Rochester single barrel carb spacer needed

[Carl Spangler]

Greetings

Anyone know where I can find a 1/4" thick spacer (heat block) for a 1971 Rochester single barrel carb?

I'm trying to cure a hot shutdown fuel boil over problem.

The fellow on ebay that sells em is "on vacation" so his spacers are currently not available.

thanks
JohnG

[68gmsee]

I owned several mono's in my time, starting back in the mid 60's and never had a problem with boil over. That intake manifold should not be getting that hot.

You might need to check to see what's causing that first or if in fact it really is boiling over. It could have the exhaust obstructed. A good place to start is the baffle for the heat riser. Sometimes they get rusted so they won't move.

[Carl Spangler]

Originally Posted by 68gmsee

I owned several mono's in my time, starting back in the mid 60's and never had a problem with boil over. That intake manifold should not be getting that hot.

You might need to check to see what's causing that first or if in fact it really is boiling over. It could have the exhaust obstructed. A good place to start is the baffle for the heat riser. Sometimes they get rusted so they won't move.

Thanks for the suggestion............ I'll check (in two weeks) to see if the baffle/valve is stuck.

I did a net search and couldn't find a spring/replacement part for the inline 6.
cheers
JohnG

[Former member Yoder213]

I've got the same issue. I know my 292 is bored to 318, and these engines run hot in original form.

have you had any luck finding a cause of excessive heat? or any luck finding a spacer?

thank you

[67 cst swb]

Did you check Speedway Motors for a spacer?

[Carl Spangler]

I used my IR temp gauge and "scoped" the bottom of the carb. Temp was around 275F about 10 minutes after the engine was shut down (heat soak).

The exhaust manifold "valve" appears to be working (not stuck) so I'm a bit at a loss why the carb is getting so hot. I still haven't found a phenolic spacer but the carb rebuild kit I recently purchased has a ~1/8" gasket that might work as a modest heat shield. Haven't had time to rebuild the carb but should get to in in a month or so.

JohnG

[Wrenchbender Ret]

A spacer for a 235 6 cyl. should work.

[cdowns]

how hard is it to make one?

[Carl Spangler]

OK, here's my big update:

Got a carb rebuild kit and there were a couple carb-manifold gaskets included. One of the "gaskets" was ~0.20" thick. After installing this thick gasket I had to bend the choke rod a bit. I also wrapped the fuel line with a bunch of aluminum foil and aluminum tape to shield it from the exhaust manifold heat.

Bottom line is that the carb no longer percolates fuel after a hot shutdown. My thermometer "gun" indicates the carb bowl hits a peak of 150F after a hot shutdown. Previously it was well over 200F.

cheers
JohnG

[68gmsee]

Originally Posted by Carl Spangler

OK, here's my big update:

Got a carb rebuild kit and there were a couple carb-manifold gaskets included. One of the "gaskets" was ~0.20" thick. After installing this thick gasket I had to bend the choke rod a bit. I also wrapped the fuel line with a bunch of aluminum foil and aluminum tape to shield it from the exhaust manifold heat.

Bottom line is that the carb no longer percolates fuel after a hot shutdown. My thermometer "gun" indicates the carb bowl hits a peak of 150F after a hot shutdown. Previously it was well over 200F. cheers JohnG

Awesome.. Thanks for update. On a stock engine, I've never had them boil over like that but I always use the thicker gaskets that come with the kits.

[Carl Spangler]

Here's a pic of the carb with the "thick base gasket". The gasket measured 0.25" in thickness. I've had a chance to run the truck under hot conditions and no more 'hot shutdown' fuel percolation. Wohooooo..............

Edit: Can someone give me a good suggestion for a pump-carb fuel line for a 250 ci six cylinder 1971? The PO FUBAR'd the nut at the end of the fuel line.

[68gmsee]

Originally Posted by Carl Spangler

.....Can someone give me a good suggestion for a pump-carb fuel line for a 250 ci six cylinder 1971? The PO FUBAR'd the nut at the end of the fuel line.

In the past, I've gotten fuel lines at local auto parts stores and done them myself, however, I have a neighbor that recently had his done on an old Dodge truck by a local auto parts. He took the old one and they did the bends exactly like the original. Cost of parts and work was minimal.

Might check local places to see if they do that.