'72 Dart bone stock 318/2bbl upgrade

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coolhandluke

coolhandluke

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I bought a '72 Dart a week ago, and want to do some upgrades. It has a 318 with the original 2 barrel carburetor, but it has electronic ignition (I don't think they came with electronic in '72?) The engine runs great, other than a little hesitation just off idle, which I attribute to the original carburetor. I want some more power, but keep the fuel mileage. I bought a Edelbrock performer intake on here and a holley 600 vacuum secondary on here. I also have a set of hooker competition headers in my garage from a project years ago, that I had forgotten about and just recently found. I've been thinking about either finding some 302 casting heads, or I have a set of J heads off a 360 (can't remember the casting number). I'm also thinking about a small cam, like one of these two
http://www.ebay.com/itm/COMP-MOPAR-...pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr
http://www.ebay.com/itm/27082756415...59&viewitem=&sspagename=STRK:MEWAX:IT&vxp=mtr

I know I'd have to have the 360 heads shaved a bunch to get the compression up, but what would be my better choice in the end, and will the performer intake work with my 318 heads I have now?
Thanks!
Luke
 
The eddy intake will definitely fit your stock heads-it's designed for the 273-318 smaller ports. I recall reading an article in Hot Rod a few years ago where they took the 302 heads, cut them for 360 valves, did some portwork and yielded a pretty nice little street engine. I can't recall the power output, but I'm sure a quick google search will yield the results.

My '72 Scamp had the same little 2bbl Carter with the off idle stumble. I just dropped in a 5.2 Magnum out of a '98 Dakota, and thus far the mileage seems no worse with a 4bbl Summit 600cfm vac sec carb (similar to a Holley 4010), so your Holley 600 should work just fine with a little tinkering.

Look up SirDan-he has a later Dart with a '70 front end (IIRC) and he's done much the same thing you're looking at. I believe he went with a 340 cam in his 318 as opposed to the ones you're looking at there, however, the 262 would probably be a good choice.

I'll claim my ignorance with the heads, but IIRC, the J heads would have to be shaved a pretty good bit to get CR back up to around 8.5:1 or so (0.040" rings a bell for some reason) and with that much material removed, your valvetrain geometry would need to be adjusted probably by shorter pushrods...otherwise potential engine damage could occur with non-adj rockers (flat lobes comes to mind-if not p/v clearance).
 
Now the next question I'm wondering about is when I'm changing the heads and everything should I put the hooker headers on, or leave the stock manifolds on and save up for some TTI or Doug's headers since I've heard so much bad stuff about the hookers?
 
I would use the 302 heads. Have a good valve job done on them, and do a little portwork. I would use this cam
with your headers and 2.25 or 2.5" dual exhaust. I think it would be strong running car with good economy.
 
Im planning on using the XE262 in the 318 in my Duster, Stock TQ intake and carb, stock 340 manifolds. The smaller cam would probably be plenty though.
 
Would it be worth the money going with bigger valves like the 2.02/1.60 they went with in the Hot Rod article, or would it not be worth the $200 or so it would cost me?
 
2.02 VALVES ARE OVER KILL FOR A MILD 318/ 1.88S WOULD BE ENOUGH.

oops, sorry for the caps,. LOL
 
I use that cam and it is great, lots of torque from high port velocity at lower rpm. Agree 1.88's max for what your doing, any bigger valves, ports or cam will reduce torque and fuel economy. If your thinking of going to the next level of performance with a 318 it's all about the upper rpm range and HP only. Your combo with the 302's not the 360's will give you close to 300hp and well over 350tq.
 
1.88 valves are stock 360 size, so any engine parts dealer should be able to hook you up there, and the exhausts are bigger for 360 as well (1.60")-pretty sure the stock 318 exh are 1.50...you'd probably be ok using them, but upgrading to a 1.60 probably wouldn't hurt.
 
Yup, use the 1.60 exhaust. Or better yet buy a set of EQ Magnum heads, Its probably cheaper then redoing you 318 heads or finding some 302s.
 
txstang84 said:
Look up SirDan-he has a later Dart with a '70 front end (IIRC) and he's done much the same thing you're looking at. I believe he went with a 340 cam in his 318 as opposed to the ones you're looking at there, however, the 262 would probably be a good choice.
Click to expand...

