170 ci performance

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Anonymous

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Hello all,
I have been looking for information on performance building the 170 ci straight six, however the results have been less than conclusive. The engine is in a 1966 Bronco. I was hoping to be able to reach around 150 hp or more. What do you guys recommend? I am definitely keeping this engine so swapping something else is not an option. I am open to any ideas but the simpler the better. Do you guys have any build-ups that you have known to work and what will the estimated horsepower and cost be? I have been looking at the Clifford Performance website to try to get some ideas, but I don't know what works and what doesn't with these engines. Keep in mind that this engine will be used on the street and running 4x4 trails, so it needs to be able to lug around the heavy Bronco.

Thanks for your help,
Morgan
 
Welcom, Morgan

I would first get a head from a 200 and stick it on there. I would get a 3 angle valve job, back cut the intakes, mill it to your desired compresion, and port and polish. Keep the compresion around 9.5:1, you can go with more but youll have to run higher octane.Then i would put a 2bbl and headers on. If you want some torque for 4X4in i would put 1.6 ratio rockers on there or run a little hotter cam.

Fordsix.com has very good performance mods for your bronco. I would suggest the first thing you buy is the Ford Falcon Six Cylinder Handbook. It has everything you need to make and engine perform at its best.
As for price goes, a head from your local junk yard-$35
valve job-$400
headers-$270
5200 2bbl and stovebolt adapter- less than 100
Rocker arms- clifford has them for $300/fordsix has roller rocker arms
Cam(everything)-about $300
those are just estimates, but those prices are prety close
If your budget is tight i would invest my money into the head. IF I were gonna add anyhting, i would add the head, 2bbl carb, and headers. Which will add some very nice horsepower.

hope that helps

later, Curtis
 
Thanks for your help. Do you or anybody else have any estimates on what kind of horse power could be achieved with these mods?
 
Howdy back Morgan and All:

I hate to be the one to tell you, but 150 HP from a 170 with "simplier" hop up ideas is extremely unlikely. To approach that hp level would require a major rebuild beginning with the short block and then up. Such an engine would be very unforgiving in a Bronco. I want you to know that you can significantly improve performance on your '66 170 with a number of upgrades and specific tuning. In truth a stock 170 probably turned 60 to 70 rear wheel hp.

For a Bronco, I'm guessing you will want rock-crawling low down torque type power. If that's true then your stock 170 head may be the best. It will be easy to maitain a decent compression ratio, and maintain velocity for low end response. The flow can be improved with a three angle valve job, a compensating milling, back cut on the intake valves and pocket porting. Add an 1100 carb from a '66 200 and you'll notice a 5 to 7 HP increase right away. You'll be stepping up from a 156 cfm Autolite to a 187 cfm carb.

Clean up your exhaust system with a header and/or a 2" system behind your stock cast manifold. Use a turbo type muffler.

Add a Petronix Ignitor system to your stock distributor, or upgrade to a better distributor with both centrifugal advance and vacuum.

With all of the above in place and properly tuned, you'll notice a 10 to 15% power increase. Be sure to plan for and build a coordinated engine package, and tune, tune, tune!

Adios, David
 
Hey, thanks for your help guys. By the way, has anybody ever turbocharged one of these engines? Just a thought.
 
I have a new thin steel shim head gasket that will help keep your compression Up. It is for a 170 so if you are going to switch to a 200 or higher engine it will be no good

let me know if you want it $30

John
 
all the mods CZLN6 said with nitrous can work?? i have a 170 too.
 
Hey, good to have the site back. One other thought, can my 170 block be modified to create more cubic inches? 170 Stroker? Or can it be turned into a 200ci? Or more? Just more thoughts. Once again, I don't know very much about this family of engines, but I thought maybe with some machining and parts changes it could become a 200ci. I've abandoned the idea of simple and am now thinking of extreme.

Thanks,
Morgan
 
From what I understand, the 170 has 4 main bearings while the 200 & 250 have 7. The 200 is a bolt in swap for the 170 and the 250 fits with just minor changes. Personally I wouldn't put a lot of time and money into the 170 in the form of extreme mods.
 
I am finally back to working on turbo charging a 250 six in my '66 Bronco. It has a Oz 2v head and I am using draw thru setup from a GM 3.8. I will have pics when I get it closer to together. I am mocking up the engine/transmission (ZF 5 speed) in the frame now. May have some pics of that by the end of this weekend.

CraigS
Gresham, OR
 
Just bought a '66 Bronco. It has a 200 six, the problem it has an automobile oil pan, where can I find a rear sump pan for the Bronco?
 
I need a rear sump pan / pickup for a 250. From what I have seen, I will need to weld up my own.
 
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