Ever since I read Doug Dutra's /6 Stroker article I have been enamoured with the 170 stroker he built.

Are there any other members running 170 strokers? If so what is your recipe?

I am wondering also if anyone has built one with the 2.2 turbo pistons. I imagine these would be lighter than the vega pistons Doug used?? That would make the engine rev quicker right?

Thanks in advance for shaing any of your 170 stroker experiences.

Oh and if you are out there Doug, what weight was the car you ran your 170 in, and what kind of times did it turn?

Thanks!

Chris E.

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-76 Cordoba, 360 4bbl
-68 Valiant, 273 2bbl
-67 Dart /6 4bbl, Leaning Tower of Power!!!

Are you talking about Doug's 210, basically a bored and massaged 170 block with a 198 crank, short rods and pistons?

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"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO

Funny, so am I, which is exactly why I said I was interested in your 170. Might not be quite as big, but your only giving up 15 cid to the 225, and the motor is smaller and lighter. Shorter pistons, shorter stroke, higher revs, too intriguing.
2.2 pistons are too tall, per my numbers. Even the turbo ones as they just dish the piston, instead of reducing the compression height.

2.5 pistons look like they might work, but you almost need a flat top piston and I haven't found a good off the self source for forged ones.

Always places to go, I know you could get a set thorough the FWD Mopar guys built to your spec and I know that one set was bought custom for a 170 and a turbo, but then sold. Price wasn’t that unreasonable, either.

Here's another thread about the 2.2/2.5 pistons.

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'15 Chrysler 200S V6
'74 Duster 360, factory 4 speed car

I've been thinking about the same thing, stroking a 170 with 2.2 turbo pistons.


TopHat

The car weighed 2630, 2830 with me in it.
Best time was 14.15 on the engine. 12.97 with a 100 HP shot.

That engine will idle smoothly at 900 RPMs and rev to 7000
DD

My math tells me the KB268 2.2 turbo piston would stick above the deck about .113" or less with stock 170 rods and a 198 crank. As long as the head's combustion chamber is .113" deep and the top ring doesn't stick above the deck it could work. With a 55cc head, 18cc piston dish, .039" gasket, 3.465" bore and positive .110" deck height the compression ratio is almost smack on 10:1. Chances are good with an un-milled block deck height would be lower, say .090" and the combustion chamber would be about about 58cc. That drops the CR to 9.25:1. This nets you 206ci, BTW. Also, the 1291h Silvolite piston for the same '86-'90 2.2 Turbo is .023" shorter and has a 16.5cc dish which drops you from 9.25:1 to 9:1. The top ring placement appears to be lower which might be necessary.

You'd think I may have considered this before myself. I have. I also have a 198 crank under the bench.

So who's got a loose head and can check the chamber depth? I'll bet valve to piston clearance will be at a premium.

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Joshua

Doc thanks for the #'s. That is awesome Pretty close to the 13's and solid 14's would be perfect. 'Course I beleive my car would be a bit heavier. Especially with my butt in it

Joshie, I don't have the head off the 170 yet but when I do I'll measure her up. A 9:1 CR sounds about perfect.

Hmmmmm, thinking, thinking, thinking............

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-76 Cordoba, 360 4bbl
-68 Valiant, 273 2bbl
-67 Dart /6 4bbl, Leaning Tower of Power!!!

Wonder how 7000 rpm's would feel with 10 pounds of boost.

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'15 Chrysler 200S V6
'74 Duster 360, factory 4 speed car

Believe me, at 10 lbs boost, you don't need 7,000 rpm.

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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

The 2.5 piston will be about .200" or so shorter than a 2.2/2.5 piston.

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Official Cookie and Mater Tormentor.

OK, I'm in a little bit of a tequila fog right now, but that doesn't look right. is a 2.2/2.5 different from a 2.5 piston? Please explain.

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David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.

The late 2.5 uses the same deck height block and length of connecting rods as the late 2.2. The pistons are shorter so they don't stick out the top if the block.

The compression distance (CD) for a 198 crank in a 170 block for 0 deck height is about 1.50". The replacement 2.2 turbo piston has a CD of 1.571" and the late 2.5 piston is 1.35" and would be about .150" below deck. It's also a dished piston so the compression ratio would be very low.

Joshua

Gotta agree with you on that one.
Which is why I was looking for a flat top piston. If I remember correctly, a flat top, a deck cut of .035 and mill the head to get something like 58 cc chamber gave an 8.0 or 8.1 CR (reference the other thread I linked above for more accurate numbers). About right for boost.

I did find one reference in my FWD searches where one company had all of the info for a 2.2/2.5 piston and would build custom pistons off that base. I think it was Knuze (sp?), but I will have to go back and look.

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'15 Chrysler 200S V6
'74 Duster 360, factory 4 speed car

There is a 1.400 ch piston available for the SRT Neon that is 3.465 (that would be .065 for the /6 bore) it is also a forged Turbo designed piston. I am not sure what the piston pin size is on it though , but that shouldnt be no big deal. You could be some milling and bring that right in, or its pretty much a flat top, deck the block to put you around 8.5:1 (if it would even need it to get that CR) then put the turbo to it.

And yea, 7000rpm with 10psi would be sweat on a setup like that. This build would also make better use of the restricted head the /6 has.


Jess

Where might I find such an animal? Any idea on the size of the dish?

Pretty sure the 2.0/2.4 and the 2.2/2.5 have the same pin size, but I could be wrong.
Exactly.

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'15 Chrysler 200S V6
'74 Duster 360, factory 4 speed car