170

[thefurnacedude]

Hello Everyone,

I have a rebuilt 170, which I bought 5 years ago. I want to finalize my plans with this motor before installing.

Anyway. I want to upgrade the power on this motor without sacrificing a lot of fuel economy and breaking the bank account. I own a couple parts that can help with power and reliablility (Jacobs ignition, Weber 32/36 - 2bbl, DSII, T-5).

This car will be a daily driver. I want power leaving stop lights and passing power more than 1/4 mile ET results. In other words 1000-4000 rpms. I am thing about the Comp Cams 252 camshaft.

My question is
1 - Can a 170 head be milled flat and direct mount a 2 barrel? I own a 32/36 Weber.

2 - Do 170 motors accept the Durasprk II distributor?

3 - Are there any advantages modifications to this rebuilt 170 head or would the potential performance justify the expense of buying a 78 - 200/250 head.

Tim

Any help would be appreciated

 

[powerband]

Hello Everyone,

I have a rebuilt 170, which I bought 5 years ago. I want to finalize my plans with this motor before installing.

Anyway. I want to upgrade the power on this motor without sacrificing a lot of fuel economy and breaking the bank account. I own a couple parts that can help with power and reliablility (Jacobs ignition, Weber 32/36 - 2bbl, DSII, T-5).

This car will be a daily driver. I want power leaving stop lights and passing power more than 1/4 mile ET results. In other words 1000-4000 rpms. I am thing about the Comp Cams 252 camshaft.

My question is
1 - Can a 170 head be milled flat and direct mount a 2 barrel? I own a 32/36 Weber.

2 - Do 170 motors accept the Durasprk II distributor?

3 - Are there any advantages modifications to this rebuilt 170 head or would the potential performance justify the expense of buying a 78 - 200/250 head.

Tim

Any help would be appreciated

There is absolutely nothing wrong with the earlier heads for daily driving unless better breathing for MPG and performance is central.
If you plan on rebuilding the Head anyway, an inexpensive later model rebuildable "core" head with larger runners and better valves may be cost effective.

Here's my take on the 170 :


MPG consciousness was a dominating factor in my recent re-build of my DD - '63. It had a wheezy but reliable original 170/3spd. I replaced engine with a tight '71 170. To keep up the mileage, installed new timing set but stock cam, DSI electronic dizzy, H/W 5200 progressive 2bbl , and most importantly Overdrive tranny. Most six cars have the pre-Interstate driving 3.50 rear. with the T5 OD there is no problem cruising wiith modern traffic It has a radical built hi-compression cylinder head (kudos=Schejhldal bros ! .). Oversize valves, ported & relieved, long tube dual outs...

All the contributing aspects of the build were to allow for the fun of "sleeper" performance while maximizing the "commuter" MPG by exploiting the low rpm torque curve of the ford small six.

Powerband

 

[thefurnacedude]

I am leaning toward keeping the rebuilt head from the 170. The only factor that would make me consider changing my mind would be if I could not direct mount my 2 barrel.

The recent tests posted here prove that the direct mount 2 barrel is probably the most effective improvement ( HP/$$) that I could make, especially since I already have a 2 barrel and the head is off the engine.

I also have a NOS set of 144 intake valves. I may add those to exhaust and unshroud the chamber. I just don't want to get into too much $$$.

Tim

 

[kukm66]

65 and later should have theproper bore for a Duraspark.

 

[CZLN6]

Howdy Tim:

The critical question is what casting # block and head are you working with. AKT the smaller diameter bore and combustion chambers of the 170s really limits the effectiveness of adding larger valves.

The answer to your questions #1 is "Yes". Depending on the casting # you will have more or less metal to work with, but either can be modified.

Question #2 would depend on what the casting codes say. A casting # of C5 and later will accept the DS II. Earlier- not without considerable modification.

On your 3rd question, I'm not sure what you are asking. The later heads will flow more and have higher power and rpm potential, but for economy those features may not be what you want. The later heads have a larger combustion wedge making a lower quench-to-bore ratio with a 170 flat-top piston- not what you want for combustion efficiency and mileage. The '65 to '70 castings have a "kidney bean" shaped combustion chamber- more rounded in the corners then earlier and later. These castings are my favorite when building for mileage efficency. They have larger valves than earlier, and smaller chambers than later. Avoid any Calif. smog head casting of that era.

IIWIYS, I'd probably be looking to maximize compression, at least 8.7:1 on regular gas, and clean up and optimize the valve seats- at least 3 angle and back-cut on the intakes. That would include smoothing the chambers and pocket porting below the valves.

On the cam- that is a good question. The goal will be to maintain high cylinder pressure and vacuum. More lift would help, but don't get carried away with overlap and duration.

Akt- higher cylinder pressure, (and resulting heat) is good for economy and torque, but the resulting heat will need to be carefully monitored and controlled.

I hope that helps. Keep us posted on what you decide to do and how it works out for you.

Adios, David

 

[thefurnacedude]

Thanks for the feedback so far everyone.

The block casting is a C50E. I have not yet confirmed, but was told by the previous owner that it was a 7 main block.

I hope this block accepts the DSII distributor without any modification.

As long as the head can be milled flat to accept a 2 barrel, I will use it. I will give it a slight porting, more of a cleanup and smoothening than enlarging of ports. I will also need to give it hardened exhaust seats.

Tim

 

[kukm66]

65 170 block should be 4 mains
66 and later should be 7 mains

My 65 170 block was 4 mains

 

[CZLN6]

Howdy Back:

That casting is probably C5DE. it's hard to distinguish sometimes. the good news is that this block should accept a late model DS II distributor.

Does the heads casting # match the block?

Adios, David

 

[thefurnacedude]

David,

The head casting # is C0DE.

Tim[/quote]

 

[early ford fan]

i have a four main 170 with a 78 200 head.i have the ds 11.i have the holley 5200,but its not dialed in.it floods at idle and gets 12.5 mpg...i don't believe seven mains are nessesary for normal driving.

 

[rbohm]

8) one thing i suggest is a cam upgrade, specifically this one from classic inllines;

CSC-264-HDP-12

you will find it here;

http://www.classicinlines.com/products.asp?cat=115

it will pick up the power levels over the stock cam, and make any other mods you do more effective, especially head mods. for the 170 i the biggest valves i recommend is a 1.75in/1.50 ex. you may have to work the combustion chambers some what to unshroud the valves, but that isnt too difficult to do.

with a little ingenuity, and a good machinist you should be able to direct mount a 2bbl carb on the stock head. stovebolt sells the carter/weber carb which they believe is better than the holley/weber carb at a reasonable price.

one thing about the duraspark and your block. if you have the earlier block, you will need to drill out the small hole the distributor shaft fits into. it isnt hard, but will take some time as you are going through cast iron. you will also need to use the later oil pump and oil pump drive shaft since they are larger than the earlier ones, 5/16 vs the earlier 1/4.