I need a pre-1986 Ford 302 distributor measurement and advice

[GWL]

Well, I was headed toward a July 4th first start up but ran into a fixable problem.

In building my engine it looks like I’ve installed an aftermarket APR oil pump drive shaft that is for an older carburetor Ford 302. Ford changed from carburetor to EFI in 1986 and in doing so they shortened the oil pump drive shaft and lengthened the distributor shaft to fit. So, my distributor rides high, not sitting down upon the block.

Three solutions:

• Pull the pump drive shaft up out of the block. Can't be done on mine because I did put the clip on the driveshaft to keep it from lifting out of the pump when the distributor is pulled up out of the block

• Shorten the distributor shaft with room for expansion to allow it to sit lower into the block. Best to measure a carburetor distributor to get precise length needed.

• Pull the pan, drop the oil pump and change out the driveshaft to the stock shaft

I was thinking about dropping the pan and changing it out but it's been suggested that I grind down the end of the distributor shaft. I don’t like the ideal of breaking that oil pan seal and working from underneath the car getting it all back together properly, upside down.

My questions:

Does anyone have a pre-1986 distributor that they can give me a measurement from the gear to the end of the shaft that engages the oil pump driveshaft?

Or, do you think I should bite the bullet and remove the oil pan?

Oil pressure came up quickly using a drive for the pump and a drill and I had oil show up under the valve covers.

Thanks, George

[rich grsc]

I can find no evidence that Ford used different length shafts for their small blocks. The same shaft is used for 289's through 5.0. What happens with aftermarket shafts are they aren't tapered on the ends and getting the distributor to start can be frustrating. Use a socket to turn the shaft a small amount and try again. Or maybe the the clip is installed too high up on the shaft and the bottom of the distributor is hitting it.

[GWL]

I can find no evidence that Ford used different length shafts for their small blocks. The same shaft is used for 289's through 5.0. What happens with aftermarket shafts are they aren't tapered on the ends and getting the distributor to start can be frustrating. Use a socket to turn the shaft a small amount and try again. Or maybe the the clip is installed too high up on the shaft and the bottom of the distributor is hitting it.

Rich,

Ford Racing no longer carries the M6605A302, so they must have made the M6605B302 work with both pre-EFI and post EFI engines. I do have a pump drive I've turned the pump with to help line up the drive. I've even tapped the starter a few times to move the pump shaft just a bit but no going. See the forum listing below for discussions of this.

Check out these forums for discussions about oil pump drive shafts:

Post 8 & 10
https://www.fordmuscleforums.com/threads/87-5-0-shaft-length-w-85-dizzy-oil-driveshaft-length.451042/

Post #7
https://www.allfordmustangs.com/threads/302-and-351-distributor-shafts-the-same.133446/

Post #2 - 3 - 4
https://classicbroncos.com/forums/archive/index.php/t-239142.html

Post #3
http://www.hardcore50racing.com/vbulletin/archive/index.php/t-23519.html

I am not sure about this statement but: The length of the ARP drive shaft is not the real factor but the shoulder on its shaft limits its use for the post-86 engines.

Everyone, I still need the length of the pre-86 distributor from the cam gear to the end that drives the pump.

Thanks, George

[mike223]

Does anyone have a pre-1986 distributor that they can give me a measurement from the gear to the end of the shaft that engages the oil pump driveshaft?

Or, do you think I should bite the bullet and remove the oil pan?



Fascinating - I'd never heard of this either.

Here's another reference: https://www.onallcylinders.com/2020/01/13/mailbag-ford-302-oil-pump-driveshaft-distributor-alignment-tips/

Here's an image that gives some guidance from another reference: https://www.jalopyjournal.com/forum/attachments/5-0l-dist-drive-jpg.1351385/



Having had the oil pan off + on my 351w Mk4 more than once from underneath (on jackstands, to address oil leaks) - I would tell you that project / option is not that bad (it's not as hard as you might think).

My road race oil pan makes it harder than most due to the kickouts blocking access to some of the bolts - but it's still very "doable" and not the complete PITA you might expect (or the PITA I expected).


Good Luck,

Mike

[rich grsc]

When building an engine or replacing a new oil pump (https://www.summitracing.com/search/part-type/oil-pumps) and pump driveshaft, it’s essential to test fit the distributor, adjust the shaft retaining ring, and make any other modifications at this point.
Factory-style EFI distributor users may need to locate and use a “cupped”-style retaining washer that was used on factory Ford EFI engines to achieve the correct tolerances.

