HEI Install in Rebuilt 250 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

sixpac · 01-06-2006, 10:10 PM

I'll have my new motor back soon. I have my HEI from my 230 that I will be putting back on the original 250 motor. I can't remember the install process from the HEI when I originally got it. Obviously, I won't have a reference point off the old rotor , as the dist. was removed before going to the builder.

I remember the wiring part, but is there other info. I should be aware of?

NitroMike · 01-06-2006, 10:33 PM

First you've got to get the motor to top-dead-center on the # 1 cylinder. Pull the spark plug and rotate the motor with a wrench on the dampener bolt. Pull the valve cover and watch the rockers. Stick your finger in the plug hole and you'll feel the piston pushing air against your finger. The exhaust valve should be also open. Continue to rotate the motor (make sure tht you are going in the right direction). The next downstroke is the intake stroke (the intake valve opens) followed by the compression stroke (pressure against your finger from the plug hole, both valves fully closed). At the very top of that stroke is when the plug normally fires (top-dead-center). After that find the # 1 plug wire on your cap. You may be able to look at the old distributer to find where #1 was on there. Drop the distributer in so that the rotor points to the place on the cap where the #1 wire will be when it's attached to the distributor. That should get you close. Make sense?

sixpac · 01-06-2006, 10:48 PM

Yes,
Thanks, that makes good sense!

If I want the vacuum line to come off the the distributor toward the front of the motor, I could rearrange the wires on the cap using the known firing order couldn't I?

NitroMike · 01-07-2006, 12:42 AM

Within reason, yes.

Fred T · 01-07-2006, 02:15 AM

As long as the plug wires are in the right order, the engine doesn't care what positon the distributor is in. On the Chevy six, practice is to point the rotor toward the #1 spark plug.

Only thing I will add to NitroMike's advice is to put your thumb or finger over the plug hole, not in it. It isn't fun to lose skin in the threads when the pressure hits.

NitroMike · 01-07-2006, 06:55 PM

Ahhhh, that's what I've been doing wrong all of these years!

01-06-2006, 10:33 PM	#2
NitroMike Active Member Join Date: Dec 2005 Location: Bethlehem, PA Posts: 346	Re: HEI Install in Rebuilt 250 First you've got to get the motor to top-dead-center on the # 1 cylinder. Pull the spark plug and rotate the motor with a wrench on the dampener bolt. Pull the valve cover and watch the rockers. Stick your finger in the plug hole and you'll feel the piston pushing air against your finger. The exhaust valve should be also open. Continue to rotate the motor (make sure tht you are going in the right direction). The next downstroke is the intake stroke (the intake valve opens) followed by the compression stroke (pressure against your finger from the plug hole, both valves fully closed). At the very top of that stroke is when the plug normally fires (top-dead-center). After that find the # 1 plug wire on your cap. You may be able to look at the old distributer to find where #1 was on there. Drop the distributer in so that the rotor points to the place on the cap where the #1 wire will be when it's attached to the distributor. That should get you close. Make sense? __________________ The older I get, the faster I was!!

01-06-2006, 10:48 PM	#3
sixpac Registered User Join Date: Nov 2005 Location: Newburgh, IN Posts: 46	Re: HEI Install in Rebuilt 250 Yes, Thanks, that makes good sense! If I want the vacuum line to come off the the distributor toward the front of the motor, I could rearrange the wires on the cap using the known firing order couldn't I?

01-07-2006, 12:42 AM	#4
NitroMike Active Member Join Date: Dec 2005 Location: Bethlehem, PA Posts: 346	Re: HEI Install in Rebuilt 250 Within reason, yes. __________________ The older I get, the faster I was!!

01-07-2006, 02:15 AM	#5
Fred T Cantankerous Geezer Join Date: Aug 2002 Location: Bel Aire, KS Posts: 6,264	Re: HEI Install in Rebuilt 250 As long as the plug wires are in the right order, the engine doesn't care what positon the distributor is in. On the Chevy six, practice is to point the rotor toward the #1 spark plug. Only thing I will add to NitroMike's advice is to put your thumb or finger over the plug hole, not in it. It isn't fun to lose skin in the threads when the pressure hits. __________________ Fred There is no such thing as too much cam...just not enough engine.

01-07-2006, 06:55 PM	#6
NitroMike Active Member Join Date: Dec 2005 Location: Bethlehem, PA Posts: 346	Re: HEI Install in Rebuilt 250 Ahhhh, that's what I've been doing wrong all of these years! __________________ The older I get, the faster I was!!

01-06-2006, 10:10 PM	#1
sixpac Registered User Join Date: Nov 2005 Location: Newburgh, IN Posts: 46	HEI Install in Rebuilt 250 I'll have my new motor back soon. I have my HEI from my 230 that I will be putting back on the original 250 motor. I can't remember the install process from the HEI when I originally got it. Obviously, I won't have a reference point off the old rotor , as the dist. was removed before going to the builder. I remember the wiring part, but is there other info. I should be aware of?



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