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EATING THE ELEPHANT

Amata Bene

Well-Known Member
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Jun 3, 2024
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So I'm gonna put this stuff here, cuz restoring this car is our end goal. Not completely sure how deep it will get. I know just wading in to get it running better got deep fast.
A little history on me and the car. Me: A mechanic - not by a long shot. I'm a welder fabricator by trade for dare I say close to 40 yrs. Do I have good mechanical abilities? Yes. I Have built cars and bikes before, and yes they ran and performed as intended. Doing a restoration is something I have never attempted. So I'm gonna go slow and take one bite at a time.
The car: A 1974 Road Runner. Vin and Fender tag RM21G4G. As some of you have read in other posts, the car was a birthday gift from my wife. (She is a wonderful woman and I am blessed to have her in my life.) She was of the impression the car was original. Not knowing how to do auto archeology she still did very well. So far the only things that do not match the fender tag are the color and the motor, everything else is a match to this point. The interior is complete and still sports the brown carpet. Accessories although limited also match the fender tag. The car was originally a 318 with the 904 light duty transmission painted KT5 (Sienna Metallic). As it is now it has an early "72" 340 (forged crank) and is painted to resemble Y1 (Lemon Twist). Which I absolutely love and intend on keeping.
It's your birthday 2.jpg

The bad: While I'm quite pleased that it is a steel crank 340, it is my belief that Road Runners should have big block motors. But that's just me. The car from day one had a bit of an engine miss. At an idle it sounded like a possible cammed motor and would smoothed out on light acceleration. Under a load, it sounded like my tractor. This took me a minute to figure out. Spark to all 8 and the timing was not crazy out-a-whack. Hmm? Time to gather evidence. Engine bay painted black :(, lots of blue over-spray :(, a radiator big enough to cool a Kenworth, and look at that, the cap actually hits the HOOD! :cursin: WTF? Some acetone and a wire brush... not a G-code 318, but instead an MH 340R 38480155 stamping.
Engine clean up 10.jpg
Not bad but now paint and motor don't match. Still got an engine miss. Time for the K-Y and a scope. Well, well, well, seams to be a 30 stamped on all 8 pistons and #4 is oily as an Alaskan harbor. Not showing on the plugs though... Their new. Time to pull some bolts. Found bits of hard plastic in the rocker areas. Pulled the intake (casting say it's a 1970 4 barrel) all sorts of plastic pieces in the valley. Was told by members that it looks like valve seals. That explains #4. Now I'm pretty sure Bubba slapped an old 340 together with some laying around parts to remedy the old 318. I say this because the rest of the car does not resemble what took place in the engine bay.
Engine clean up 1.jpg

Latter part of August was my last post, I had already pulled the motor and dropped the oil pan where I found the rest of the valve seals SMH. The lifters were wiped out, so either a bad break-in or a s##t load of miles. Did I mention the broken valve spring on #4 intake. What a mess. We were heading to vacation in CO over the labor-day week-end. Gonna hang out with family, just have a good time. Came home with COVID:eek:. That sucked. 1st time for me and my wife. Good thing I got all the work out of the shop before we left. Did give me time to start ordering parts to put the 340 back together. Funny thing, when you tell customers you have covid, they don't stay long. Finally got to the point about a week latter where I could walk across the shop with out resting, so I pulled the tranny. It would slip on hard acceleration. Freshen that up too. Have most of the motor parts need a few little things then go back together with that. Do a trans overhaul then back on the road.
Make it run 2.jpg

While making all the discoveries we (wife and I) discussed the direction of the car as far as cost to restore or build. She said it was up to me. With that I started hunting. My 1st Road Runner was an early "68" hard post with the infamous 383. I want something similar in this. Say hello to my little friend
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Some disassembly and off to the machine shop. Now... To stroke or not to stroke. 500 HP or 700 HP that is the question. Defiantly blue printing this b###h so it doesn't meet the same fate as my las 383.
Stay tuned.
 
Great car, and I wish you well.

