All Small Six engine upgrade 170-> ??

[timbo1]

Hello all. Newbie here. Excited to find this resource. I have an early-vintage industrial 170 in a Thiokol snowcat. Long story, but after limping along for several years, the engine seized up. Now I need to fix. Goals: reliable and more power. Torque more than HP. Questions: would you just rebuild the engine? Bore it out? Swap with a 200 or 300? Push it off a cliff with a D8 that I needed when I got stuck in the snow and had to walk 2 miles the other day?

Thanks in advance for opinions & input. For those who aren't familiar, these beasts are basically a tractor on tracks, built in Logan, Utah, with mechanicals from the Ford parts bin. Engines were industrial straight-6's (170, 200, 300). Latter ones had bigger engines, with C-4 or C-6. Mine has 4-speed NP435. If I could get it to work consistently, then maybe the family would be willing again to ride in it?! They like walking in the snow even less than I do.

 

[powerband]

unless your up for serious fab'n, swapping in a 200, would be simplest - with a few bolt-on and/or internal mods it could give a nice increase in power you could use and feel. ( sure it's still a 170?) .

'Modern" electronic ignition (DSII) and better carb or aftermarket FI, could eliminate most common problems forcing a tow or walk home.

hav efun


here in N.E. legendary Mountain Houses needed all kinds of snow machines to groom downhill , CC and and snobile' trails. I had privilege of working in maintenance in one with 'Hedco' VW engined snow-makers and tracked groomers...


. .

 

[TrickSix]

Cool! The Snowcat looks to be in great shape. Some pictures of the engine bay area would help, as well as be interesting! I would think that a 200 should be pretty much a bolt-in. But I'm not sure if there's anything unusual about the transmission in a Snowcat. As said, the extra power from a bigger displacement engine should be noticeable, and there are a few simple and cheap mods to help. I'm not sure if your money would be well-spent doing a lot of extra work on it. Since the engine will be used in cold weather, it might be a good idea to see if the fuel injection systems work better than a carb in below zero temperatures. They are expensive, at least the one barrel version doesn't require the extra head work a 2 barrel does. Good luck with your project!

 

[timbo1]

Well, that isn't my cat in the photo...it's a shot I grabbed off the web. But mine is the same, albeit with dull paint and a roof rack. Honestly, I believed it was a 200, until a friend showed me the 170 plate. But who knows.

Multiple, unsuccessful carb rebuilds--so EFI would be wonderful, as long as a dork like me can program the dang thing. Altitude compensation would be nice, as it's at 8000' in the winter. Any recommendations? Holley Sniper? I know opinions are mixed, but I'm into learning from others' experiences. I'll post engine pics when the beast returns from being broken-down in the mountains. A friend is gonna pull it out with a log skidder.

More questions: Can I bore it out to 200 c.i. and find compatible pistons? Or better to just find a remanufactured engine off a shelf? If so, any recommendations for a trusted source? Yes, Trick Six, the trans isn't anything unique, although, it would be nice to have a 5th gear for the flats. I'll have to figure out the Ford bell housing and read through .

 

[bubba22349]

Well, that isn't my cat in the photo...it's a shot I grabbed off the web. But mine is the same, albeit with dull paint and a roof rack. Honestly, I believed it was a 200, until a friend showed me the 170 plate. But who knows.

The Industrials 170 Six's were used for many years in all kinds of equipment and they were very good engines.

Multiple, unsuccessful carb rebuilds--so EFI would be wonderful, as long as a dork like me can program the dang thing. Altitude compensation would be nice, as it's at 8000' in the winter. Any recommendations? Holley Sniper? I know opinions are mixed, but I'm into learning from others' experiences. I'll post engine pics when the beast returns from being broken-down in the mountains. A friend is gonna pull it out with a log skidder.

There are some brand new replacement carbs being made many on this site have used them with excellent results. Getting the Distributor in good operating condition is also a good plan for making it trouble free. It should be easy to get that old 170 back to being very dependable with just a little work. Yes there are also the EFI systems too and many have been using them if you don't mind the extra cost.

More questions: Can I bore it out to 200 c.i. and find compatible pistons? Or better to just find a remanufactured engine off a shelf? If so, any recommendations for a trusted source? Yes, Trick Six, the trans isn't anything unique, although, it would be nice to have a 5th gear for the flats. I'll have to figure out the Ford bell housing and read through .

I agree that a 200 six is a direct bolt in for your 170. No you can't Bore out a 170 engine (they have a 3.50 Bore Size) that is to much to be able to make it into a 200 (3.680 Bore). But you can come closer to the 200 Torque if you wanted and Torque is what your really after. This can be done by finding a 1963 1/2 to 1964 200 Six Crankshaft they have the 4 Main Crankshaft layout just like the 170's do so its a drop in swap giving you a good increase from your 170's 2.940 Stoke up to the 200 Six's 3.126 Stroke that will add lots more Torque to that 170. Your current Connecting Rods are still used for this Combo and if your planning on Boring the Block any during the rebuild you will need a new set of oversize Pistons. Which might even be the 170 stock spec piston's so far I can't find the stock Compression Height (C.H.) for the 170 Piston or their block deck Height (Down the Bore), the 200 used a 1.511 C.H. and was .019 down the Bore. Also a Custom Made Piston that is easy enough to get in a Forged version for a reasonable price too. I have been thinking of this Combo in a 170 for a long time the only thing I am not sure of is the Piston Compression Height that it would need, this is easy to figure out if you have the Cylinder Head off the Block with the engine on a stand. There are many other little things that can be done to increase the Torque and Power some more with out causing any troubles. The C4 or a T5 speed can be adapted or you can just use the excellent NP435 and add a Gear Vendors OD unit behind it. Best of luck on your rebuild.

