170 or 225?

[mopar_nocar]

I have the original 170/903 combo in my 64 Valiant. I have a good running 69 225/904 that needs a home...170 needs a rebuild. Should I stick with the 170 or go ahead with the 225?

NOT going to put a V8 into it, so skip that suggestion.

 

[Hyper_pak]

I have had plenty of 225s over the years, just built my first 170. Haven't run it yet so not sure how I will like it. 225 gives you more cubes, more torque. 170 should turn up faster. Cost the same to build them, maybe more to build a 170. Maybe it depends on your use and plans for it. 225 might be better choice unless you want all original.

 

[pishta]

225 makes torque lower in the powerband, both can make the same HP (same head), 170 will take more RPMs to do it though. I would use the 225 and not look back unless you are going to rev it Jr. NASCAR style.

 

[273]

Id do the 170, but i always wanted to do a high revving /6 with 4.88+ gears.

 

[Killer6]

I have the original 170/903 combo in my 64 Valiant. I have a good running 69 225/904 that needs a home...170 needs a rebuild. Should I stick with the 170 or go ahead with the 225?

NOT going to put a V8 into it, so skip that suggestion.

Just rebuild what You've got, everybody is giving You advice on "How Much Power", but the thing's original & it's not a race car. You're going to pooch a bunch of stuff for
little overall gain by switching in the later combo, driveshaft, exhaust, shifters/pedals, rad w/o to one with cooler for trans etc. etc............the 170 is a fine little engine &
can run really well w/o turning it into a racing mill with just a few upgrades during the rebuild.

 

[Phily]

Ls swap it lol kidding. I'd keep it all original myself if possible

 

[Darter6]

If your not planning on doing a bunch of hot rod stuff stay with the 170
If you can afford to rebuild,stay with the 170
If you are doing it low buck,go with the good running 225.Insert and drive.
If originality is of no concern,go with the 225
Old saying= "No substitute for cubic inches."

 

[273]

Two things when building small displacement rpm and gearing.
And really the 225 is really small engine in the first place.

Rpm shouldn't be a big problem unless your looking to build a 300+ hp engine. Should have to spin the 170 about a 1000 rpm higher to reach the same power as the 225.

2nd and probably the most important is gearing. To put the same torque to the ground and to put the 170 in the powerband.
You'll need to go about one full ratio deeper.
So a 3.55 225 = 4.65 170.

Sure you can run 3.55 in both. But 220 hp 170 is not gonna keep up with a 220 hp 225 and no chance with a 220 hp v8 if all running 3.55. Thats why people spend big bucks to gain 50 + cid and you can practically for free.

My rule for small displacement is if your willing to gear it build it. If not go bigger or except the lesser performance.

 

[Slantsix64]

I have the original 170/903 combo in my 64 Valiant. I have a good running 69 225/904 that needs a home...170 needs a rebuild. Should I stick with the 170 or go ahead with the 225?

NOT going to put a V8 into it, so skip that suggestion.

I would drop in the 225 and keep the original 170 on the side. If you plan on keeping it a three on the tree you just need to swap the flywheel to a larger diameter center to a slant six 1968 and up manual flywheel. With a super six and that a903 gearbox you should be churping. I'm pretty sure your rear ended ratio is a 323.


And in the future you have the set up already to convert to a four speed just need a hump and shifter with linkages.The first year four speeds are the best 3.09 first

 

[Valiant63]

I agree with Slantsix64. Drop in the 225 with a newer flywheel, if needed, and drive it while you disassemble and rebuild the 170. No driveshaft mods or swap needed.

 

[valiantpatrol]

I have driven both the 170 and 225 over the years, mostly in '60-'66 "A" bodies and agree with all that say how you intend to use the car is what matters most. If just a fun, daily/street driven, driver the 225 is the better choice due to it's increased low end torque in my opinion. You can leave on a lot of faster cars from a static start (not rolling), at least to the other side of the intersection, even if it's bone stock. For "performance" either the 170 or 225 can be built but will cost more than a V8 usually and will rarely perform as well. Not to mention a built slant 6 uses nearly the same amount of fuel as a warmed up V8. They loose all economy in "hot rod" mode. I still enjoy crushing the tuner guys in a stop light grand prix with my hard launching, bone stock , 225/auto. They'll always catch you and pass but they are getting a long look at my taillights while doing it !!

 

[AJ/FormS]

Is this a trick question?

