V-8 LeRoi

[John Deck]

We are looking for any information about the V-8 LeRoi we have in a locomotive.

Model RX1V-C14
Ser 162969

This is in a Plymouth locomotive and was built in 1942 for the US Army. It has two dual point distributors, 16 spark plugs and large single barrel Zenith Carb. We have a large amount of the original paper work but we still can not get it to run smooth and not back fire. Any help would be great.

John Deck
johndeck@att.net

[Bud Tierney]

Fire truck engines sometimes have dual distributors, each firing its own set of plugs, and I've seen comments on those sites that synchronization can be a real pain; trying to set dual dual point systems sounds like a nightmare!!
To be precise about what's happening, you're getting uneven running and backfiring back thru or out thru the exhaust system, NOT "coughing" back thru the carb (the terminology on these two effects is often used in both cases, confusing matters).
If it's possible to do so without damaging any of the ignition system, have you tried running it on one distributor at a time, to see if the problem can be isolated to one distributor??
My only real suggestion would be to (if no solution shows up here) try the fire truck sites for advice on the ignition idiosyncrasies. I assume you've already reviewed the RR collectors sites for another running engine like yours.
With sympathy, Bud

[John Schwiebert]

How does it run on just one distributor? Have you had a vacuum gauge on the engine>

[John Deck]

We have been able to run it on one distributor with limited sucess. We did find out that there was a major wiring issue and that has been taken care of. We have not put a vac gage on it that I know of but will suggest that tonight when I see the guy working on it. It is backfire not coughing thru the carb. I do know about fire trucks using the same dual system and if we dont have any more success with it will start talking to them.

Thanks John Deck
PS I also play with and own a traction engine and can be found over on the steam side of this site.

[Ed Malcom]

Information below from a LeRoi manual.


This is a 2004 cubic inch engine. Two wiring arrangements have been used for firing the spark plugs on 8 or 12 cylinder engines where dual ignition is employed. On the older engines, the left bank distributor or magneto was wired to fire the spark plugs in the cylinder heads of both banks and the right bank distributor or magneto was wired to fire the spark plugs in the cylinder blocks.
On the newer engines the left bank distributor or magneto is wired to fire the spark plugs located in the left bank heads and the right bank cylinder blocks. The right bank distributor or magneto is wired to fire the spark plugs located in the right bank cylinder head and the left bank cylinder blocks. Either wiring arrangement may be employed but different wiring harnesses are required for the two arrangements.

[Bud Tierney]

I love the way these manuals leave you hanging; I've numerous notes in parts catalogs about "early" and "late" engines having different parts, with only rare notations where the change occurs.
I don't suppose that manual said when or at what serial number they decided to change the firing arrangement??