70 RPO 28
Veteran Member
LT1 350
Mallory Hi-Fire 6 box w/ Series 47 Unilite distributor
AC R43TS plugs
Packard TV-R Suppression wires - look like 7mm(1-Q-68 / these were on it when I bought)
186 angle plug heads
Stock exhaust manifold
The engine was recently rebuilt/refreshed before I bought it a few months ago, and has only been on short trips, without the hood on, as I've worked on the many different things.
Recently put the hood on it, and drove 20 mile round trip to get an exhaust installed (longest it's been on the road since it was all put back together).
On the way home, with the new crappily welded exhaust, it started running rough, especially when accelerating >3000 rpm. Felt like was missing and loosing power.
I pulled several plugs and they are clean...which kind of surprised me. (I expected #7 to possibly be fowled due to clearance issue below)
They #7 plug boot, which pretty much sits right on the exhaust manifold(previous owner had ground out some material here for clearance) was no more melted on the bottom as it was before, and I expected it to be way worse.
I checked the resistance on a few wires, and they all are between 12k & 15k ohms.
Starts and idles fine, but runs rougher when up to temp, and really bogs down/looses power on acceleration to hotter it gets.
Two things changed here from the previous test runs where it ran fine, albeit the timing issue noted below:
1. Hood was on and it was a hot day
2. Lots of crappy welding on the exhaust, and I'm pretty sure the dude did not disconnect the (-) battery or the Unilite dizzy plug, which I asked him to do.
Could the small, 50yr old wires; when heated up (near melting probably) cause the loss of power, or
Could the welding have dome something to the Mallory ignition/distributor?
I've read through posts I could find on the subject, but could find no Eureka moment, so thought I'd create a new post.
I am currently waiting on a new DUI distributor/Live wires, because I don't like the advance on the Unilite
-Couldn't get the advance "all in" until >44 BTDC at +4000RPM
-Couldn't hook up the vac advance at all because it's already way to advanced at idle 14 BTDC
But...even with these ignition issues, it ran fine and was MORE than aggressive...just can't get the idle below 1200.
Mallory Hi-Fire 6 box w/ Series 47 Unilite distributor
AC R43TS plugs
Packard TV-R Suppression wires - look like 7mm(1-Q-68 / these were on it when I bought)
186 angle plug heads
Stock exhaust manifold
The engine was recently rebuilt/refreshed before I bought it a few months ago, and has only been on short trips, without the hood on, as I've worked on the many different things.
Recently put the hood on it, and drove 20 mile round trip to get an exhaust installed (longest it's been on the road since it was all put back together).
On the way home, with the new crappily welded exhaust, it started running rough, especially when accelerating >3000 rpm. Felt like was missing and loosing power.
I pulled several plugs and they are clean...which kind of surprised me. (I expected #7 to possibly be fowled due to clearance issue below)
They #7 plug boot, which pretty much sits right on the exhaust manifold(previous owner had ground out some material here for clearance) was no more melted on the bottom as it was before, and I expected it to be way worse.
I checked the resistance on a few wires, and they all are between 12k & 15k ohms.
Starts and idles fine, but runs rougher when up to temp, and really bogs down/looses power on acceleration to hotter it gets.
Two things changed here from the previous test runs where it ran fine, albeit the timing issue noted below:
1. Hood was on and it was a hot day
2. Lots of crappy welding on the exhaust, and I'm pretty sure the dude did not disconnect the (-) battery or the Unilite dizzy plug, which I asked him to do.
Could the small, 50yr old wires; when heated up (near melting probably) cause the loss of power, or
Could the welding have dome something to the Mallory ignition/distributor?
I've read through posts I could find on the subject, but could find no Eureka moment, so thought I'd create a new post.
I am currently waiting on a new DUI distributor/Live wires, because I don't like the advance on the Unilite
-Couldn't get the advance "all in" until >44 BTDC at +4000RPM
-Couldn't hook up the vac advance at all because it's already way to advanced at idle 14 BTDC
But...even with these ignition issues, it ran fine and was MORE than aggressive...just can't get the idle below 1200.
