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My first 300. Could use some insight.

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KorunRaa
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My first 300. Could use some insight.

Post #1 by KorunRaa » Sun Aug 12, 2018 8:07 am

Hello everyone,

I found this forum last year when my 81 F-150 Ranger started having problems, but I had to put it on the back burner due to a severe lack of time. I'm resisting pressure to get rid of it as I really like the truck.

So a bit about my ol' gal; As I said she's an 81 F-150 Ranger Lariat. 300 I6 with the 3spd w/ OD manual transmission. I picked her up last year for $1500 to use as a work truck since she had a rack and toolbox on her. Figured decent gas mileage also, being a 6. Hahaha! Found out the opposite real quick. The guy I bought it from kept referring to her having "tall" gears. Tall was an unfamiliar term to me, but I discovered that he meant they had extremely broad range. I never get beyond 2nd when in town (35-45mph). 3rd is strictly interstate driving, 55-65+. OD? Ha!! I've tried to get into OD around 60-70 (my local interstate speed limits) and she feels as though I've shifted early. I've many other manuals and it's comparable to going from 1st to 3rd in say a Honda or Toyota 5spd. I've had to push to around 80 or better to get a proper feeling shift. And unless I get up to and maintain a spd of at least 90mph, the motor feels as though it's being bogged down, leading to downshifting back to 3rd. Curious if anyone has some insight as to why this is.

Within a couple days of driving her the 80+ miles a day as a work truck, she just wasn't right. I began the basics of a tune up and quickly discovered a burnt out center electrode in my #5 spark plug. I suspect the seller tuned around the non firing cylinder as new plugs, wires, air filter (aftermarket cleaner, original was missing the lid) all made the truck run much worse. I made some best guesses in regards to adjusting the Carter 1bbl, and adjusted the timing by ear with slight adjustments of the distributor. Not the ideal way, I know, but I was working with what I had to be able to go to work.

She soon developed quite the appetite for motor oil. I changed the valve cover gasket since that was where the oil appeared to be coming from. While that did slow the oil consumption,I was mistaken about it being the sole source. The oil was being blown back out through the breather cap. She also spews a ton of smoke out the breather cap as well. So much so I was actually pulled over for it. A note about the smoking, periodically, when under load, the smoke would stop for a few moments.

The seller also admittedly removed all the "smog crap". I did replace the PCV but it made lil to no difference. She still fires up and gets up and moves. I don't want to get rid of her and would love to pass her along to my son as well as be what I teach him about mechanics on when he finally gets to that stage. I do want it mostly operating properly before then and have some time as he's not quite crawling yet. :D

I know I need a larger carb for better mileage and I'm thinking I at least have to have the head redone to eliminate the smoking. I'm guessing the smoking and oil out the breather is bad valve guide seals, at least that was what I got from much of what I read. The valve cover has 2 baffles and just a small piece of defecting metal over the breather hole location.

A father/son performance project later on, but any insights, suggestions, tidbits of info about her, I would greatly appreciate. I've given what info I know, except she is a 2wd.
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bubba22349
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Re: My first 300. Could use some insight.

Post #2 by bubba22349 » Mon Aug 13, 2018 11:06 am

Welcome to the site KorunRaa, yes the 300 six can get some decent economy (MPG) when everthing is in good condition. With the discription of the symptoms I suspect that the number 5 cylinder has no or very low compression. You need to do a compression check of all the cylinders to be able to analyze lthe engines condition. Good luck :thumbup: :nod:
A bad day Drag Racing is still better than a good day at work!

I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

KorunRaa
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Re: My first 300. Could use some insight.

Post #3 by KorunRaa » Mon Aug 13, 2018 11:18 am

I suppose I should have added but I replaced all the plugs and retuned the carburetor and timing and it runs quite well other than the excessive smoke.

I plan to call the machine shop today and get a quote I'm having the head redone because it seems that the valve guide seals are the most likely culprit based on what I've read here and other forums. Either way I've pretty much decided on a complete rebuild. What still baffles me is the gearing for the transmission and rear end. I've never experienced a vehicle was such a wide range in each gear.

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bubba22349
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Re: My first 300. Could use some insight.

Post #4 by bubba22349 » Mon Aug 13, 2018 2:46 pm

You can check what gear ratio your truck was built with by decoding the door tag info (Warntee or ID tag). Once you have that you can compare what the rear axle ratio that's installed. Sure sounds like it's not geared properly, changing the rear gears to what is normally used with that trans will help a lot.

Yes the valve guide seals maybe bad and it's pertty common with a truck of that age. Or there can also be excess valve guide clearance, and or worn rings. In any case a compression test would still help in determining the engines condition and point to the areas to check. Good luck on the rebuild when the engines is back in top condition again you will have a great truck to use for work or play. :thumbup: :nod:
A bad day Drag Racing is still better than a good day at work!

I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

Mdixon300f100
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Re: My first 300. Could use some insight.

Post #5 by Mdixon300f100 » Mon Aug 13, 2018 2:51 pm

I have the same gearing issues with mine. The 2.75 rear gears are terrible with any tire size over stock, which for mine was 26.5x6r15. They are no longer available at an affordable price. With the 31x10.5 rears I can't use OD much below 75, and my head has a fresh gasket and valve job. Smaller tires will help, and they're cheaper than a rear gears swap.

