So whats your opinion....

[Marv D]

Was it just being anal,, or..... warranted

Motor is back in the truck, but went to prime the oiling system and something was just not right. I pulled the oil pump apart and inspected, checked, blueprinted cleaned, and re-used the oil pump from the last build with this assembly (in a GM block before) Everything was fine. Dropped the ARP shaft in, put the oil pump on and went happily about my way with the rest of the assembly.
Fastforward a month and the motor is built in a Dart LittleM block, Have to prime the oiling system before I can put the carbs on (cant get the distributor in and out once the carbs are in place and is a MAJOR PITA to pull the carbs).

Anyways something was wrong. I could 'feel a drag on the oil pump primer trying to turn it by hand before I even put any oil in the pan. It would 'turn' but it was WAY too tight. Put a Dewalt cordless on it and it would spin ,, used a 1/4" ratchet and it would turn, but it was too stinking tight. Suspected the oil pump shaft when I put it in, but was too stupid to think it through. Anyways,, end result is I can't get the pan all the way off with the motor in the chassis (motor plate, mid plate and rear trans mount so it's a big PITA to even raise or try to pivot the motor in the chassis, but the pan iwill hang down enough to get the scraper tray and oil pump out (with MUCH cussing and knashing of teeth!!)

So here is what I found. The ARP pump shaft is about 0.002" smaller than the hole bored in the Dart Little-M rear main cap. It clears until you put a distributor (or primer) in it and pull the shaft into alignment. If the ARP shaft was tapered just 1/4" farther up, it would clear. But JUST CLEAR doesn't sound right to me. I'm taking the shadt to my sons and chucking it in a lathe and cutting about 0.050" off the whole polished area to have 0.020"+ clearance all around.

So which would have happened if I hadn't decided I wasn't going to risk the motor over pulling it apart in the truck to check WTF was wrong. Would it have heated up and split the rear main, siezed and twisted the shaft in half, or would the oil flooding down the back of the block been enough to make this OK??????

The Macro lense shows what little actual material was pushed around spinning it with the primer and dewalt drill. Really only polished off the black oxide coating.




I mean it's apart and getting fixed right,, but be aware,, the Dart Little M block / ARP pump shaft has this issue. Actually it's not exclusive to the ARP shaft, the stock 400 shaft has the same diamerer within 0.002" and extends even taller . This wouldn't be so bad if I didn't have a similar issue withthe Motorw block in the Nova and a Titian oil pump. Almost same problem withthe Titian shaft binding under the pump and had to pull the motor to correct it. You'd think I'd learn from m mistakes. Apparently NOT!!!!

[68 C-10 KID]

Marv,
I think you did the right thing.
Then again look at the lifters and cam shafts. They have friction. The oil keeps them cool and lubed.

[djracer]

Better to be safe than sorry!

[Marv D]

Yup,, here's the revised piece and even tho it cost me a day,, Now I don't have to worry about it. I could just see the metal gaulling and the lower portion of the shaft twisting off. BEEN THERE,, the distributor turns, the motor continues to run,, bearings burn, blues up main caps, destroys a LOT of crap in about 9 seconds Put a 15psi warning light in everything I race because of that,, but why invite headaches


I can't wait for delivery of my stinking Grizzley mill/lathe combo. I am at my sons borrowing his 3 times a month or more to make some silly crap. Have a couple hundred things I want to make when it gets here next month

[BigDan3131]

I'm a nut about things that seem and or feel rough. I would have right away hand lapped it smooth then polished until shiny.

[BR3W CITY]

for a "just get it going" build I'm the type to say screw it, it will most likely be fine. BUT, I've said that before and been burned. If it was my build, I'd want the peice of mind in knowing that issue was taken care of BEFORE i decided to run it

[dbmx66]

would there be any metal shavings that you have to worry about? doesnt look like it cut into shaft. but maybe you should check block just to make sure there were no tiny pieces of shavings from the rubbing.

[nxtruck]

I'd say you did the right thing Marv. I don't know about you, but that kinda stuff keeps me awake at night. I sleep a lot better knowing that sort of thing is right.

[dbmx66]

Originally Posted by nxtruck

I'd say you did the right thing Marv. I don't know about you, but that kinda stuff keeps me awake at night. I sleep a lot better knowing that sort of thing is right.

id agree too. the smallest thing can lead to a big disaster.

