318 engine build

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72_Durstya

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Hey guys & gals. I'm currently looking @ building up a LA 318 engine I have at my disposale. I am aiming for a minimal of 300-325 hp or a maximum of 350-400 hp as cheap as possible and without sending the heads and block to get machined etc..

The engine I have is a 1972 model that was re-built in the mid 80's, it is still very clean as I can clearly see the cross hatching from when it was honed.

Other things I have:

- Large valve J heads
- LD4B Eddy intake

What I have thought about so far is getting a performance water pump, doube timing chainf setup, new bearings piston rings roller rocker assembley and bearings as well as a street/strip cam that has some lumpyness to it. And re-using the original rod/pistons if they are still good.

I know a lot of ppl are goin to say get 302 or Magnum heads, I would rather work with what I have and do what I can with it. I also dont wanna send the heads and block to a machine shop, I'd rather clean them up and use. I dont have much of a budget and will have to do things as I can afford them. Plus it is only a 318 and I don't think it's worth dumping the $ into machining just to have a nice fun ride after all I'm not after having the fast ride just an enjoyable ride.

Any Input will help! i.e cam selection etc... Thank You!
 
1.88 valves or 2.02's?

The 318 is very low on compresion and if your going to mill the 360 heads to fit, your gonna have a hard time between all the milling and bolt hole alighnment on the intake to head.
The power level you want isn't difficult, it just takes money and since your not willing to go to the machine shop with the block, your behind the 8 ball in the worst way.


I would see about selling/trading the intake for a RPM or like intake.

What tranny stall converter and gears do you have or ed up with.
 
im building a 318 right now i did a lot of home work first and still doing more one thing i can tell you for sure is the J heads will drop you compression and thats not good for horsepower from all i have read and talked with people about your better off with the 318 heads they just need a little work most of which you can do yourself with a die grinder and dremal tool like i say im still talking with people so guys if you read this and don't agree please let me know if im talking thru my @#%$%$$&^$ i can use the help as well
 
I'd take Rumblefish up on his manifold swap. The LD4B is designed for the smaller 273/318 intake ports. With the low compression, the engine won't tolerate a lot of whoopee on the cam and be decent to drive on the street.

You can gain a little compression by using the thinest head gasket you can find. Using pistons from a 67-70 318 will also help.
 
Rumblefish to answer you questions, I belive they're the 2.02 J heads, and trans wise I have a 727. This whole setup was on the car when I bought it 3 years ago along with an (overkill) 850 carb that is no good.
 
This would be my first engine build. My dad built up his 1970 340 3-speed Duster back when it was new so I'd have a lot of help from him. My goal is to get enough HP and TQ that the car would be enjoyable to drive (not tryin to be the fastest car on the street) at the same time relatively light on the wallet and not too expensive to drive gas wise. Hense why I thought about building the 318 I own up.

Am I goin in the right direction with this. I did think of finding a 360 but that means more $$$ off the bat when I have a very clean 318 already.
 
This is easier than you think but cost is going to depend on your assessment of the engine when you tear it down.

You need to examine your internal components. Do lots of measuring/plastigage.

You need to know if
1) Your crank needs regrinding.
2) Your rods need resizing or if they are bent.
3) Your pistons are reusable
4) Valve guides/seats in good shape.
5) The bores need to go oversize. You cant guess about this. Get a new single standard piston ring, square it up in the bore with a piston and measure the gap.
6) Check to see how far out the decks are. Use a 4 foot level and feeler gauges.

The cheapest route I think you can go ( I've researched VERY extensively )
is the enginetech kit. The prices I'll give are for the premium kit. The economy kit is $20 less,so not much different. Engineteck pistons are made in the states (Sealed power I think) and thier parts are fine.

RMCR318BP kit will give you the following:
Rings
Rod bearings
Main bearings
Gaskets
Rear main seal

Thats $100 and it's really basic

The next step up adds the following:
Pistons
Cam bearings
Full gasket set
Timing set
Oil pump
expansion plugs

$251,but still no cam

The next step gets you a cam and lifters and costs $348. That is a stocker cam though.

Another $14 gets the stage 1 cam which has 106/116 centrelines 204/214 duration and .281/.296 lift @.050. Another $10 gets you a double roller timing chain/gears. $41 gets the hi volume oil pump.

O.K,now heres the deal. If the motor needs machining and you dont do it it wont last and more than likely will have catastrophic failure. There goes the money you just spent. May have well just wipe your *** with it.

Trust me on this. I have gone cheap and been bit.

