School me on the 318?

[KottonGin]

Hey everyone im a first time mopar owner and have never had any experience with the Mopar small-blocks. I have a couple questions so i thought it would be better to lump 'em together than in individual threads. I have a 73 Dart with a 318.

1 - Where are all the stampings located on the block, intake, and trans.

2 - How many years does the 318 have interchangeable cylinder heads? Which of those w/hardened seats?

3 - Which motors have interchangealbe cylinder heads and what machining (head & block) is necessary for good compression and valve adjustment?

4 - Are the crank and cam compatible between the different size small-blocks and what affects does it have?

5 - If i removed the A/C could i just swap brackets and belts from a NON-A/C 318?

6 - Im shooting for a daily driver 318, with the best mpg possible. I wouldnt mind a little performance if the mpg doesnt drop significantely. Is there any tried and approved combo that acheives something like that?

Ok so i thought i had more questions, but im guessing the answers will be more substantial. Thanks ahead of time for anybody that takes the time to give me some knowledge. :read2: Im just a MOPAR newb tryin to get to work and school....in a MOPAR!! :-D

 

[BJR Racing]

KottonGin,

1. The block has it on the drivers side front in the block and the engine build date is on the side of the block with the casting #'s.

2. 67 - 91 for LA type heads and 73 and newer for the hard seats.

3. All heads are interchangeable, as for compression ratios it's dependant on the stroke of the engine and the bore size. Anything more than .030 off either the block or heads or the combination of the two will need to have the rockers and pushrods changed to mechanical setup.

4. As for crankshafts they are interchangeable between the 273/318/340's only but the counterweights are different so the rods and pistons weights will have to be taken into consideration and or rebalancing will have to be done.
As for camshafts they are all interchangeable between the LA engines but over camming is quite easy for the 273/318 engines, and not so much for the 340/360 engines.

5. Yes as long as they are close in the production year.

6. I would start with a 70's or 80's block either a roller or non - roller. Then I would get a .441 lift for the non - roller engine and use a set of 302/318 heads from 85-90, I would also over bore the engine and use the roller engines pistons in the proper bore size as they are .020/.025 taller. Balance the engine assembly. Then I would use a 600 or 670 street avenger carb and a good dual plane intake, set the timing @ 30* total. This should give you a good start on which way to go. I'm sure there will be others that have good suggestions also. This is just one way of doing it.

 

[KottonGin]

SWEET! Thank you BJR Racing

So my 318 should have hardened seats, thats good to know. It did some smoke when i started it at the place i bought it and i thought i could have been worn valve seats. If it sat for awhile before i bought it, could it just need to be cleared out? or is this a sure sign that i need a rebuild or atleast a freshen of the motor? The smoke wasnt that bad and it stopped shortly after starting and driving a little bit.

Also im pretty green to the engine machining and the lingo, i get simple things like bore and im guessing over-bore is increasing the cylinder diameter but there are some things i dont get. When you say roller or non-roller are you talking about the rocker arms? and what does .441 lift refer to? Ive also seen the term Zero-decked i believe and what i got from that is the block is milled down the be flush with the pistons at TDC? Just a guess.I might be asking alot of questions but i just like to be educated on the cars i own and work on if i have no experience.

 

[Prine]

I would run the 85-89 Roller 318 as the complete foundation for a 318/321ci build....instead of zero decking it....just clean up the surfaces and use a Mopar Headgasket.

Reason being you can get and build these engines cheap.

They are found in 85+ Chyrsler 5th Avenues, and Dodge Diplomats, 85-91 Dodge Rams and some Vans....I have also had luck finding the Roller 360 in 89-91 D250 trucks and vans.

The Roller 360 engine has 30"8" casting heads which are "said" to be good buildup cores too....(I have no experience with 308' heads...but quite bit with the 302's)

If you go with a roller engine, just remember the pushrods are specific to them because of the added size of the Roller Lifters.

I was able to get a Crane Cams 228/232 @ .050/.528" @ 112 cam directly from Crane for $285.00 through Summitracing., I also ordered Dual Springs with dampeners from them.

The 302' heads have smog ports in the bottom of the exhaust port, remember to get those welded up.

I was pretty impressed with the power of my 321ci engine. Not supped up 440 performance, but it would light up a 3.23 geared 69 Swinger from a 20 mph roll in 1st...and bark 2nd pretty good.


