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?

[Hot_Rodder]

As you might already know, the single plane intakes are good for motors that are going to be turning higher rpm's, great on race motors. Dual plane intakes are good for idle, or off idle, motors and up to a mid to higher rpm range, nice street intakes.... There's nothing wrong with an M1 intake as far as I can tell. As it's been suggested, since you are pretty much going to be on the street with an automatic tranny, it is suggested to try and hunt down a nice priced dual plane intake b/c it helps out in the department of lower end torque (off the line power).

On my '72 it came with a low deck big block (these usually love higher rpm's), I was told that it was a 383, when they got the car that's what was in it (not original either way though), when I pulled it, well, it ended up turning out to be a 361, joy.... I don't have that anymore, got rid of it for good reason. Anyway, it had an Edelbrock TM6 single plane intake on it, this I kept more for looks. The intake that I'm going to be running on the 505 that I'm in the process of building will have an Indy cylinder head dual plane intake. This is supposedly the largest dual plane intake that you can currently get for big block Mopars... I'm not suggesting this intake for you esp at the price.... You do not even want to know, just trust me on this.

As for your choices, if you want to keep your intake, that's fine, it's your car, build it the way you want. As for making suggestions, I would say look into an Edelbrock Performer RPM...
RPM regular: http://www.summitracing.com/parts/EDL-7176/
RPM Air Gap regular: http://www.summitracing.com/parts/EDL-7576/
RPM Air Gap polished: http://www.summitracing.com/parts/EDL-75764/
There are more to check out here, as reference, http://www.summitracing.com/search/Make/DODGE/Engine-Size/5-2L-318/?keyword=Edelbrock%20Performer%20RPM%20intake

Now these prices are higher than you paid for yours, but if you look around, you can find one of these used in great shape for cheaper. Also, if you did decide to go ahead and go this route, you could always resale the intake you bought, or hang on to it for another motor down the road....

Hope this helps some...

Also you can check this link also, lists all the intakes that Summit carries.... http://www.summitracing.com/search/make/DODGE/engine-size/5-2L-318/engine-family/Mopar-small-block-LA/Department/Air-Fuel-Delivery/Section/Intake-Manifolds/?Ns=Price|Asc

[firefighter3931]

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??

I would make a few changes ;


The M1 single plane is all wrong and you won't like it. That manifold is better suited to a race 340-360 or a street/strip smallblock stroker with 400+ ci displacement. You need a dual plane because the car is heavy and you don't have a lot of cubes. Torque and as much of it that you can make is the right way to go.

Here's an intake/carb combo that should work real nice for you :

http://www.summitracing.com/parts/CMB-03-0171/

The 302 heads are excellent and will bump the compression up. Just do a good valvejob and use the appropriate valvesprings to match your cam and leave them alone. Hogging them out will reduce velocity and hurt throttle response and low end power.

That cam is a little on the large size for a mostly stock 318. I would use something more conservative like the Lunati 220* VooDoo grind. It will make better power down low where you need it yet still pull well up top. It's easy to overcam a small engine so be careful. This cam will work fine with the stock torque converter as well :
 
http://www.summitracing.com/parts/LUN-60402LK/



Ron

[SeattleCharger]

40charger68,     that carb/intake deal is a great deal for a holley carb AND a weiand dual plane intake,

   If I was you, I would follow what firefighter says exactly, I don't know that much, but from my time on this site I will say that he has to be a rocket scientist of mopar building or something, no kidding,   
Nate

[Sublime69]

I'm not sure where you're thinking of getting that much of a compression bump on a 318 by using the 302 heads. The stock compression with the closed chamber 318 heads is about 9:1, unless that's what your shooting for.

You could always swap to the Magnum heads if your looking for an easy power adder. They're easy to find too.
http://www.dippy.org/forum2/index.php/topic,295.0.html

As far as the rocker arm debate goes, I'd make the switch. The stamped stuff can be hardly called dead-nuts 1.5 ratio...more like 1.4 or thereabouts really. You do have the chance of punching through the rocker, especially on a used set. I've done this myself as well, impaling rocker arms. Finally, depending on how the cam was ground, the extra lift may be coming from a smaller base circle - that means the lobe height itself stays the same, but the opposite side of the lobe gets ground down, effectively, causing the lifter to travel further up as it rides up the lobe from that base circle area. Anyways, if the base circle is small you may not be able to use the stock pushrods and stock rocker arms, either one will have to be replaced. The proper pushrod length is probably the more critical thing here though. So if you get the right pushrods you may be able to re-use the rocker arms.

With due respect though, I have to point-blank disagree with some of the other guys on the non-adjustable rockers here...adjustable rocker setups are NOT solid cam only these days, way back, yes, not now. Heck, put a nice anti-pump up lifter on a hydraulic cam, set lifter pre-load to 0" and you've got yourself a nice 500 RPM for free.

