Another guy with a 318 build
08-06-2013, 04:44 PM
#31
Mopar Fanatic
2.02 valves ? Where's your RPM range with a 318? 3000-7000+?
A stock pair of Magnum heads with small chambers & ready to run on unleaded gas & really nice sized valves use cheap narrow body(centerbolt small block chevy) roller rockers
A cheap & easy 75 - 100 horses without mods on a smogger LA just in flow & chamber size
A stock pair of Magnum heads with small chambers & ready to run on unleaded gas & really nice sized valves use cheap narrow body(centerbolt small block chevy) roller rockers
A cheap & easy 75 - 100 horses without mods on a smogger LA just in flow & chamber size
08-06-2013, 04:57 PM
#32
Mopar Fanatic
Here's a 59k 75' 360 that's got Mag heads that I'm doing right now I've got just enough Purple Stripe for it to run the A/C & should make 350 horse when I'm done
This combo with stock rockers 1.6 ratio steel made 330 horse through 92 model Magnum manifolds on the Dyno with a 4412 Holley
This combo with stock rockers 1.6 ratio steel made 330 horse through 92 model Magnum manifolds on the Dyno with a 4412 Holley
08-06-2013, 05:37 PM
#33
ive seen the heads on a 318 with no issues. if the heads were cut woth a stock bore on a smog motor nabey but if anyone said they were doing that to my block id tell them to eat dick
08-06-2013, 07:22 PM
#36
Mopar Fanatic
What RPM range does the OP want his 318 to operate in?
A mid 70's B-body Charger?
More power without sacrificing too much economy I think were his words.
X-heads & a XE268h cam + 318 makes for power beginning around 2700-3000 RPMs
That X-Headed 340 with a A/T came standard with what is called a Factory Hi-Stall converter (2200 RPM) in a 3200# A-body with less camshaft.
I'm not knocking X or J heads I've used them for years & years but on a 318 in a 3700# or more B-body I just don't see the use
A mid 70's B-body Charger?
More power without sacrificing too much economy I think were his words.
X-heads & a XE268h cam + 318 makes for power beginning around 2700-3000 RPMs
That X-Headed 340 with a A/T came standard with what is called a Factory Hi-Stall converter (2200 RPM) in a 3200# A-body with less camshaft.
I'm not knocking X or J heads I've used them for years & years but on a 318 in a 3700# or more B-body I just don't see the use
08-06-2013, 07:38 PM
#37
nmw hes not going to get fuel economy lol. x heads will breath the best for him the only down fall is the price. x heads are money and mags are dirt cheap. i will say this mag heads built are really good
08-06-2013, 07:54 PM
#38
Mopar Lover
I did a 318 with J's 2.02" + 1.60" a 284 .484" purple and 2500rpm converter.
Off idle it was a mutt, once it hit 3500rpm it was like someone turned a switch and went like hell up to 6500rpm. It sounded real snotty, was a lot of fun but I would do it different now for the street.
Off idle it was a mutt, once it hit 3500rpm it was like someone turned a switch and went like hell up to 6500rpm. It sounded real snotty, was a lot of fun but I would do it different now for the street.
08-06-2013, 08:37 PM
#42
Mopar Fanatic
We built a 318 with X's & the same cam we ran in our 340's & had to change the gears from 5.38's to 5.56's to get it out of the corner 7200 RPM down the straightaway & still pulling
09-06-2013, 01:51 AM
#43
09-06-2013, 09:30 PM
#44
My ten cents:
318 is an excellent motor. When set up right you can get good mileage and great power.
If you have heads and valves that are good then run them. But I wouldnt spend a nickle on old castings unless they were free and even then it would have to be a restoration or something of personal valve.
The technology is ancient and when you add up the gains vs dollars, its poor.
You can use the magnum heads on 318 you just need and oil thru lifter from an amc and an oil thru pushrod. You get the best flowing head they made for the small block with better oiling, a 62cc chamber with better design and a light 8mm valve.
