Ford 170 expectations

[Nowik35]

So I'm new to bronco world. I have been building my 69 bronco for 6 years and in the last few weeks I've been driving it for the first time ever. I rebuilt everything my self. Kept it all stock. Including the 170 with the original RAN 3 on the tree. I only put on maybe 30 miles since I first start it but it's constant tweeking since. Anyways, today's joy ride I've noticed. It starts nice in first I can rev it up to about 20 miles in first and switch into second. Very smooth and "healthy" . In second if I accelerate slowly it does fine getting up to 35mph before I pop it into 3rd (all nice and healthy feeling) . But if I'm going about 30 and I step on it in second. It miss fires maybe once or twice, once I back off it sounds fine again. When I'm going about 40 in third and a hill starts to come up. It seems to struggle a bit getting up that hill. So I end up down shifting at about 30 and it still seems to struggle up steep hills. Anyways my question is, is this basically the power of an 170 with a 3 speed or is there tweeking for me to do? Or maybe I'm just not driving the manual correctly. I'm still learning the 3 of the tree. I'm thinking my timing is not correct at high speed? Or my mixture is too lean? No idea. I have no idea what to expect maybe I'm just expecting 302 power out of a 170?

 

[Broncobowsher]

I'll ask for 2 more bits of info. What size tires and what axle ratio?

The 170 isn't a power house, but it sounds like yours isn't running like it should.

 

[Bajabrewer]

What carb & what distributor? I had a 170 & it had the 1100 SCV carb if that's what you have it needs the distributor that matches it for the proper vacuum signal for the advance. If you have a Carter YF or similar then the distributor should be a later model that will work with a stronger vacuum than the SCV carb. I know you built your truck "stock" but if you can swing an HEI distributor(to full manifold vacuum) you will pick up power, reliability & economy at least that's what happened for me.

 

[Nowik35]

So I have stock 235/75R15 tires. I don't know ratio but it's the stock Ford 9 . It said that year the 6 cylinder came 4.11 out of the factory. So I assume that's what I have. I just bought a brand new Holly 1904 replica carb on Amazon. Seems to work good. And a point distributor Carquest, with single vacuum. Stock

 

[73azbronco]

to much advance.

 

[okie4570]

So I have stock 235/75R15 tires. I don't know ratio but it's the stock Ford 9 . It said that year the 6 cylinder came 4.11 out of the factory. So I assume that's what I have. I just bought a brand new Holly 1904 replica carb on Amazon. Seems to work good. And a point distributor Carquest, with single vacuum. Stock

4.11 was standard and 4.57 was an option also for the 170.

 

[thegreatjustino]

Other than the misfire, it sounds exactly like driving a Bronco with a 170.

Horrible engine for a heavy vehicle like a Bronco. I have a bone stock '68 with a 170. 60mph top speed on flat ground. 30mph going up hills in second gear.

 

[Broncobowsher]

235s are good. Rules out you are trying to push too tall of a tire.
The new Amazon carb is likely an issue. Although new, the factory in China making them probably doesn't have great tolerance to build to. Hopefully you still have the original and can get it rebuilt.

A lot of people think a 351 is a good engine for a Bronco. The 170 is less than half that size. Only 30 cubes larger than the 2.3 Pinto engine, but those had the advantage of a better flowing head/manifolds.

 

[bmbm]

Fordsix.com is all about the Ford small sixes 170, 200, 250. Good forums with helpful people.

 

[Bajabrewer]

X2 on the Fordsix.com - I think you will get it dialed in with some trial & error on the timing. If the distributor is for a 170 with a SCV carb it may not work well with the 1904 but if it's a later model then it just needs dialing in. I looked at the carquest site & I can't tell from the listing if it's for an SCV carb or not?

 

[Broncobowsher]

If you are not sure what distributor you have, pull the cap off and check for a mechanical advance. They will both have vacuum.
The SCV is what Ford used up to the mid 60's before transitioning to the more traditional (and better running) mechanical advance.

The SCV only works with the matching carb. It is a wonky system that pulls advance when it senses engine speed from high venturi vacuum and throttles/amplifies with manifold vacuum. All the advance, speed and load, is done through the vacuum advance. It really is a horrible system that barely worked when everything is completely stock. Requires a correct SCV carb, correct for the application, with the correct SCV valve. It was not one of Ford's better ideas.

The vacuum signal from an SCV carb is completely wrong for a mechanical advance distributor. It will build a vacuum signal under high loads giving too much advance added to the mechanical advance. Doing it the other way around will result in an engine that will have no power, no timing advance except a little bit at light cruise, if you can even get the engine to run good enough there.

 

[Bajabrewer]

If you are not sure what distributor you have, pull the cap off and check for a mechanical advance. They will both have vacuum.
The SCV is what Ford used up to the mid 60's before transitioning to the more traditional (and better running) mechanical advance.

The SCV only works with the matching carb. It is a wonky system that pulls advance when it senses engine speed from high venturi vacuum and throttles/amplifies with manifold vacuum. All the advance, speed and load, is done through the vacuum advance. It really is a horrible system that barely worked when everything is completely stock. Requires a correct SCV carb, correct for the application, with the correct SCV valve. It was not one of Ford's better ideas.

