Hot Rod Forum banner

21 - 30 of 30 Posts

·
Hates: Liver. Loves: Diesel
Joined
·
5,743 Posts
Sorry for the delay guys. Finally got another timing light. Hoping this weekend or next I'll get to finally time it.

Last day I toyed with it, I turned the APT screw all the way out (richer), and it revved MUCH easier, and made the popping better. May be a carb tuning issue. A few day or so prior to that I smoked an ignition coil messing with distributor wires while it was running. Spent most of that allotted time pulling coil, testing, checking wiring and cap.



Hoping to get some more time/weather to dig deeper into all recommendations. I'll bet you I'm dying more :) It's been too long since I've drove the car!!



Correct- ran fine before intake AND carb swap. Carb is brand new Jet performance. Will check valve train after timing is set.

I should be able to visually "go/no go" the pushrods and bolt interference, correct?



Going off of memory, the only ones I likely kept in the same holes were the front due to alt bracket, etc. I do recall swapping a couple bolts with 'new' since there was either an issue with getting access with the allen wrench or box end. Been long enough ago I don't recall.



Correct on idles and WOT. It seems fine cold until the choke opens. Richening the APT helped out some. Leads me to believe it's a lean condition at this point. I shouldn't have to tear down a brand new carb, but stranger things have happened. I'll check into that and the other mechanical possibilities above once I get it timed.

Here's a couple videos from just before messing with APT. Didn't think to get any after. We're looking at a new truck tonight since mine was totalled Christmas day. If I have time after we get back I'll see about getting a comparison vid.

Cold

Warmed up
Look for fuel dripping from the boosters. A float set too high can drop liquid fuel making it run pig rich on a few cylinders and making the pop. The first video (cold) sounds like a vacuum leak or low compression on a cylinder. Spray some brake cleaner or starting fluid at the seam between the intake and head... particularly at the #8 and #6 cylinders. If the idle changes, you have a vacuum leak.

Triple check the timing, and double check that the piston is actually at TDC when the indicator says it is. The ring on the balancer may have slipped. As a quick way to check, advance the timing "some" and see if the problem changes.
 

·
True Hotrodder
Joined
·
1,420 Posts
Doesn't matter whether it's points or HEI or something else - if he had it on number 6 to fire by mistake and installed it to number 1, on a mild cam, it will try to start and run - terribly. And that is 180 out. I have seen a lot of people do it to themselves after doing a cam change. They'll line up the marks on the timing gearset, button everything up and drop the distributor in on number 1 and can't figure out why it has problems.
 

·
Hates: Liver. Loves: Diesel
Joined
·
5,743 Posts
You're confusing the term "180 out." being off by 180 degrees in a points system means that the points are breaking at the wrong time causing problems. With an HEI, there is no such thing as 180-out. It is possible to install the wires on the wrong posts, but that isn't called 180-out. That's called "wires on the wrong posts."

If he installed the wires starting at 6 instead of 1, it wouldn't be running nearly as well as it does in the videos.

With an HEI, you can install it on any tooth you want and point the distributor any way that is convenient. As long as you put the #1 wire on the post by the rotor when it's at TDC on the compression stroke, you will be fine. But the term "180 out" doesn't apply here because it's not a points system.
 

·
I know Victoria's secret....
Joined
·
117 Posts
Discussion Starter #24
Look for fuel dripping from the boosters. A float set too high can drop liquid fuel making it run pig rich on a few cylinders and making the pop. The first video (cold) sounds like a vacuum leak or low compression on a cylinder. Spray some brake cleaner or starting fluid at the seam between the intake and head... particularly at the #8 and #6 cylinders. If the idle changes, you have a vacuum leak.

Triple check the timing, and double check that the piston is actually at TDC when the indicator says it is. The ring on the balancer may have slipped. As a quick way to check, advance the timing "some" and see if the problem changes.
Why between 6/8? Is that a common spot to leak for sbc's?
 

·
Hates: Liver. Loves: Diesel
Joined
·
5,743 Posts
No, it's just that my ear has heard a lot of misfires and if you slow the video down it sounds like somewhere around cyl 6. Let's see how good I am :)
 

·
True Hotrodder
Joined
·
1,420 Posts
You're confusing the term "180 out." being off by 180 degrees in a points system means that the points are breaking at the wrong time causing problems. With an HEI, there is no such thing as 180-out. It is possible to install the wires on the wrong posts, but that isn't called 180-out. That's called "wires on the wrong posts."

