues when it was running warm in the summer.

If your having issues its the tune itself not because its just too much carburation

 

[rocklord]

Don't forget to upgrade the distributor. Go with either a Duraspark (rebuilt ones are available) or a DUI from Classic Inlines.

 

[s_montgomery]

I run a stock holley 2 barrel off my sisters 289 mustang on my stock internals falcon and have not had any driveability issues in fact my car runs better. The old one barrel (wasn't that old, was a pony carb too, way too much money spent on that POS) would always get really bad issues when it was running warm in the summer.

If your having issues its the tune itself not because its just too much carburation

I dont have it on the car yet since Im still working on the mounting. Should I just see if it will run like it is and check the plugs to see if it might be too rich or lean and go from there? Did you just swap the carbs or did you need to change jets to get the A/F right?

So far Ive had a sock in the hole, and I planned on just getting any out with a magnetic screwdriver and maybe hit it with a vacuum when im done. If it gets messy and I dont think it will all come out, I can pull the head.

I forgot to mention this is a 80 Fairmont so I've got the DSII already. I will want to order the springs and do the recurve once I get everything back together.
Its a pretty sluggish and tired 6, but I think a lot of it is in the carb and crap that they attached to the holley 1946: EGR, the thermactor thing, etc. I remember once the fan belt snapped and I think the one for the P/S too. The first thing I noticed when driving it home was that it was noticably more powerful!

 

[CZLN6]

Howdy All:

Stuff the two sides of the log with oily rags to catch any shavings or filings.

The 1.21 2100 is probably too big for an otherwise stock 200, but the annular discharge venturi design and accelerator pump arms will help with driveability some. I'd suggust that you put it on stock and then do some assessments to determine A/F ratio. Unfortunately, the idle and mid range circuits are not easily accessible or modified on the 2100s. THe Idle is an internal channel restriction, same as the Holley 2300s. But the mid-range and high and low speed air bleeds are built into the "K" cluster. And since the 1.21 was used on everthing from 351 cars to 390 truck engines the "K" clusters varied a bunch.

As far as switching to the 1.08, it would be a better match for the 200. Personally we like the earlier ('65 - '67) 1.14 as they had a slightly richer low end. The 1.21 on your 302 will really wake it up. Again, I'd try it stock first, then assess and tune.

The other inhibitors for the 80's 200s, besides the Holley #1946 carb, are advanced cam timing to enhance low end torque at the expense of the high end, the quick-light cat converter exhaust manifold many had, 8:1 compression and ridiculously high gearing. To really wake this engine up you will need to change to a better cam, increase the compression back up to the 9:1 neighborhood, and lower gearing. The Fairmont is a great, light platform, with many modern features already in place. Much of the Fox-bodied Mustang stuff will be a direct bolt-in

Be sure to increase your initial advance setting to about 5 degrees more then stock specs call for. What trans is in the car? What is your elevation?

THe pluses for an 80 200 are a very good ignition system, the best OEM heads, a great air cleaner system.

Keep the info coming and we'll keep helping.

Adios, David

 

[mach1 mark]

Unless you've already mentioned it, you are going to need some headers and a better muffler system. I believe the ford 2v will work fine, the stock 200 will take it, however all that air and fuel needs to exit just as easy as it came in. W/headers and a good exhaust I believe you will be amazed.

 

[s_montgomery]

Thanks for all the great info.

Yeah I've been keeping my eye on ebay lately for a used header, Ive seen them from time to time in the past.
I'm not in any rush and have been busy with my DD ford focus and other things.

David the trans is the C4 and Im not sure of the rear end. Its always shifted fine but Ive never beat on it... I plan on finding a T5 at a pick and pull junkyard sometime, just after I do a little research on what years 4cyl stang has the better geared one. BTW when I order my carb spacer I will be picking up a copy of the handbook.

The elevation here is around 1100 foot. I live in SWVA at the foot of a mountain below the Blue Ridge parkway I think its around 2500 ft up there but Im guessing thats not a big difference air wise?