The vacuum signal from an SCV carb is completely wrong for a mechanical advance distributor. It will build a vacuum signal under high loads giving too much advance added to the mechanical advance. Doing it the other way around will result in an engine that will have no power, no timing advance except a little bit at light cruise, if you can even get the engine to run good enough there.

Thanks for that explanation - It's been a couple years since I messed with the 170/SCV & couldn't remember the details of why they only worked well together.

 

[73azbronco]

my last 170 EB, quickly gets to 40, then seems to take about 10 minutes to get to 55-60. No coughing or backfires

Recommend strongly rebuild OEM carb, or have some good shop do it..

 

[bmbm]

So I'm new to bronco world. I have been building my 69 bronco for 6 years and in the last few weeks I've been driving it for the first time ever. I rebuilt everything my self. Kept it all stock. Including the 170 with the original RAN 3 on the tree. I only put on maybe 30 miles since I first start it but it's constant tweeking since. Anyways, today's joy ride I've noticed. It starts nice in first I can rev it up to about 20 miles in first and switch into second. Very smooth and "healthy" . In second if I accelerate slowly it does fine getting up to 35mph before I pop it into 3rd (all nice and healthy feeling) . But if I'm going about 30 and I step on it in second. It miss fires maybe once or twice, once I back off it sounds fine again. When I'm going about 40 in third and a hill starts to come up. It seems to struggle a bit getting up that hill. So I end up down shifting at about 30 and it still seems to struggle up steep hills. Anyways my question is, is this basically the power of an 170 with a 3 speed or is there tweeking for me to do? Or maybe I'm just not driving the manual correctly. I'm still learning the 3 of the tree. I'm thinking my timing is not correct at high speed? Or my mixture is too lean? No idea. I have no idea what to expect maybe I'm just expecting 302 power out of a 170?

It will never be fast, less than a 100 hp pulling close to 4000 lb. But get it dialed in and you will probably be happy. Don't know your definition of hills but steep hills will require second gear.

 

[Nowik35]

X2 on the Fordsix.com - I think you will get it dialed in with some trial & error on the timing. If the distributor is for a 170 with a SCV carb it may not work well with the 1904 but if it's a later model then it just needs dialing in. I looked at the carquest site & I can't tell from the listing if it's for an SCV carb or not?

Is there some feature on the carb I can look for that identifies it is an SCV? I'm more confused now. To add to the story. The original carb on it was a real Holley 1940. I did rebuild it but it was having idling issues when I first installed it so out of frustration I just went online and bought a Chinese replica of a 1904. ( Couldn't find a 1940) The new carb seems to be operating properly. Idles perfect and smells less like gas like the old one did. But now got me thinking did I screw up the SCV.

 

[Nowik35]

If you are not sure what distributor you have, pull the cap off and check for a mechanical advance. They will both have vacuum.
The SCV is what Ford used up to the mid 60's before transitioning to the more traditional (and better running) mechanical advance.

The SCV only works with the matching carb. It is a wonky system that pulls advance when it senses engine speed from high venturi vacuum and throttles/amplifies with manifold vacuum. All the advance, speed and load, is done through the vacuum advance. It really is a horrible system that barely worked when everything is completely stock. Requires a correct SCV carb, correct for the application, with the correct SCV valve. It was not one of Ford's better ideas.

The vacuum signal from an SCV carb is completely wrong for a mechanical advance distributor. It will build a vacuum signal under high loads giving too much advance added to the mechanical advance. Doing it the other way around will result in an engine that will have no power, no timing advance except a little bit at light cruise, if you can even get the engine to run good enough there.

So the distributor is a T2613 carquest. I have no idea how to identity if it's SCV? And reading on the 1904 it seems like it was popular for 50/60 Ford applications so probably did require an SCV. How can I tell if my carb is SCV?

 

[Jonathan_Cole]

I have a 66 170. Even after replacing the carb I had issues with stalling, spitting, etc. I replaced the coil and put in a pertronix electric ignition conversion and it has probably been the best simple upgrade I've added.

 

[Bajabrewer]

Here's some more info on the SCV/"Load-O-Matic" distributor - From what I can tell your new distributor is NOT a Load-O-Matic and the 1904 probably doesn't have a SCV - look at the pictures in this article to see if your 1904 has it or not. This is good news because the 1904 & T2613 carquest should work together.

https://fordsix.com/ams/load-o-matic-distributor-spark-control-valve.28/

I'd start by plugging off the vacuum from the carb and setting the timing at around 10 degrees - plug in the vacuum line & see if she runs & adjust it from there.
Good Luck & keep us posted on your results.

 

[357Bronco]

When is the last time the carburetor was cleaned ? Fuel filter changed ?

 

[Nowik35]

When is the last time the carburetor was cleaned ? Fuel filter changed ?

Fuel filter and carburetor is brand new. Maybe 30 miles on it.