198ci

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1970Dart198

1970Dart198

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Compared to the much more plentiful 225's and 170's, the 198 seems like the oddball of the group. I know it was introduced to make production easier by using the same block as the 225, but why make different models of the slant 6? I have a 198 (3.2 L) in my Swinger, and I was just wondering the specs/performance and pros/cons, and maybe why it was taken out of production in the mid 70's.

I've heard of some performance build with 198 rods in a engine and was wondering if someone could elaborate on this?

Thanks
 
It goes back to the initial introduction of the /6. Originally the 225 was for the larger cars while the 170 was intended for what became the A-body. The 170 was about sipping fuel while delivering the car to its destination. FWIW, FoMoCo offered a 170 in the Falcon and Rustang. As engines lost power due to emissions requirements, the 170 became a performance liability which led to the development of the 198. The 170 used a shorter block, while the 225 and 198 used the same block yielding some cost savings at a time when Mopar needed it.
The 198 uses the longest connecting rod of the 3 Mopar /6 engines. To over-simplify the modification, installing the 198 rod in a 225 raises the piston in the bore raising compression ratio. Go to www.slantsix.org and do a search on long rod 225 for details. Since the 198 was made for such a short period of time, not many rods are out there.
 
why make different models of the slant 6?
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Mostly so as to charge money for the optional 225. The 198 and the 225 cost Chrysler the same to dress, build, and install, and the fuel economy difference was negligible. When Federal exhaust emission and fuel economy type-approval testing grew more complicated and expensive and the increasingly strict emission limits started taking a bigger bite out of performance and driveability because the US auto industry wouldn't spend the money to do the job properly, the 198 turned from a cash-maker to a cash-coster, and so it was dropped after the 1974 model year.

(Interestingly, the 1970-'71 198 gave better driveability than the 225; the Carter BBS carburetor, used on the 198, worked better than the Holley 1920 they put on the 225 in those years)
 
This is why I like my 198, its a unique setup in an already unique engine. I have a holley 1920 with it right now. I've done some minor modifications with the fuel line and electronic ignition to make the engine a pretty decent daily driver. Any other tricks (like the ngk spark plugs) to increase driveability?
 
Are you sure you have the 198 in the car ......on several occasions I have come across cars coded for a 198 and in fact they had a 225 under the hood. I don't know if that is co-incidence or if someone (dealer maybe) was changing them for a reason, but I have seen this repeatedly.
 
slantsixdan said:
... the 1970-'71 198 gave better driveability than the 225; the Carter BBS carburetor, used on the 198, worked better than the Holley 1920 they put on the 225 in those years)
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Encouraging, since my 64 225 slant has a BBS. It idles so smooth you can hardly tell the engine is running. I fought w/ a 1920 in my 69 Dart for decades before I finally got a good one that made it run perfect.

198 in^3 (3.2 L) is not small compared with many current engines. It may even be better after turbo-charging than a 225. Most turbo'ed engines are much smaller than their NA brethren, say 1.8 L vs 2.4 L in a 4-cyl, yet produce more power and performance. Add MPFI and electronic ignition and 3.2 L should more than suffice for such a light car.
 
RaniDart70 said:
Are you sure you have the 198 in the car ......on several occasions I have come across cars coded for a 198 and in fact they had a 225 under the hood. I don't know if that is co-incidence or if someone (dealer maybe) was changing them for a reason, but I have seen this repeatedly.
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Most likely the reason is that 225s vastly outnumber 198s, so when it came time to swap in a replacement engine, a 225 was installed.

(How are you (particularly) discerning a 198 from a 225?)
 
slantsixdan said:
Most likely the reason is that 225s vastly outnumber 198s, so when it came time to swap in a replacement engine, a 225 was installed.

(How are you (particularly) discerning a 198 from a 225?)
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I had three cars come out of a local yard and I checked the displacement on the block rail right behind the alternator. All three were "B" codes on the vin and all were 225. And I heard someone else here on FABO say he saw the same thing.

Because of that I have had three 198 slant six cars, yet I have never actually had a 198 engine
 
I also heard that the 170 was developed for government use. Back in the day a government organization (I want to say post office?) had a restriction on the amount of cubes (had to be below 200 c.i.). Which I think was why the 170 was created. I never heard of the 198, interesting...
 
Having daily driven all three, 170, 198 and 225 A bodies they all gave different experiences.

The 170 is in my '64 dart with a 3 on the tree and 3.23 gears. It gets mid 20s mpgs all day long and is a quick revving engine that's fun to drive.

The 198 is in my current daily driven '70 Swinger backed by an auto an 3.55 gears. It gets high teens for mileage and is a super smooth runner. However it's a fairly boring drive and the motor is uninspiring to drive and while torquey, it is much less sporty to drive than my 170.

My last 225 was in a '76 Dart Sport, backed by a 3 by the knee and a 3.23 rear. It seemed to be the best combination over all. Consistantly got 21-23mpgs, as well as being the most powerful and fun to drive.
 
Also, my '70 Swinger has the factory 225 under hood sticker but it's a factory 198 car. If nothing else these cars seem to be consistently inconsistent.
 
RaniDart70 said:
I checked the displacement on the block rail right behind the alternator. All three were "B" codes on the vin and all were 225.
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Fair 'nuff. Remember, "B" was the VIN code for a 225 engine in '66 through '69; the 198 was available (and was coded "B" in the VIN) in the '70 through '74 model years only.
 
