Questions about 250 inline 6 cyl

[indymachinist]

Almost on a "bet" we will say with a couple coworkers... I am preparing to go down a strange path with my 250 straight 6.

So I have a couple questions about the stock parts with this engine.

#1 The bolted together intake and exhaust manifolds. I understand this was to get heat into the intake manifold. To what extent was this achieved? I just separated my manifolds today and found the bottom area of the intake manifold was packed almost solid with carbon deposits. The exhaust manifold has a flapper valve in it that I had not noticed before. The connection or whatever controlled the flapper is long since gone and it was just hanging there. Did some amount of exhaust actually enter the intake manifold thru this connection? Or was this just to kind of "surround" the bottom of the intake with hot exhaust?

#2 The distributor setup. Does the distributor tip drive the oil pump on these engines? I assume so since that seemed common on older engines but want to be sure. What I am doing with this engine it will no longer need a distributor.

Thanks for the thoughts!

[trac209]

Yes the distributor drives the oil pump iirc

[Z10]

Check out my friend Diceman's six cylinder build. He's also a great source if you need questions answered about these engines.

http://67-72chevytrucks.com/vboard/s...hlight=diceman

[GRX]

No actual exhaust enters the intake (image below). Only heats it for initial cold start up. The flap in the exhaust manifold is attached to a spring with a counterweight that holds it closed until engine heat expands the spring, then the flap moves forcing full exhaust out the pipe.

Sounds like yours is broken heating the carb base all the time. You could make it stay open constantly if you do not mind babysitting the gas pedal on cold mornings.

[1970 charlie]

Took my flapper out and plugged the ends with pipe plugs surprised in the cold mornings (today 28 degrees) the carb doesn't freeze up. also I am running the stock air cleaner and no preheat tube.

[GRX]

Similar here. Installed a split header on my 250 which totally eliminates any manifold heating. A bit of work with the manual choke for the first couple minutes is all that is needed.

[yuccales]

Originally Posted by indymachinist

What I am doing with this engine it will no longer need a distributor.

Don't leave us hanging, what are you planing?

[Grumpy old man]

You can't convert a gas engine to diesel ( no dist) or propane/ natural gas without a distributor . But being your indymachinist I'd be willing to bet your gonna try .
Posted via Mobile Device

[68panelman]

Curious to see what the plan is also

[indymachinist]

I don't want to over hype it and then have it not end up happening but the plan is to convert it to modern electronic fuel injection for fun. This will be done with parts I already have. So it will go from carb and distributor to sequential fuel injection and individual coil packs.

Something like this picture.

Oh, and also a turbo. Just to be obnoxious.

[indymachinist]

Note: I openly admit this is kind of a dumb idea. I already have almost all of the parts laying around waiting for my LS engine build. If I didnt, I would not otherwise spend the money buying them just to use on the 250.

[GRX]

Interesting. What are your plans for a crank position sensor?

[indymachinist]

Current plans are to attach a 2005ish Ford 4.6/5.4 crank trigger wheel to the crank pulley and possibly use a 2003ish Chevy 4 cyl S-10 cam sensor as a crank sensor. Not sure how to go about a cam sensor yet. Might not actually need a cam sensor though with the "missing teeth"style of crank trigger wheel.

[yuccales]

Originally Posted by indymachinist

Note: I openly admit this is kind of a dumb idea.

Nope, not dumb. Cool and different is the way I see it. Do it cuz it's fun!