MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - Mallory Distributor

Anyone fitted the Mallory dual point distributor to their MGB.

This is what I found.

http://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=32603&SortOrder=1

Dave

I use Mallory distributors for the mgb race car fo a couple reasons:

1) I have find them new relatively cheap on e-bay

2) They have no vacuum advance can.

3) I can easily fit a pertronix ignitor in the case.

No B engine needs dual points. With twice the point dwell time of a V8, there are no coil saturation issues.

Mallory has had increasing quality issues with points sets. When asked about them, I was told to switch to a unilite.

So, if you want a new distributor body, rather then rebuilding your Lucas, you can pop big money for the Mallory and may have problems with points, or purchase a new lucas.

Just dropping the Mallory should provide no performance advantage over an unworn lucas, and may prove to provide lower performance.

I'm not bashing Mallory's dual point distributors- it's just that they aren't needed, and they do have some quality problems with poinys sets (an at $12 a set locally, they shouldn't have any problems)
Greg Fast

Dave-
The real advantage of A maalory distributor is for those who want to develop a customized spark advance curve to meet their individual needs. It is available in both vacuum advance and centrifugal advance versions (Victoria British Part #'s 17-501 and 17-500, respectively). Victoria British has a website at http://www.victoriabritish.com/ . In both versions, the centrifugal advance mechanism is adjustable from 16 to 28 degrees by means of a simple Allen wrench, the vacuum advance curve of the vacuum advance version of the distributor is adjustable by using a 3/32" Allen wrench and inserting it into the hose connection nipple and altering the tension value on the diaphragm. An advance curve kit consisting of both an assortment of centrifugal advance weight springs and the Allen wrench is readily available (Moss Motors Part # 143-236). It also has the advantage of having a dual point spark triggering system. In this type of system both sets of points are joined by a wire so that when the first set of points open, nothing happens until the second set of points open. The second set of points open just as the first set are closing. This quick closing of the circuit (approximately 5 degrees) gives the coil a maximum amount of dwell time (72 degrees) to charge, thus increasing the voltage of any given coil. This makes the system highly appropriate for engines equipped with a camshaft designed for high engine speed applications. However, other than the ability to have the spark advance curve custom tailored to work with almost any camshaft, there is no practical advantage to the increased coil charging time of the Mallory distributor when used on a four cylinder engine. For the MGB with a special camshaft, however, a custom spark curve can help exploit that last bit of potential power as well as deliver better response to changes of the throttle while avoiding the dangers of preignition. A six cylinder engine fires 50% more often and an eight cylinder engine fires twice as often. In such engines equipped with radical camshafts, the increased coil charge time can become critical at high engine speeds. Both versions are also available as Unilite distributors with solid state triggering (Victoria British Part #'s 17-503 and 17-502, respectively).
Steve S.

The choice for me was to:

Refit the standard Lucas distributor,
Buy a new Lucas distributor,
Buy a Mallory distributor,
Buy an Aldon distributor.

I was thinking of the Mallory because someone told me that the quality of Aldon could be variable, ie the build quality, and some friends of mine with Jaguars, rated the Mallory very highly.

Greg's comments call into question the choice of Mallory.

Steve leaves me with the impression that a Mallory is better for a race car rather than a Stage II Fast Road.

Help me choose the path to salvation.



Dave

There are places cheaper than VB to buy a Mallory. Do a Google search. Mallory has also had problems with condensors which causes points problems. They are very well built.
Mike MaGee

Anyone know the part number for the Mallory, not the Moss number, but the actual number.

Also who are Mallory, and what is their relationship to Unilite.

I'm sure they are part of FORD.
Paul

Like the man says, do a Google.

http://www.centuryperformance.com/mallory/dizzymatrix8.asp

Don't take any notice of the pictures, they all seem to be for the V8. Unilite means it has the optical trigger instead of points.
Paul Hunt

Dave-
The real advantage of the Mallory distributor for an MGB owner is its adjustability of the spark advance curve. However, you don't necessarily have to go such a big bucks route, and you don't have to place your trust in the appropriateness of Aldon's spark advance curve, either. If your Lucas 45D distributor is in good shape and you don't mind doing it the labor-intensive way, Cambridge Motorsport in the UK sells a package of five advance springs that will enable you to tailor the rates of your spark advance curve. Unless you've got an assortment of spare bobweights to work with, however, your total advance will remain the same.

Paul-
A Unilite distributor is just a Mallory distributor converted to pointless triggering.
Steve S.

Dave-
Made a mistake! You don't need an assortment of spare bobweights because they all weigh the same. Doh! What's needed is an assortment of advance plates.
Steve S.

Unless Camnbridge Motorsports are selling different springs now the ones I got from them were nowhere near the existing springs, so will only give major changes not fine tuning.
Paul Hunt

I want to be clear I don't like the Mallory DUAL POINT setup, as it appears they've let the quality of points sets slip since the introduction of e;ectronic triggers. I got mad enough at those boys i refuse to purchase the unilite conversion when I went electronic trigger.

The Mallory distributor body is a well constructed, if expensive, piece.

For the race car, I use no vaccum advance and run 28° BTC (that's right) static with total advance of 36° in at 2800. The car will idle at 1100 rpm that way (the cam is a bit lumpy)

For me, for a street car, I'd rebuild the lucas unit and install a modern trigger system. Rebush the shaft, make sure the the axial clearance is tightened up (although not as critical with this distributor and drive dog arrangement as compared to US distrubutors that have a helical gear drive on the distributor shaft.