So a suggestion: I had a 73 Road Runner with a 340 - a lot like yours (see pictures below) . I stroked it with a "budget build" to make a 416, and it was one of the most fun and amazing engines I have driven. Tons of torque and power, while still being lighter and allowed the car to handle better. We drove it across country, both ways, and it was sooo nice to drive.

Remember that switching to a big block will require LOTS or brackets and other stuff to make everything fit. Yes, it is possible, of course, but that will drive up costs. Build your 340 into a stroker and it will run like a scalded ape! Plus, you won't need to hunt down lots of brackets and other stuff to make the swap.

Of course, do what you like - I just wanted to offer you another possibility to consider.

Good luck with your project either way!

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My buddy has a '71 Charger with a 340 and I'd agree with what HawkRod suggested. He kept right up with me and my mildly-built 383 Magnum in my '70 Charger, until 3rd gear, when the big block cubes kick in. A done-up 340 is no slouch and will kick all kinds of ***. It was called the "baby Hemi" and the nickname was well-deserved.
 
Beautiful Car. I agree, road runners should be Big Block 4 speed cars. That being said...my first Mopar was a '73 340 4 speed. Had a blast with it.

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Good write up and a nice car, even nicer wife! I would ask that you don't start a new thread each time you update progress. Just come back to this thread and post a reply. Good luck. Is that a 383, 400 or 440?
 
I will follow along as well. My big take away is....does your wife have a sister? What a gift regardless of what you have to unsort. She's a keeper for sure.
 
Nice project. Nice of your wife to do for you. I would certainly bore and stroke the 340 since you already have it. I have had a couple of mildly built 340's that would run right with some 440's. 340's are no slouch.
 
Good write up and a nice car, even nicer wife! I would ask that you don't start a new thread each time you update progress. Just come back to this thread and post a reply. Good luck. Is that a 383, 400 or 440?
The motor in the photo is a 400 with the legendary 727TF. The donor car was (is?) a 1973 Fury. The vehicle belonged to a fella in GA. He said it was his father's car and he got it 20 yrs or so ago. Moved it around a few times but it hasn't been started in years. Crank turns and he thinks with some fuel and effort it would fire up again. Still had all the fluids in it. A lot of them came out in the back of my truck on the journey home. Nice SMH.
DONOR CAR 73 FURY.JPG
 
Great car, and I wish you well.

So a suggestion: I had a 73 Road Runner with a 340 - a lot like yours (see pictures below) . I stroked it with a "budget build" to make a 416, and it was one of the most fun and amazing engines I have driven. Tons of torque and power, while still being lighter and allowed the car to handle better. We drove it across country, both ways, and it was sooo nice to drive.

Remember that switching to a big block will require LOTS or brackets and other stuff to make everything fit. Yes, it is possible, of course, but that will drive up costs. Build your 340 into a stroker and it will run like a scalded ape! Plus, you won't need to hunt down lots of brackets and other stuff to make the swap.

Of course, do what you like - I just wanted to offer you another possibility to consider.

Good luck with your project either way!

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View attachment 1744869

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HawkRod, I completely agree with you and the rest of these folks about the 340 AKA "The Giant Killer". It will be going back in the car for a while. Need to have A LOT of machine work done. That will take time and money. Both are scarce these days, more so money. I have a few pokers in the fire. The big one is I'm clearing a large area of land at the homestead for a new shop, complete with one portion dedicated to my motorhead hobbies, lift included. We are shooting for 18 -24 months for that to be complete. We'll see. I have future plans for the 340 also :p. It's not going anywhere.
 
I love the 383 and especially the 68-9 B bodies until they got priced out of what and most all rusted to dirt. But like said, that 340 stroked is an amazing engine.
 
Nice write up. I'm in the big block camp, but thought I'd mention the different passenger fender apron for the BB.
 
I hope you got all of the pullies/brackets/spacers etc when you harvested that 400. Nothing sucks like trying to match accessories up when you have nothing.
 
