For what it's worth, Hot Rod magazine 318 build used Magnum heads on their 400 horse build. Could they have got there with a 318 head? Just guessing but probably.
My version of a factory parts build 318
- Thread starter Dan the man
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Not a as cast 318 head - IMO
Dartswinger70
Well-Known Member
Lets see, First. I wasn't comparing a truck engine to a mustang I was saying there is a base utilty 5.0 then there is a performance 5.0 HO . basically a 318 is a utility engine a 340 is a performance engine. calling me dumb or crazy or any other expletives well you started that didn't you the name calling.
Second i am not helping with what? Im putting information out there that maybe someone is better off buying a performance paltform to start with because nothing is cheap and unless somoene has access to a machine shop, parts and information where are they really going starting with a utility engine as a base for a performance engine? They are going to spend $$$
Third why should I be kicked off the forums for looking at it differently for having another point of view? I started out with a 318 then I went looknig for and found a 340..in the long run its more cost effective.
There is a guy on YT touting that the 318 is better than the 340 but he is comparing the blocks. where do these young guys get this misinformation? there is more to a 340 than just the block and no it isn't just as good as a 340 not in its stock form.
Oops I meant 920 head in post #47. Dan was talking about 915's. My bad.
Dan the man
Well-Known Member
Your response is very educational and interesting. I'm sure that this has been asked millions of times, but if the builder already has a 318 and limited funding, what would be the best cylinder head for getting better performance from his 318? He's not looking to build a race car just something with a little extra zip. I suggested a 360, a rebuild able engine is like $400.
The reason why these threads go on forever and there's hundreds of them is there is no definitive answer. Too many variables.
Dan the man
Well-Known Member
I understand and that makes sense.
So here are several factors.......The magnum head, stock, is more of a performance head on a 318 as oppose to a 360. The 3.91 bore is not pulling as much into the cylinder so the ports act larger. This allows more RPM on a 318. Also, the valve size per cylinder diameter is acting as a performance valve in the 318 as a 1.92. If you ever drove or owned 5.2 and a 5.9 in the same vehicle (I have), the part throttle response is better with the 5.9 BUT wide open throttle the 5.2 really pulls just as strong as the 5.9. Seat of the pants, really no difference at all. That is because the heads and cam are acting more of a performance part per C.I.
There is no "best" head for a 318. No "best" aftermarket cam. #302's may be a bit better than a stock #675 318 head and a 340 head better than that. What about aluminum heads. That's a whole other story and selection. Let's not even get started talking about cams for a teen.
Dan the man
Well-Known Member
It seems that for somebody who wants to get a little extra zip from his 318 can open up a can of worms rather quickly.
My point exactly. Low budget? just some bolt on's as long as the engine is in good enough shape. Dual exhaust first. I would recurve the distributor next followed with a 4 barrel and intake. ANy further and you may get into "point of no return" territory. (cam, heads, headers, converter, rear gears)
thing is, Dan, is there are a lot of ways to do this. If on a budget, why not follow some of the very simple recipe's already provided by members here. I did one myself called the "Low dollar 318". For less than 500 bucks (498 to be exact), I ran the same numbers as a factory '73 340 Duster with 3.21's (and I did it with 2.76's). And others have documented similar builds.
First off, all said not to get upset/take it personal. But it seems you did anyway. OK then, I’m sorry Mr. Snowflake for calling you names that was ment for all that discourages the use of a 318 and such.
Is that OK Cupcake?
No and here’s why, oh wait! I already explained that!
So yea, your not helping.
Why not? You did so. Even though the performance engine has a better compression ratio, a bigger cam and better heads, only a tool would give and take the advice on parts heavily used since the 60’s and early ‘70’s. While he heads of both engines are more likely to be in need of a full rebuild, costing the same (?) would not be better to purchase an aluminum head of the performance level is easier to reach?
But then again, like in the case of a block, your advocating to spend another, $400?
Now where behind $1100? $400 for heads & $700 for a 340 block? To fit what build parameters? On how thick of a wallet?
That you love spending there internet money on as if they have loads of cash?
Sometimes your thought pattern works great, sometimes it doesn’t!
Where you kicked off? Then it was perhaps you were being a dick. Did you learn your lesson? Do you understand why you were kicked off? Are you repeating the process?
For what goal? With how much money?
I’m not arguing the direction. You think I am.
Well, stock 318 vs a stock 340, what are the differences between them?
Bore is one. What else?
Now this is an “IF!” IF both the 318 & the 330 are cast with the exact same cylinder sleeve, and the. Bored to there respective sizes of 3.91 & 4.04, which one has the stronger cylinder walls?
The 318 has stronger cylinder walls of course! This is the only difference between them now. So, which one is better to use? The bigger but thinner cylinder wall or the smaller but way beefier cylinder wall)
The answer doesn’t automatically mean which one can output a higher HP & Tq level. While that could be one factor in choice, the one thing I left out on purpose is how much meat is left on the bigger bore engine.
So, from a certain point of view, someone is right…..
Someone is wrong.
Dan the man
Well-Known Member
Is your "Low dollar 318" on your uTube channel?
it's actually here. But yes, just some of it is on youtube. Actually, that motor is the reason why I even started youtube so I could post certain parts of the project here.
my Low dollar 318 hop-up project
Dan, I’d reply pretty much what 318WR said.
“A little more zip.” Is a very broad and general term.
This is what I would do. First! Find out if the Duster owner is willing to use headers.
Second, use the step by step KISS program. This starts with the basic but of on parts and a cam last. The following is my suggestion to this process.
1st, are headers going to be used?
Ether way, headers or not, install a dual exhaust n the car with the muffler or choice. In a blind and broad decision here, use 2-1/2 exhaust pipe size. If you use headers, go with the sun I exhaust package. Relatively inexpensive and complete.
Works great!
2: A 4bbl. carb and intake. Again, in a blind choice, a RPM or Weiand Stealth with a 750 cfm carb of choice will be an excellent set up.
3: Upgrade the ignition system.
4: Camshaft swap. This has to work with the rear gears and the converter.
After this path is completed, the owner can decide if the next stall is needed. It comes as a toss up between an overdrive transmission or rear gears.
On cylinder heads, the stock ones, not matter which ones, can be rebuilt and given a competition valve job. That’s all that’s needed for a low lift cam under .500.
@Dartswinger70 Now would you look at that! A request for a cheap inexpensive low dollar 318 enhancement build that doesn’t have money to the side for a expensive 340 block like you said is needed.
Hoooooooly Cooooooooooow!
Someone actually wants to use the 318 that’s in there car!
O-M-G! The world is ending in your corner of the world!
What could be next? Someone building on a 400 block but not stroking it? Building a Poly engine? Making use of the first gen HEMI? Hop up parts on a slant 6?!?!
Hell fire is escaping!!! Quick! Make a rush to type out how dumb we are!!!! The world needs saving!!!!
Hoooooooly Cooooooooooow!
Someone actually wants to use the 318 that’s in there car!
O-M-G! The world is ending in your corner of the world!
What could be next? Someone building on a 400 block but not stroking it? Building a Poly engine? Making use of the first gen HEMI? Hop up parts on a slant 6?!?!
Hell fire is escaping!!! Quick! Make a rush to type out how dumb we are!!!! The world needs saving!!!!
Thanks Dan!
Dan the man
Well-Known Member
Your welcome Sir.
Dan the man
Well-Known Member
I'm going to see how good the car actually runs first before tearing into it as a good tune up may make a difference
There’s a lot in distributor timing. A recurve would do wonders. Don @4secondsflat.com has a simple kit that works great. Limit the mechanical advance with a plate, find out him much vacuum advance is available, set the timing and your good to go.
I’d start at an initial of 15* and see what that brings me in terms of seat of the pants feel. (You could) Advance it until the starter has to work to start the engine. Then go from there. How much initial that is and then limit the mechanical a bunch.
I’d start at an initial of 15* and see what that brings me in terms of seat of the pants feel. (You could) Advance it until the starter has to work to start the engine. Then go from there. How much initial that is and then limit the mechanical a bunch.
318WR has a few videos out that should be really helpful in this area.
AustinGriggs
Well-Known Member
In my '69 Dart, I dialed in 9.00 and ran 9.02-3 (1/8th) every pass on my way to redlighting in the finals with a stock piston 318, stock 915s with 1.88/1.60s, RPM intake, Headers, MP474 Purpleshaft, and factory converter w/ 3.91s. I can't prove it now but I pretty sure a set of stock 302 castings would have slowed me down. I'm a believer in the 302s but only when worked. Stock for Stock.... give me the X, J, O, U's for a 318! My times aren't earth shattering but for factory piston 318's.....
A High Performance small block is easy. Not sure why everyone wants to make it hard. Ma Mopar gave you the blueprint. 340 is the blueprint, not the Holy Grail. Good factory head castings. As cast 318 heads will flow about 170 cfm, while 360 heads will flow about 190 to 200 cfm. 360/340 heads can be milled to about 65 cc chambers. Pistons to give the compression to work with the available octane. A cam and valve springs to let the heads breath. A good 4 barrel carb and intake to breath. A good distributor with a fast curve and tailored to the max timing at WOT. A double roller timing set, a high pressure oil pump and a windage tray to keep everything together @ 6,000 rpm. This will work on any 273, 318, 340, or a 360.
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