Advice on carb conversion

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08-31-2014, 02:24 PM
leroylem

Advice on carb conversion

Since I had to pull the K-Jet intake on 2126 to repair a distributor problem, I decided this would be a good time to at least "mock up" a carb/intake manifold. I have read all the carb posts on this forum, and find this to be an interesting and challenging project. I am an old hot rodder, and have done quite a lot of fab work over the years. SO ,I have completed the intake, fabbed a throttle bracket to utilize the original cable/spool bracket, and found a Motorcraft 2100 carb, which appears to be rebuildable.I do have a few questions, and would appreciate advice/opinions.
1. I am contemplating using an in-line pump, mounted in the engine compartment, running a new line from the tank. I understand most conversions have an in- tank pump ---what advice/opinions on pumps/installations? I plan to run new pump wiring from the original pump connector to the new pump in the engine compartment, and retain the RPM relay pump power as original. Comments??

2. What about PCV ---crankcase ventilation---the MOTORCRAFT 2100 I purchased does not appear to have a PCV outlet---what air cleaners have PCV hose connections in the base ---have found none locally. I know the engine needs to be vented. Ideas???

3. Distributor vac advance----should I leave connected as it now is, or come off the carb ported vac connection?

4. Plan on installing a Pertronix 40K coil---I read somewhere about wiring the resistor differently to increase the primary voltage to the coil, thus a hotter spark/enabling a wider plug gap---Comments???

I will appreciate any advice/comments----would enjoy conversations with anyone with experience with the carb conversion.
Thanks, Leroy
09-01-2014, 12:41 AM
Rich_NYS

Bill Robertson is the main carb dude....could probably answer every question you have. He's on http://dmctoday.com/forum.php , username: content22207.

The guy who restored the Barney car also did some type of badass carb conversion, as did Andrew (here on Talk as well as Today.) The Barney car dude is Matt; he's on both forums but I haven't seen him in a while and don't recall what his username is.
09-01-2014, 12:43 AM
Dracula

While I can't personally answer your questions, I'd advise you join DMCToday.com as the foremost experts in the world, in regards to DeLorean carburetion, can be found there.

This forum is significantly less interested in carburetion.

I'm in the process of converting my car to a carb, but I'm far from an expert.
09-01-2014, 02:53 AM
djdogbone

And there is the mechanical pump option as well If you're doing your own intake. Ask the DMCToday folks about that.
09-01-2014, 12:31 PM
Ron

1 Attachment(s)

Quote:

Originally Posted by leroylem

Since I had to pull the K-Jet intake on 2126 to repair a distributor problem, I decided this would be a good time to at least "mock up" a carb/intake manifold. I have read all the carb posts on this forum, and find this to be an interesting and challenging project. I am an old hot rodder, and have done quite a lot of fab work over the years. SO ,I have completed the intake, fabbed a throttle bracket to utilize the original cable/spool bracket, and found a Motorcraft 2100 carb, which appears to be rebuildable.I do have a few questions, and would appreciate advice/opinions.
1. I am contemplating using an in-line pump, mounted in the engine compartment, running a new line from the tank. I understand most conversions have an in- tank pump ---what advice/opinions on pumps/installations? I plan to run new pump wiring from the original pump connector to the new pump in the engine compartment, and retain the RPM relay pump power as original. Comments??

2. What about PCV ---crankcase ventilation---the MOTORCRAFT 2100 I purchased does not appear to have a PCV outlet---what air cleaners have PCV hose connections in the base ---have found none locally. I know the engine needs to be vented. Ideas???

3. Distributor vac advance----should I leave connected as it now is, or come off the carb ported vac connection?

4. Plan on installing a Pertronix 40K coil---I read somewhere about wiring the resistor differently to increase the primary voltage to the coil, thus a hotter spark/enabling a wider plug gap---Comments???

I will appreciate any advice/comments----would enjoy conversations with anyone with experience with the carb conversion.
Thanks, Leroy

$.02

1. If you don't want to go mechanical- AC pump, a time proven, simple install, unit. Get the pressure controlled version...
Attachment 30462

2. Ford made a spacer that mounts under the carb for the earlier models...later models have a port (supply side).
Most aftermarket breathers come with a knockout and mounting hardware for the vent side.
[Make sure you don't eliminate/defeat the purge signal for the canister (closed system fuel tank pressure is involved...)]

3. Leave it where it is, if I'm on the same page with "connected as it now is". IE you fabed an adapter for the manifold, or altered and adapted it, rather than pitched it...

4. The stock coil can provide all the spark you need and then some.
FYI- A "bigger" coil does not mean more voltage is delivered, but that more is available -- What is needed to jump the gap is what ya get, nothing more/less.
Changing the coil/voltages/gap/etc will change burn characteristics etc. so timing specs, etc. will be a bit different.....
[So best left alone if keeping K-Jet setup]

Good luck!
09-01-2014, 01:23 PM
Andrew

2 Attachment(s)

I'm running a mechanical pump on 5052. Airtex part #1436 bolts directly to the PRV, in fact it crosses to a 1978 Peugeot 604. I'm running a stock Peugeot manifold and carbs on 5052, but I can't see any reason why the 1436 wouldn't work with other carb setups.

Andrew

Sent from my LGL55C using Tapatalk 2
09-01-2014, 01:33 PM
DMCMW Dave

Quote:

Originally Posted by Ron

$.02
Changing the coil/voltages/gap/etc will change burn characteristics etc. so timing specs, etc. will be a bit different
!

As will the stress on the cap and rotor which are not really designed for 40K volts. The original system was designed around approx. 28K volts. Higher voltage to jump a wide gap = higher current through the resistor built in to the rotor. Not ideal IMO. And voltages appearing inside the cap that were never envisioned by the original engineers. Leads to some potential for interesting new problems. Some folks are doing it but I can't imagine what benefit there would be over a fresh OE setup. Improvements claimed are probably over a worn OE setup. When you go from worn out to "high performance" you can't really tell what improvement you got over new OEM.

But I'm sure there will be some religious arguments about this.
09-01-2014, 05:28 PM
Ron

Quote:

Originally Posted by DMCMW Dave

But I'm sure there will be some religious arguments about this.

Did someone say "Far..", ...I mean "Fire"?

Just kidding! Jusssssst kidding!
09-01-2014, 10:41 PM
dustybarn

The stock fuel pump can be used with carburetors IF you use a bypass-style fuel pressure regulator such as

https://www.holley.com/products/fuel...parts/12-803BP

It will relieve at a user-adjustable pressure between 4.5 and 9 PSI (I have no experience with Motorcraft/Autolite carbs and don't know what pressure they expect).

There is IMHO nothing inherently wrong with the stock ignition system. If present, I would leave it as-is and connect the vacuum advance to ported vacuum.