Doctor Doug, and Charles. After pouring over the many article I have found on this very information rich library, thanks to you guys, I have decided to go with a 210 cu in version of the 170. I have a few questions.
Are the 198 cranks forged steel?
Which is better, Using trick pistons, or milling the head and block to gain compression ratio.
What year and model did the 198 most commonly appear in. I will need to find a crank, or can I just buy a crank from some supplier. I prefer to buy a new crank, I have a stock 170 engine, and several 225's.
If I bore a stock 170 out .100, how much cylinder wall thickness do I need to maintain to prevent failure in the cylinder. I have a "D" meter and can readily measure the wall thickness before I start boring.

Thanks for all the research you guys have made available to us "Would be" weekend warriors at the digs.

Pat.

Pat, are you talking abouy running an NHRA/IHRA type class car? If so what class, what is the cubic inch per pound break? Remember everthing else being equal, the lighter car/smaller engine will go quicker. In other words, if you run a class, with a break of 10 lbs/cu. If the car weighs 1700 lbs with 170 cubes, and the engine makes 340 HP(2hp/cu), it will go quicker then the same car weighing 2100 lbs, with 210 cubes, making 420 hp(still 2hp/cu). I feel the slant head is capable of makeing more hp/cube on a smaller motor, however a larger engine will make more total hp. (talking no power adders). For a class car, the correct way to build, is to figure the weight of the car, then build the motor to fit the car.
Relating to your question about pistons, no matter what you do to the head or block, you will need custom racing pistons, for the type of engine build you are talking about.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

The 198 replaced the 170 as the 'base'/small slant six engine from 1970-1974, it should be a forged unit (cast cranks start in the 1976 model year on 225's).

With the amount of guys pulling 198's for the rods for their long rod 225 build up someone should have one 'lying' around...


good luck on the parts hunt!

-D.Idiot

DI has the info.
1970 to 74, base engine is the 198 Slant so look for those "strippo" cars vans and fleet trucks.
The 198 crank is a nice forged unit, it has the larger crank to flywheel pilot hole so get the later flexplate or flywheel.

Grab the whole short block if you find 1 198, as DI said, many are looking for the super long 7 inch 198 connecting rods.

Some nice custom pistons would be the best way to go but the 2.2 slugs are also an option. There are a number of pistons at 3.5 diameter that could be made to work if you want to open-up the small end of the con rod. Be sure there is lots of piston head thickness, this screamer will need some cam and o/s valves so some good valve notches will be in order.

Also get another 170 block or two so you can compare and select the best, if you can end-up with .200 on the cylinder thrust side, you will be "sweet".
Review the block prep article, I would think about adding a little "block-rock" into this engine.
DD

I just got off the phone with Jack. Goodness, what an experience -- I'd forgotten.

Here's the story: There's nobody in charge of the magazine. Jack gave it up and the supplies have been passed from person who hasn't done anything with it to person who hasn't done anything with it to person who hasn't done anything with it.

Questions of ethics are, therefore, academic and theoretical at this point -- there's nobody to go after anyone who puts up old material from the Slant-6 News.

The Slant-6 engine history is, as I recall, copyright Chrysler Corp, therefore now copyright DaimlerChrysler. Nevertheless, I'm pretty sure they'd never go out after anyone who put up stuff about the Slant-6.