Mopar Gurus, I need help on a 318-3 set of heads

I bought a 318-3 motor out of a 68 dodge motorhome to go into my 53 dodge truck and took it to the machine shop for a rebuild. the short block is done, but when he went to do the heads, He found that these particular heads are set up with a water jacket that goes across and heats the intake. He tells me that putting a 1984 318 police 4 barrel manifold on the 68 heads wont work because they are heated with exhaust instead of water. From what he says, the heads I have are kinda rare??? In looking up the numbers (2658234-1) they show to be 67 273 or 318 heads. What I need to know is if there is a 4 barrel manifold that will fit these heads or do I need to find another pair? This is my first 318 build and I sure could use the expertise. thanks in advance. Bud

 

The 318-3 truck heads arent compatable with any aftermarket intakes that Im aware of. If iremember correctly, thay also have sodium filled valves. Your best bet is different heads.
If you can find a set of heads from '87-'91 318 these are the best non magnum heads for a mild built engine, but you can use any passenger car heads from a 318 up to 1991. you can use '92 up magnum heads, but thay require different intake, exhaust manifolds, and basicly all new valve gear.

 

yup, found a site that tells me that my head numbers are the only set of numbers with the water jacketed intakes. just my luck. anybody need a set of heads and intake??? made in 1967 only? anyone.....

 

Can you take some pics of the heads and intake ?Ithought id seen almost every thing Ma Mopar made but this is a first here,seen tons of big block motor home stuff but not this..Dont be so quick to junk of give em away yet,please post some pics i know others would like to see them also...Chime in men if you agree with pics.....YG

 

I will get pics of the heads and intakes, the research I did shows them to be 2658234 heads, made only in 1967. the research says "used only on 1967 trucks with water heated intake manifolds. THis head will interchange with other 318 heads only if a water heated intake manifold is used". Since I need to change to a 4 barrel set up, this will not do me any good, but I will not junk the heads, I figure someone out there might need them and I will try to recoup some of the loss. The heads have already been bead blasted and ready for grinding.

 

Not sure where you are located (where's Stanwood?). But, I've got several sets of 318 heads. If you want a set, PM me and you can have a set of them - either pick them up or pay for shipping. They aren't doing me any good any more. I'll have to look and see what casting they are. I know, however, that they aren't the type you have.

Also, the most preferred heads are typically 302 heads (casting number). They are swirl port heads and seem to flow better than most others. They were available in 85-91 vehicles. I'm don't think I have any of either the 302 heads, though (its been a while since I've looked).

 

PM sent

 

Without seeing a pic of the intake rail, just how much difference in the centre port is there compared to an exhaust port? Are the gaskets similar? Will the 'normal' pass car manifold cover and seal the wet port? If so, why not use them?

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The crossover is isolated from other passages so it wouldn't matter if it was ex gas or hot water. If head/intake passages don't match he could get the openings in the head welded to match the intake, I'd think.

 

If I remember correctly, the 302 heads have the closed heart shaped chambers. Anyone know how much of a compression increase you would get from rennung these?

 

Yep...they are closed chamber. I think all the other heads for small blocks were open chamber.

Compression increases are a little tricky to measure - lots of factors like what pistons and thickness of the head gasket, etc. I think you can get up 10% with a straight bolt-on I think...but I'm not sure on that. The 302's will really come alive with some mild porting.

Mopar Muscle did a "budget build" 318 that got 10:1 using a zero deck short block/piston combo and a .040 head gasket. But, they used Magnum heads instead of 302's. But, its a good guideline for building a nice Mopar small block on a budget. Use this combo with the ported 302's and you'd have a really nice streetable motor. You may not have to go all the way to zero deck, either. Its been a while since I've gone through a 318 and the combos. I'm trying to remember it all!

http://www.moparmusclemagazine.com/techarticles/mopp_0409_318_engine_build/index.html

 

okay...think...heat...riser...choke...are you done...man - doesn't anyone know these LA motors?

 

huh????

 

One could always make a 392 stroker out of a 318 V8,,,,,,,,Whack a set of J heads and port and polish the hell out of them and you would have a real mean machine........................

Good luck with the 318........

