What are these?

[SenorCole86]

Could somebody please tell me what these things are and how necessary they are? On the right, one of the lines is a vacuum line and the other actually goes to the fuel filter . . . On the left, I believe all three are vacuum lines of some sort. Any help at all would be great guys. On a side note, those pistons look pretty black. I've never had my head off before, is it normal for them to be black like that or does it indicate rich conditions or excess carbon deposits? Thanks a lot guys, have a good one.

 

[jay79cj7]

I have the one towards the front of the engine in my block but its not hooked to anything. I know that it is a temp based vacuum switch. I think it is called a CTO and is supposed to turn on the vacuum to the charcoal canister when the engine gets up to temperature. I think newer 258s have them in the intake manifold water passage rather than on the block. It was disconnected when I bought it and it works, so I have not messed with it. I can't see how you have a line from the fuel filter going to the other one. My fuel filter has 3 fittings; in, out to the carb, out to the return line. Are you sure you don't mean the charcoal canister?

 

[SenorCole86]

Yeah, the one on the front of the engine (left) definitely had a line running to the fuel filter, which I thought was weird as well. I suppose if it doesn't need it I'll disconnect it and plug it. I was under the impression however that all carbs use returnless fuel systems. Am I wrong?

 

[redrooster]

The carb should have a return line.
While you have the head off, check the wear on the cylinder walls. You can feel around the top edge down about a quarter inch. If there is a defined ridge there, you might want to get some inside micrometers and measure it. Then you can look up the stock specs to see how worn it is. The more wear, the less compression.
Boring the engine removes the ridge, but requires complete disassembly of the engine.

 

[jay79cj7]

I have the stock carb and it definitely has a return line. I'd recommend finding what your return line is hooked to.

 

[SenorCole86]

Oh I'm sorry Jay, you're right, it was a air line of some sort. I went back out and checked and the fuel return follows the same path down, I just never bothered to check where it terminated. Sorry about that. I'll look at that red, thanks.

 

[almostcj7]

8) Been a while since someone in te old school posted! On my '84 both the lines you are showing are dead-ended. All is good and dont know what the did. I'm not running pump gas anymore and still dont have any problems. If I were going to have problems, 110 octane should show it. Hope this helps.8)