HEI conversion 250 distributor gear problem

['68OrangeSunshine]

Well, yeah, I knew the difference between 6 and 8 cylinders. I was hoping there was a parallel unit for V8s. I'll look up MSD. They merged recently with Mallory who are all owned by Mr Gasket, including Accel. I looked at the MSD Blaster HEI coil at O'Reilly's.
They wanted $82 for a Chicom coil.
I wonder why the low cap clocks differently than the coil-in cap? If you snap the #1 plug wire on the first terminal closest to Cyl #1, and follow 1-5-3-6-2-4 clockwise with the successive plugwires, isn't the effect the same? Or does that put the Vac Can out of position? So you are saying the Coil-in-cap base is different and incompatible with the lowboy external coil cap?
Or is it that the V8 cap has a different index notch than the L6 caps? Might make more sense.
Do they use the same HEI caps for L6s and V6s? The base would be different from the 'Late' L6 since the 231 V6 is a cut down 3/4 of the SBC. GMC big V6s likely have an even different distributor configuration. Who knows?

[Sixteen Tons]

When you sort out your issue you will not be disappointed. I freshened up and installed an Ebay OEM HEI and it runs like a different truck. Search board member Sharps40, he has a helpful thread on the swap from points to electronic.

[bretcopsey]

Well, I followed 68orangesunshine's lead and ordered the Assault HEI. It arrived earlier this week and I got it dropped in today.

Now another problem has cropped up. Sometime during the week while I was at work my son took off the gas cap and said there was a loud wooshing sound. I noticed there was fuel all over the intake, so I decided to pull the carb and the intake was full of gas. The plugs were wet too. Drained the oil which was full of gas.


So, now looking at a carb rebuild.

[71CHEVYSHORTBED402]

First thing that comes to mind is, possible something fell into that carb?

[bretcopsey]

My theory is that the rush of air pressure created a surge in fuel pressure feeding to the carb lodging some crud that created an internal leak?? Shouldn't the cap be vented to revent that vacuum for occurring?

Either way I have to tear it down to confirm. It's soaking in carb cleaner now and I'm picking up the rebuild kit in the morning. I've bever rebuilt a carb before, hope it's as easy as everyone says.

['68OrangeSunshine]

I don't think '68s had vented caps. [But I'm not infallable.]
What carb? If it's a Carter AFB or Edlebrock Performer (the same thing in different wrappers) you may need a Fuel Pressure Regulator in line between the fuel pump and carb.
Mechanical or electric fuel pump? Those carbs like 5.5 PSI, no more. Can't say about QJets, I know nothing.
This is on the 250 L6 in the '68 Camaro? That's a rare gripe on an L6.

['68OrangeSunshine]

Originally Posted by bretcopsey

Well, I followed 68orangesunshine's lead and ordered the Assault HEI. It arrived earlier this week and I got it dropped in today.

You're ahead of me. Mine is still on the bench. First the '68 Stepside gets a new water pump, new heater- and radiator- hoses and coolant. Then I'll deal with ignition.

[bretcopsey]

This is an all stock 250 L6 in my son's 68 C10 with factory mech pump and Rochester monojet carb. We had no fuel issues until the gas cap removal "incident". Could just be a coincidence...?

Aside from draining the oil and allowing the engine to air out a couple days, are any other precautions recommended before we try firing it back up? This assuming I get the carb rebuilt successfully.

['68OrangeSunshine]

Since I haven't played with the Rochester Monojet in about 28 years, I'll leave room for someone more qualified to further advise you.
How new is the fuel pump? Stock 22 Gal. tank behind the seat?
The gas they sell in the summer has many extra volatile additives in it like alcohol and ether. If these gases can't escape, they may build up excess pressure and force thru the fuel line and out thru the carb.

[firedemon]

mine is a 67 its vented only one line coming out of sender

[bretcopsey]

SUCCESS!!

Carb is rebuilt and we drive into town for gas. Still needs fine tuning and I've got something messed up with the cast idle cam and linkage because it stuck wide oen on the way home. Had to shut off the engine and pull over to unjam it.