 

302's are closed chamber, swirl port heads and were made from 85-91. They can be found on 318's with roller tappets, primarily in trucks. They use a exhaust port design that was inspired by the W2 race heads, and flow better on the exhaust side than most of the other stock 318 heads. They should have 1.88/1.60 valves as well, although they still have the smaller 318 sized ports.

The 302's have 62cc chambers. For comparison, 68-74 318's used 60 cc chambers and 75-80 used 63 cc chambers. I'm pretty sure all the LA 318's have closed chamber heads, the 340/360's used open chambers and larger ports.

The other bad news is if you set your rebuild up around those '67 truck heads you may really have a compression problem, they have 57 cc chambers...

 

YUP, understood. that is why I am looking for the older heads starting with "2". With the right casting numbers, they have 60 cc chambers and can be milled to work.

 

Yeah, thats where I was headed George.

So now the concern is whether or not the 57cc chamber will work or not, correct? Your opening post says that the short block is done, so, what did you do to it? Stock (truck) replacement pistons or something with more compression height? If you used the truck part then the heads will, obiviously, work ok. If you swapped to a taller pass car piston what was the logic and did your machinist not understand the compression issue?

BTW, starting with a 60 cc hole vs a 57 cc hole is a difference of about ½ point in compression. Has the assembly been physically measured for final c.r.?

Doesn't anyone plan ahead these days?


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There was a guy on Hot Rod Magazine's Forum who finished his overhaul & then began thinking of stuff like alloy heads, ect.

 

They are bar none some of the best heads to run on 318's, you can produce some good power, there is a a lot info on them at" For A-Bodies only" website. i ahve a couple sets of heads in my garage also. I'll pull the numbers, let ya have them for cheap.......

 

I think this will help..Pick up MAY-2010 issue of Car Craft mag.There is a pc called Budget building street cyl heads ,and its about the 318 Mopar.Lots of info,best casting #,s ect. Ck it out its on the news stands now and i dont work for Car Craft mag,i got the sub as a Christmas gift.................YG

 

Doesn't anyone plan ahead these days?


.[/QUOTE]

actually, yes, the machinist and I planned it out for a lightly built motor with 30 over pistons and the 57 cc heads that my disabled wife could drive with ease. we even ran everything thru a computer program to make sure all the numbers worked, he cc'd the heads, we just didn't realize the heads were different than all the others. I have since found a set of heads that will still workfor my application. I do think you are a bit presumptious about your planning ahead remark without knowing or asking the full story.

 

I also forgot to say if you ck out e-bay buy a mopar small block book,lots of info for your builder if hes not real familar with chrysler products.I dont mean that in a bad way,i know a Ford guy who knows nothing (except basic,s) about other brands.If he takes his time(your builder) you will be just fine.Ive always liked finding things ive never seen,keep,s intrest up..........good luck...............YG

 

...I'm so sorry, I actually thought that it was the OP's job to tell the whole story in order to get the best information...I'll certainly be more cautious in the future.

 

I appreciate that. actually, I thought I gave enough info to find if I needed different heads or if a different intake would fit. apparently not....

 

You did, but the thread got diverted to comp ratio wich was off the original topic.

 

Ok, I re-read the original post. I previously asked about the differences between the two intake rails, water vs. exhaust. No reply, no pics. Your original post only says that a 4-bbl manifold apparently will not work because of the water/exhaust issue. What do the ports look like? Why will the pass car manifold not work? Is there a port shape issue? Or location issue?


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Pics of the heads and intake manifolds. the first pic is the water heated head, the second is a regular exhaust heated 318 head. the third pic is the exh heated intake and the last one is the water heated intake. I found a set of heads, but when I took the heads off the motor, they had apparently gotten water in the intake at some point and were pretty darn rusty. One of the combustion chambers is pretty pitted. I will take it to the machinist and see what he thinks.

 

I could be wrong, and someone will point out my error, but looking at the pic's the only difference I see is in the heads. So, you're building a daily cruiser, why not use the truck head? It looks like the pass car manifold has the same size and shaped cross-over so gaskets should cover what needs to be covered.
Now, if you live in cold country and plan on driving in cold weather then exhaust heat is a good thing. If you are in warm-hot country then the water is a better deal.

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I understand what you are saying, I was wondering the same thing when I looked over the intakes. The web site I found says they can't be interchanged, it doesn't say why. I live in the western part of Washington state, we get more cold than hot weather.

 

good job!