[Bob Cowan]

0.993 inches. Measured on a 1969 Autolite.

[GWL]

0.993 inches. Measured on a 1969 Autolite.

Thank you Bob

George

[Big Blocker]

Any chance you are having the same issue that egchewy79 is having? https://thefactoryfiveforum.com/showthread.php?36598-Help-me-stick-it-in-(dizzy).

Shafts should be the same length to the best of my recollection . . .

Doc

[GWL]

Any chance you are having the same issue that egchewy79 is having? https://thefactoryfiveforum.com/showthread.php?36598-Help-me-stick-it-in-(dizzy).

Shafts should be the same length to the best of my recollection . . .

Doc

Doc,

I was part of that discussion you noted on the other forum after you posted on it.

I can actually engage the oil pump shaft with my distributor and the cam gear enough that while turning the engine over I get oil pressure. I only did this for a very short time as I had already pre-primed the engine with a drill and priming drive shaft. The distributor just wouldn't go down all the way onto the block after engaging the shaft. I've tried two different distributors. I think the problem lies with the ARP shaft.

I've just ordered a Ford M6605B302 shaft which is the only shaft Ford Racing now sells, so I think I'm going to pull the pan and the oil pump and replace the shaft with the Ford part.

I just measured the length of my stock 1989 Ford distributor shaft from the cam gear to the very end of the shaft. It measures 1.537". So, with Bob's measurement of .993" for the 1969 Autolite, the difference is just over a 1/2" at .544". I have read elsewhere that you need to take 1/2" off to make it work. But as I said, I think I'm pulling the oil pan and change out the shaft.

Thanks for the input, George

[Bob Cowan]

IIRC, the 351W and the 302W use the same lengths of distributor and shaft. But the 302W shaft is a different diameter. They are not interchangeable.

With a long screwdriver, put a small blob of whit lithium grease on the tip of the drive shaft. Drop the distributor in as far as it will go. Remove the distributor and take a close look at the grease blob. You can tell if the shaft is bottoming out in the distributor.

[Jeff Kleiner]

IIRC, the 351W and the 302W use the same lengths of distributor and shaft. But the 302W shaft is a different diameter. They are not interchangeable.



Correct; 302 is 1/4" and 351 is 5/16"

Jeff

[GWL]

Happy Solution

So, I ordered a Ford Performance oil pump driveshaft and Summit Racing sent me in a Ford box an ARP driveshaft, the same one I have in the engine. So, I figured I could get what I have in the engine to work.

Just got off the phone with Steve at Ford Performance.

I can use my priming driveshaft to drive the retaining circular clip down the shaft in order to allow the post '86 distributor to fit down against the block. I'll slowly move the clip until I get the distributor to fit against the block. Happy days.

Turns out that the driveshafts are all the same lengths, it's the distributor that is different. Post '86 distributors have a longer shaft, as noted above, past the gear to more fully engage the oil pump drive.

He also recommended that I don't drive the clip all the way down to the larger part of the shaft in order to better ensure the drive shaft does not get pulled out of the pump when removing the distributor. He also recommended that when removing the distributor to pull it up a little bit and give it a bit of time to let the weight of the oil pump driveshaft to drop down out of the distributor drive.

I'm now headed out to the shop to work on fitting the distributor again.

Thanks all, George ;););)

[jwhit]

i dont think the clip is issue is all about getting pump drive lined up in dist somtimes this can take 10-15 trys i use a dist with no gear to turn oil pump shaft about 1/8 turn and test fit dist it takes some time

[GWL]

i dont think the clip is issue is all about getting pump drive lined up in dist somtimes this can take 10-15 trys i use a dist with no gear to turn oil pump shaft about 1/8 turn and test fit dist it takes some time

I have always been able to engage the distributor to the oil pump driveshaft and cam, just enough to get oil pressure when turning the engine over. That was after I had primed the engine with a pump drive and drill running backwards. However, the distributor would not sit down against the block thus moving the clip a bit should do it.

George

[rich grsc]

Happy Solution

So, I ordered a Ford Performance oil pump driveshaft and Summit Racing sent me in a Ford box an ARP driveshaft, the same one I have in the engine. So, I figured I could get what I have in the engine to work.

Just got off the phone with Steve at Ford Performance.

I can use my priming driveshaft to drive the retaining circular clip down the shaft in order to allow the post '86 distributor to fit down against the block. I'll slowly move the clip until I get the distributor to fit against the block. Happy days.