The thing I like about the stock rocker set-up though is just bolt on and go, which doesn't sound like your doing here. 

[SeattleCharger]

ok, didn't mean to discount other's knowledge when I said my opinion of firefighter being an expert, lots of knowledgeable people here, that's why this site is so great   

[firefighter3931]

I'm not sure where you're thinking of getting that much of a compression bump on a 318 by using the 302 heads. The stock compression with the closed chamber 318 heads is about 9:1, unless that's what your shooting for.

You could always swap to the Magnum heads if your looking for an easy power adder. They're easy to find too.
http://www.dippy.org/forum2/index.php/topic,295.0.html

The 302's are approx 10cc smaller than the heads that would have originally come on that engine and also employ a modern high swirl closed combustion chamber. This is a no-brainer upgrade, inmo.

As far as the rocker arm debate goes, I'd make the switch. The stamped stuff can be hardly called dead-nuts 1.5 ratio...more like 1.4 or thereabouts really. You do have the chance of punching through the rocker, especially on a used set. I've done this myself as well, impaling rocker arms. Finally, depending on how the cam was ground, the extra lift may be coming from a smaller base circle - that means the lobe height itself stays the same, but the opposite side of the lobe gets ground down, effectively, causing the lifter to travel further up as it rides up the lobe from that base circle area. Anyways, if the base circle is small you may not be able to use the stock pushrods and stock rocker arms, either one will have to be replaced. The proper pushrod length is probably the more critical thing here though. So if you get the right pushrods you may be able to re-use the rocker arms.

With due respect though, I have to point-blank disagree with some of the other guys on the non-adjustable rockers here...adjustable rocker setups are NOT solid cam only these days, way back, yes, not now. Heck, put a nice anti-pump up lifter on a hydraulic cam, set lifter pre-load to 0" and you've got yourself a nice 500 RPM for free.

The thing I like about the stock rocker set-up though is just bolt on and go, which doesn't sound like your doing here. 

Points taken on the rocker arms but i'll add this : we're talking about a very mild cam profile here with modest spring pressures and less than .500 lift at the valve. The reduced base circle is a non-issue on a cam of this size and the stock rockers are more than adequate. On a build like this i doubt you would see more than a few horsepower difference going to a higher ratio. Not really worth the added expense inmho.

Engle also uses a fast rate of lift lobe design and many are running the stock valvetrain with zero issues. Sure the rocker ratio is less than desirable but in the context of a mild street machine the stock stuff is in most cases more than adequate. I've known of one guy who ran a .540 lift hydraulic stick in his 360 and raced the car for years....using all the stock valvetrain components and with zero failures.....hundreds if not thousands of passes. Is it perfect....No, but it gets the job done and his engine makes enough power to run mid 11's in a Duster.



Ron

[440charger68]

Wow im vary happy with this forum  alot of great tips and suggestions so here is my new set up let me know what u think....
-Edelbrock 650cfm carb
-Edelbrock air gap intake manifold
-Lunati 262/268, Lift .475/.494
-Hooker Competition Headers
-Summit dual 2.5in exhaust system
-302 heads with a good port and polish job
-and maybe some heavier duty valve springs
What do you guys think?? improvement yes

[SeattleCharger]

Wow im vary happy with this forum  alot of great tips and suggestions so here is my new set up let me know what u think....
-Edelbrock 650cfm carb
-Edelbrock air gap intake manifold
-Lunati 262/268, Lift .475/.494
-Hooker Competition Headers
-Summit dual 2.5in exhaust system
-302 heads with a good port and polish job
-and maybe some heavier duty valve springs
What do you guys think?? improvement yes

  I would be curious what is the best price you can find on the two items above, Eddy carb/intake, compared to the link Ron put on here of the holley carb and weiand intake:
                    http://www.summitracing.com/parts/CMB-03-0171/

[Foreman72]

Wow im vary happy with this forum  alot of great tips and suggestions so here is my new set up let me know what u think....
-Edelbrock 650cfm carb
-Edelbrock air gap intake manifold
-Lunati 262/268, Lift .475/.494
-Hooker Competition Headers
-Summit dual 2.5in exhaust system
-302 heads with a good port and polish job
-and maybe some heavier duty valve springs
What do you guys think?? improvement yes

  I would be curious what is the best price you can find on the two items above, Eddy carb/intake, compared to the link Ron put on here of the holley carb and weiand intake:
                    http://www.summitracing.com/parts/CMB-03-0171/

sounds awesome...air gap is the best...

might i suggest the following carb 

http://www.holley.com/0-80670.asp

[440charger68]

yea maybe a carb switch too will be nice