Need advice on heads for 318

Mason73

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So I got this 1973 charger with the original 318 and 727. No, it does not have a smog pump nor does it have any of the smog ports on the heads, But the car sat for the better part of 30 years. I had it running and driving but I went to replace the intake manifold and the cam was absolutely destroyed (pic included). I bought everything to replace the cam the right way (timing chain, lifters, cam bearings), and the cam I bought has similar specs to a 340 cam because I’ve read it’s a nice mild cam, But I don’t know if I should just replace the valve springs on the original heads or just get new 360 heads? Or what goes into putting a new set of heads on a motor. I’m a very young motorhead, still learning a lot.

35906724-F3E8-42A3-A399-1D2C8EFFDAAC.jpeg
 

pnora

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To be honest you should consider a complete rebuild. That motor looks dirty and all that cam debris is now in the oiling system. My bets if you pull the pan you will see more warn parts.
 

Kern Dog

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A "bitch slap" of reality really sucks to receive but sometimes......the actual truth will save you a lot of trouble down the line.
Pnora above may be right, he may not. The lifter valley does look dirty though. All that crud does fall in and land in the oil pan. From there, there is a suction pipe with what looks sort of like a shower head on the end. That is the "oil pickup" and it draws in oil to send it throughout the engine. The problem is, when crud falls into the pan, it sometimes gets into the oil pickup and blocks oil flow. That is bad.
The 318 engines can be made to run strong but you have to know the limitations. They were built with really low lift camshafts and soft valvesprings. They also had small valves in the heads until 1985 or so. Think about the intended applications the 318 was used for: Basic transportation with a huge priority of reliability. My opinion....the 318 was the Mopar version of the Honda civic 1.5 or the Toyota 22R. The 318 will run and run a long time but they are not a performance engine when they are kept stock.
A 340 cam with matching valvesprings AND a decent set of heads will really wake up a 318. The 340 from 68-71 was "rated" at 275 HP while the same 318 was closer to 150 HP.
If the car were mine, because I LOVE to save and rescue things.....I'd pull the oil pan. Clean out the lifter valley of all loose debris. Clean the oil pickup if it has any stuff blocking the screen. Reinstall the oil pan using Superformance gaskets and The Right Stuff sealant.
The cam may look dirty but still be okay. You can pull out one lifter at a time. Any lifter that looks like THIS is bad:

84 R.JPG

That bowl like dish you see indicates a failed lifter and surely the cam lobe it was riding on. All it takes is ONE lobe to go bad to warrant a cam and lifter replacement. This is a big job for a new enthusiast. I'd strongly suggest you find a friend that knows engines well enough to help you out. There are so many small details to know, it can be difficult to walk you though all of it from here.
If all the lifters look like these....

87 R (3).JPG



Flat across the bottom, your cam might be fine. Lifters actually have a very slight dome to them...we call it crown.
When running, the lifters have to spin to protect themselves and the cam lobes. A lifter that does not spin will soon wear out the bottom and the cam lobe too.
 

Mason73

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To be honest you should consider a complete rebuild. That motor looks dirty and all that cam debris is now in the oiling system. My bets if you pull the pan you will see more warn parts.
I pulled out as much garbage as a could from the top using shop towels, but I still plan on pulling the motor soon to drop the pan as well as inspect everything
A "bitch slap" of reality really sucks to receive but sometimes......the actual truth will save you a lot of trouble down the line.
Pnora above may be right, he may not. The lifter valley does look dirty though. All that crud does fall in and land in the oil pan. From there, there is a suction pipe with what looks sort of like a shower head on the end. That is the "oil pickup" and it draws in oil to send it throughout the engine. The problem is, when crud falls into the pan, it sometimes gets into the oil pickup and blocks oil flow. That is bad.
The 318 engines can be made to run strong but you have to know the limitations. They were built with really low lift camshafts and soft valvesprings. They also had small valves in the heads until 1985 or so. Think about the intended applications the 318 was used for: Basic transportation with a huge priority of reliability. My opinion....the 318 was the Mopar version of the Honda civic 1.5 or the Toyota 22R. The 318 will run and run a long time but they are not a performance engine when they are kept stock.
A 340 cam with matching valvesprings AND a decent set of heads will really wake up a 318. The 340 from 68-71 was "rated" at 275 HP while the same 318 was closer to 150 HP.
If the car were mine, because I LOVE to save and rescue things.....I'd pull the oil pan. Clean out the lifter valley of all loose debris. Clean the oil pickup if it has any stuff blocking the screen. Reinstall the oil pan using Superformance gaskets and The Right Stuff sealant.
The cam may look dirty but still be okay. You can pull out one lifter at a time. Any lifter that looks like THIS is bad:

View attachment 1306202
That bowl like dish you see indicates a failed lifter and surely the cam lobe it was riding on. All it takes is ONE lobe to go bad to warrant a cam and lifter replacement. This is a big job for a new enthusiast. I'd strongly suggest you find a friend that knows engines well enough to help you out. There are so many small details to know, it can be difficult to walk you though all of it from here.
If all the lifters look like these....

View attachment 1306204


Flat across the bottom, your cam might be fine. Lifters actually have a very slight dome to them...we call it crown.
When running, the lifters have to spin to protect themselves and the cam lobes. A lifter that does not spin will soon wear out the bottom and the cam lobe too.
Another option I’ve been thinking about is theirs an 80s 360 for sale for $500, guy says it runs good and has compression. But buying that motor might just puts me in the same boat with a different platform. If it turns out the cam on my 318 needs replacing, I might just put another stock 318 cam into it because I’m not looking for huge power out of this motor, I just want it to run and drive. Also would oil pressure reflect a clogged pickup screen, Because the car has always had good oil pressure?
 

