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Discussion Starter #1
I am going to build a spare distributor for my B20 competition motor. I have a number of old units I have accumulated over the years, but never looked closely at them. Of the three in stock, no two are the same. My question: Are any of these useable?<p>The original distributor is from a B20B (vacuum retard!) that has been converted to electronic (Crane system). The vacuum system isn't used. No Volvo part number, but the Bosch number is JFUR 4 and the part #0 231 146 099.<p>Two others are on my bench:<p>JGFU 4 (0 327 002 002) appears to be an old Bosch "pointless" system and has a vacuum advance. Will probably be hard to convert this one, since it has no base plate.<p>JFR 4 (0 231 153 003) is an oldie and has no vacuum advance/retard system at all, and would be a good candidate for conversion.<p>The devil is in the details: What are the advance curves? How do I find out?<p>Any guidance is welcome.<p>Thanks,<p>Doug Mepham<br>Belleville, Ontario, Canada
 

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Re: Distributors for B20s (mepham)

Depends very greatly on what your "competition" motor wants, and how you intend to use it. A serious high-performance B20 may very well want MORE advance at idle than at full-throttle redline. If your intended use involves a lot of full throttle and high revs, you probably want very little advance from a purely centrifugal distributor. You'll have to modify the curve on any of the stock distributors, and doesn't much matter which one you start with.<p>A good solution that gives you a lot more flexibility is to use a vacuum advance dizzy. If you can find a VJU4BL33 from an early B18 (typically from a 544), that's a good candidate to refurbish.<p>My burliest B20 gets best peak power at 29 degrees BTDC (full throttle = no vac advance), which is only 7 BTDC at idle with the vacuum disconnected... but it's not disconnected -- it's plumbed to the manifold, so it idles nicely at 30 BTDC with the vac advance full on.<p>Again, it's all going to depend on how your engine is modified.
 

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Re: Distributors for B20s (Phil Singher)

(cooked this up before reading Phil's better post)<p>If this will be a spare what distributor is to be in the B20?<p>The 003 is a good candidate if you need no vacuum control and will not employ active spark control. The weights can be changed but most folks just run different springs for different advance curves. This setup is vulnerable to worn components and has limits at higher rpm's.<p>The aftermarket has bolt-in distributors for the B20 which compliment the engine management system employed.<p><A HREF="http://1800philes.com/splitting_hairs.html" TARGET="_blank">http://1800philes.com/splitting_hairs.html</A><p><A HREF="http://1800philes.com/engine_article.html" TARGET="_blank">http://1800philes.com/engine_article.html</A><p><A HREF="http://www.v-performance.com/recent.html" TARGET="_blank">http://www.v-performance.com/recent.html</A><p><A HREF="http://turbobricks.com/feature.php?content=winter_05" TARGET="_blank">http://turbobricks.com/feature...er_05</A><p>George Dill<br>
 

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Re: Distributors for B20s (gdill2)

Thanks to you both.<p>Distributor is in a 142S rally car. Current model is a JFUR 4 0 231 146 099. It is not used with a vacuum advance, and timing varies depending on the cylinder head (CR) and other details but never more than about 30-degrees total advance. It will go back in the car; this task for me is to build a spare.<p>I am curious about your suggestion about higher initial advance: I have had the mechanical advance 'hang' and not retard when it should with unfortunate results.<p>I assume from your responses that either of the other distributors will work. Both have bearings and other mechanicals that are in good shape. Interestingly, I also have a VJU 4 BL33 in the bin (early B18, I believe) and considered it a candidate to be the spare but concentrated on the later versions. I will dig it out and look at it. <p>Any other advice?<p>Thanks<br>
 

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Re: Distributors for B20s (mepham)

<A HREF="http://performance.drivewire.com" TARGET="_blank">http://performance.drivewire.com</A>/<br>
 

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Re: Distributors for B20s (mepham)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD><i>Quote, originally posted by <b>mepham</b> »</i></TD></TR><TR><TD CLASS="quote">I am curious about your suggestion about higher initial advance: I have had the mechanical advance 'hang' and not retard when it should with unfortunate results.</TD></TR></TABLE><p>Not higher static timing -- it's the vacuum that runs up the timing at idle with the throttles closed. With lots of overlap in the cam and big chokes in the Webers on mine, burn rate is really slow, so it wants all that advance to idle smoothly. There's not enough vacuum when cranking the engine to advance the timing enough to kick back on the starter.<p>When you open the throttles coming off idle, the timing retards until RPMs come up enough for the mechanical advance to take over. Pinging at lower engine speeds is therefore not a problem.<p>Once it comes up on the cam and there's enough flow to warrant the choke size, VE and burn rate increase drastically, and it needs less advance than a stock motor.<p>You can adjust the length of the rod that goes between the vacuum module and the breaker plate to limit the amount of vac advance possible.
 