If he installed the wires starting at 6 instead of 1, it wouldn't be running nearly as well as it does in the videos.

With an HEI, you can install it on any tooth you want and point the distributor any way that is convenient. As long as you put the #1 wire on the post by the rotor when it's at TDC on the compression stroke, you will be fine. But the term "180 out" doesn't apply here because it's not a points system.
180 out simply means it's pointing at #6 instead of the #1 cylinder and again, it has nothing to do with how the coil is triggered - that's nothing but BS!
 

·
Registered
Joined
·
28 Posts
You're confusing the term "180 out." being off by 180 degrees in a points system means that the points are breaking at the wrong time causing problems. With an HEI, there is no such thing as 180-out. It is possible to install the wires on the wrong posts, but that isn't called 180-out. That's called "wires on the wrong posts."

If he installed the wires starting at 6 instead of 1, it wouldn't be running nearly as well as it does in the videos.

With an HEI, you can install it on any tooth you want and point the distributor any way that is convenient. As long as you put the #1 wire on the post by the rotor when it's at TDC on the compression stroke, you will be fine. But the term "180 out" doesn't apply here because it's not a points system.
A common problem is intake gasket leaks, hence it is important to use a vacuum gauge to get a reference before starting such projects but even now it’s a good idea. These are a valuable diagnostic tool. While perhaps not giving a specific answer in terms of off timing versus a vacuum leak it is a tool that identifies problems and narrows the bandwidth of possible places to look rather than just heaving parts at it and hoping something sticks as that gets expensive and doesn’t usually solve the problem.

A good vacuum gauge is part of my instrument panel as well as a couple test models in my roll around, that’s how important a tool I consider these. Price is not an indicator of quality, I have a Stuart Warner that against a manometer reads high by 5 inches where I, also, have two cheap Harbor Freight units that are balls on.

Bogie
A common problem is intake gasket leaks, hence it is important to use a vacuum gauge to get a reference before starting such projects but even now it’s a good idea. These are a valuable diagnostic tool. While perhaps not giving a specific answer in terms of off timing versus a vacuum leak it is a tool that identifies problems and narrows the bandwidth of possible places to look rather than just heaving parts at it and hoping something sticks as that gets expensive and doesn’t usually solve the problem.

A good vacuum gauge is part of my instrument panel as well as a couple test models in my roll around, that’s how important a tool I consider these. Price is not an indicator of quality, I have a Stuart Warner that against a manometer reads high by 5 inches where I, also, have two cheap Harbor Freight units that are balls on.

Bogie
 

Attachments

·
I know Victoria's secret....
Joined
·
117 Posts
Discussion Starter #29
Appreciate the gauge guide! That's more thorough than the "destructions" they came with mine 20+ years ago. I saved to my phone to reference when I connect.

Had decent weather and about 30 minutes tonight to get it warmed up and and set timing. Set at 14*.

I found part of the problem, too. When I first started timing it it had a huge amount of advance at idle and couldn't get it to idle below 20*. I realized I had forgotten to unplug the vacuum advance can. As soon as I unplugged the can it idled below 20*. I set at 14*, adjusted idle back up to 700rpm, and revved it a few times. Revved easier and no popping until lift off. If I held it at say 3k, it would pop like in the videos. I believe I have a medium and heavy spring in the hei.
 

·
Registered
Joined
·
28 Posts
Appreciate the gauge guide! That's more thorough than the "destructions" they came with mine 20+ years ago. I saved to my phone to reference when I connect.

Had decent weather and about 30 minutes tonight to get it warmed up and and set timing. Set at 14*.

I found part of the problem, too. When I first started timing it it had a huge amount of advance at idle and couldn't get it to idle below 20*. I realized I had forgotten to unplug the vacuum advance can. As soon as I unplugged the can it idled below 20*. I set at 14*, adjusted idle back up to 700rpm, and revved it a few times. Revved easier and no popping until lift off. If I held it at say 3k, it would pop like in the videos. I believe I have a medium and heavy spring in the hei.
You did plug off the vacuum hose as it then disrupts the air-fuel to the cylinders that the carb puts out.
there's an interesting read on the vacuum advance being on manifold vs ported vacuum you won't believe how many get that wrong ! its almost as elusive as victoria's secret! By the way, What is victoria's secret ???????
 
21 - 30 of 30 Posts
Top