Mason73

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To be honest you should consider a complete rebuild. That motor looks dirty and all that cam debris is now in the oiling system. My bets if you pull the pan you will see more warn parts.
I think what trashed the cam was when I first got the motor to where I tired to start it, I only primed the oil from that bolt under the distributor. And when it first started it shot to 4,000 rpms because a butterfly was stuck open on the carb.
 

Darter6

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This is just a thought for your heads questions.
There are a few reports on You Tube about Speedmaster Aluminum Heads that work well on the 318.
A member on A bodies, 318 Will Run, has allot of YT videos of work and parts he uses to make good running 318's.
 

rumblefish360

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Being a small block nut myself, I would not rebuild the 318 unless it was strictly for driving. The car is heavy for the engine and overall will not perform very well on take off. The 360 is a better choice. You will take a slight hit on mileage. I myself have gotten 20 mpg with a 360 and 2.76 gears. The 360 was a stock ‘79 vintage with a factory 4bbl intake and a Carter (Edelbrock) 600 & dual exhaust
 

PRHeads

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For a stock 318, I’d use stock 318 heads.

Call around to some local machine shops and get some prices on what it would take to go thru them.
They should be able to give you a ball park on what it might cost without seeing them........ or at least price “range”.

The “find a running 360” is an option I’d look into as well.
 

JR_Charger

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If you want to build the 318 it wouldn't hurt to watch all of Uncle Tony's "Bottle Rocket" videos -

"Bottle Rocket" is that Coronet in the background, basically a 4 door Charger. Uncle Tony has Bottle Rocket ripping along pretty good on a budget 318 build. He broke the 8 1/4 axle on a hard launch, so don't do that without upgrading your rear end.
 

Mr. Cranky

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360 heads will lower the compression ratio to probably in the high 7 range.....and the teen is already low to start with but at least it's probably in the mid 8s. On the 360 that's for sale for 500....considering what 500 bucks is worth today it might not be a bad deal but I would want to at least pull the valve covers off of it to get look to see if it's not all sludged up in there. If the guy has it on an engine stand, I would even want to pull the oil pan off too. If the guy balks at that, offer less money.
 

haywire 440

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Recently the subject of the mid-80’s 302 swirl heads where brought to my attention. They will raise the compression a little but are basically useful for higher mpg. Stock cam, two barrel applications and a possible 25mpg at 70mph. Some folks say they could be hot rodded a bit.

What’s the fellow members think?
 

toolmanmike

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Recently the subject of the mid-80’s 302 swirl heads where brought to my attention. They will raise the compression a little but are basically useful for higher mpg. Stock cam, two barrel applications and a possible 25mpg at 70mph. Some folks say they could be hot rodded a bit.

What’s the fellow members think?
The 302's are good heads as long as they aren't cracked. They are known for cracking between the seats. They are very similar to the 1966 #920 heads with the closed chamber. Yes it will save a half point of compression which helps a little but bigger valves and ports helps performance more. It all depends on how far you are going on your engine build. Just bolting on a pair of heads won't light your tires on fire.
 

rumblefish360

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Recently the subject of the mid-80’s 302 swirl heads where brought to my attention. They will raise the compression a little but are basically useful for higher mpg. Stock cam, two barrel applications and a possible 25mpg at 70mph. Some folks say they could be hot rodded a bit.

What’s the fellow members think?
@Mason73 -

The “302” head is junk in terms of port flow as cast and designed for emissions and mileage. In order to get the head to perform, they need to be ported, a lot! There is enough meat in the heads ports to do some major reworking, and that’s what’s needed. Once properly done, they should easily output power a stock 360 head.

IMO, you’ll be dollars ahead of the game with Edelbrock heads. I’ll take flow over compression any day. The closed chambered Edelbrock heads are 63cc. I’m not sure what cc your heads are on the ‘73. But it’ll be very close. Should you decide to rebuild the 318, Kieth Black (KB) has 2 Hyperutecic pistons to choose from. The small dome piston would help a lot with compression. The flat top doesn’t raise compression that much and IMO, if it is not placed at a zero deck height, why bother.

If you decide to do the 360, a KB-107 zero decked is a good way to go. You don’t want the piston down in the hole more than .010 with a .038-.040 head gasket. Otherwise you will loose the quench. But that is not the end of the world ether. I run a set .020 down the hole with a thin head gasket coming in @ 10.45-1 compression ratio.

If your going the hot rod route on the engine, go with the rpm intake and use headers for a nice all around package.
 

451Mopar

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The 1967 318 and 1966 273 heads are a closed chamber design that could be used to increase compression. I don't know how they flow?
Put some '67 318 heads on a friends 1970 Challenger 318, mild cam, 4-bbl intake, stock manifolds with dual exhaust and it runs pretty good.
 

Rusty 72

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My 318 was trashed in my 72. I got a 5.9L Dodge truck motor (360ci) for $250. These motors are super clean and fine to use up to 200,000 miles IMO.

Use the 5.9L flexplate for balance, get a new oil pan, replace the intake and you'll need an electric fuel pump but that's pretty much it. Everything else from your 318 will bolt onto the 5.9L.
My $0.02
 
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