Thread: 318 Buildup

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What can i do to further the performance of my Heinz-57 318? I'm far from an expert on Mopars but I know enough to be pretty dangerous. I'm looking for more streetable power for my '74 Duster that is driven daily. It'll have to be pretty torky on the bottom end because I had crud 2.94for rear gears and 255/60R15 Rear feet. I haved had the engine apart for a re-seal and re-paint whe I bout the car in 2000 but now it's starting to get tired as I saw it was comming when i put 'er back together. Here's what I know of the engine so far:

'70 318 std. bore w/cast true flattop pistons (.080 DIB@TDC)
'71 360 "J" heads with 2.02/1.60 valves 65cc chambers
Approx 8.26:1 C/R
Later Heavy Duty Crank (can't remember year for sure)
Never had pistons out to see if they were floating pins or not.
The rods appeared to be 360 units by the casting #
Stock non-adj rocker arm assys
360 4bbl Cast Iron Intake
Headman headers and 2.5 Exhaust through Super Turbos

My current cam specs are as follows: (suppose to be anyways)
Lift@valve .429/.444
Dur@.050 210/220
LCA 114
Int. Centerline 113
IVO: -8 IVC: 38
EVO: 45 EVC: -5

This is suppose to be a factory 340 cam of some sort. I had the cam custom ground but never degreed it to be sure. I have a degreeing kit now, so I can check this when it's time to tear down.

Any ideas and/or suggestions would be great! Thanks- Dan

Back in the early eighties, my stepson built a 74 Duster/318. He used a 2 four Edelbrock with a pair of 450 holleys. Made a bunch of tourqe. He did all the other thingys that you al ready have.

Thanks Tech! Yeah I'd like to move up to a 360 but since the old lady drive it most of the time she wants a little milage too. (i have to build it up a little bit so I can stand driving it) But i was hoping to keep the cubes down a bit and besides, for some reason 360 blocks are somewhat hard to come by wheras the 318s are pretty plentiful.
I may just freshen up the one I have and I know what you mean by a huge combustion space. I couldn't believe the depth I saw the piston at! Unreal! And I thought the mid-late 70's ford 302's were bad....
I do have a 360 rotating assy in the shed as wellas applicable oil pan but no block. I'll keep my eyes peeled for a bare 360 block if nothing else. Now with a 360, I'll need to change the TQ converter as well, right? I have a 904 trans now, I'm guessing that 727 TQ converters don't interchange? Thanks again

A well tuned fresh 360 will get pretty good mileage.
You will need the B&M flex plate, I just finished a swap from 318 to 360 and Am willing to share any info you need. I did mine on a budget so I think differently than 'Horsepower TV' ..real world type of a swap.
I used my 904 trans and went to an 8 1/4 diff.

I have $1500.00 in parts in my HP 360..took me two years to save and build though..WORTH IT to the MAX.

Actually yes I would be interested in knowing the formula! Right now the Duster is de-commisioned and is in much need of work. I was thinking 360 lately because I got the wife a '66 Mustang instead so that means I can get "nasty" with the Duster. I have an 833 4 speed and 98% of the swap stuff to do it. I also have access to a polished dual quad tunnel ram for the SB Mopar that would really look sweet and I figured that the TR would run alot better with more cubes. But- until the TR is in my posession, I'd rather just be sensible about the 360 build and would like to hear about your build.

Oh- What's the deal with the B&M flexplate? Does it make up for not having the counterweight on the 318 TQ converter?

When I started planning my 360 I looked at the crate recipes available..Then, did my own twist from that.
I have an 87' 360 out of a B-350 van with only 30K on it when I took it apart. (old military Van).

I put in 9.5 to 1 pistons ,but, that was the comp rate with stock heads. I used the 1991 Dakota heads which are closed chamber and have positive valve seals. Used my stock rods and crank, Went with the Crane timing set at 4' advance for bottom end torque. I am running the stock cast iron 4 bbl intake with a Holly on top. 2 1/8" stainless steel dual exhaust.
I did ALL the machine work by myself..ie .,, ported the heads, exhaust manifolds, intake etc. I also flatened the valve cover gasket surface with a dremel and removed any casting 'flaws' inside and outside of the block. I chased all the holes and threads and oiled everything.
Took me over a year to do all this, but, when I had no $ the dremel was handy to keep going.
My best friend is an Engine builder and helped me put it in. He guesstimates 9.8 to 1 comp and 425HP..I guess more like 395

I'm somewhat new to the world of Mopar and still learning quite alot. I'm actually a born and bread Ford guy and have exceptional knowlege of them. I've been doing alot of research on the I-net, books and stuff trying to learn as much as I can. Sadly it's hard to find any good info (mainly specs) on the '80 and newer SmBlk Mopars. Sounds like you've got a good combo and to me worth investigating. Right now I have 360J heads on my 318 and was hoping to retain them. Unaffortunately the large combustion chambers are a great drawback. The key to fixing the crappy compression ratio was either to deck the block or heads or try to find a reasonable cast of hypereutectic piston with a little dome to it. I wish i could find more info on the '80 and newer heads to be able to compare. Did Chrysler ever change the 360 or 318's deck height to increase compression? Thanks for the tips and help. It's much appreciated!

The 318 stayed pretty much the same until '87' I think, when they started using a roller cam. The block and heads will interchange until '92' which are different. I am guessing so don't quote me for missing by a year or so. The late model heads were closed chamber and flow better too. Also I was told that the 90 and 91 318's had stock 1.6 rockers on them.

You can deck your block or cut the heads but, then you change your valve train and have to go with custom stuff, shims,pushrods etc...those are good heads but not for a 318.

Speed pro makes a good set of higher comp pistons for cheap,as in less than $200.00 a set. About $40.00 to have them pressed on to your stock rods.
Idealy a roller engine would be best to build. I couldn't find a decent core in my price range so I bought the 360 for $150.00 carb to pan.
Future plans..I got em, want roller rockers,roller cam kit,air gap intake,but sadly I know how much Santa Dave can afford $0000.00

Thanks for the info. Looks like I'll have to keep my eyes open for a good late model core. I also heard rumor of a 2 or 3 year 318 "Fast Burn" head used on some of the PIs in the 80's that were small chamber heads. Not sure if they are a hot ticket item or not. I don't know if I'll go roller cam or not. For what the car is used for, I don't think it's really necessary, at least for money spent.
It'll be a while till i get back to the Duster. Right now I'm kinda tying up what $$ Santa Dan has in his "T" C-Cab, at least till it's mobile again and not deplete what $$ he's got saved up for his shop this spring...

*cough*
http://www.clubhotrod.com/forums/sho...threadid=16681
*cough*

I sort of like the 318 motors. It's the under-dog of the Mopars, sort of a similar contrast to the FEs Fords of the big block 385 series. You can build a solid 400HP motor with relatively inexpensive parts.

If you're going to keep the 318 Iron heads than consider a small Mopar stroker crank, add some compression to aid in the quench, and a dual plane manifold with a vacuum secondary carburetor. With your high geared rearend you don't want too much carburetor or she's going to run like poop. This combo should make a solid 300HP.

For a few more dollars you could build a 400HP Aluminum headed motor with a little more stroke and a small double pumper carburetor. You will need to lower the gear to around 3.55 or so, but the throttle response and torque will be ear to ear grinning. Your wife will never even remember the bill after she's felt this set-up.

Just some food for thought. Don't give up....Fords Rule!