All Small Six Is a Distributor For a 200 Xflow Possible?

This relates to all small sixes

rocklord

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When MustangSix came up with the modifications necessary to install an Australian 4.1 Crossflow head to a US 200 block, he noted that the intake manifold on the left side of the engine made fitting a distributor very difficult. Link below for your reading:
I emailed MustangSix (Jack) after he installed the 200 Xflow in his Locost to see if the distributor issue was solved. Jack replied the only distributor that would fit under the intake was the Load-O-Matic (LOM). He only used the LOM to trigger a programmable ignition box (He didn't say which one).

I am mocking up a crossflow head on a 200 block and decided to show my progress and thoughts.

First, a stock points distributor (67+) will not fit under the intake. I didn't take any pictures, but trust me, no distributor from 67 on (including DSI, DSII, or aftermarket) will fit.

I installed a LOM with stock cap and then measured clearance (pictures attached). There's about 3/16" clearance between the manifold and coil electrode on the cap. If 90-degree ignition wire plugs are used and the plastic above the center coil electrode shortened, then a LOM will work. The LOM will not have advance without a Spark Control Valve (SCV) carburetor, so the vacuum canister needs removed, the advance plate locked-out and a trigger installed for an external ignition box.

In Jack's writeup on the head installation, he mentioned a crab-style distributor cap as a solution. I did some searching on the Internets (GW Bush) and found a 1941-47 crab-style distributor cap. I purchased a '41-'47 cap and rotor and attempted to fit them to the LOM. To my amazement, the '41-'47 rotor fit the LOM shaft perfectly. When installing the cap the clips on the LOM held the cap in place with tension on the rotor tab, but there's a gap between the cap and distributor body (pictures attached). The gap is about 1/4". An adapter could be made (3-D printed?) to bridge the gap and make the crab-style cap a viable choice. A downside of the crab-style cap could be its' size (3-3/8" compared to the LOM's 3-7/16) which may cause arcing. There is a possibility the crab-style cap and rotor could be adapted to a '67+ points distributor. This option would allow a vacuum canister to be used along with stock points, pertronix, or other spark ignitor.

If anybody finds a different distributor cap that would solve the clearance issue, please let me know.

This post only addresses the issue of using a distributor on a 200 Xflow. A 250 has a taller deck height, so a later 67+ points distributor may fit. I don't have a 250 block to check for clearances. If you don't want to use a distributor, then a trigger wheel on the balancer along with a dummy drive, or cam sync, could be installed.
 

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  • LOM on 200 Xflow 00.jpg
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  • LOM on 200 Xflow 01.jpg
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  • 41-47 Crab Cap on LOM 01.jpg
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  • 41-47 Crab Cap on LOM 02.jpg
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How hard would it be to make an adapter for the crap cap and its rotor. I think that would work best if keeping the dist.
 
Just use a 250 engine, i still dont get what you guys see in the 200s, all the stuff about better RPM is just old wives tales, given you are using a alloy head (hopefully the bigger valve version) it will rev Ok and give heaps for torque than any 200 will.
 
How hard would it be to make an adapter for the crap cap and its rotor. I think that would work best if keeping the dist.
3-D printing an adapter would be the best way to make one. You might be able to use a heat resistant plastic tube with the right diameter.

If retrofitting the later points distributor, the shaft would have to be turned down to fit the crab-style rotor. The rotor just snaps in place in the LOM.
 
Maybe try an EDIS in lieu of a distributor system?
As stated in my original post, you could install a trigger wheel on the balancer.
The intent of my post is to show the problems installing a distributor system and, hopefully, gather ideas how to solve the issue.
If a solution is possible.
 
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