Turns out that the driveshafts are all the same lengths, it's the distributor that is different. Post '86 distributors have a longer shaft, as noted above, past the gear to more fully engage the oil pump drive.

He also recommended that I don't drive the clip all the way down to the larger part of the shaft in order to better ensure the drive shaft does not get pulled out of the pump when removing the distributor. He also recommended that when removing the distributor to pull it up a little bit and give it a bit of time to let the weight of the oil pump driveshaft to drop down out of the distributor drive.

I'm now headed out to the shop to work on fitting the distributor again.

Thanks all, George ;););)

WHAT :rolleyes::rolleyes::rolleyes: Glad you can get it to work

[GWL]

It is done and the distributor fits down on the block properly. ;) It was very easy to do. I'll detail how I did it with pictures later.

George

[GWL]

I posted on Summit Racing a question about what I wanted to do and this is the response I got:

Ford Performance, So, to fit the longer distributor of post '86 Ford distributors, do I need to move the circular clip down to the larger portion of the shaft? Will that clip still keep the oil pump driveshaft in the oil pump when lifting the distributor out? Lastly, the engine is built with oil in the pan and by priming I've got good oil pressure. I would like to use a tube to fit over the hex drive to drive the circlip down the oil pump shaft to allow the distributor to fit down further onto the pump drive shaft and then allow the distributor to fit onto the block, will that work?

Answer:
Hello George, Yes you can do that if needed, the circlip cannot be pushed down past the hexagon/machined portion of the oil pump drive however if pushed down towards the base of the machined area it will allow plenty of room for the distributor shaft to engage with the oil pump driveshaft and not interfere with the circlip and still allow the clip to do it's job of not allowing the oil pump drive to pop out if the distributor gets pulled out.
Ford Performance Parts - July 8, 2020

George

[egchewy79]

I posted on Summit Racing a question about what I wanted to do and this is the response I got:

Ford Performance, So, to fit the longer distributor of post '86 Ford distributors, do I need to move the circular clip down to the larger portion of the shaft? Will that clip still keep the oil pump driveshaft in the oil pump when lifting the distributor out? Lastly, the engine is built with oil in the pan and by priming I've got good oil pressure. I would like to use a tube to fit over the hex drive to drive the circlip down the oil pump shaft to allow the distributor to fit down further onto the pump drive shaft and then allow the distributor to fit onto the block, will that work?

Answer:
Hello George, Yes you can do that if needed, the circlip cannot be pushed down past the hexagon/machined portion of the oil pump drive however if pushed down towards the base of the machined area it will allow plenty of room for the distributor shaft to engage with the oil pump driveshaft and not interfere with the circlip and still allow the clip to do it's job of not allowing the oil pump drive to pop out if the distributor gets pulled out.
Ford Performance Parts - July 8, 2020

George
george
did you figure this out? i think i'm running into the same issue. 1966 289 block. bought a RTR pro billet dizzy from jegs and am not able to fully insert dizzy into block. there's about 1/16-1/8" showing, or just at the level of the O ring.
oil pump and pump shaft are currently out of the engine and pan is off.
is the bottom of the dizzy bottoming out in the block? also, with the dizzy in it's current position, when I mock up the pump and pump shaft, there's zero up/down play in the pumpshaft. If I trim the end of the dizzy, i'll likely need to trim the pump shaft as well to get a bit of play. I don't think the "shoulder" of the dizzy is bottoming out on the pumpshaft, and the clip is well below where the hex widens out to the fatter part of the middle of the shaft. Pump shaft is symmetric w/ around 1" of hex on either end, so no real orientation issue there. Clip won't go further than the tapered part of the hex on the shaft.
any advice would be helpful.

[Big Blocker]

Not sure I understand the "cut off the bottom of the distributor shaft" statement . . . unless the dizzy shaft is too long to fit in the block guide bore at the bottom because of gear placement, there is no need to modify the dizzy shaft. Making the shaft shorter won't change the socket aspect of the shaft.The bottom of the shaft is a socket designed to engage the pump drive shaft - it is of a specified depth. The oil pump drive hub is also a socket of a specified depth. IF everything is assembled correctly, there is a specified distance between the pump hub socket bottom and the dizzy shaft socket top. Your pump drive shaft needs to be a minimum of 1/8" less then this distance . . . tapered shafts have nothing to do with this distance unless the taper isn't allowing the shaft to fit completely into its designated socket. This is basic engine blueprinting procedure.