Basically I figure I'll have 2 stages in building up the 200: do the carb swap, tweak the DSII, header and exhaust, T5.

Then later on swap the head and put in a comp cam. I have a 80 granada at my disposal, so Ive got another late model 200 head I can have shaved, ported, and some valve train work done so I wont have any real downtime, because by after the first set of mods I know I'll want it on the road!

Definitly is a light platform, I wish they had used a little more metal in some places...I remember once one of the rear shock mounts broke apart from the inside of the trunk. The thing has air shocks in the back and I probably had them filled too much and was going through a field when it mustve happened haha.

If I can get some gas into this 302 I'll swap the carbs out (bad fuel pump ) and then get back to work on the fairmont.

 

[Vin Man]

Just as a point of reference, I had the 1.08 on my non-stock 200. I went with the OZ head and intake which is made for the 2 bbl. The 1.08 was still a little big for me. I went to Pony carbs and they agreed that the 1.06 would be ideal. I purchased it and put it on and it works great.

 

[CZLN6]

Howdy Back:

The Autolite 2100 in the early 1.14 and the larger 1.23 are the hot ticket in retrofitting to a six. The new editions of the Handbook has a section on 2100s that should help you out.

Check the vehicle ID sticker on the door frame for trans and axle codes. Post it here and we can help you decode. Before deciding on a cam check out the specs on Classic Inlines dual pattern hydraulic lines. I bought and installed my Comp 260 when it was one of very few choices. I would definitely go with a CI dual pattern today. Check it out.

Your 1980 three speed auto in a Fairmont is likely a C3. It is a very light weight, light duty version of the C4. The rearend is most likely a 7.5" Salsbury type with an integral carrier assembly. Most came with 2.73:1, with a few 3.08:1 at higher elevation. Oh, in jetting, 3,500 feet elevation is sort of a line to begin to think about leaning A/F ratio.

I like your build plan. Minimize down time.

Keep the info coming.

Adios, David

 

[s_montgomery]

I looked in my haynes manual and couldnt figure out what rear I have I think theyre using codes off the rear itself. Anyway on the door jamb it says:

VIN OK91B226980 F0198
9D R0183

R Ax TR
Z 8 VVVSS

 

[JackFish]

I looked in my haynes manual and couldnt figure out what rear I have I think theyre using codes off the rear itself. Anyway on the door jamb it says:

VIN OK91B226980 F0198
9D R0183

R Ax TR
Z 8 VVVSS

Looks like a 1980, built in Kansas City. 91 is the body serial code, Fairmont 2dr base sedan.

9D is the paint, white. "B" I don't get, it's supposed to be the engine code, but I can't find it in the shop manual I have. A 200 should have a "T" in that spot.

Axle is a 2.73. If "Z" is the transmission code then my manual says "XPL (Special)".

A "V" tranny code is a C3, a "W" is the C4.

A picture of the actual tag would be good.

 

[s_montgomery]

I tried to get a picture of the tag but my camera couldnt take one that you can make out the letters on it.
Anyway the trans code definitly starts with V so it is a c3
And if the Axle code 8 is a 2.73 then I believe I have everything I needed to know.
I found a section in my haynes manual that has a vin decoder and tells you what each thing on the tag means, but it doesnt tell you what different codes are...completely useless.

I was looking at ther gear ratios on the t5 in 4cyl mustangs nonSVO (3.97 2.34 1.46 1:1 .79)

I guess it would be pretty tall geared with the 2.73, when I looked at the calculator first would end just after 30mph. The shift points would be somewhere as follows:
1st 30 4800> 2nd 2850
2nd 50 4700> 3rd 3000
3rd 85 5000

Since the inline six has a pretty wide powerband the main disadvantage with the taller gears is that would have to get it wound up in first gear? 10 mph - 1600 rpm and 15mph - 2400 rpm. I think I would like the fact that you can cruise at 70 at 2200 rpm.

I made some progress on the head the other day, I just need to hog it out some more and block off the egr hole on the head with a metal plate.