And remember- your doing this for you. After all is said and done, make the decisions that make YOU happy. Advice from this board can be taken or ignored- we won't get offended. It's not like your paying big bucks for it.

If you decide on Mallory, I bought a new unit (shopworn box) off e-bay for $140, and a second one for $100 through the grapvine. Most of the used Mallorys I have seen are relatively low miles, and are still in good shape. Remember you need to get a drive dog or strip it off your old distributor
Greg Fast

Greg, you say you refused to purchase the Unilite conversion when you went electronic trigger.

What brand did you fit?

Also can you be a little more specific about why or how the quality of points sets slipped.
Paul

Can't tell you why quality slipped, but several other users I know and I have had the contacts on the points come off, as in detached, so the distributor becomes effectively a single point again and timing sliped (in my case) about 8 degrees.

Ruined my weekend

Sure it can happen to any points set, but it seems to happen way more with the Mallory points, based on the sample size of people who a) have the distributor and b) have points failures.

And Malloy's response was BS- not we'll fix the problem, or we know of the problem and are working on it (A mechanic friend has spent a week on the phone over the last couple years with Mallory about points- they know there's a problem). The response was, spend more money on our products!

Sorry, not me

I've fitted a pertronix, and I can't give any information on if I like it yet. I've needed to rebuild the engine as a result of the first paragraph.

The weekend really wasn't good
Greg Fast

Paul in Glasgow- re-reading the entire thread, you asked a question I don't think was truley answered

"Also who are Mallory, and what is their relationship to Unilite."

Mallory is an old line automotive electrical parts company, made famous in the 50's and 60's with ignition products. I believe it's currently owned by Mr Gasket, a speed equipment holding comapy. Much like most other manufacturing industries, the performance equipment industry is now controlled by a few companies that make and market the products under the brands that originally developed them.

My first exposure to Mr. Gasket was the chrome plated bolt kits the are in the window of storefronts. Branched into shifters (in the states, most manual transmission shift linkages were external until the development of the T-5. Some earlier T-10's (I've been told) also have integral shift linkages but most were bolted to the outside of the gearbox with external shift rods.) competing with Hurst.

So that's who Mallory was and now is.

Unilite is their proprietary optical trigger. Developed by Mallory in the early 70's (?), it uses a chopper wheel and light to trigger the ignition.
Greg Fast

Paul, Glasgow

Oh dear I was hoping Mallory was going to be a class act, the damned things are expensive enough.

The reason I was hopeful about Mallory was that I'd heard that Aldon build quality was not quite up to scratch.

Greg, when you say you've fitted a Pertronix, have you fitted their Igniter into the Mallory or what?

Please explain more.
Paul

I do like the Mallory distributor housings, and I have use a Pertronix Ignitor II in the Mallory body to replace the points sets.

The reason i do this rather than in a Lucas housing is that the ancillaries- the cap and rotor- are of good quality in my experience, and I can get a near new Mallory distributor used for about the same price I could rebuild the Lucas.

I'll reinterate again, I think Mallory points sets are junk, and bloody expensive junk at that. If you were to be able to find quality points (and I believe with the decreasing use of mechanical points sets in the world this will become tougher and tougher to do), that were compatible with the Mallory, it would be a wonderful little distributor, what with the availability w/ and w/o an adjustable vacuum can, adjustable maximum advance, and simple advance curve adjustment- it's a nice bit of kit.

Looking on e-bay I have found several new distributors in shopworn boxes, or lo mileage distributors for a fraction of the new price.

Hope this answers some questions
Greg Fast

Greg, many thanks for your comments.

Sounds as though the only thing wrong with the Mallory is the points, so if I pop a Pertronix Ignitor II in, I should have a tuneable high quality distributor.

Looked on the website Paul hunt specified, and came up with a reference MAL-2332001.

Is this the one I should be after on E-Bay etc, or is that not important.

http://www.centuryperformance.com/mallory/dizzymatrix8.asp
Paul

2332001H is the part number you are looking for.

Covers a Mallory for an MGB with the points set up.

MAL-2332001 is probably just the vendors prefix ie MAL as in Mallory.
John

Price is actually pretty good. If you wait for one to show up on e-bay, it may be awhile. Just that I scored a couple of deals there. It's OK if you know what you want and don't need it immediately. Other sources are equally OK

Century doesn't list a vacuum advance- If it's a street application, i'd be looking for one with vacuum advance in addition to the mechanical- actually don't know if they buid this in a vaccum can configuration. Possible exception to vacuum advance advice is if you run a huge cam with little manifold vacuum- you then nees to run alot of lead in initial timing, and limit centrifugal advance.

I'm using the ignitor II in the Mallory shell for the race car.

Once again, don't discount a modified lucas for a street application. You've not been particularly specific about application, so all of us are kind of shooting in the dark as to what to advise.

For street cars, I'm using the ignitor II in a lucas ehousing, and having the advance set up at a local speed shop (one of the few that still has a Sun distributor machine
Greg Fast

My car will have the usual upgrades to the engine, new cam and bored out, but I'm looking at it as a sportier road going car not a racer.

Paul

This thread was discussed between 15/11/2003 and 01/12/2003

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.