KorunRaa
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Re: My first 300. Could use some insight.

Post #6 by KorunRaa » Mon Aug 13, 2018 3:28 pm

That would explain it then. I have 31's on mine as well. Oddly enough my 96 Ranger's tires are an equivalent of the stock size, LT 235 65R15's. It doesn't bother me about the gears, it was just really odd to me. Would it hurt to leave the 31's on? They look so much better than the smaller ones, but if it's going to cause problems down the road I'll just put them on my 96 and vice versa.

Mdixon300f100
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Re: My first 300. Could use some insight.

Post #7 by Mdixon300f100 » Mon Aug 13, 2018 7:30 pm

No problems, per se, other than drivability. If you have the t170 trans with high (numerically low) rear gears, then yes, big tires suck. I'm planning on smaller tires when the bfg's r shot. I cruise around 1800rpm at 80mph (speedo indicated accuracy unknown) highway in od, and downshift for hills. But I shift out of first at 40mph and 3800rpm. I do like that :lol:

Mdixon300f100
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Re: My first 300. Could use some insight.

Post #8 by Mdixon300f100 » Mon Aug 13, 2018 7:36 pm

Whats the ranger trim btw? I had a 99 3.0 5sp 4x4 with 3in body lift and 33x10.5 ats. I'd do terrible things to get another, but I can't justify the cost. I bought mine for $450 and put under 1000 into it and it is honestly the best ride I ever owned. Got totaled in my driveway by a distracted 17yo late for hs exams. :bang:

KorunRaa
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Re: My first 300. Could use some insight.

Post #9 by KorunRaa » Wed Aug 15, 2018 10:19 pm

My '96? It's an XLT I think. 3.0L 4x4 without any exterior 4x4 markings. The only way to tell from the outside is the hub locks. I'm in the process of dropping the transmission to have it rebuilt.

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broncr
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Re: My first 300. Could use some insight.

Post #10 by broncr » Tue Aug 21, 2018 7:48 pm

Do yourself a favor and do a complete rebuild all at once.

There's some sage advise along those lines. Never rebuild just the head(s) on a worn engine. If you just do the head, it will increase the strain on the bottom end, and hasten the need to redo the block. Maybe, if the block was relatively fresh, you might get away with it. The exception might be if you can change out just the valve seals. Otherwise you'll be putting more work ( dupicating the head R&R), more gaskets, more time, more cost.

There will always be someone who "got away with it" ( but likely many more who didn't.. and "don't want to talk about it".)
I'll admit, I tried the "head first", contrary to that advice, once. I was young, dumb, and couldn't "afford" a full rebuild. A few months later I had NO choice - the rings cratered under the strain of a fresh head and it was "smoke on".

'Another saying- "Some folks refuse to learn from the mistakes of others - they have to experience it first hand".
'82 FSP Bronco. Just about every mod ever mentioned. ( Too much to list - or remember...)

BigBlue94
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Re: My first 300. Could use some insight.

Post #11 by BigBlue94 » Fri Sep 14, 2018 6:50 pm

In the 70s and early 80s, ranger was a trim level just above custom or base. There was also ranger XLT, explorer, prospector (or was that dodge?), and lariat.

You most likely have 2.73 or 3.08 gears in the axle(s). Good for economy when everything was new, but severely underpowered. You should find a 9" rear third member from a bronco or f150 with 3.50 or 4.10. That along with a new carb or even a new intake and 2bbl carb would wake it up.

As for the smoke, I think that's been covered better than I could have.
1985 Bronco. 309ci I6, NP435, 4.56 gears, Detroit locker and tru-trac, 4" lift, and 37" swamper tires. The 309 is 9.75:1 CR with a Schneider 140H cam, 4bbl, roller rockers, larger valves, and headers.

Lazy JW
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Re: My first 300. Could use some insight.

Post #12 by Lazy JW » Mon Sep 17, 2018 12:04 pm

KorunRaa wrote:
The seller also admittedly removed all the "smog crap". I did replace the PCV but it made lil to no difference.


Whenever some proclaims that they have "removed all the smog crap" and the engine runs worse than before, I have to question if they really knew what they were doing; therefore I wonder if the PCV system is functioning correctly.

KorunRaa wrote:I know I need a larger carb for better mileage ...

I doubt that a larger carb will help.

Your pickup may have the 2.47 gears in the rear end. These are stupidly "tall" gears with the overdrive transmission.

My 81 F-150 has 2.75 gears with a T-18 granny-tranny and it is borderline too tall; even so, it will run smoothly down to 25 mph in 4th gear (direct drive) and will accelerate smoothly (but not rapidly) up from there to highway speeds. This is equivalent to 3rd gear in your transmission.

Broken pistons/rings can also cause the symptoms you describe.
"The White OX" 1974 F-350 300-6, Stock single exhaust, Carter YF, T-18A, Dana70 w/4.11, Flatbed dually w/dump bed. "Where no oxen are, the crib is clean, but much increase is by the strength of the ox" (Proverbs 14:4)
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