Some notes on my most recent "Voyage of Discovery." Long, but if you've done an H.O. swap into an earlier Ford, you may want to read this.
'86 5.0L H.O. with a 1978 302 timing cover -- the serpentine belts wouldn't fit in my engine bay. When I assembled the engine the 5.0 timing mark didn't remotely line up with the window on the timing cover. I didn't bother to make a new timing mark; just put her at TDC and tuned it by ear.
Yeah, I know.
Fast-forward one year.
I put the car in gear one morning, and it died. It had idled great while it was warming up. I fired it up again, it dies again as soon as I put it into reverse. I've been having problems with my carbs -- they're Holleys, natch -- so I took off the scoop and air cleaners (dual quads) and fired it up once more, to see if anything was leaking or stuck. This time it died -- and backfired, blowing flames about 12" above the carbs. Tunnel ram intake = LOTS of gas to catch fire. Looked cool as hell.
Started at the beginning. Took the carbs off, checked everything. Replaced power valves.
Tried again. BOOM! More flames.
Eventually I got to the distributor, took off the ignitor module and plate -- I had swapped out the Duraspark with a Pertronix. . . .
Shrapnel.
The entire mechanical advance unit had come apart. Weights, pins, retaining clips, the whole thing. For reasons I don't understand, the shaft had developed about 1/2" of vertical play, and had pushed the weights off the pins and then beaten the bejeezus out of them.
I don't even want to go into details about how many different distributors I tried; this would be a VERY long post.
It turns out that, no matter what the guy at the Ford parts counter and the kid at Schucks tell you, 302 and 351W distributors are NOT interchangeable, and the diameter of the distributor shaft in the 5.0 H.O. varies -- the 1987 and up 5.0, and 351W, shafts are .51" diameter, and the pre-1987 5.0 and 302 shafts are .49" diameter. The later dizzys will NOT fit the earlier blocks. Period.
Plus, the diameter of the hex driver for the oil pump varies from year to year, as well. Because of the sump location in the 1978 pan -- I had to use the '78 oil pan because of tranny clearance issues in my Mustang II -- I had to use the 1978 oil pump, which uses a 1/4" drive shaft, not the 5/16" shaft on the 1987-up blocks. Mallory et al do not appear to make a small-shaft 5.0 distributor; much less one that fits the 1/4" oil pump driver. At least, not that I'm aware of.
I ended up BUILDING a new distributor. Here's how.
I took a 302 distributor from a 302 E150 van, disassembled it, went over it with 600-grit sandpaper inside the housing (on a 29/64" drill bit) and over the shaft until it shone, then took off the old iron gear and hammered and pinned a steel drive gear on it -- had a bastard of a time finding a steel drive gear for the smaller-shaft distributor, BTW -- Stan at www.fordpowertrain.com has them -- and soaked the whole assembly with Tri-Flow until it spun like sex on ice.
This older distributor came with a 10- and 13-degree advance. I'd been running a 15-degree in my other dizzy and I had a hunch that she'd run better with more advance, so I did some careful math and some scribing with a protractor, and opened the 10-degree side into a 21-degree advance curve with a rat-tail file. Took about three hours. I used the heavier springs on both sides of the mechanical advance upon reassembly to give it more of a logarithmic advance curve over the power band, and secured the weights with 1/8" one-way seat spring washers, the ones with the little teeth that only bend one way.
Dropping it in was a laugh a minute, but that's par for the course with a 5.0, I'm told. Problem is, I hadn't indexed the steel drive gear when I put it on. I had just measured the old gear, drilled a hole in the new gear, heated and hammered it onto the shaft, and then very carefully through-drilled the other side.
Which meant that now my rotor would not, for love or money, line up with #1. At least, not with the registration marks that I'd laid down on the block.
Easy fix, no? Just advance the distributor housing. . .
Except that, with no timing mark on the balancer. . . .
. . . see where this is going?
Welcome to my personal hell.
Eight hours, today. Finding TDC by hot-wiring the starter. REALLY finding it. Down to the nano-millimeter. Painting on a new timing mark. Shuffling the plug wires around so that I could rotate the dizzy to get the advance I wanted. Then the fun part -- running it up and down the street at redline to get the dwell just right. Even built a homemade dwell meter.
Then, moved on to the carbs. Lots of screwdriver time, splitting hairs each direction. Burned up half a tank of gas laying rubber this afternoon.
The good news is, the car runs better than ever, now. The hesitation at launch is gone. The weird little periodic shudder at idle is gone. It idles at 800 without dying -- it used to have to idle at about 1000 in gear. It rolls with much less effort and with 21 degrees of advance curve, it pulls way past what my tach will show (6K.) She's much more civilized at idle and she jumps out of her skin when I goose it. I had always felt that my 5.0 ran rough, and attributed it being "overcarbed" (I still don't believe it is) and on a tunnel-ram; frankly, I didn't care that much, as it made the car sound nasty. Turns out she just wasn't tuned. Really, really, tuned. She purrs, now. I'm very, very happy.