My .02

 

[furz4]

If you remove the AC you should use non ac pulleys as well as they are different. I made mine non AC by finding a shorter belt but is realy not the recomended way to go. As far as power and milage just about anything you do will improve both. A distributor re-curve, dual exhaust and a good tune up is a good place to start. If you don't go deeper then 3.23's and drive moderatly 20 mpg should come easy. I would also recomend you stay with small port heads, stock or the 302's are realy nice if your interested in best possible milage. My combo for my 73 dart is a good performer and is by no means optimum but is pretty represenitive of how these motors respond posatibly to changes. I can easily get 20 mpg and have gotten over 22 on occasion. Am running 73 block .030 over 79 stock heads with 340 valve springs. Compression is a true 8.5 to run on anything. Am using factory 340 hipo cam, 210 & 220@.050 with .429 &.444 on lift, double roller chain, have full lenght dual exhaust with stock manifolds and turbo mufflers 2 1/4" and on top an old Streetmaster single plane intake with a 600 holley. Dist has performance advance curve and vacume advance. Performance with 2.76 gearing is pretty good mid 15.7 with not a lot of tuning. I think 3.23's would help that time a lot without costing much MPG. You could pick up anothe 30 horses or so with a more modern cam and a better intake but I used the Streetmaster since it was cheap, I had it and it is a small port intake well matched to the heads. I think it was Mopar Muscle that did a 318 build on a recon re-man and using stock heads picked up 100 hp over stock with headers, performer intake, and comp 260 cam I beleve.

 

[longarm]

I'd spend my money on a 360 as you will always want more down the road.
The mileage wont be that much different and you will have a bigger base
motor to work with later.

 

[rumblefish360]

SWEET! Thank you BJR Racing

Also im pretty green to the engine machining and the lingo, i get simple things like bore and im guessing over-bore is increasing the cylinder diameter but there are some things i dont get. When you say roller or non-roller are you talking about the rocker arms? and what does .441 lift refer to? Ive also seen the term Zero-decked i believe and what i got from that is the block is milled down the be flush with the pistons at TDC? Just a guess.I might be asking alot of questions but i just like to be educated on the cars i own and work on if i have no experience.

Allow me clear up a term or two.

The roller, non-roller issue is for the cam. But, also, different year engines use different parts, like the pistons BJR mentioned are taller in a roller cam engine, shorter in a regular Hyd. cam engine. The rocker arms are not rollerized in a stock small block. Just the tappets. They must ride on a roller cam.

Now, there is also roller cam blocks. There slightly different than the older Hyd. cam blocks. You'll see the difference in the lifter valley (Under the intake manifold) where the tappets are. It is a taller bore for the tappets. They need to be because the lifters are taller and need the extra height of the tappet bore to keep them right and in.

Also, in the valley, in the center of the block, above the cam, you'll notice there 3 tapped holes for bolts. This is where the "Spider" gets bolted down. The spiders job is to hold the roller tappets in place a certain way. Older Hyd. cam blocks do not have this.

.441 lift; This would be the lift of the cam at the rocker tip. As in actual lift the engine should see. A cam by Sumitt racing has this lift. You can serach around for other cams as well that have lift in this area.

The term Zero-decked Or zero deck. You have on half of it right. The other half is that a piston may very well indeed come up flush with the deck without machine work. This is not allways the case and therefore a machining of the deck to make it shorter is needed like you wrote.

 

[rumblefish360]

A good mileage 318 engine will be a varied mileage engine with people. Certainly 20 or better would be absoultely great. In order to achieve a high mileage getting engine, keep the cam small and the gear ratio high. (Numericaly low, 2.76, 2.94)

If you use a 4bbl. intake manifold, keep the carb small. 600 cfm is fine. Theres no need to go larger. However, theres also the stock Thermo Quad (T-Q) carb. It has tiny primary's and huge secondarys.
Once Carter went out of biz, Rochester took over. They also make a spreadbore carb. Personnnaly, I do not think it as good as a T-Q, but others have found it very good. Edelbrock has them new and are a bit expensive. You'll have to want one at the price.

The only problem with the spreadbore carbs is they need a spreadbore intake manifold (Edelbrocks Performer will fit the bill nicely) or make use of an adapter witch adds an inch of height you may not have under the hood.

Use dual exhaust with or without headers. At 2-1/4 inch in pipe size, it'll be enuff. An H or X pipe would help power. An X pipe is prefured.

 

[66dartgt]

If you switch to a non ac pulley set up be sure to change the water pump to match the non ac pulley. The waterpump impellers are different sizes, the ac pump uses a smaller impeller and a non ac pump uses a larger impeller. The non ac pulley is larger than an AC pulley and slows the pump down, thus the impeller is larger ! Not smaller !

 

[KottonGin]

Thanks alot guys. You've posted some great info and im glad you all are helping me out. I can only work on a little at a time but with all this info i know where to start and where im going. Thanks again. :thumblef: