Money, Money, Money 4 heads.

[diego-ted]

I want to do some head work to boost the H.P. of my 318, What is the least expensive but most productive way to go.

1. Have my existing heads worked.
2. Buy a set of 360 heads and have them milled.
3. Buy a set of 302 cast heads and have them upgraded, valves springs ect.

diego-ted

[72Challenger]

Like most things performance related, the correct answer is:

It depends.

Yeah, I know. You're welcome. But really, it depends on how you intend to use the engine. You asked how to boost the HP for the least expense. If that's all you care about, then the 360 heads are the way to go.

But if you're going to drive this car on the street, that may not be the best answer. Part-throttle drivability and gas mileage will suffer compared to a set of worked 318 heads.

Also, if the valves and guides are shot on the 360 heads or the 302s, you're going to end up spending a pile anyway. Maybe as much as a set of new Edelbrocks.

Tell us how you plan to use the car, we'll give you better answers.

[diego-ted]

well, mostly I plan to use the car on the street, not as a daily driver, but as a weekender, However I want to be able to "smoke em" when I want, but I want it to be fair on the hiway. I will put in a mild cam, I have the MP ignition upgrade, and headers. I will run 245 tires in the rear.

[72Challenger]

Hmmm, still sounds like some conflicting parameters. Most people who have a "weekender" tend to want something a little radical. You say you want it to be fair on the hiway and you plan on using a mild cam. Okay, so it's more of a weekend cruiser. Fair enough.

For the best throttle reponse and low end torque, the 302s are your best bet. They will keep port velocity up, which will improve throttle response and give you good off-the-line power. The swirl ports will allow you to run a slightly higher compression ratio. You don't mention if you are running an auto or stick, or what your rear-end ratio is. Also, those 245 tires can have a wide range of diameters depending on aspect ratio. 14" or 15" (or larger)? What manifold are you planning on running? Cam? Carb?

Planning a complete package can be time consuming, but it's the only way (except for pure dumb luck) that you will get the most for your money, and be happy with the results. Start by defining exactly what your goals are. Then tell us all the details about what you already have, and how much money you can spend. What sort of skills and tools do you have? There is a tremendous amount of knowledge on this board and we'd be happy to help you, give us more to work with and we'll be able to offer more help.

[turbododge]

Unless you are looking to go over 350 hp, use the 302 casting 318 heads, with a little work on them.

[Doug Wilson]

If you just want to warm it up a little, port-matched and bowl ported 302s sound good to me.

I know that it's tough to do, but the very best approach for me is to: 1st- define your budget over what period of time, like $150.00 per month for 18 months. 2nd - figure out how you'll be PRIMARILY using the car - try not to kid yourself on this one - if what you really want to be able to do is a big smoke show in the parking lot now and then - then make that your goal. 3rd - look closely at what you are starting with - if you have 100,000 miles on the short block, you probably don't want a 300 horsepower nitrous shot, unless a new short block is in your immediate future. 4th - the hard part is to be harshly realistic about what you CAN accomplish versus what you'd LIKE to have.

Let us know all the details about your car that you can, and we will all give you our best advice.

There are some super-sharp people on this forum who will give you as much help as you want (someteimes WAY more than you want).

Good luck from... Doug

[diego-ted]

My goals with this car are as follows, I want a car that has some pull on the low end, able to smoke the tires and make you take notice. I want to be able to drive 8 hours straight if I want "to go to events" and not have any problems. I know with my 318 I am not going to try and out run the big boys in the 1\4 I just want good all around performance. This is what is in the car now.

Re-manufactured Napa 318
Re-built 904 slapstick with a shift kit "not sure which one"
8 3\4 with 325 gears
eddi 650 carb with aluminum intake
headman headers
MP performance ignition "orange"
I will run 245-15s on the rear.

This is what I want to do
I will install a mild cam with double chain rollers
Some sort of head work

Please bare with me, I am new to this MOPAR stuff, but I am excited. One of the mechanics I know says I should just forget about the 318, and put in a re-built 360. Money is tight, but more importantly I do not want to waste it. How much will it cost to do the head work on the 302's?

Thanks for all the help.

[rumblefish360]

At tony's page there a 2 318 build ups. I like the larger camed build. There the same minus cam, but can vary with ease from each other. He did some homework on the matter. A good job really. I like to recomend this to people with the weekend warrior idea, but mild manored enuff to cruise wants. After the peek at it, click on the 360 build ups and see what your mech.'s are talking about. Food dor thought for the future.
http://www.geocities.com/alwest_83/index.html

[Doug Wilson]

Ted - Do you know how many miles are on the short block?

Have you figured out a budget?

How good are your mechanical skills?

Do you enjoy wrenching on your Challenger?

If your short block is new or in pretty good shape (compression test is in order), then you can probably get 275 Horsepower from it without a great deal of expense, and with not (much) danger of blowing it up.

If you are willing to chance doing your own head work, you can save a bunch. If you send your heads out, or buy a set from a reputable porting service, you can expect to spend $400 to $500 for a mild job - plus core if you buy them direct. If you do it yourself, you should buy a set from a wrecking yard and expect to wreck at least one head. As a novice at porting, and doing it slowly and carefully, you will wind up with maybe 100 hours in them before you are ready to bolt them on. Templates for porting are available from MOPAR Performance for around $30.

On the other hand, you can buy a complete set of Edelbrock heads for about $1200, and bolt them on next weekend - probably should get the closed chamber ones (guys??) - and go. I put these on a fairly hot 340 and you really get a lot of benefits from them - including better HANDLING!!!, 'cause they take a bunch - 40 pounds - off the front end. They are a no-brainer, look sharp, and work nice.

Right now, if you put in a 360 short block, and bought some wrecking yard 360 heads, you could put on the components you already have, have the heads freshened, put in a decent cam (which you're going to do anyway) and drive away with 300 to 325 horsepower, and more street development potential than you can get with your 318. That could be achieved with unported iron heads for maybe about $2000.

The preceding are issues that need to be addressed through your budget and time constraints.

You have already made a great start by hooking up with the folks on this forum, most of whom - like ... well I was going to name some names, but the list would be too long to fit - anyway, there are some true experts and professionals here that will help along the way. Besides them, I'll be here to spread Fear, Uncertainty, and Doubt.

[rumblefish360]

Yep, closed chambered heads they are. The standard issue units (If you will) will be fine. The other units are for the pop up pistoned 340.
The flow of these heads are about equal to mildly ported iron heads. The port windows are 340-360 sized. That will create a little low end loss. Of course that is the normal trade off for Hi end HP.

[Doug Wilson]

That from one of those really smart guys I was tellin' you about!!