EG; Put the dizzy in without its o-ring. verify that it is completely down. Flip the engine over (it's on a stand, right?) and instal the pump drive shaft into the bottom of the dizzy without the circlip retainer on the shaft. Place the oil pump on the block aligning the pump shaft to the pump socketed hub. The pump should be able to sit on the block and not be held up at all. hand tighten the pump bolts. Now test for up-n-down play in the pump shaft, there should be about 1/8" free play.

If everything went together and the free play is there, you are good to go. Disassemble everything and install the dizzy o-ring and the pump shaft circlip and then repeat the instructions above.

FWIW, the dizzy shaft (gear) sits on the lower block guide bore by gravity, the pump shaft sits in the pump by gravity - there should be no pressure on any of these components.

Doc

[rich grsc]

Doc, this is one of those instances where advice isn't followed. Twice I have advised to lubricate the O-ring, but that hasn't been tried, The pump and the shaft are not installed, and he said he applied grease to the bottom of the gear but it wasn't transferred onto the block when he tried to install the distributor. I know it takes force to install the distributor if you don't lube the O-ring, at least that was the case on my install.
It could be something else, but TRY the simple stuff first. I see no reason to go cutting up a brand new distributor.

[egchewy79]

Not sure I understand the "cut off the bottom of the distributor shaft" statement . . . unless the dizzy shaft is too long to fit in the block guide bore at the bottom because of gear placement, there is no need to modify the dizzy shaft. Making the shaft shorter won't change the socket aspect of the shaft.The bottom of the shaft is a socket designed to engage the pump drive shaft - it is of a specified depth. The oil pump drive hub is also a socket of a specified depth. IF everything is assembled correctly, there is a specified distance between the pump hub socket bottom and the dizzy shaft socket top. Your pump drive shaft needs to be a minimum of 1/8" less then this distance . . . tapered shafts have nothing to do with this distance unless the taper isn't allowing the shaft to fit completely into its designated socket. This is basic engine blueprinting procedure.

EG; Put the dizzy in without its o-ring. verify that it is completely down. Flip the engine over (it's on a stand, right?) and instal the pump drive shaft into the bottom of the dizzy without the circlip retainer on the shaft. Place the oil pump on the block aligning the pump shaft to the pump socketed hub. The pump should be able to sit on the block and not be held up at all. hand tighten the pump bolts. Now test for up-n-down play in the pump shaft, there should be about 1/8" free play.

If everything went together and the free play is there, you are good to go. Disassemble everything and install the dizzy o-ring and the pump shaft circlip and then repeat the instructions above.

FWIW, the dizzy shaft (gear) sits on the lower block guide bore by gravity, the pump shaft sits in the pump by gravity - there should be no pressure on any of these components.

Doc

I apologize, I was under the impression that the longer dizzy shaft would hit the block, but after some more reading realize that it would interfere possibly with the pump shaft, esp if it's an aftermarket one w/ the wider center portion.
My engine is actually in the car, not on a stand. I'll try pushing a bit harder to see if it's hanging up at the O ring and then investigate my pump shaft to see if there's a binding situation. Pump shaft is 7.5" which I believe is standard.

[egchewy79]

Doc, this is one of those instances where advice isn't followed. Twice I have advised to lubricate the O-ring, but that hasn't been tried, The pump and the shaft are not installed, and he said he applied grease to the bottom of the gear but it wasn't transferred onto the block when he tried to install the distributor. I know it takes force to install the distributor if you don't lube the O-ring, at least that was the case on my install.
It could be something else, but TRY the simple stuff first. I see no reason to go cutting up a brand new distributor.
Understood, rich. I was under the impression that the longer dizzy might be hitting the block internally, but the issue is actually w/ the pump shaft. I haven't tried lubing or removing the O ring yet. i'll try that tonight. thanks for trying to help.

[Big Blocker]

Rich, I understand your (our) pain completely . . . many a time both you and I have given advice only to be second guessed by the original poster.

I agree 110%, lube or pull the o-ring and see if the dizzy drops in without any pump shaft in the way. Once we know that part works (fits), the rest is simple.

EG; it doesn't matter if the dizzy shaft is longer, it rides in a bore that is bottomless - it could be 2" long below the gear and not interfere with its installation into the block.

Doc

Doc

[Badfish]

Too many words for me to read on this page, but I can tell you I’m running a reman’d 85 distributor in an HO block. No issues, was a little snug on top when initially installed. A little scotch-brite and some lube, it’s perfect. No change to the oil pump or shaft.