Duraspark Dizzy for a 170. Can it be done?

[blueroo]

Hey all,
Will a Duraspark or Duraspark II setup work in a 1964 170 cubic inch engine? I've seen things done to and made for the 200 but I don't understand why they're not used with the 170 since they are the same block except for when the 200 got 7 mains in 65 (or was it 66?) from what I understand. Can anyone help me out with this?

 

[CoupeBoy]

maybe there is some hope IF its possible to
machine the dizzy hole in the block large enough to fit the DII dist housing
and
change the oilpump (or its drive unit) with one from a newer engine that matches with the DII dist shaft

I thought the older blocks had smaller dist holes (cannot confirm) and I am completely unsure if you can do anything with the oil pump or shaft.

-ron

 

[addo]

Easy; there are a few solutions. Whichever you choose will require a 66-up oil pump for a 200, and the 5/16" hex drive shaft. You can't avoid these two parts.

Now you can buy an Aussie electronic distributor which will drop in with a little grinding to reduce the mount tab.

Or, pull apart a Duraspark and machine down the pilot section of the shaft, below the gear. This is machine shop territory but quite feasible and very straighforward.

Both options are easier than altering the block.

Regards, Adam.

 

[jamyers]

...pull apart a Duraspark and machine down the pilot section of the shaft, below the gear....

OK, I'm confused now...wouldn't you need to machine down the dist body above the gear also?

Anybody got a pic of a distributor?

 

[jamyers]

Here's a pic of a '62 Load-O-Matic distributor from the NAPA website:

And a Duraspark (II?) from a '75 Maverick 200, same source:

 

[addo]

As Mr Myers' pictures show, the pilot area is below the gear. This is the part which intereferes by being too large on a DS-II. There's no need to thin down any more of it than this first section.

The big portion of the hole, where the dizzy body slips in, remains unchanged through the years.

Regards, Adam.

 

[jamyers]

...The big portion of the hole, where the dizzy body slips in, remains unchanged through the years.
Regards, Adam.

Aha! I always thought that it was the hole for the dizzy body that was too small on early engines.

Heck, this looks easy enough even for me to do!

Thanks!

 

[jamyers]

Can this thread be made into a sticky?

 

[addo]

If someone goes through with it - why not?

Actually, if we can get a report on how easy or hard it is to resize the shaft's pilot end, it's almost material for D&D Schjeldahl's next edition.

 

[XFlow_Fairlane]

I woul djsut be afraid of the metal getting thin in the "corners" of the shaft and possibly splitting out.

 

[addo]

There's so little in it - a radial reduction of 20 thou, and it's well suppported in its position.

 

[Lazy JW]

I could do that with a file.
Joe

 

[addo]

By just spinning the shaft up in the lathe and carefully filing? Sounds potentially the easiest trick. Plenty of "rat rod" cred in the method.

 

[jamyers]

I'm waiting for an excuse to pull the pan, then I'm all over this swap.

I don't have a lathe, but I have a vise, and figure I can spin the shaft with a drill and use a carbide burr on a die grinder to reduce it down.

 

[XFlow_Fairlane]

I would check with a shop about turning it down correctly. you are gonna want a smooth finish on that shaft or else it is gonna wobble alot and rip up the gear.

 

[jamyers]

I would check with a shop about turning it down correctly. you are gonna want a smooth finish on that shaft or else it is gonna wobble alot and rip up the gear.

Good point - as steady as I am, I'd hate to go too far - and it surely wouldn't cost that much...

 

[Hot 6t Falcon]

WHOAAAAA!!!

The first response from Coupeboy was correct, The rest gets a little smokey.

The difference between the 170 and 200 blocks (besides the number of main bearing and other things) that we are talking about here - is the diameter of the hole for the distributor.

The 170 distributor hole is XXX inches.

The 200 distributor hole is 1.29 inches.
Dang, I can't find where I have it written down... I'll post and then go look again - I'm thinking about 1/8 inch less.

Look at the pictures I drew a big ARROW to the area that would need to be filed/turned down.

The arrow points to an O-ring area. The pictures are NOT to scale. The DS II is a larger diameter than the '62.

The other difficulty is the oil pump drive shaft. The driveshaft slides into the small shiny end where the "?" is in the picture. The 170 has a 1/4 inch shaft; The 200 ha a 5/16 inch shaft. The "best" solution is to pull the oil pan and use a 200 pump. I 'spose you could get a 200 oil pump drive shaft and compare it to your 170 shaft - grind one end down to 1/4 inch - BUT this is the hardened OIL PUMP driveshaft you're fooling with.

If the "OIL" light comes on on your dash, you'll know it snapped.

Good Luck on this one!

 

[addo]

Dennis, my experience has been that the two differ only in the lower, or pilot bore.

One is 0.490"
The other 0.530"

I am curious as to any differences up top, as this may explain the slight difficulty some people experience fitting the part - metrication, maybe?

 

[XFlow_Fairlane]

I think the top is the same size too....

I tried putting a DS in my 170 and it went in part of the way....jsut would not drop all the way in (IE the shaft bottomed out on the hole...) you could just get out a mic and check your dizzy shaft and someone else check the 200 to see the differences.


another thing I have always wondered......how tough would it be to put a US shaft in an AUSSIE body (IE get a drop in EEC4)

 

[addo]

I've got a reshafted electronic one.

0.530" shaft in an electronic body. It was $125 or so for the conversion, which used a donor shaft TIG'd to the upper section, and a new (super limited old stock) shaft bushing. EEC-IV would be the same process.