170 tune up mysteries

rmcphearson

Well-known member
As discussed in another thread my '62 170 is seeping coolant from the head gasket on the driver's side. But before I schedule the gasket job I'm trying to unravel some other general carb and distributor mysteries.

1) My vacuum gauge is not indicating any vacuum from the port on the passenger side of the Autolite 1100 while idling or revved up. A hose runs from this port to the distributor diaphragm. My gauge works, I can move the needle to 5 in. by sucking on it. I've been adjusting the carb screw for max rpms while idling. I can't use the vacuum gauge because it doesn't read anything. The rpms max with the screw 2 full turns out. If I unscrew it further (several turns) the rpms do not change. Aren't the rpms supposed to drop and the engine start to stumble as I unscrew it too far?

2) The engine pings under load. If there is no vacuum at the carb port that runs to the distributor does that explain why it's pinging? Because the timing is always advanced?

-Roland
 
rmcphearson said:
As discussed in another thread my '62 170 is seeping coolant from the head gasket on the driver's side. But before I schedule the gasket job I'm trying to unravel some other general carb and distributor mysteries.

1) My vacuum gauge is not indicating any vacuum from the port on the passenger side of the Autolite 1100 while idling or revved up. A hose runs from this port to the distributor diaphragm. My gauge works, I can move the needle to 5 in. by sucking on it. I've been adjusting the carb screw for max rpms while idling. I can't use the vacuum gauge because it doesn't read anything. The rpms max with the screw 2 full turns out. If I unscrew it further (several turns) the rpms do not change. Aren't the rpms supposed to drop and the engine start to stumble as I unscrew it too far?

2) The engine pings under load. If there is no vacuum at the carb port that runs to the distributor does that explain why it's pinging? Because the timing is always advanced?

-Roland

First on your head gasket seepage depending on how bad this is, you might try warming up the engine to operating temp then retorquing the head bolts. Another thing to try is flushing out the cooling system good then using some KW block sealer.

1. No it's mostly the opposite the RPMs will drop and stumble when you turn the mixture screw into the carb there will be a smaller change in RPMs as the mixture becomes too rich! If you want to use your vaccum gauge for tuning hook it up below carb on the side of the heads manafold log there is a plug or T fitting that's a full Vacuum sorce.

Idle mixture should be set correctly for best reasults to the lean best idle and only after all other tune up settings have been made. In this order: First set the spark plug gap to .034. Then the Distribitor dewell angle is set to 39 degrees. Next set base timing to 6 degrees for a manual trans or 12 degrees for an auto trans. With the engine warmed up good all the valves need to set to .016. Then with engine warmed up again set idle to highest RPM then turn the mixture screw in 1/4 turn. Next set the curb idle speed to spec about 500-525 RPM for a manual trans or 475-500 RPM with an auto trans in drive with the parking brake set.

2. Yes and No. If there isn't any vaccum at Distribitor port then the timing isn't advancing at all, so you only have whatever the base timing has been set at! But it also maybe pinging due to an excessive amount of base timing, do you know what it's been set at?

3. Since you don't have any vaccum at the distributor line you might have a bad SCV on your carb, a plugged up vacuum line or in the carb internal ports, and or also the Distribitors vaccum canister is bad and not advanceing the timing.

You can read even more how these Load O Matic systems work in the very good article in our tech section (see the below link). Good luck (y) :nod:

ci/Loadomatic.html
 
Got it! Thank you!

I don't have a timing light yet. I retarded the timing a bit and this thing is running smoother with more power and almost no pinging! I will try the sealer, head bolt snug, and adjust the valves, then plan on rebuilding the carb.

On the rear of the valve cover the vent hose goes to the air cleaner- that I understand. On the front of the valve cover is what looks like a pcv valve which is routed via hose to the "riser" beneath the carb. What is that? Should I have both of these "vents" or just one?
 
Glad you got it runing a little better keep up the good work. Some pictures would be helpful of the PCV system, though I think it maybe right. Yes if you want the best PCV system you do need both for a PCV (closed) type system. On an inline six the PCV valve needs to be located at one end of the internally baffled valve cover yes the other end goes to bottom of some carb's below the throttle blade or to an adapter plate between the carb and intake log. The oil fill / breather cap sometimes has a stub hose fitting for the crankcase vent hose and yes the hose goes to the air cleaner, installing it in the bottom base plate usally looks cleanest. A Modded (open) PCV system can use a open type oil / breather cap without the hose into the air cleaner. Good luck on the repairs (y) :nod:
 
I have the valve cover off, I tightened the head bolts, and I don't see any way to adjust these valves. I'm going to measure the lash.

The casting numbers on the intake are:
OD29 DODE-6080-A
 
Those casting numbers indicate it’s a 1970 head, check the block numbers too maybe a newer engine was swapped in. Almost all sixes built in 1963 and newer will have hydraulic lifters and stock most of those are non adjustable rocker arms. So my best guess is you have a 1970 engine and there wouldn’t be any lash adjustment. Good luck (y) :nod:
 
bubba22349":149jsjf9 said:
Almost all sixes built in 1963 and newer will have hydraulic lifters and stock most of those are non adjustable rocker arms.

