A Week Long Restoration turning into a Summer Time Adventure! 86 XLT Lariat Explorer

[ArdWrknTrk]

What's my point, you ask?

I know this thing is a one and a half ton vehicle....

Um, a ton is 2,000 lbs.

One and a half tons would be 3,000 lbs.

I saw where you said the truck weighs 6,000 lbs. I'm a bit surprised by that, given its lighter running gear, but I guess it's possible?

John may know better as Blackie is comparable to your '85.

I'm sorry, I guess I don't have any better advice given that you seem to have done everything and it still can't get ten mpg.

Have you considered an LS swap?

 

[ArdWrknTrk]

Both vacuum advance (12 degrees @14"hg) and mechanical 13 degrees at 1750) advance are working properly. and With of initial set at 10, it has 35 degrees of total timing. No issues there.

Cats have been hollowed out.

I would be thrilled if this thing got 10mpg! Just for the hell of it, I am going to rebuild that 4180. I personally HATE those things, but hey, ya never know! I always wondered if the 2 stage power valve from a 4180 would work properly in a 4160.

I don't think Holley has produced a two stage power jet in decades, and If I found one I'd be concerned about the diaphragm compatibility with ethanol.

There isn't any reason why one wouldn't work in a 4160.

If you look at Holley's old calibration tables they were listed, but the Old School Hot Rodder usually has the better data.

I might suggest that you'd be better off with a heavier advance spring.

After messing with my curve I've found that my truck definitely pulls harder if it doesn't get full advance until around 3k.

 

[mat in tn]

Just FYI, I am the 2nd owner and the mileage is 100% actual!

50k is truly a great find! that tells me all steel parts are most likely barely broken in. many miles to go before major service is needed. that said you are looking at soft parts given the age. degradable parts! but it sounds as if you are already working on that. I had a truck in last year which was comparable. the owner was concerned at how the 5.8 ho 4bbl had less power than he expected. " Hell, it won't even chirp the tires" he said. so, after I knew he had run a couple tanks through it and had gotten a few more miles on it I had him bring it back in for a carb check. I had rebuilt the carb and it was a replacement, Holley. I believe that it was an oem design if not an economizer. all tests came out great and the truck ran great. not a lot of off idle throttle response so I looked closely at the accel pump cam and it was at a very light setting. a simple cam swap and accel pump was advancing more aggressively and it really woke it up. there are a few tweaks that can be done with a Holley that can make or break one's opinion of them. we cannot love the fords and call them stupid for choosing the 4180. the fact is that when they are right, they are great. and neglect is all too often the cause of them being wrong.

[Jake Papageorge]

I have the same engine, trans, and gearing, though I think it's 3:55, not 3:50. My truck is also 4x4. I bought it new and at first it got "okay" fuel mileage....14-15 mpg. As time past, that fuel mileage went to 8 mpg. Fed up with the crappy fuel mileage and poor performance, I pulled all the emission garbage off of it and added an Edelbrock 600CFM carb and intake. Also put a set of headers on it with true dual exhaust. Not only was the fuel mileage markedly improved, so was the performance.

It definitely has a 3.50 gear. I literally just had to replace it, the carrier and all the bearings and axles on this thing last week. LOL!!! One of the very few ring and pinions that actually have to be indexed.

So tell me more! I am intrigued by your carburetor choice Machspeed. Did you retain the kickdown linkage or have to switch to a cable when using that Edelbrock carburetor. I have a few of these laying around, but was reluctant to use one because the 4160 had the OEM style kickdown lever.

[Gary Lewis]

It definitely has a 3.50 gear. I literally just had to replace it, the carrier and all the bearings and axles on this thing last week. LOL!!! One of the very few ring and pinions that actually have to be indexed.

So tell me more! I am intrigued by your carburetor choice Machspeed. Did you retain the kickdown linkage or have to switch to a cable when using that Edelbrock carburetor. I have a few of these laying around, but was reluctant to use one because the 4160 had the OEM style kickdown lever.