OK besides all the technical stuff, (I know of a few examples) is there ANY "visual" ways besides the block coding, to know which slant 6 is a 170, 198, or the 225? I ask as I know of a few locations of the block not able to "look" for casting numbers and was wondering if there is an easy way to determine what one is which CID????

My Step-Son lives across the street from such a place out ion the sticks, and i mean the skeeters are strong enough to carry you right the hell off! They're in cars, and trucks kind of like those found "Cars left for Dead" sort of deal trees and undergrowth grown up all around difficult to get too, etc....This is why I'm looking for a "visual" way if any exist! The deals on the valve covers or air cleaners are all non-existant!
 
67 Power Wagon said:
OK besides all the technical stuff, (I know of a few examples) is there ANY "visual" ways besides the block coding, to know which slant 6 is a 170, 198, or the 225?
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198 and 225 are externally identical. The block stampings aren't even reliable, because the 198 and 225 blocks, year by year, are the same, the only difference between 198 and 225 is the crankshaft and connecting rods. So so who knows what's been rebuilt into what; you can't know for absolute 100% sure until you open the engine.

The G-block (170) is easy to tell from the RG-block (198/225). The G-block has a very short bypass hose between the top of the water pump and the bottom of the cylinder head; most of the hose is covered by the clamps and the whole thing is barely an inch and a half long. This hose on the RG-block is visibly much longer, you've got a couple inches of bare hose between the clamps.
 
My engine was repainted, its in orange now! But what I don't get is why repaint the engine and leave it stock? The sticker on the inner fender says 198 ci, but who knows? The Oil pan and places where a spraycan won't fit are painted. I guess the previous owners left it stock and put a different color on it.
 

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slantsixdan said:
198 and 225 are externally identical. The block stampings aren't even reliable, because the 198 and 225 blocks, year by year, are the same, the only difference between 198 and 225 is the crankshaft and connecting rods. So so who knows what's been rebuilt into what; you can't know for absolute 100% sure until you open the engine.

The G-block (170) is easy to tell from the RG-block (198/225). The G-block has a very short bypass hose between the top of the water pump and the bottom of the cylinder head; most of the hose is covered by the clamps and the whole thing is barely an inch and a half long. This hose on the RG-block is visibly much longer, you've got a couple inches of bare hose between the clamps.
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Dan,
THANKS I has assumed that the 198 and 225 were identical, BUT I wanted to know if my assumption was correct.

As for the 198, this one I was and am still unsure of....

As for them all, all 3 of them, were they normally in the same year painted the same color? I ask this as the engines I've "spotted" around are different colors, OR seem to be, as they have a blue one, one looks as tho it may have been red (rusty as hell) and one other one, I'm just not sure on, its the most difficult to get at so.....

I want to figure out if this guy has any or all of them the same CID.....As I may get a whole engine from him, to rebuild.....then possibly sell.
 
Yup, the only colour Slant-6 engines were painted in the 198 years (1970-'74) in the North American market was blue.

Slant-6 colours from the factory:

Metallic deep turquoise: Some 1960-'61 Plymouth-Dodge full size cars, North American market

Silver: 1961 (RV1 sold as "1962") Valiant, Australian market, some '60-'61 Plymouth-Dodge full size cars, some '61 Valiant/Lancer.

Red: 1962-68 all passenger cars, all markets, except as specified below, plus most 1960-61 Valiant/Lancer, North American market

Turquoise-blue: 1962 thru 1966 Canada-market 170 engines, plus all slant-6s in 1969 passenger cars & trucks throughout the North American market

Blue: 1970-1982 all passenger cars & trucks, North American market

Turquoise-green: 1967-1969, w/2bbl carb, Australian market

Orange: 1967-19??, w/2bbl carb, South African market

Yellow: 1962-early 1969 truck/bus, North American market (some '61-'62 got red)

Black: 1983-up, all applications, North American and probably other markets.

This list almost certainly omits some versions of the slant-6 sold in some non-North-American markets.
 
This is some great information, my thanks to slantsixdan and the others.
I have a question though, for a daily driver, what year 225 would everyone recommend for all around ease of maintainance and driveability?
I have several cores from several different years available. (excluding the all aluminum ones)
 
Thanks Dan! The colors of the Slants at least were consecutive and wasn't "in-question" as much as the remaining Mopar engines were.....No matter what, if you have a '77 slant 6, it was blue no exceptions, from factory. these sort of things are GREAT to know!

This will be useful when I'm out in the yard at my Step-Sons neighbor glorified junk yard looking......THANKS again!
 
Dartnut said:
for a daily driver, what year 225 would everyone recommend for all around ease of maintainance and driveability?
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Well, the '81-up engines have hydraulic lifters so never need tappet clearance ("valve") adjustment, but the camshaft they use is wimpy, there's a much smaller selection of aftermarket cam grinds available, and you have other issues that can compensate for the periodic nuisance of having to adjust the valves. So I tend to prefer the solid lifters unless the application makes it impossible to remove the valve cover and get at the adjustors.

Beyond that, maintenance and driveability are mostly a question of what's bolted onto the engine. Various intake manifolds and carburetors, various ignition systems, etc. More specific specs on the car you are building an engine for, perhaps in a separate "help me spec my build" thread, will get you good answers.

(If you're choosing used engines and not building up a fresh one, the answer's easy: whichever one is in the best condition and runs the best).
 
I didn't even know the 198 existed until I bought my 71 scamp and looked into it. It's a B engine code and the casting behind the alternator matches. It has the Super six setup with a carter bbd and lokar kickdown cable gets a steady combined 21mpg with the ignitor II and flamethrower coil. I love my slant!
 
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