EQ and RHS make excellent castings and can be set up for short money with a 5/16 chevy valve.
318 is an excellent motor. When set up right you can get good mileage and great power.
If you have heads and valves that are good then run them. But I wouldnt spend a nickle on old castings unless they were free and even then it would have to be a restoration or something of personal valve.
The technology is ancient and when you add up the gains vs dollars, its poor.
You can use the magnum heads on 318 you just need and oil thru lifter from an amc and an oil thru pushrod. You get the best flowing head they made for the small block with better oiling, a 62cc chamber with better design and a light 8mm valve.
EQ and RHS make excellent castings and can be set up for short money with a 5/16 chevy valve.
09-07-2013, 06:13 AM
#47
X and J heads are great. Set up correctly they are good runners. No doubt. And for a true resto or OE engine I would run them all day!
My point:
I would not go bone yard picking technology that old if you are starting from scratch for a "street driver". Much better stuff out there. Recast (EQ or RHS) Magnums with a 2.02 valve will flow 245+ out of the box. No porting or grinding needed. Stock Magnums flow better than X or J heads. And with machining costs today there is no value to putting the time on those X or J heads for a street runner (Meaning the total cost of machining per achieved CFM needed is poor). Money could be better spent.
A simple price sheet on dollars needed to reach say 225 cfm with a light valve on X or Js to help the rpm range desired in the 318 build above will prove the point.
My point:
I would not go bone yard picking technology that old if you are starting from scratch for a "street driver". Much better stuff out there. Recast (EQ or RHS) Magnums with a 2.02 valve will flow 245+ out of the box. No porting or grinding needed. Stock Magnums flow better than X or J heads. And with machining costs today there is no value to putting the time on those X or J heads for a street runner (Meaning the total cost of machining per achieved CFM needed is poor). Money could be better spent.
A simple price sheet on dollars needed to reach say 225 cfm with a light valve on X or Js to help the rpm range desired in the 318 build above will prove the point.
10-15-2013, 09:30 AM
#48
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Looks like this post has been dead for a little bit but I am planning a similar 318 build for my 70 Charger. Been looking at the Comp 268H and XE262 cams, kb167-20's, ARP rod bolts, 596 or Magnum heads, dual plane intake, 650 carb, long tube headers....... In desktop dyno the 596 heads and 268H cam are getting similar numbers to the ones seen in the above simulation post. There's some changes to make to convert to Magnum heads like different intake, the proper lifters, special length pushrods and such but there is plenty of info on the conversion out there and I have heard that it's worth the extra work. I haven't run simulations with the Magnum heads yet, I hear they work real well with single pattern cams like the 268H, maybe I will do that today if I get bored.
Last edited by 7T_ChargerBlues; 10-15-2013 at 09:48 AM.
10-15-2013, 10:06 AM
#49
I like the kit idea from one manufacturer.
As far as the 256 goes, it is the best cam I have had in 35 yrs that matches this application. Maybe I'm wiser and don't over cam everything like I probably have in the past.
It's a '92 D250 with an LA, stock lock-up torque convertor 904, 3.91 9.25". I thought it was pretty spunky but always felt like it needed one more gear. We just finished putting in the other axle with new everything, Auburn LSD and a 3.55 gear. My son has been breaking it in and he says with the 3.55 it pulls harder, likely 'cause it has the engine in the right rpm range to use the torque. Very happy with the XE series cam.
As far as the 256 goes, it is the best cam I have had in 35 yrs that matches this application. Maybe I'm wiser and don't over cam everything like I probably have in the past.
It's a '92 D250 with an LA, stock lock-up torque convertor 904, 3.91 9.25". I thought it was pretty spunky but always felt like it needed one more gear. We just finished putting in the other axle with new everything, Auburn LSD and a 3.55 gear. My son has been breaking it in and he says with the 3.55 it pulls harder, likely 'cause it has the engine in the right rpm range to use the torque. Very happy with the XE series cam.
point is, getting into the right rpm range is very important.
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