[Marv D]

dbm it just touched just enough to knock the black annodizing (or whatever process they use to blacken the steel) The thing that made me really concerned was the contact was in the bottom of the rear main cap. Anything that had the potential to make the rear main cap heat,, makes the bearing heat. With recovering from this back surgery, and just the frustration of working on it with the pan hanging down 'just enough' to say it can be done without pulling the motor........

She's alive!!!!!! bwahhaaaaa!

(in my best Vincent Price impersonation)


So nice to have the ol girl back mobile and makin noise again.

[1968SWBBigBlock]

FWIW - I ran into the same issue when I built my BB.
Stock block, melling pump and ARP shaft.
According to my builder ARP shafts have this tendancy - they are just a smidge bigger.
We also got lucky and found it before we fired the motor - but had to take the pan off to fix it.

[Marv D]

Good to know. Apparently this is more common than just me having the same deal in 2 blocks. This one is all Dart tho,, I mic'd a stock shaft for a 350, and a stock necked down shaft for a 400, and the ARP shafts for both and they are all .4985 to .492,, If the hole in the main is .500",, .008 is TIGHT if the shaft were to be a perfect alighment between the pump, the hole and the distributor. But somethig is off 'just enough' to pull the shaft against one side of the hole in the cap. The 400 has the 'necked down' shaft to let oil washing down the back of the block somewhere to go. But ARP and the beefier Dart cap just dont have the clearance where needed.

[bigsnookmaster]

You would think ARP would clearance these shafts a bit more. I inherited a small machine shop a few years ago,(Thanks Jack!) and I think I would have killed someone during my build, if I didn't have access to a lathe and mill to modify about everything I put into my truck! I even had to machine 1 bolt for clearance on each of my Jesel shaft rocker assemblys. It rubbed the rocker, only on one side. Good Luck Marv, it's about time things start going right for you!

[nxtruck]

Glad to hear you got it running Marv!

[regan wilson]

Originally Posted by Marv D

Was it just being anal,, or..... warranted

Motor is back in the truck, but went to prime the oiling system and something was just not right. I pulled the oil pump apart and inspected, checked, blueprinted cleaned, and re-used the oil pump from the last build with this assembly (in a GM block before) Everything was fine. Dropped the ARP shaft in, put the oil pump on and went happily about my way with the rest of the assembly.
Fastforward a month and the motor is built in a Dart LittleM block, Have to prime the oiling system before I can put the carbs on (cant get the distributor in and out once the carbs are in place and is a MAJOR PITA to pull the carbs).

Anyways something was wrong. I could 'feel a drag on the oil pump primer trying to turn it by hand before I even put any oil in the pan. It would 'turn' but it was WAY too tight. Put a Dewalt cordless on it and it would spin ,, used a 1/4" ratchet and it would turn, but it was too stinking tight. Suspected the oil pump shaft when I put it in, but was too stupid to think it through. Anyways,, end result is I can't get the pan all the way off with the motor in the chassis (motor plate, mid plate and rear trans mount so it's a big PITA to even raise or try to pivot the motor in the chassis, but the pan iwill hang down enough to get the scraper tray and oil pump out (with MUCH cussing and knashing of teeth!!)

So here is what I found. The ARP pump shaft is about 0.002" smaller than the hole bored in the Dart Little-M rear main cap. It clears until you put a distributor (or primer) in it and pull the shaft into alignment. If the ARP shaft was tapered just 1/4" farther up, it would clear. But JUST CLEAR doesn't sound right to me. I'm taking the shadt to my sons and chucking it in a lathe and cutting about 0.050" off the whole polished area to have 0.020"+ clearance all around.

So which would have happened if I hadn't decided I wasn't going to risk the motor over pulling it apart in the truck to check WTF was wrong. Would it have heated up and split the rear main, siezed and twisted the shaft in half, or would the oil flooding down the back of the block been enough to make this OK??????

The Macro lense shows what little actual material was pushed around spinning it with the primer and dewalt drill. Really only polished off the black oxide coating.




I mean it's apart and getting fixed right,, but be aware,, the Dart Little M block / ARP pump shaft has this issue. Actually it's not exclusive to the ARP shaft, the stock 400 shaft has the same diamerer within 0.002" and extends even taller . This wouldn't be so bad if I didn't have a similar issue withthe Motorw block in the Nova and a Titian oil pump. Almost same problem withthe Titian shaft binding under the pump and had to pull the motor to correct it. You'd think I'd learn from m mistakes. Apparently NOT!!!!

Yup you did the right thing ....And yup I'm still alive ....