Been a minute. So here's where I'm at with the elephant. First, yes @ckessel if it was bolted to the motor I got it. Alt brackets, a/c, p.s. let's see, what else. I took everything but the radiator and condenser, hell I even got the driveline. Now I won't have to count splines, 3 times and get a different number each time. SHARPIE!:lol:
So if there is one thing that is certain, it is when I start a personal project at the shop customers will come in by the handfuls. I'm no genius by a long shot but I know making money is better than spending money, for my home life any way. Kinda like to keep the missis happy. So I got all the customer jobs out by Thursday afternoon and a couple more on hold till I get back. I may have lied a little bit and said I was leaving today :D. Heading to the beach for the week. I'll either be drunk with celebration or drowning my sorrows. GO VOTE!
So I got the 400 on the engine stand took a few things off and got it ready for some degreaser and a pressure washer
400 Clean up 1.jpg
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Then I started the disassembly. This girl has been ridden hard and put away wet, no pun intended. Top of the motor is heavy with carbon build up. Had to pull all the lifters out of their holes with effort. Inside of the heads don't look to bad nor did the top of the pistons. There is definitely a ridge in all 8 holes. Timing chain was slack but at least it was there. Getting into the bottom and I start to see signs of lack of oiling. Cam is all whack. Only shinny surface is the top of the lobes and bearing surfaces. It's like this thing lived at valve float with low oil pressure. Now the big rotating parts. Rod bearings are all burned up and wore slap out.
400 Clean up 3.jpg

They're all Keltec bearings... no wait that's my 32. They're all Clevite .010 bearings, what's left of them. On the up side none of them were spun. This is # 5 & 6 but you can see the aluminum-bronze in the others also. #5 is much better than it should have been, see next photo.

400 Clean up 2.jpg

I don't know if y'all can make it out, but the oil passage on #5 is completely blocked.
400 Clean up 4.jpg

I was able to get a small piece out with a pick. It was steel from somewhere. Had to use a .0625 bit and drill the other piece, then insert a tinny screw to pull it out. Oddly it was a chunk of lead. Things that make you go "Hmmm". No, there are no bullet hole in the motor. Found other small pieces of steel around the crank area while tearing it down.
400 Clean up 5.jpg

Finished the tear down and while it wasn't terrible it wasn't good either. Let's just say it's a good that this thing is headed to the machine shop. Like I said, this motor looks like it had an oil pressure issue. It was getting some but not all that was needed. Was this an issue with these motor?
Cylinders have some scaring nothing to serious, should clean up with what my plans are. I am stroking it (the motor). Stay tuned to see how much. I'm gonna keep it streetable.
400 Clean up 7.jpg

Now I'm just hoping there are no surprises when I take it to the machine shop. Gotta get after it with scrub brushes inside and out. Do some flashing clean up with a die-grinder and all that good stuff first.
No, first I'm gonna go vote then go to the beach for the election results. :praying: Then celebrate, or cry in my beer. I'm kidding.... I don't drink beer.:rofl:
 
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I bought a '73 RR with the 400. It had been sitting for several years. I was able to get it started in the field it sat in. After about 15 minutes the oil pressure gauge still read 0 psi. I shut it off and bought a new oil pump and installed it. It read normal. I had #2 rod bearing fail shortly after that. Just sharing an experience that may help you diagnose the cause.

RR2.jpg
 
I bought a '73 RR with the 400. It had been sitting for several years. I was able to get it started in the field it sat in. After about 15 minutes the oil pressure gauge still read 0 psi. I shut it off and bought a new oil pump and installed it. It read normal. I had #2 rod bearing fail shortly after that. Just sharing an experience that may help you diagnose the cause.

View attachment 1752514
Nice looking car. Not to concerned with the oil issue. I'm sure it won't be a problem when the motor is finished. Just curious because my last BB MOPAR (a 383) spun all but two rod bearings. I attributed it to my own cheap stupidity. Young and dumb, just wanted to go fast. And it did...for a while. I have heard others talk about low oil pres. on the 400. Just wondering if it was common or sporadic.
 
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