32% more cubes. 32% more cubes!
2.786liters, versus 3.687 liters
903M/T no-low-syncro, versus TF904; Fully automatic shifts.
No more trying to match roadspeed to rpm to get back into first.
This has to be a trick question.
32%! is like superchargin' it, like a turbo,allbeit a small turbo. In a 64 Valiant, BAM!

Has your neighbor stopped beating his wife yet?
See that's a trick question too.
Like; how often do you speed?
What has your wife got to say about your extra-marital sexual activity?
How much alcohol do you consume in a year?
Why do you lie about that chit?
How come your tires are always bald?
Sir! Where did you put the receipt for that item?
How much bigger is a 360?
360what? Compared to what? Using what measuring method? Absolute or figuratively? Under what conditions? Why would I care about that?
My neighbor says I shoulda built a 340; everybody knows they were faster than Hemis.I think he has an IQ of 38. Is that high? His wife has assets out to here; you see what I'm saying? Her chest is no bigger than his IQ. Who would you rather take to the party?
That's a triple tricky one.I love trick questions.

 

[mopar_nocar]

I am thinking the 225/904 will get to live in the car. I will need to use the oil pan from the 170 and build a drive shaft for the 904....the 225 will be a super six set up, using a 2100 Motorcraft carburetor.

Today my son and I put the spindles/LCA/UCA to install disc brakes and rebuild the front end. I already have new torsion bars and leaf springs for it.

Thanks for all the replies and votes.

sb

 

[273]

Id get an 80's trans with deeper 1st and 2 nd
and at least 3.55 out back.

 

[mopar_nocar]

Id get an 80's trans with deeper 1st and 2 nd
and at least 3.55 out back.

I already have a 998 transmission, the car has 3.23 gears in a 7.25 rear. I would love to find an 8.25 to pop in there, but otherwise a gear change is unlikely.

sb

 

[Bill Crowell]

I've owned them both. The 225 has more power for acceleration, but it thrashes pretty bad at 75, whereas the 170 had little power but was comfortably and smoothly buzzing at 75.

 

[diymirage]

if you dont want to stick a V8 in there, just go with the 225, since it is ready to drop in
no point in throwing good money at a car to rebuild an engine that will not even perform as well as the 225 you allready got in the garage

 

[slantsixdan]

Motorcraft 2100/225/904 is gonna be a really nice combo. Y'didn't ask me, but y'might also look at HEI ignition and Dutra Duals, and speaking of Dutra, you can get his RV10RDP excellent-street-driveability camshaft easily and inexpensively from Oregon Cam Grinding as their grind № 2106R.

 

[MILO]

You already have a good running 225 I would use it they are great engines. And put the 170 in the back of the garage

 

[valiantwagonguy]

My 65 Valiant wagon was a 225 /904 .It was a basket case when I was given it.It ran well but was totally rusted.Well I fixed it up and used it.That was in 1997.In 2013 the 225 was making so much blow by that I had to pull it or I'd die driving.It had 350,000 miles on it at that point .When I tore it down to see what failed I found broken rings in 4 pistons. It still ran when pulled ! I dropped in a sweet 170 I had from this 66 Valiant I had for many years. The 170 was well cared for by me so it was in good shape.I put in a 3.09 first gear 4 speed from a 65 Barracuda and a 7 1/4 323 sure grip out back. I LOVE IT ! It is real responsive and when I drive it up to my camp in the Adirondacks 380 miles away from home it does the trip fully loaded with gear and tools on one tank of gas . At high way speeds it's a little screamer .Hit the gas at 60 and it just takes off.That short stroke is wonderful. So,my advice is to go with the 170.

 

[Morepower]

Ok I am lost thought I had a 225 in my wagon found out it’s a 170 now I don’t know if I should drop my 408 stroker motor in it now or turbo charged 170 to get some horsepower what’s everybody’s opinion on that my 62 wagon Lancer

 

[RustyRatRod]

I'm happy as HECK with my 170. It has way more go than I ever thought it would. I attribute that to the short stroke that gets everything turnin quick. The only reason I'm doing an engine swap is because it needs bearings. The oil light stays on a long time when started cold and it rattles until it gets oil pressure. If it was in good shape, I'd leave it alone.

 

[Morepower]

I'm happy as HECK with my 170. It has way more go than I ever thought it would. I attribute that to the short stroke that gets everything turnin quick. The only reason I'm doing an engine swap is because it needs bearings. The oil light stays on a long time when started cold and it rattles until it gets oil pressure. If it was in good shape, I'd leave it alone.

You replied to me one time that you have a turbo what else do you have to help me get my ride together