rewiring, HEI dist, firing order, Got a few questions before i am done....

[tankwilson]

Ok here is what i have been up to this winter.

I am rewiring my 49 plymouth. Installed a mopar alternator, ENOS fuse panel, and misc.

When installing my HEI dist (from langdon's) i rotated the engine so that the front cylinder was 10 degrees BTDC and installed the dist. I can either put the rotor facing 4 O clock or 10 O clock. I have it at 10 O clock now. I gapped my plugs (ac delco rts45) to .60

First question.... does what i have done above sound right?? Will the car start and then should i time it then or just run it???

Second question.... This sounds like a stupid queston but what order is the spark plugs in the head. 1 starting at the radiator and going back in order???

Not sure if any of this makes sense but please help if it does..

Thanks

matt

[martybose]

There are no such things as stupid questions; they're only stupid if you don't ask them.

The cylinders are number 1 through 6 from the front to the back. Your head should have the firing order cast into it.

Having the rotor pointing either way will work, as long as you put the spark plug leads into the cap with #1 where the rotor is pointed, then plug in the rest in the firing order.

Marty

[tankwilson]

Thanks thats what i thought. Should i set the diz up to 0 degrees TDC or 10 degrees BTDC??? The instructions say 10-18 BTDC. Also what plug gap works the best??? I have mine set at .60

My car always started really well on the old system. I hope it does with the new.

[martybose]

Thanks thats what i thought. Should i set the diz up to 0 degrees TDC or 10 degrees BTDC??? The instructions say 10-18 BTDC. Also what plug gap works the best??? I have mine set at .60

My car always started really well on the old system. I hope it does with the new.

I'd try 10 degrees; my motor has higher compression and didn't like that much. Once you get it running you can experiment with other settings. I found a nice long hill that is steep enough to need a fair amount of throttle, and I fiddled with the initial advance until I came up with a number that didn't ping on that hill. It turned out to be 5 degrees for my combo.

Assuming you meant 0.060" (60 thousandths), that's what mine are set at right now. If I can find a later sparkplug meant for a larger gap, I'll probably go to 0.080".

Marty

[hkestes41]

I am going to hijack this a little, but we are still talking about the Langdon HEI.

I am trying to install mine. #1 is at TDC and the stock disty has the rotor pointing at 7 o'clock with the vacuum advance can at about 10 o'clock.

When I try to install the Langdon HEI with the vacuum advance can in approximately the same position the can hits the block before the disty shaft engages. The only way that I can get it in far enough to engage the shaft is to turn the disty to where the vacuum advance can is pointing at 6 o'clock and then the shaft engages with the rotor pointing to either 3 or 9 o'clock.

Here is a picture of the Langdon and stock side by side. There is a big difference in the location of the vacuum advance can. Has anyone else with this disty had this issue?

[james curl]

It would appear that Tank Wilson also had that problem as his #1 location is either 10 or 4 O clock position where yours is 9 or 3 O clock.

[greg g]

you can just reindex yor firing order to the distributer. Just put the engine at TDC for #1, put the dist in what ever position give you the necessary clearance for the vacuum pot, then make the firing order start at where the rotor is pointing, reindexing the wires in firing order pattern from that position.

[martybose]

I had the same issue, and did just what Greg suggested. I actually did it twice because I guessed wrong on how much initial advance I needed.

I also had a problem with the junk clamp that Langdon included, so I wound up making my own out of some tubing with a setscrew that had the adjustment section from a stock distributor pinned to it. Much better!

Marty

[tankwilson]

Could you describ how you made the clamp? Got a pic?? Yea the one i got is a pain in the ass and not sure how to get to it to loosen it up for adjustment.

OK set the intial timing at TDC or BTDC?????

[greg g]

I would set it about 6 BTDC initial. just to make up for todays's gas slower burn rate.

[Guest mjmcorbett]

I have posted a few lately concerning my hei from Tom Langdon. As of today, after much fiddleing, it doesn't work properly. Here is the deal. First do as Tom suggests and leave yorr oil pump alone and put #1 plug at about 3:00 on your distributor (instead of the stock position of 7:00. This is because he sets his rotor and shaft differently from stock. It can be delt with later. Keep it simple for now) Rater than fight the vacuum advance location issue, I did as Tom says and put your vacuum can pointing down, point at about 5:00. 60 th. is what I did my plugs at (am useing a drop point plug supplied by Tom). Provide #10 wire to the coil. The truck runs at idle and some rpm in the shop and here is what I found yesterday.

Stock distributor in place. Run engine without vacuum atttached. With timing light note amount of cent. advance. Connect vacuum advance and note total amount of advance with timing light.

Install new hei as described. Start engine. Disconnect vacuum. With timing light set advance (I used 5 degrees before). Sounds good, sharp, crisp. Now give it gas and note the centrifugal advance. The centrifugal does not indicate advance with the timing light but retard instead. Thats right, retards.Nice curve but in the wrong direction. The engine only runs worse as the rpm's increase. The amount of retard increases as rpm increase. Why ??? I really don't know. With Vacuum attached the advance curve is wrong, the retarding is still there. Cent adv. weights only go on one way. I tried different springs. Maybe the module. At this point I don't know what is causeing it. Tom is on vacation for another week so hopefully I can get truck and dist. into a shop and check it out. It's probably something simple.

The stock dist is now back on and it runs fine.

[martybose]

When I was checking the centrifugal advance on my HEI, the very first time it moved it did retard just a little, then continued back into advance. On mine nothing happened until 1300 engine RPM, then it retarded a couple of degrees, then started advancing. I picked up a total of 13 degrees by 2800 RPM. When I looked at the mechanics of the centrifugal advance, it is designed to retard when it starts moving, probably to keep from jerking the car when it started advancing.

What I eventually found was that at high RPM (like highway speed without an overdrive) I had 5 degrees initial, plus 13 degrees centrifugal, plus 19 degrees vaccuum, for a total of 37 degrees at cruise, which is a lot for these old girls! If I stood on it at that speed, I would lose the vaccuum advance but still have 18 degrees advance, which my mechanic said was too much for a built flathead under full power. His comments made sense to me, because the car was pinging badly on my favorite test hill and the water temp went up a lot, even though I am running 91 octane gas. So I tiewrapped the counterweights to disable the centrifugal advance and left everything else as is, so I now have 24 degrees at cruising and 5 degrees under power, and seems to run fine. There is absolutely no pinging on my test hill anymore, and the water temp only goes up maybe 5 degrees after a couple of minutes of hard running (it's a long hill!).

Don't give up yet!

Marty

[Guest mjmcorbett]

Thanks Marty, I'll keep you posted. Wednesday is when I'm going to go after it !

Mike C.

[steveplym]

I would set it about 6 BTDC initial. just to make up for todays's gas slower burn rate.

Greg, Would you suggest this same setting for a points type distributor as well? I've got mine set a tdc and it pulls hard up hills.

[james curl]

Last summer I set mine at 10 degrees initial and took a 4600 mile trip in the car. After arriving home I had a very loud click in the engine. It turned out to be the piston wrist pin bushings in the rod had been hammered out. When I tore the engine down I found two broken top rings also. The 10 degrees initinal combined with the maximun vacuum and centrifical can give close to 50 degrees advance at 3000 RPM which is where I spent hours crusing down the Interstate highways on the way home from Bonneville Utah. I now think the book setting is probably the correct one to use.