The 9" came in 3.50 gearing and the 8.8" in 3.55.

[ArdWrknTrk]

50k is truly a great find! that tells me all steel parts are most likely barely broken in. many miles to go before major service is needed. that said you are looking at soft parts given the age. degradable parts! but it sounds as if you are already working on that. I had a truck in last year which was comparable. the owner was concerned at how the 5.8 ho 4bbl had less power than he expected. " Hell, it won't even chirp the tires" he said. so, after I knew he had run a couple tanks through it and had gotten a few more miles on it I had him bring it back in for a carb check. I had rebuilt the carb and it was a replacement, Holley. I believe that it was an oem design if not an economizer. all tests came out great and the truck ran great. not a lot of off idle throttle response so I looked closely at the accel pump cam and it was at a very light setting. a simple cam swap and accel pump was advancing more aggressively and it really woke it up. there are a few tweaks that can be done with a Holley that can make or break one's opinion of them. we cannot love the fords and call them stupid for choosing the 4180. the fact is that when they are right, they are great. and neglect is all too often the cause of them being wrong.

Mat, didn't the 351 HO also come with a nylon cam gear and hy-vo chain?

While you say they can last 150,000 miles polyamide is subject to degradation in hydrocarbons like oil and gets brittle when it absorbs moisture from air.

Jake's chain could very well have skipped time, and that would make it sluggish and extremely thirsty.

I would definitely be checking for slop and confirming tdc #1 early in the troubleshooting process.

And I agree, the 4180 was a highly developed carb that returned good fuel mileage.

Breakaway choke screws and plugged idle adjusters are easy to get around.

The annular boosters and vacuum secondaries we're well matched to the Ford products they were tuned for.

Unfortunately the detailed Hot Rod article dealing with them, reprinted on flemworld.com, returns a 404

[Jake Papageorge]

50k is truly a great find! that tells me all steel parts are most likely barely broken in. many miles to go before major service is needed. that said you are looking at soft parts given the age. degradable parts! but it sounds as if you are already working on that. I had a truck in last year which was comparable. the owner was concerned at how the 5.8 ho 4bbl had less power than he expected. " Hell, it won't even chirp the tires" he said. so, after I knew he had run a couple tanks through it and had gotten a few more miles on it I had him bring it back in for a carb check. I had rebuilt the carb and it was a replacement, Holley. I believe that it was an oem design if not an economizer. all tests came out great and the truck ran great. not a lot of off idle throttle response so I looked closely at the accel pump cam and it was at a very light setting. a simple cam swap and accel pump was advancing more aggressively and it really woke it up. there are a few tweaks that can be done with a Holley that can make or break one's opinion of them. we cannot love the fords and call them stupid for choosing the 4180. the fact is that when they are right, they are great. and neglect is all too often the cause of them being wrong.

I am not a big fan of that 4180 at all! One would think that it would be a great carb with the annular discharge boosters in the primaries and all the extra air bleeds and 4 corner idle mixture that this thing would be awesome! When they work, and are set up right, they run fine! It is just that getting them there is a real hassle!

It has been my experience over the years that the 4180 is favored by a lot of folks with stock or mildly modified engines because the primary boosters turn on so much more quickly and atomize fuel so much better(more evenly). The annular booster coupled with the 2 stage power valve makes the main metering system a lot more responsive at low engine speeds. The 4150 replacement has straight leg boosters which are about the worst for atomization and sensitivity.

Just on a lark, I went up to my local O'Reilly and picked up a Standard Motor Parts rebuild kit. My price was only 30 bucks, so I figured what the hell! I might as well rebuild the OE carb and see if I can affect a mileage change. Damn if it didn't have a 2 stage PV in there! I called my good friend up at Kirks Carburetor in Detroit ( I used to work there back in the eighties when I was in HS), and sure enough, Holley still makes that power valve! I can get you a P/N if you want). He was telling me that when people bring those carbs in, they usually replace the PV with a single stage 6.5 (assuming it is a stock rebuild) and they don't get any complaints.