'86 5.0L H.O. with a 1978 302 timing cover -- the serpentine belts wouldn't fit in my engine bay. When I assembled the engine the 5.0 timing mark didn't remotely line up with the window on the timing cover. I didn't bother to make a new timing mark; just put her at TDC and tuned it by ear.
Yeah, I know.
Fast-forward one year.
I put the car in gear one morning, and it died. It had idled great while it was warming up. I fired it up again, it dies again as soon as I put it into reverse. I've been having problems with my carbs -- they're Holleys, natch -- so I took off the scoop and air cleaners (dual quads) and fired it up once more, to see if anything was leaking or stuck. This time it died -- and backfired, blowing flames about 12" above the carbs. Tunnel ram intake = LOTS of gas to catch fire. Looked cool as hell.
Started at the beginning. Took the carbs off, checked everything. Replaced power valves.
Tried again. BOOM! More flames.
Eventually I got to the distributor, took off the ignitor module and plate -- I had swapped out the Duraspark with a Pertronix. . . .
Shrapnel.
The entire mechanical advance unit had come apart. Weights, pins, retaining clips, the whole thing. For reasons I don't understand, the shaft had developed about 1/2" of vertical play, and had pushed the weights off the pins and then beaten the bejeezus out of them.
I don't even want to go into details about how many different distributors I tried; this would be a VERY long post.
It turns out that, no matter what the guy at the Ford parts counter and the kid at Schucks tell you, 302 and 351W distributors are NOT interchangeable, and the diameter of the distributor shaft in the 5.0 H.O. varies -- the 1987 and up 5.0, and 351W, shafts are .51" diameter, and the pre-1987 5.0 and 302 shafts are .49" diameter. The later dizzys will NOT fit the earlier blocks. Period.
Plus, the diameter of the hex driver for the oil pump varies from year to year, as well. Because of the sump location in the 1978 pan -- I had to use the '78 oil pan because of tranny clearance issues in my Mustang II -- I had to use the 1978 oil pump, which uses a 1/4" drive shaft, not the 5/16" shaft on the 1987-up blocks. Mallory et al do not appear to make a small-shaft 5.0 distributor; much less one that fits the 1/4" oil pump driver. At least, not that I'm aware of.
I ended up BUILDING a new distributor. Here's how.
I took a 302 distributor from a 302 E150 van, disassembled it, went over it with 600-grit sandpaper inside the housing (on a 29/64" drill bit) and over the shaft until it shone, then took off the old iron gear and hammered and pinned a steel drive gear on it -- had a bastard of a time finding a steel drive gear for the smaller-shaft distributor, BTW -- Stan at www.fordpowertrain.com has them -- and soaked the whole assembly with Tri-Flow until it spun like sex on ice.
This older distributor came with a 10- and 13-degree advance. I'd been running a 15-degree in my other dizzy and I had a hunch that she'd run better with more advance, so I did some careful math and some scribing with a protractor, and opened the 10-degree side into a 21-degree advance curve with a rat-tail file. Took about three hours. I used the heavier springs on both sides of the mechanical advance upon reassembly to give it more of a logarithmic advance curve over the power band, and secured the weights with 1/8" one-way seat spring washers, the ones with the little teeth that only bend one way.
Dropping it in was a laugh a minute, but that's par for the course with a 5.0, I'm told. Problem is, I hadn't indexed the steel drive gear when I put it on. I had just measured the old gear, drilled a hole in the new gear, heated and hammered it onto the shaft, and then very carefully through-drilled the other side.
Which meant that now my rotor would not, for love or money, line up with #1. At least, not with the registration marks that I'd laid down on the block.
Easy fix, no? Just advance the distributor housing. . .
Except that, with no timing mark on the balancer. . . .
. . . see where this is going?
Welcome to my personal hell.
Eight hours, today. Finding TDC by hot-wiring the starter. REALLY finding it. Down to the nano-millimeter. Painting on a new timing mark. Shuffling the plug wires around so that I could rotate the dizzy to get the advance I wanted. Then the fun part -- running it up and down the street at redline to get the dwell just right. Even built a homemade dwell meter.
Then, moved on to the carbs. Lots of screwdriver time, splitting hairs each direction. Burned up half a tank of gas laying rubber this afternoon.The good news is, the car runs better than ever, now. The hesitation at launch is gone. The weird little periodic shudder at idle is gone. It idles at 800 without dying -- it used to have to idle at about 1000 in gear. It rolls with much less effort and with 21 degrees of advance curve, it pulls way past what my tach will show (6K.) She's much more civilized at idle and she jumps out of her skin when I goose it. I had always felt that my 5.0 ran rough, and attributed it being "overcarbed" (I still don't believe it is) and on a tunnel-ram; frankly, I didn't care that much, as it made the car sound nasty. Turns out she just wasn't tuned. Really, really, tuned. She purrs, now. I'm very, very happy.
