Need advice on my 318

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KevinB

KevinB

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Picking up my 318 on Wednesday...it is already partially torn down. My goal is to get some extra horsepower out of it for a little money as possible.

I'd already planned on a rebuild kit for it, but while it's torn down I was thinking it might be a good idea to give it new pistons to improve the CR, and a new cam/timing chain set.

Assuming I use Keith Black domed pistons, and with the new cam (but not a new intake, headers, or carb), how much of a increase in HP can I expect?

Or would it be better to rebuild it to factory specs with a new cam and replace the intake and carb? Or machine work on the heads even? I'm ok with milling the head as long as I don't have to shave the intake as well.

In other words, of the following items, what should I go with to get to around 275-300hp?

Pistons
Cam
Intake
Carb
Head porting/bigger valves

If a new cam is definitely in the equation, what cam should I go with? I want the car to be a bit aggressive, but nothing too crazy.
 
Depending on how in depth you get with the build you could probably buy a bigger engine and just drop it in for less money. Cheap, fast, reliable. Pick two.
 
275 hp can be attained without replacing pistons. Really, just a 4bbl (600 cfm), dual plane intake (I like the Weiand action plus), a cam with about .450 lift and 268-270 advertised duration (try for a 112 or 114 centerline), and of course dual exhaust. If you really want to be sure, go headers or better manifolds. Tune it well (timing, jetting). If you have any extra money, work on the heads (open bowl area, intake ports where the intake mates, maybe even larger valves...).
 
You're better off with a flat top piston and closed chamber heads vs the dome/pop up pistons.
 
9:1 cr, something like comps xe268, rpm intake, 650 carb, headers and 3.55:1 gears, porting couldn't hurt but not needed to reach your power goals.
 
I'm getting this engine with a 904 tranny for $300, so buying a different engine isn't going to be cheaper. Regarding headers, my car is a 66 dart so the only reliable source is TTI to the tune of $850....I'm going with manifolds to save money.

Locally a guy is selling a week rock performer for a 318 that requires a square bore carb. Not sure what that means but if I can get it for $50 maybe that's the way to go
 
FYI.... 300 for a 318 that needs to be rebuilt is not a great deal. You could buy a good running 318/360 magnum for about 350-450 bucks (not needing rebuilt). Spend about another 350-400.00 getting it prepped for the "LA" installation (intake, oil pan, etc). Your talking 7-9 hundred total. Don't know if you can rebuild your 318, install cam, intake for that amount. If you went 360 mag, you would have 345 lbs of torque and 300 hp just by installing a dual plane intake, plus roller cam for todays oils. Not advising, just saying....
 
^^^^that or a late 80s/early 90s LA Roller Block.
 
just to note also, not suggesting just saying, the kb pistons for that build are nearly $400 alone, not counting machine shop, cam,springs,timing chain etc. i'm in the same dilemma, debating the 318 build for the sake of keeping it a 318 or spending my money and going bigger.
 
Right and then how much is a new 904 tranny or 727 gonna cost me on top of that? Cuz a 318 won't hook up to my current tranny.
 
I agree with 318willrun, A low mileage Magnum is the best bang for the buck, factory long block including cam is said to dyno 320hp with headers. Add a some what of a decent cam and you'll get 1 hp per cid or more. Unless your looking for over 400 hp rebuilding ain't necessary and even then can be done on a stock short block with eddy heads.
 
Peyote said:
Right and then how much is a new 904 tranny or 727 gonna cost me on top of that? Cuz a 318 won't hook up to my current tranny.
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Look around, they are available and cheap. I put a 727 on CL for 100 bucks and no calls. I would say a used but "good" tranny will run ya 100 - 150. But shoot, someone wants one out of there garage, you might land it for a 50 dollar bill....
 
I hear what you guys are saying, and thanks for your opinions. However The base 318 is already 230hp, I'm only looking for 275 to 300. If I wanted more than that I would have said that. I'll hopefully pass this car down to my son and it needs to not be a beast. That's why I'm not looking for a 340 or 360.

The dart currently has a /6 and 904. I've read a v8 won't bolt up.

Mopar parts are not that plentiful in central Texas. Looking on Craigslist there are only 3 318s available in Austin and San Antinio combined. And 0 340s. As far as trannys you guys act like they are a dime a dozen...maybe where you are...there are none available on CL as of this moment.

The other thing is you guys say 300 isn't a good deal for the 318/904 because I have to rebuild it, but I WANT to rebuild whatever's going in because I want that experience and I want to know what's in it.

Like I said I appreciate all the feedback but I feel like most of you are focusing on the why rather than the how. Maybe I'm being narrow minded but this engine and tranny seem to fit my needs so I just thought I could get some answers on how to reach my goal.
 
i've got a couple thoughts or questions
1. what if you used the stock pistons and used 302 casting heads slightly milled, where would that land your CR
2. what if you bored the block .030 used factory type pistons and used the factory heads milled CR?
3. bored .030 with stock type pistons and 302 castings milled or not?
don't wanna mill too much though cause of alignment issues.
 
The factory rating of gross 230hp is very generous
There was a build I read were they took a factory long block (dead stock) added 650 4 bbl headers and a comp xe262 cam and made 282 hp, right in the middle where you want to be add a little cr (9.1) and head work should put you at 300.
 
P.S. the baseline was complete stock including 2 bbl except with headers was 182 hp, so cam and intake was worth 100 hp.
 
