Engine rebuild

Header's can facilitate other high RPM mods that won't work without the headers. Usually making for a high stung motor that's no fun to drive.
I don't use them on a sub 6 grand motor. Except my blown 572 v-drive boat.
 
Header's can facilitate other high RPM mods that won't work without the headers. Usually making for a high stung motor that's no fun to drive.
I don't use them on a sub 6 grand motor. Except my blown 572 v-drive boat.
Everything is better in ‘murica. We even have a speedlimit of 3mph on water
 
My son wanted a project car so we got a '67 Fury; it needed many things due to age, wear or lack of past craftsmanship. Of the many tasks so far that I undertook, I would like to share a before and after of the engine. Just as a note...the manifolds look the same after months of the engine running without any fading, peeling. All paint I used was normal spray can, the prep is the most critical.

Fury before.jpg


Fury after.jpg


318 after.jpg


318.jpg
 
The 318 is a great little motor with the older ones even having 9:1 compression which really helps fuel economy and torque compared to 73 up which would barley make 8:1. An Edelbrock Performer with a small 600 CFM would be fine. The stock Chrysler electronic ignition is fine and not expensive conversion to make. The stock factory 340 grind cam is about all you want for this engine. It can actually give a mileage boost as well as torque increase. Having hardened exhaust seats installed is a must for lead free gas. After 60 years of working on cars for a living the only thing I can say about headers is that you really have to like constantly changing burnt spark plug wires (and burnt fingers, and wrists, and fore arms etc, just ask me how I know this). When you rebuild an engine with flat tappets remember to use an oil with ZDDP (zinc) in it. This prevents lifter and cam lobe failure. All oil used to have this in it but now only the specialty hot rod oils do or you have to buy as an additive. Very critical for cam break in at start up. In the past I spent several years as the Technical Manager of a large engine engine remanufacturer saw a lot of this happen. Flat tappet takes on a whole new meaning when a cam lobe is no longer a lobe but a circle and the lifter bottom is concave with a hole worn right through it. A quicker advance curve is a must, Chrysler used to sell a quick curve advance kit that was about $10.00 that was perfect. Keep the vacuum advance and if you decide to change gearing the best that mopar ever had for the street was 3.23. going more than that will increase acceleration but hurt fuel economy. I had 72 340 Challenger that with a little carb tuning and the spring kit that would leave a 350 Camaro in the dust and still give 25 miles to the Imperial gallon at a cruise speed of 75 mph. You just gotta love that Big Carter Thermoquad spread bore that came on these cars. But enough of that for now, you really have to determine what is causing your current problem first other wise you just might end up putting that same problem right back on to your new engine.
Possibilities? Compression test should 125 on that old engine with a variation of no more 10 to 15 from cylinder to cylinder. Under 90 in a cylinder and it probably won't ignite properly especially with a load on it. Ignition ( cap, rotor, wires, worn out distributor bushings or lobes for the points, bad points or condensor, coil, low voltage, charging system problems, corroded or blackened battery cables and terminals, poor electrical connection at the bulkhead connector or on the back of the ammeter. Carb problems, accelerator pump, plugged air bleeds, stuck power piston, could be a lean condition at mid throttle. How badly is your timing chain worn? Put a socket and a long handled ratchet on the crankshaft bolt, line up your timing mark to zero and remove your dist cap. Then turn the engine clock wise until you see the rotor move. Now slowly turn it counter clockwise until the just starts to move in the opposite direction. How many degrees do you see between the first stop and the second one. 5 degrees will affect drivability, 10 degrees is on the verge of throwing the timing chain. Any more than that count it as pure luck your not sitting on the side of the road somewhere waiting for a tow home. I have seen a 318 that still ran ( very poorly but made it into the shop) with the nylon teeth completely gone from the cam gear and just on the aluminum gear itself. I guess there really is such things as miracles.
My philosophy over the years has always that a car must be safe, reliable and fun. Once a small block goes over about 350 HP it starts be a chore to drive daily, costs a lot of fuel and the price of reaching those higher numbers goes up like rocket headed for the moon. Yes I have 500 plus engines in both small blocks and big blocks but the owners had deep pockets. If you want to see how expensive it can get check out Nick's Garage on You Tube. He has over 50 years experience building Mopar engines and at the moment is putting together a 541 cubic inch Hemi for a customer with all new parts including an aftermarket race block , stroker crank rods etc the parts to date are $35,000 with no carbs yet, and no custom pushrods for the roller rockers and whole load of other stuff.

I am currently doing up a 440 for my 67 Newport Convertible and roughly following the factory 440 TNT specs but with a slightly milder cam and lowering the compression from 10.3:1 to 9.3:1 so I can run regular gas instead of premium. Should come in between 350 and 375 HP and I am changing gears to 3.23 and taking out the 2.72s that are in it now.

More than enough for now. Let us all know what you find out and what you decide to do.
 
Use the 340 HP exhaust manifolds. Better flow, no leaks, no rust out issues.
 
If you want good power on the cheap, get a 5.2L Magnum long block
Jam an Eddy intake and carb on it, shorty headers, ekectronic ignition.
Use your timing cover to run the mechznical fuel pump.
Even your 68 valve covers will fit!
Being a heavy car, an RV cam will give lots of torque to get moving
The Magnums have roller lifters, better heads overall and xan providedecent MPG.
 
