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Vacuum Advance on Buick Chris Craft Engine

7

70lancer

New member
Hello,

I'm looking at buying an old lancer that has the odd fire Buick v6. I notice this has a vacuum advance on it which seems odd for a marine engine, yet there are plenty of pictures on the Internet of these engines and they all seem to have it, leading me to believe that this was done from the factory and not some aftermarket thing on my boat.

Does anyone know why they did this? Is this engine actually using an automotive distributor (and therefore unsafe)?

Thanks!
 
OMC I/O I assume?

I believe the 150 hp 1 barrel carb models (64 thru 66) had a vacuum advance that was never used. The '67 & later 155 2 barrel did not have a vac advance that I've ever seen. I've owned 69 & 70 models.
Can't find digital parts manuals prior to '68. I'd have to search my microfiche cards or possibly an old maintenance manual to verify.
 
It's a Volvo drive from 70 in a Chris. I'm starting to think it's factory since some other setups I see online also have it. AI tells me they did it to smooth out the rough idle from the odd fire engine, but I don't trust ai
 
I can't answer that one. But I'd say no.
In an OMC the odd fire at idle wasn't really noticeable but just off idle, a bit. Maybe the big rubber feet of a stringer drive isolated the vibration a bit?
 
It's not a stringer drive, it's a Volvo 250. These still weren't the quietest things in the world but it's still super strange to see vac advance.

My best guess is that they were planning on selling very few and didn't feel like re-engineeing anything from the automotive world
 
I understood from your last post it wasn't an OMC. ChrisCraft maximized their own branded engines back in the day. Or at least some of their own. I'm not a ChrisCraft guy but periodically end up tinkering with a few woodies, all straight onboard.

I'm thinking maybe they licensed the rights from OMC to use their design & adapted it to a Volvo drive.

Regarding the distributor, like I said early OMC 150 1 barrel models seem to have a vacuum advance unit that is not used. The 155 2 barrel models do not have a vacuum advance, at least not the 1969 & 1970 models I've owned.
My guess is the unused vac advance simply holds the breaker plate in place. The later distributors had a solidly mounted plate.

BTW, the rotor on an odd fire has a rotor with a hook shaped electrode unlike the V8 or later even fire V6's. It is possible to install the incorrect rotor if you're not aware.

The hook shape of the electrode helps to align the electrode with the contacts in the cap as the cap towers are evenly spaced.
 
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