Hi guys,

I read the stroke your slant six in the articles and was really intrigued by the stroked 170 that doug built. I want to build a sportsman motor that will be consistant, so a turbo is out, so that leaves me with a stroker motor.
My questions to start are:

1. Are the 170 cu in motors common enough to find, any years in particular better than others?

2. I plan to inject it on alcohol so how much compression can be made with a slant?

3. If memory serves me from reading numerous posts the K1 198 rods look like the rods to go with, are there better pistons out now from the time Doug build his?

These are enough questions for now, oh ya I should give the the rundown of the car I plan on putting it in.

67 notchback barracuda "racecar"
the car has a 360 automatic in it now with an 8 3/4 4.56 gears. It weighs 2925 with me in it. 2725 without...
It has ladderbars, fully adjustable shocks and an alterkation frontend. Wilwood brakes all around and a 12 point cage.

The future plans are to eventually gut it and build it similar to Wills blue notchback.

thanks for the input.

You won't be using the k1 rods, iirc he used 170 connecting rods with pistons equivalent the the wisecos offered today.

Why start off handicapping yourself with less ci to start with?

Same money in a 225 motor will be a ton faster.

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Official Cookie and Mater Tormentor.

my fault mixed up the 198 from the crank... So my question again, are the 170 block and rods available still? or are they quite scarce? How about the 198 crankshaft?

2. I plan to inject it on alcohol so how much compression can be made with a slant

what kind of compression can I get out of a slant? this is not a street car so drivablity will not be an issue.

Hey Slantzilla,

would not the higher compression along with the faster, higher revving make up for cubic inches? From what I have read the 225 does not rev very high, about 5400ish?

You can't get any more compression in a 170 then you can any other Slant, and anything above 12-1 or so will eat head gaskets like candy anyway.

My 225 turned 6500 easily and had been shifted over 6700 a few times. Stock 198 rods/KB 2.2 turbo piston motor.

A 170 will not rev much more than that, and will take longer to get there.

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Official Cookie and Mater Tormentor.

I like the little 170. Mine runs better then my 225. BUT, that is because I have spent more time with the 170. That said, Why handicap yourself 50 cubic inches.
You can actually get more compression out of a 225, then out of a 170. Use the CR formulas, and plug the numbers in.

With a 3.460 bore, 39 cc head, 6 cc valve reliefs, .041 thick gasket with a 3.5 bore and a zero deck (stock 170 spec) a 170 has 10.25-1 CR, and a 225 with everything the same except using the 225 stroke, has a CR of 13.21-1.

A 170 can rev higher, but a 225 will have more torque, and you adjust the gear ratio to get into the RPM range of the engine. The only down side of the 225 over the 170, is the cyl head. both engines use the same head, so the engine will "think" the head is bigger (flow) on the 170.

The other problem with using a 170 is, there are not that many around any more. And the ones that are out there, are mostly the small crank pilot versions. The small crank versions were made from 1960 to 1967. The large crank version were made from 1968 to 1970(?). Usually when a 170 engine wore out, It was scrapped and replaced with 225.

My personal opinion, the only reason to use a 170 is if you already have one/some, and would rather save money then run as quick as possible (me). or are a class racer, in a cubic inch to weight class (where a lighter car with a small engine will be quicker then a heavier car with a larger engine)

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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

Thanks for the input guys! That is why I came on here in the first place. It costs nothing to plan it out and ask questions before you buy. Nothing except a little humility...lol

I am not new to a slant but as far as building HP with them yes. The next question is can I realistically run low 12's using the Long rod build like Slantzilla uses. Using high compression and FI with alcohol?

May be pissing in the wind but its not the first time I've gotten wet

I have never run a slant that quick, but I would guess, if you build it right, it would be possible. But I think you would need to get the weight down.

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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

MIne runs 12's, but its a dedicated drag car.12;1 compression, K1 rods and weisco pistons. New engine is going to be a little different.

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Wife's: 64 Valiant
My: 70 Road Runner, 67 Barracuda, AND the 62 Valiant drag car!!

do you have a build for your motor? how about your new one, whats going to be different? or is your new one going to be a turbo?

To run low 12's with a motor like mine you will need:

Compression of around 11.5-1.
A really good head
A lot of camshaft
Lose more weight if possible

Any higher on compression and you'll be getting into O-ring and copper gasket territory. Any less and you'll be leaving horsepower on the table.

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Official Cookie and Mater Tormentor.

Does Mike Jeffries have a web site?

Would you recommend o ringing the block or do you do the head?



Thanks

Mike does all his business over the phone. 308/324-3576

You may be too late for this year. Mike does engines in the winter, farms in spring and fall, and races a Slant car in the summer.

The highest compression I have ever run is 11.5-1ish. I have never had to O-ring yet. Most do the block.

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Official Cookie and Mater Tormentor.