If you want good power on the cheap, get a 5.2L Magnum long block
Jam an Eddy intake and carb on it, shorty headers, ekectronic ignition.
Use your timing cover to run the mechznical fuel pump.
Even your 68 valve covers will fit!
Being a heavy car, an RV cam will give lots of torque to get moving
The Magnums have roller lifters, better heads overall and xan providedecent MPG.
I was reading thru all these responses waiting to see if this got mentioned.
A 5.2 Magnum does have some things that need changed to install it (timing cover/belt drive, special intake manifold) but that's a wash vs trying to add power into an old LA 318.
The 5.2 is rated at 220-230hp, so that's a boost of 40-50 hp, and you'll gain a bit more out of the 5.2 if you add duals to it.
The Magnum exh manifolds are reported to flow almost as good as the best of teh 340 manifolds (which are pricey!).
Early 92-93 manifolds have larger outlets (2-1/8"?) vs the later ones (2")?

If you wanted to add a cam, that's a big pick-up over the OEM version, and it's a roller, so no flat-lobe concerns.

The Magnum has a lot of technical details that allow it to make more torque/hp AND get better fuel economy.
The heads are a big part of it, they allow the fuel to burn better.

And - you could be getting the 5.2 prepped while the 318 is still in the car.

If you go to Dippy.org, there used to be some good posts on all the things to consider.
There was a guy on there that swapped a 5.2 in to replace a cammed 360, and his car went faster and got better MPG after the swap. (the 5.2 had a cam also, but a milder one)
 
All the 5.2 Magnum's that I've had from years 91 to 97 turned on at 3,100 rpm. I don't know if it's the cam or the tuning.
3.91 and 3.55 gears work well in the Dakotas with 235/75-15 tire. The Dakotas weigh 4200 full of gas with two people.
The 3.55 with 235/75-15 tire isn't enough gear in the heavier passenger vans with all the aerodynamics of a brick. Too much 3/4 trans shifting. The van needs the 3.91 gear.
I don't know what gear the big sedan will need. But it's something to think about. I suspect the sedan with a stock 5.2 Magnum, overdrive and 3.91 would be a nice setup.
 
Something that I noticed is that no one here has made any comments on your desire to use LPG/LNG fuel. These are gaseous fuels not liquid like gasoline and burns in a completely different maner. 1. They take three times longer to burn in the cylinder. This requires way more initial timing as well full advance by 22 to 24 degrees, otherwise the bulk of the burn is happening while the exhaust valve is open, totaly destroying the valve and seat in only a very few miles of driving. The valve looks like it has shrunk and has recessed into the head by a huge amount. Hardened valve seats are a must. 2. Unless you are going dual fuel you have no need for a gasoline carb at all. These fuels require a converter to change from a liquid state into a gas. It is only liquid when in the tank under very high pressure. This is plumbed into your heater hose feeding hot water to your heater and must be mounted a bit lower than your heater on the inner fender so that it always has antifreeze in it and no air. The carb operates on engine load and the big round diaphram lifts a cone shaped valve up off of a nylon seat to allow the gaseous fuel into the engine. 3. The pcv must be plumbed into the plenum under the carb. If it goes to a fitting on one runner like a power brake hose it will lean out that cylinder and it won't fire at all. 4. These fuels also require a much higher compression in the order of 12:1 to recover the horsepower lost to their slow burn. They can actually run over 13:1 in a race car. 5. Colder spark plugs and a very high output ignition are a must. A long spark duration is needed, 2milliseconds or longer firing time. Capacitive disharge ignitions only fire for about 1/8 of a millisecond. The Chrysler electronic ignition was way above points at 1 1/2, but GM's HEI and Ford's Duraspark managed about 2 1/4 and worked great.

A low cost fuel yes. A straight one for one change over not. Works well for couriers and fleet operators but maybe not so much for the individual. Also be aware that the convertors build up wax in them and have to be rebuilt on a regular basis to clean them out and the nylon seat in the carbs wear out and cannot be replaced so when they have a lot of miles on them it means a new carb.

Oh and be aware that it is against the law to park in an enclosed parkade or garage, even your own. If you fuel up when it's cold outside and then park in the warm the fuel will expand and the pressure safety valve on the tank will pop off releasing the extra pressure and turning the garage into a very, very big bomb. Back in 1980's LPG was the big fad around here and some people did not take this serious enough. Saw a Shell service station that left a propane powered truck inside the shop for the night and about midnight the whole shop blew about a hundred feet in the air. Thank goodness there was no one near when this happened.

I had a Snap On guy order a 460 for his truck who figured he could save some money by ordering a standard truck engine for hius big tool truck rather than order a propane engine. It lasted about two weeks on propane and then he was screaming for warranty. Sorry to say but I would not give it to him.

Just a little story from my over 50 years in the engine and tune up world.
Good night to all and happy wrenching,
Terry
 
Hi everyone,

Thanks again for all the replies and help.
I finally got to the root of the problem: correct setup of LPG and timing.
We did not change anything yet and it runs and drives wonderfull. Now it still sputters a little under power, but this is probably the ignition part.

I want to keep the original motor, so we are going to change the following first:
- replace the carburetor for a Impco 425
- change the intake for a 4-barrel and a correct baseplate
- upgrade ignition to HEI

When i am ready (or the engine needs rebuild) we'll do the cam, hardened valveseats and valves and different pistons etc.

What aircleaner would be most accurate for the time, considering it now is a 4-barrel? Dual snorkel wouldn't be correct in my opinion..
 
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