Unless they were out of an Econoline or a Bronco. Those 170's all used solid lifters until '71 afaik. It's hard to imagine, but they were still installing 170's into 2nd gen snub nosed Econolines until 1971. With solid lifters It's a little workhorse of an engine but it had to be at least somewhat underpowered driving a 1968-70 Econo with a 170. Thats a big van.
 
The block has 3 freezed plugs. The casting #s are:
14 C8DE ?015-A ( the ? is either a 6 or 8 or G)

According to my Schjeldahl bible this is a '68 or '69 170 block that "has a dual bell housing bolt pattern"

Is there an easy way to confirm I have a "dual bell housing bolt pattern" block?

-Roland
 
must B a "6" as that's an 'engine' 'part'.

Never saw the preface "14" on a block (pass. side behind the dwn tube of exh.)
Or any preface. Usually just starts w/"C8DE" as I know - so, am interested on additional info the informed will soon add...
(The 2nd grouping "6015-A" I C as usually a 2nd line under/lower than the previous 4 ltr/numbers.

List out the head castings as well - just 4 nods'n giggles (if you'd like, I would!)
(y)
 
rmcphearson":7xu52zwk said:
The block has 3 freezed plugs. The casting #s are:
14 C8DE ?015-A ( the ? is either a 6 or 8 or G)

According to my Schjeldahl bible this is a '68 or '69 170 block that "has a dual bell housing bolt pattern"

Is there an easy way to confirm I have a "dual bell housing bolt pattern" block?

-Roland

So the number Has to be C8DE-6015-A

C is 1960 + 8 = 1968 to know if it's a 1968, 69, or 70 you would need the 3 or 4 combo of numbers and a letter that is the date casting code.

D is the Ford Model Line the part was orginally made for = Falcon
E is the Ford Department that made the part = Engine
6015 is Fords basic number for a cylinder block. A is for the number of times the part was redesigned or improved. :nod:
 
The 14 was above, not preceding, the other numbers.

The head is a 1970 as pointed out above.

I also have the following in my garage that I got out of a '68 Mustang recently:

200 head- 1969

200 block- 1968

200 bellhousing, new clutch, 3.03 trans w/ floor shifter

Holley 1940 carb

That all came out as a unit.

-Roland
 
In your above post the "0D29" is the heads casting date code this tells us that that head was cast at the Ford Engine Foundry on April 29, 1970. The blocks date code will be something like that, it looks like a little metal tag with a screw head on each end with that you can know the exact year, month, and day that the block was cast at the Ford engine foundry. Also with your 170 being at least a 1968 and posablely up to 1970 engine there is about a 100% chance that it's a duel bell housing bolt pattern block.
 
Ok back to the tune up mysteries. As I mentioned, the carb is not pulling any vacuum at any speed at the distributor outlet nipple (above the venturi). Now, regarding the PCV nipple on the carb adapter plate, if I pull the PCV hose off of that nipple the engine dies, and if I plug it back in and plug the PCV valve with my finger the engine dies. Is this normal?

I should note, on the other end of the valve cover I installed a breather cap and ditched the hose that goes to the air cleaner (because my new air cleaner does not have a port). I reckon this has no bearing on my question.

-Roland
 
rmcphearson":2nz9ksp0 said:
Ok back to the tune up mysteries. As I mentioned, the carb is not pulling any vacuum at any speed at the distributor outlet nipple (above the venturi).

"Now, regarding the PCV nipple on the carb adapter plate, if I pull the PCV hose off of that nipple the engine dies,"

[Yes this would be normal since when pull the PCV hose off the adapter plate nipple you would have a big vaccum leak.]

and if I plug it back in and plug the PCV valve with my finger the engine dies. Is this normal?

[No this wouldn't be normal, however until you get the Carb clean and rebuilt and the Distribitor also in working condistion I don't think you can count on any normal operation.]

I should note, on the other end of the valve cover I installed a breather cap and ditched the hose that goes to the air cleaner (because my new air cleaner does not have a port). I reckon this has no bearing on my question.

-Roland

So your next step is to get the Carb and Distribitor in good working order! Good luck (y) :nod:
 
rmcphearson":v29l4is7 said:
and ditched the hose that goes to the air cleaner (because my new air cleaner does not have a port).
Roland
I'm 1 who likes to have a complete pvc system...or a 'closed PVC system".
The pvc may lie to the back somewhere above the oil spray frm back of valve cover (oem is a baffel inside cover so 'all set' if so equipped) it's hose going to carb/intake.
The front often has a "L" shaped fitting frm a less perminant screw type or pressure fitted cap to the frnt of valve cover. This is 2 ease crankcase top offs when low on the dipstick. As U know there's a hose back to the air cleaner to return the crankcase pressure to B cleaned by the filter paper in the ac housing. This completes the 'loop'. The air circle actually goes in the reverse direction as - air in thru filter,thru VC then engine, up pvc to be burned in CC. Some 1 here posted a nice link or a sketch...
 
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