That being said,if you check the motor out and everything is good,You can be happy and simply rering/regasket it. Throw the Summit cam/lifters at it and mud ball hone the cylinders. Use a new oil pump,bearings. If the rods are crap,cheap ones can be had from PAW. They are on sale right now. $80 gets you a set of stock reconditioned rods that has been checked resized/shotpeened. I think ones with ARP bolts can be had for $60 more.

Do the measuring.
 
I don't think the 318 is an engine that you can make very good power with, without some machine work. The compression and airflow hurdles are very high.

Here's an article that shows what you're up against.

http://www.compcams.com/Community/Articles/Details.asp?ID=1968181674

Don't run the 360 heads. It'll kill your compression even worse. For more info, see this thread:

http://www.forabodiesonly.com/mopar/showthread.php?t=57169

The LD4B isn't a bad intake (and you've already got it), especially for the RPM range you'll be looking at, and it has the 318 sized ports. If you're going to hog the intake ports out to the 360 size, then there are better choices.

Headers and good dual exhaust would help a lot, or rather you're going to have a hard time making power without doing it.

If you've got an automatic, a small stall converter (a converter is the biggest bang for the buck short of nitrous)

Gears. They shouldnt be anything too crazy in a non-overdrive street car, but I'll bet you're rolling something like 2.73 right now. A 3.55 is the highest I'd go if you do much highway driving. If you've got a 7.25 rear, forget everything else and replace it. making more power is just going to break it anyways.

For a cam, I'd do something small from the Voodoo or Comp range.

This is the biggest I'd go:
http://www.lunatipower.com/Product.aspx?id=1543&gid=287

In my opinion, with the limitations you have mentioned, you're best off reducing parasitic losses to gain power, or speed. They'll also benefit whatever you throw in there to replace the 318.

Examples:
Windage tray and/or good oil pan.
underdrive pullies, or eliminating power steering and AC
Sealing it up good so you can use synthetic oil.
Taking weight out of the car. To a point, its the cheapest acceleration you can get.
Electronic ignition with a good amount of advance.

This isn't the sexy approach necessarily, but it does work well, and the money you spend will still be in the car if/when you get a 360 or something.

Steve
 
Oh and recently, Mopar action did a super cheapy rebuild on a 318. New rings, bearings, Comp 224/230 .477/.480 cam, Chinese Air gap and a speed demon carb. They did mill the heads .020 and port on them a little too.

They made 220 rwhp @ 5000 RPM through a stick shift, which is approximately the same power the 318 in the article above made. So the home port job probably isn't worth much, or they went too big on the cam or something.

I forgot to mention electric fan in the parasitic losses department above.
 
Hey 280 hp aint bad for a stock compression 318 with no head work and small valves. I dont think they did much for tuning either.Could have been another 20 h.p right there.

300 h.p from a stock low comp 318 looks doable to me! Especially if you break out the die grinder...

Agree on the windage tray. Oil control is cheap h.p. So are thin head gaskets.

Blueprinting the engine will free up a bit more as well. Polishing internal components like crank journals, rod beams valve stems and heads, rocker shafts and rockers,hand cutting banana grooves for oiling in the shafts,checking installed spring height and shimming if necessary,checking all internal clearances, painting the inside of the block,degreeing the cam, recurving the distributor,porting the heads can all be done at home for cheap.
 
needsaresto said:
Hey 280 hp aint bad for a stock compression 318 with no head work and small valves. I dont think they did much for tuning either.Could have been another 20 h.p right there.
Click to expand...

Agreed.

I think you're going to have to find a way to turn some better RPMs to make 300 hp.

I'd recommend at least getting the heads milled, and finding the thinnest head gasket you can get your hands on. Also, if you re-ring it, get some Total Seal rings or something of that ilk.

Steve
 
Thanx for the input guys, the more I read both here and other websites etc... the more it seams to me that in the long run just buckin up and gettin a 360 would be the better and cheaper route to get the horse power I want.
I was at the local wreckers looking to see if they had any 360's (or SB mopars in general) but no luck.

Another question if I were to go with a 360 would using the 318 crank be an inexpensive way to stroke it out being that the 340 and 318 cranks are the same?
 
72_Durstya said:
Another question if I were to go with a 360 would using the 318 crank be an inexpensive way to stroke it out being that the 340 and 318 cranks are the same?
Click to expand...

Spending the extra cash on a 360 for the cubes and a higher ceiling on performance future is a great idea only if you have the money. The 318 crank or the 340/273 will not fit the 360's larger journals.

If you stick with the 318, I would seriously look into piston replacement and if your going to use what you have in the area of heads, fine, just cam it up well and ad a set of gear and a converter to match.
Idealy, the 340 heads are to large. A smaller valve 360 head would be better on the cheap. Ported 318 heads would be what your looking for.
 
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