318 combo, any type of guess on power?? Finally Kinda finished!!!! pics

[440charger68]

I have a 318 in my 68 dodge charger that was rebuilt about ten years ago and is a solid running motor. Everything looks factory, 2 barrel, cast exhaust manifold and cam. So i decided to see if i can get some power out of it, here is what i plan on ordering.
-600cfm edelbrock carb
-Mopar performance single plane intake manifold (its a air gap) i already have this    manifold
-Summit racing cam 272/272, Lift .454/.454
-Hooker competition headers
-3in exhaust system flowmaster
-Also i might go with the 302 cast number 318 heads and port the hell out of them
Any other suggestions?? I have been saving for a while to get all this done, im only 18 haha so it alot of money to me. Any idea of what kind of horse power gain im lookin at???

[moparguy01]

that exhaust system is WAAAY massive for a 318. I think it will actually end up killing power rather than making it, go with dual 2.25" pipes, and maybe bigger tips if you want the look. other than that use what you can get cheap, its a 318 so its going to be plagued with low compression. Maybe you could get those new heads shaved down abit to make it a smaller combustion chamber to boost up the compression ratio.

[440charger68]

i was told that the mid 80's heads casting#302 have a 58cc closed combustion chamber and i would think that should be fine for compression

[Sublime69]

This may help you:
http://www.dippy.org/forum2/index.php/topic,242.0.html

I have a 318 in my '89 Diplomat cop car with the same Air Gap intake and a 1406 Edelbrock carb (600 cfm), MP distributer and orange ECU, MP wires and the rest is the factory cop stuff (HD manifolds, 360 heads (rebuilt), coolers everywhere, 2.94 Sure Grip etc.)

It runs really good but I'm upgrading to a 360 sometime near the winter months.

I agree the 3" exhaust is too big for that 318. I have a 3" Y-pipe on my Dip, but it has 2 1/4" pipes that collect into it from the manifolds. It's got a 3" Summit Turbo muffler that dumps before the rear axle and makes a pretty cool rumble considering stock cam, CR etc. Definitely makes people look and wonder why anyone would be driving a "worn out" cop car. Smokes the V6 earlier model Mustangs easily

Good luck with your car.

[440charger68]

thank you that helps alot the only thing is my car starts out stock with 235hp as the dimplomat starts with 186hp

[SeattleCharger]

I have a 318 in my '89 Diplomat cop car with the same Air Gap intake and a 1406 Edelbrock carb (600 cfm), MP distributer and orange ECU, MP wires and the rest is the factory cop stuff (HD manifolds, 360 heads (rebuilt), coolers everywhere, 2.94 Sure Grip etc.)

Good luck with your car.

Plus you have the "locked" posi rear on that cop car don't you?  I had a dimlomat cop car around that year, 360 heads on 318, thermoquad 800,  3 sway bars, locked posi, fast ration steering box, heavy springs, looked lowered a little from factory,  was the "salon" model it said on little chrome side tag on front fender.  friggin great in snow too!
  only problem was the secondaries were not hooked up or something, so as soon as it reached mid rpm's it would crap out and starve for fuel, so was obviously never fast at all, don't know if the auction people did that to it or what and I didn't know crap about carbs back then so I never tried to fix it really, but dang that car could take a corner

[moparguy01]

While the 80's heads do have a smaller combustion chamber than earlier models, bear in mind that the pistons in your particular engine will more than likely be quite aways down the hole and that needs to be figured in. I can't remember how far down they are in earlier 318s but when i rebuilt mine they were down a decent distance.

as another note, don't put too much faith into factory HP numbers. most of them are way off from real life numbers, just giving you a heads up so you dont say something to the wrong person and get embarrassed in a race.

[c00nhunterjoe]

the single plane intake will hurt you with that cam. its too small for a big intake, a dual plane would be much better for your application, especially with the heads. porting is a good thing for it, might invest in bigger valves. the 3 inch is overkill but i would go with dual 2.5's. that would be perfect with the headers. in my opinion the 600 is too small as well, a well tuned 650 holley will work wonders on your motor. the 600 edlybrock's are just cruisers, i dont care for them if you are trying to get any kind of real power out of a motor.

[Sublime69]

I have a 318 in my '89 Diplomat cop car with the same Air Gap intake and a 1406 Edelbrock carb (600 cfm), MP distributer and orange ECU, MP wires and the rest is the factory cop stuff (HD manifolds, 360 heads (rebuilt), coolers everywhere, 2.94 Sure Grip etc.)

Good luck with your car.

Plus you have the "locked" posi rear on that cop car don't you?  I had a dimlomat cop car around that year, 360 heads on 318, thermoquad 800,  3 sway bars, locked posi, fast ration steering box, heavy springs, looked lowered a little from factory,  was the "salon" model it said on little chrome side tag on front fender.  friggin great in snow too!
  only problem was the secondaries were not hooked up or something, so as soon as it reached mid rpm's it would crap out and starve for fuel, so was obviously never fast at all, don't know if the auction people did that to it or what and I didn't know crap about carbs back then so I never tried to fix it really, but dang that car could take a corner

Not sure if it's a "locked posi" or not, it's a factory Sure Grip. I know it leaves 2 black marks when you peel out. 

It'll take some sharp corners pretty darn well too for being an old car. My wife has a new Charger and my Diplomat out handles it easily. It's a very fun handling car.