 

[timbo1]

Bubba, thanks so much for your input. Geez, I wouldda never thought of swapping just the crank. I'll research forged pistons and report back.

Curious...I wonder what the final drive ratio is on the C4 vs. my manual. I'll have to research further.

Now I've gone from super bummed about the beast to excited to get her going again. At the rate we're going, there might be snow up there 'til July. Thanks, all.

 

[bubba22349]

You are very welcome timbo1, those 4 Main 200 Crankshafts are still out there but it may take some looking to find one. On forged Pistons check with AutoTec they had about the best deal on a Custom set of Forged Pistons, last I heard they were $550..00 per set. http://racetecpistons.com/
Some of the other Piston Companies might also make you a custom Cast Piston too though not sure it will be as reasonable in price as the AutoTec's. The Final Drive Ratio on almost all USA made 2 Speed's, 3 Speeds, and 4 Speeds, Auto's or Manual Transmissions are usually a 1 to 1 Ratio.

 

[Kritas]

Mmmmm.....turbo diesel swap....

 

[sixtseventwo4d]

Could it be the multiple carburetor issues led to the engine's demise? Oil/fuel dilution can really take a toll

 

[B RON CO]

Hi, I would see what went wrong with the original engine. These engines are quite durable, but they do wear out.
A 200 swap makes a lot of sense, of you can find a good one close by.
Learn about the engines from the tech section here and the Ford Falcon Performance Handbook.
Later engined have better heads and other parts. Early engines have adjustable rocker arms and you want to keep them.
Putting a milled late head, with the matching late carb and ignition will give you better performance, even better with a performance cam.
I assume most old engines need a rebuild.
Good luck

 

[timbo1]

Mmmmm.....turbo diesel swap....

While I do love me a TD, like the small Cummins, MB 5 cyl, and even VW PD, I'd have to run Diesel #1 due to temps. Plus mating to the tranny could be a nightmare. If you've got specific ideas or recommencations, I'd love to hear, Kritas!

 

[TrickSix]

Spring is coming (or so we've heard up here) and projects will be started. Garages and sheds will be cleaned out. And lots of people with an old Ford six cylinder car will be converting to an eight. Keep an eye on your local Craigslist ads and the like, you might get lucky and find a good running engine for cheap. If you can have some patience it may pay off for you.

 

[Kritas]

Hi Cesar,
What kind of adapter are you looking for? A big log 1 bbl to Weber 32/36 or 38/38 2bbl?
Darrell

While I do love me a TD, like the small Cummins, MB 5 cyl, and even VW PD, I'd have to run Diesel #1 due to temps. Plus mating to the tranny could be a nightmare. If you've got specific ideas or recommencations, I'd love to hear, Kritas!

No ideas. We rarely see snow here. I've just always thought those were cool.

 

[bubba22349]

Hi timbo1, did you get started on the rebuild of the 170 six yet? Thanks to site long time site member "super4ord" one of the questions I had on the 170 Pistons was answered today. The stock type aftermarket 170 Six replacement Pistons have a Compression Height of 1.580 with a 8.4 to 1 C.R. and are still made new in Cast Piston's in the Silv-O-Lite Brand there is the STD size as well as in the .020 .030 .040 .060 over sizes. Working the Calculations out a 170 Piston would need a .040 to .050 Mill cut off the top to use with the 200 Six 4 Main Crankshaft (Assuming a still stock Block Deck Height of 7.808 or more) or else a Custom Forged Piston Made with a 1.530 Compression Height this would give a Zero Deck Height with the 200 Six Crankshaft install. This Factory Parts Stroker Combo would give you a displacement of 183.56 CID assuming a .030 over bore during the rebuild, with a Compression Ratio of 9.17 this should be quite a boost in the 170's Torque and Horsepower. Best of luck on your rebuild.

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[Jmustang_65]

I would find a 200 or if you want more torque and have a bit more space add a 250 and use a sbf transmission as they share the same bolt pattern. 200/250 can be found fairly cheap to free at times.

 

[chad]

I wuz thinkin the 4.1 or 250 too (200 more buzzy, 250 isa 200 stroked so more tq). A 170 aint bad tho. They put them in the rig in my pic. Huge counter weights. I go upa hill w/a 6ft plow full of wet sno easily. The NP435 is such a nice unit. 6:1 in 'granny'.
I now havea 4.2 (250 rebuilt) in the bronk. Also an NV (same company) 3550 behind (5 speed) for 1) low 1st, and 2) OD for hiwy. The above ("...a 250 and use a sbf transmission...") can B nice. Lotsa choices. They call the 4.9/300 "the gasser thats a diesel". Might B over kill w/o a trac change?
I'd like to hear more on application B4 advising (80% of the normal operating RPMs, use of implements, weight of skid-be-hind, or just personal transportation, % gradients & ratio of flats mixed in w/them, octane used, etc) Wouldnt B fair to say w/o these. We used one for sugarin'n that had the 4.9 due to the 350 gal heating oil (typical house basement oil tank) tank on the back for bringin in the sap (overa T).