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Discussion Starter #7
Re: Distributors for B20s (Phil Singher)

Again, thanks.<p>Perhaps the VJU 4 BL33 is the best candidate; I can experiment with the vacuum advance. With no vacuum advance on the current distributor and a pair of Solex side-drafts (I also have newly refurbished Dellorto 48s I want to try), and a lot of on-throttle/off-throttle/on-throttle activity in rally stages, responsiveness is a big issue for me. I have not felt I lacked responsiveness, so I will be interested to see the result.<p>I have just taken my MSD 6A system out of the car after a brief experiment. That may also change things.<p>Any more guidance?<p>Thanks,<p>D
 

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Re: Distributors for B20s (mepham)

1972 to 1972 Volvo 142 E L4 2.0 MFI <p>4561001<br> Mallory Distributor<br>Volvo 142 E Distributor<p>Fits: 1972 to 1972 Volvo 142 E<br>Brand: Mallory<br>Notes: Unilite Electronic Ignition Distributor Series 45; LH; $550.89 $444.69<br>Free Shipping<br>May Apply <p>--------------------------------------------------------------------------------<p><br>Performance Volvo 142 Distributor<br>Drivewire.com has been selling Volvo 142 Distributors online for over 5 years and has one of the largest inventories of Volvo 142 Distributors on the web. We have multiple warehouses that have performance and aftermarket accessories in stock ready for immediate shipment. Please browse our online catalog of Volvo 142 Distributors, and you will find all of the Distributors you need for your Volvo 142 car or pickup truck. We buy from the leading suppliers of performance parts allowing us to sell to you at a discount of up to 60% on all Volvo 142 Distributor. Whether you need a performance part or accessory for your Volvo 142 car or truck, please give us a try! You will find an easy and pleasant no-hassle shopping experience. If you can not find the part you need, please call our Volvo 142 performance part experts at 800.895.8910.
 

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Re: Distributors for B20s (mepham)

Doug,<p>I was going to ask why you don't just update it to a modern system, then I realized who asked the question and what car it is probably going to go into.<p>- John
 

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Discussion Starter #10
Re: Distributors for B20s (jwernerny)

Has anyone had any experience with the Mallory distributor? Good reports? Ease of setting up?<p>Does anyone have other recommendations?<p>Thanks,<p>Doug Mepham
 

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Re: Distributors for B20s (mepham)

Mallory dual-points are/were popular with the boat people (B20) and I installed one in my second ex's B20 hot-rod 122 wagon in 1979.<p>Dependable hot spark is just one element of engine performance. Spark at the optimum moment is just as critical. This means you could run a stock set of points/condensor with a hot coil/capacitor and good wires getting super spark to the plugs but still need active control of the spark arrival tiime. I ran a full Jacobs system in my '86 245 B230F using the stock distributor. This setup measures the resistance at the spark plug gap and fires a follow-up spark on the same power stroke. Plug gap is more than double stock settings and performance is improved in all areas of engine operation.<p>George Dill<p><A HREF="http://www.centuryperformance.com/mallory/index.asp" TARGET="_blank">http://www.centuryperformance....x.asp</A><p><A HREF="http://www.minimania.com/web/Item/LU-ML141/AddedFrom/BrandPage/InvDetail.cfm" TARGET="_blank">http://www.minimania.com/web/I...l.cfm</A><p><A HREF="http://www.outperformanceshop.com/Mallory_s/1902.htm" TARGET="_blank">http://www.outperformanceshop....2.htm</A><p><A HREF="http://go.mrgasket.com/newproducts/CAT_PDF/MALLORY.PDF" TARGET="_blank">http://go.mrgasket.com/newprod...Y.PDF</A><p>
 

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Re: Distributors for B20s (gdill2)

Ignition systems have taken another advance in technology from these folks. I've haven't used one of these but they seem like a great product. The setup and ease of use is fantastic. <A HREF="http://www.123ignition.nl" TARGET="_blank">http://www.123ignition.nl</A>/<br>I've seen them for sale from some of the British car specialists. If you are going to consider spending a lot of money on a system. I'd seriously consider this since you have a choice of advance curves, possibly even custom ones and it's an electronic ignition, too.
 

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Discussion Starter #13
Re: Distributors for B20s (242gti)

Thanks. I had seen various in-distributor conversions but not a complete distributor. I am now more inclined to a new Mallory but I will certainly follow-up with these folks to see if they have a North American distributor.<p>Cheers,<p>/d<br>
 
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