Not sure about 3 sway bars though  , it has 2, one front and one rear.

[Foreman72]

check this out...these articles were very helpful to me...between these 4 i'm gonna build my 318 to 400+ hp and at least 400+ ft/lbs

http://www.popularhotrodding.com/tech/0810phr_chrysler_318_engine/index.html


http://www.moparmusclemagazine.com/techarticles/engine/mopp_0901_318_small_block_budget_build_part3/index.html


http://www.moparmusclemagazine.com/techarticles/mopp_0811_318_small_block_budget_build_part2/index.html


http://www.moparmusclemagazine.com/techarticles/engine
/mopp_0810_318ci_budget_engine_build/index.html

[440charger68]

what cam do you recommend??

[Foreman72]

COMP Cams Xtreme Energy High-Lift series of cams designed just for Mopar engines...i'm going with the XE275HL (231/237 deg, .525-inch lift with a 1.5:1 rocker ratio) part number 20-227-4

[wayfast1500]

IMO don't get a summit cam, I researched them when I built my chevy and heard a lot of horror storys.  Their made from cheap metal and the lobes don't last long.  I got a brand new lunati cam with litters on eBay for $100.

[SeattleCharger]

IMO don't get a summit cam, I researched them when I built my chevy and heard a lot of horror storys.  Their made from cheap metal and the lobes don't last long.  I got a brand new lunati cam with litters on eBay for $100.

ya, I have read firefighter moderator on this site say to get a lunati cam many many times.  At least for big block, but probably applies to all mopar V-8s, don't know for sure, maybe he will chime in here. 

   With a cam and bigger dual exhaust and trick mufflers, your car will sound sweet and be more fun to drive with the sound it makes, maybe won't be real high horsepower, but the fun factor will be worth it of doing all this to your 318 when you drive down the road       

[440charger68]

im not getteing the summit cam anymore i heard a few bad things too this is now the set up i have written down
-650cfm edelbrock carb
-Mopar performance single plane intake manifold (its a air gap) i already have this    manifold
-2.5in complete exhaust system dual
-231/237 deg, .525-inch lift comp cam
-casting number 302 heads with 59cc cumbustion chamber (boost up compression)
-And finish it off with some hooker competion headers
What do you think??

[SeattleCharger]

the single plane manifold  (I realize you already have this, but you can find an old eddy CH4B, great top and low end intake, very similar to an edlebrock rpm intake for 135 maybe on ebay)  is not good for low end.  Unless you have low gears in rear and a big stall, you will have crummy low end probably.  When you try and floor it off the line, it will prob. bog down and sputter pretty much, until you reach higher rpm's?     
  I don't know about the cam specs, interested to hear others opinions. 
    oh ya, why not get  a lunati  cam?   ?
 

[440charger68]

the single plane manifold  (I realize you already have this, but you can find an old eddy CH4B, great top and low end intake, very similar to an edlebrock rpm intake for 135 maybe on ebay)  is not good for low end.  Unless you have low gears in rear and a big stall, you will have crummy low end probably.  When you try and floor it off the line, it will prob. bog down and sputter pretty much, until you reach higher rpm's?     
  I don't know about the cam specs, interested to hear others opinions. 
    oh ya, why not get  a lunati  cam?   ?
 

Im just trying to get some hp out of my 318 so i can keep up with the new cars if u know what i mean  i would like to use the manifold i got now and try to figure out a way to get a combo to work good with it. Its been professional ported to match up with the gasket, its pretty sweet looking and i like the look of a high rise. What the differece between a comp cam and a lunati?? arent both pretty good quality?? Im shooting for at least 330hp in my 318, i was hoping i can do that by cam, headers, carb, manifold, and the late 80's closed chamber 318 heads with a good port and polish job. But any kind of suggestions would be great  i just want to see if i can still use manifold and find a way for it to work with my 318

[440charger68]

heres the manifold i picked up for a 100$ at a swap meet, same brand and everything mine just has some machining work done to it

[Foreman72]

Nice M1!

[ACUDANUT]

Is that M1 a air flow ?

[Sublime69]

I'm not completely sure, but I don't think the 302 heads will bump your compression up at all. IIRC, I have the same heads that came stock on my 318 cop motor and the CR is around 8-8.5:1. You may have to mill them.  

It sounds like a good set-up, the only thing you will need to change is get a set of adjustable rockers for that high lift cam. About the highest lift you can go without shimming etc is roughly a .440 lift. I would also port and polish the heads and possible polish the intake ports to give you better flow for that cam. Swap the valve springs and possibly bigger valves as well 

[440charger68]

well if i mill them by .050 that will make the cumbustion chamber about 52cc my stock 318 heads are about 72cc i think My intake has already been polished. So with the .512 lift im going to need adjustable rockers?

[Hot_Rodder]

If it will be a hyd flat tappet cam, then I don't see the need in it needing adj valve train, unless the cam manufacture suggests running it, but normally the hyd flat tappet cams don't require it. If it were a solid flat or roller then I'd say yes, you'd need the adj valve train. As for the hyd roller, I've heard of those being an adjustable valve train.

[440charger68]

yea its hydraulic roller

[440charger68]

Is that M1 a air flow ?

I think so, not completely sure though, it looks exactly like the one in the pick but mine is polished aluminum and the intake ports have been machined and polished. Is the m1 a good manifold?