I had a edelbrock 600cfm, ld4b intake, 340 cam and a set of headers on my original high mileage 1973 318 motor. It ran really good until It got a rod knock. I only got 10-12mpg but I never tuned the carb. Now I am building another 318 with 360 heads and planning to overcome the low compression with forced induction at some point.:D

Your motor will go good with a few bolt on parts. 302 or EQ magnums would be good, i just checked and the EQ mags are available in a la intake pattern so your intake will work. Also a bit higher stall converter will help the 318 as it doesn't have much down low grunt.
 
I'd follow moturbopar or AdamR's cam advice, stick with the stock valve size 318 heads and add the intake and tuned carb with the headers. The biggest advantage you can give the car is a decent set of gears. With the cam's above, you'll not need a converter with the cam. Just add 3.91 gears or better and a 26-1/2 to 27 inch tire. Letter rip and rip she'll do.

IF you want to keep the 318 heads, just port them with 360 valves from Ferra.

Keeping your heads vs. a new head purchase is a catch 22 between a better more expensive head or making the OE head better, but not quite toe to toe standing with a new head, for less.
 
coolhandluke said:
I bought a '72 Dart a week ago, and want to do some upgrades. It has a 318 with the original 2 barrel carburetor, but it has electronic ignition (I don't think they came with electronic in '72?)

My GF (now wife) ordered a new 1972 Satellite Sebring Plus in October 71. She came up with a preliminary list of options and asked me my opinion. I had her add the dual body-colored racing mirrors AND the electronic ignition. She went with the 318. Can't remember the price ($30?) but it WAS an option on the 318 and definitely standard on the 340's for 72. Maybe later in the model year it became standard.
Click to expand...
 
Yep, very true. It was an option in '72, standard in '73.
 
Where can I find more information on the EQ magnum heads?

And 3.91 gears??? I had 4.10's in my scamp for awhile, and it ran the 318 in it so hard at highway speeds that it killed the motor pretty quick. I'd be scared of anything higher than a 3.73 before I get my 5 speed in.
 
If you drive on the hiway much i would look at 3.23 or 3.55s. After running comp cams and lunati cams, I have been happier with the lunati brand. if you are going to use 1.88 1.60 you will need to have the pockets bowl hogged and blended, otherwise you wont see much gain for the cash.
 
I had 4.10's in my Cuda for the last ... Oh goood gravy, Umm, I think it's been 20+ years. Spinning the engine @ approx. 3300 for the Hwy. It was a slow go. You can not travel consistently at 3K plus and expect it to live a long time with thrashings in between. I have used that engine for approx. 10 or 11 years before I toasted it racing. (No oil system mods are a bad thing above 7,000 RPM.) It also had several cam changes, intakes, carbs, headers changed out on it. Just to see what happens, how it performs, acts, reacts etc.......

The numerical lower gear set should also use a smaller tire. I used a 3.21 sure grip equipped 8-1/4 in my last Duster with a Crane cam with very similar spec's. IIRC, the tire was a 225/70/14. I do not know the RPM which it cruised at. No tach. IMO, I think it a good combo for daily driving and the abilty to hustle a bit. I could get 17 MPG's on the Hwy. Not great, but, not bad either. It was a very tired low comp. 318 with over 300,000 miles when the record keeping ended in 1989.

I very much agree with the above statement of bowl porting with the bigger valves. Even with the OE valves, it would be a nice improvement, but I wouldn't do it unless I used the bigger valves.
 
coolhandluke said:
Where can I find more information on the EQ magnum heads?

And 3.91 gears??? I had 4.10's in my scamp for awhile, and it ran the 318 in it so hard at highway speeds that it killed the motor pretty quick. I'd be scared of anything higher than a 3.73 before I get my 5 speed in.
Click to expand...
INFO:


http://www.streetlegaltv.com/news/eqs-magnum-cylinder-head-provides-durable-alternative-to-stock/

http://blogs.popularhotrodding.com/6625159/tech/small-block-mopar/index.html

Purchase;

http://www.4secondsflat.com/FBO_EQ Cylinder heads.htm

http://www.dragtimes.com/parts/NEW-DODGE-EQ-MONSTER-MAGNUMS-318-360-CYLINDER-HEAD_370227327117.html
 
Well, I'm getting the 302 heads. I found a guy in TN who has some, who wants to trade me for a set of Ford 351 heads I have sitting around that I got for free. I have my intake and carburetor coming, so all I really need now is my cam. Should I go ahead and replace the springs even if they don't seem too bad?
 
Get new springs to match the new cam.
 
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