Yea, I hear ya on the "stupid 4180" comment. These things have so much extra baggage and wirdo one of a kind parts that I have always been annoyed having to work with them when an easy and cheap alternative is so radially available. With the price of fuel now, however, I have been forced to re-evaluate my opinion on this carburetor, much to my chagrin! LOL!!!! I used to have to repair these things when I worked at the dealership back in the day. I just hated always having to wrestle around the base of the carb with a flexible Allen after knocking the caps off of the idle mixture screws!

[Jake Papageorge]

Mat, didn't the 351 HO also come with a nylon cam gear and hy-vo chain?

While you say they can last 150,000 miles polyamide is subject to degradation in hydrocarbons like oil and gets brittle when it absorbs moisture from air.

Jake's chain could very well have skipped time, and that would make it sluggish and extremely thirsty.

I would definitely be checking for slop and confirming tdc #1 early in the troubleshooting process.

And I agree, the 4180 was a highly developed carb that returned good fuel mileage.

Breakaway choke screws and plugged idle adjusters are easy to get around.

The annular boosters and vacuum secondaries we're well matched to the Ford products they were tuned for.

Unfortunately the detailed Hot Rod article dealing with them, reprinted on flemworld.com, returns a 404

Jumping time would have been apparent when checking the ignition timing. None the less, after turning the crankshaft against rotation to take the slack out of the chain, it only took 6 degrees of engine rotation to make the rotor move. I don't think this thing has a timing chain problem.

[mat in tn]

Mat, didn't the 351 HO also come with a nylon cam gear and hy-vo chain?

While you say they can last 150,000 miles polyamide is subject to degradation in hydrocarbons like oil and gets brittle when it absorbs moisture from air.

Jake's chain could very well have skipped time, and that would make it sluggish and extremely thirsty.

I would definitely be checking for slop and confirming tdc #1 early in the troubleshooting process.

And I agree, the 4180 was a highly developed carb that returned good fuel mileage.

Breakaway choke screws and plugged idle adjusters are easy to get around.

The annular boosters and vacuum secondaries we're well matched to the Ford products they were tuned for.

Unfortunately the detailed Hot Rod article dealing with them, reprinted on flemworld.com, returns a 404

the last few 5.8 ho engines that I have redone or replaced the timing sets in had steel gears. that does not certify what they should have left the factory with, only what I dealt with. that said only one of them seemed to have had the front cover off before. but none had what I would have called a replacement set. I normally put back a melling or cloyes at least and usually a double roller. even still it is a little disappointing to see how much play they acquire in a short time. but in order for it to have enough slack to jump time in 50k it seems to me that it would mean a total cam gear failure and 6 degrees of take up does not indicate that but composite over aluminum gears is not anything I would want. that is what was in my 86 4.9 and it now has steel. that engine I rebuilt 20 years ago.

[85lebaront2]

What's my point, you ask?

I know this thing is a one and a half ton vehicle....

Um, a ton is 2,000 lbs.

One and a half tons would be 3,000 lbs.

I saw where you said the truck weighs 6,000 lbs. I'm a bit surprised by that, given its lighter running gear, but I guess it's possible?

John may know better as Blackie is comparable to your '85.

I'm sorry, I guess I don't have any better advice given that you seem to have done everything and it still can't get ten mpg.

Have you considered an LS swap?

Jim, I would like to know where he got 6000 lbs. Darth weighed on a certified scale (not a truck stop one) with both tanks essentially empty, a maybe 100 lb aluminum cap and no one in him, 6400 lbs and that is after installing the E4OD and EFI top end. I am darn sure the 35" more cab, including a bench seat, two more doors with internals and two more 245/85R16 tires even on the Alcoas should easily add over 400 lbs.