273 said:
The factory rating of gross 230hp is very generous
There was a build I read were they took a factory long block (dead stock) added 650 4 bbl headers and a comp xe262 cam and made 282 hp, right in the middle where you want to be add a little cr (9.1) and head work should put you at 300.
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That sounds pretty good...although I really don't think headers are in my future...at least not for a long while. Maybe this is the way to go:

Don't rebuild the bottom end
Mill the head and get a valve job
4bbl carb and performer intake
Comp xe262 cam
Dual exhaust
Upgraded ignition
 
If I get the head milled by a conservative amount AND used a thin head gasket, could I get up to 9.5:1 and not have to shave the intake?
 
Peyote said:
I hear what you guys are saying, and thanks for your opinions. However The base 318 is already 230hp, I'm only looking for 275 to 300. If I wanted more than that I would have said that. I'll hopefully pass this car down to my son and it needs to not be a beast. That's why I'm not looking for a 340 or 360.

The dart currently has a /6 and 904. I've read a v8 won't bolt up.

Mopar parts are not that plentiful in central Texas. Looking on Craigslist there are only 3 318s available in Austin and San Antinio combined. And 0 340s. As far as trannys you guys act like they are a dime a dozen...maybe where you are...there are none available on CL as of this moment.

The other thing is you guys say 300 isn't a good deal for the 318/904 because I have to rebuild it, but I WANT to rebuild whatever's going in because I want that experience and I want to know what's in it.

Like I said I appreciate all the feedback but I feel like most of you are focusing on the why rather than the how. Maybe I'm being narrow minded but this engine and tranny seem to fit my needs so I just thought I could get some answers on how to reach my goal.
Click to expand...


Hey Peyote (most young kids may not know about the psychedelic drug), I live in Corpus Christi and you're absolutely correct...no Mopar parts for hundreds of miles. When you can find them they cost a small fortune. That's why I stuck a Chevy 2004R in my Barracuda, total cost $1850. I did all the work myself except for the tranny overhaul. The 2004R core was only $25. Since Chevy rear ends are also abundant around here I installed a Chevy 10 bolt posi in the Cuda with 12 bolt axles and 390 gears. I got beat up pretty good here on FABO for using Chevy parts on a Mopar but I saved tons of money and the 10 bolt was just sitting in my garage anyway. I have a extra 904 sitting in my garage that you can have for $75. I also have 2 318 blocks. One is a short block ready to go and the other is a bare block. I also have the original high compression heads that came off my '69 Barracuda (9.2:1 CR) sitting on the shelf. Other various Mopar parts. Lots of 340 and 360 magnum small block exhaust manifolds.
The 318 engines, depending on the year, came with pistons sunk down in the hole. '69 pistons were the tallest. My pistons sit .039" down in the hole, some are as deep as .100" (or more) so be aware of what year engine you buy as it will determine the compression.

Treblig
Good luck with your build
 

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Manifolds will cost you 15-25 hp, thats not the big of deal, 360 or magnum manifolds will give you a few hp's back, but if your gonna stay with manifolds I'd pick a cam designed work with manifolds like comps 265 DEH but if headers are in your future then use the xe262
 
Treblig said:
Hey Peyote (most young kids may not know about the psychedelic drug), I live in Corpus Christi and you're absolutely correct...no Mopar parts for hundreds of miles. When you can find them they cost a small fortune. That's why I stuck a Chevy 2004R in my Barracuda, total cost $1850. I did all the work myself except for the tranny overhaul. The 2004R core was only $25. Since Chevy rear ends are also abundant around here I installed a Chevy 10 bolt posi in the Cuda with 12 bolt axles and 390 gears. I got beat up pretty good here on FABO for using Chevy parts on a Mopar but I saved tons of money and the 10 bolt was just sitting in my garage anyway. I have a extra 904 sitting in my garage that you can have for $75. I also have 2 318 blocks. One is a short block ready to go and the other is a bare block. I also have the original high compression heads that came off my '69 Barracuda (9.2:1 CR) sitting on the shelf. Other various Mopar parts. Lots of 340 and 360 magnum small block exhaust manifolds.
The 318 engines, depending on the year, came with pistons sunk down in the hole. '69 pistons were the tallest. My pistons sit .039" down in the hole, some are as deep as .100" (or more) so be aware of what year engine you buy as it will determine the compression.

Treblig
Good luck with your build
Click to expand...




Thanks man, and love the cuda... That's what I want for my next project. I know the engine is a 68 but I'll just have to measure how close or far the pistions sit in there. I'll pass on the offer, I don't have a vehicle to haul a tranny or motor that far...local only use of my company van.

I think I'll be able to get the 318/904 for $200....he's had it for sale for almost a month now.
 
273 said:
Manifolds will cost you 15-25 hp, thats not the big of deal, 360 or magnum manifolds will give you a few hp's back, but if your gonna stay with manifolds I'd pick a cam designed work with manifolds like comps 265 DEH but if headers are in your future then use the xe262
Click to expand...

Good to know, thanks. I wonder if there's anything to be gained from trying to open up the manifolds with a backyard grinding job
 
Peyote said:
Good to know, thanks. I wonder if there's anything to be gained from trying to open up the manifolds with a backyard grinding job
Click to expand...

That's what I do. I buy the 360 magnum manifolds and machine out to 2 1/4"+ to match the 340 driver. Then I sell them here on FABO. I know you're on a budget but thought I would mention it just in case. It's really funny I've sold maybe 20 pairs of the manifolds and the great majority have gone up North!! That's where all the Mopar parts are!!!!!

treblig
 
Treblig said:
That's what I do. I buy the 360 magnum manifolds and machine out to 2 1/4"+ to match the 340 driver. Then I sell them here on FABO. I know you're on a budget but thought I would mention it just in case. It's really funny I've sold maybe 20 pairs of the manifolds and the great majority have gone up North!! That's where all the Mopar parts are!!!!!

treblig
Click to expand...



The problem with using anything other than 273 manifolds is they won't fit in a 66 dart with auto tranny and ps
 
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