ARP Main Stud BB problem

[Steve009]

Has anyone ever installed big block arp main studs and noticed that the #5 main cap studs are too long and hit the oil pan? I think about 1/8” less would clear it with the oil pan gasket. They are all the same length but I think these 2 need to be a bit shorter than the others? Some comments on summit racing say that a couple other people have come across this. Am I missing something here?

 

[451Mopar]

Never had that problem, but have had to clearance the rear seal retainer for the nuts.
All the main studs should be the same length and screw all the way into the block. No threads showing where the main caps mate to the block. What stud kit part number? Maybe I used a different kit?

 

[rlem1977]

Has anyone ever installed big block arp main studs and noticed that the #5 main cap studs are too long and hit the oil pan? I think about 1/8” less would clear it with the oil pan gasket. They are all the same length but I think these 2 need to be a bit shorter than the others? Some comments on summit racing say that a couple other people have come across this. Am I missing something here?

I've had that issue on a SBC.

 

[malex]

I recall that problem when not using a main girdle. The thickness of the girdle makes the diff. You'll also likely have to take a little off of the seal retainer for the rear main stud nuts/socket to clear as well.

 

[MOPOWER871]

Had the same issue, with the two gaskets and windage tray I needed to grind off about an 1/8" I used a belt sanded and compressed air to keep it cool as I took the excess material away so the stud would never get hot or glow red, light pressure. also had to clearance the rear main seal housing for the main stud washer and nuts

 

[fbs63]

Common problem. Bottom tap all the bolt holes in the block and grind the extra length off the # 5 studs. Geuss ARP can't be bothered to make the correct length.

 

[69Bee]

If you called ARP, they would send you, free of charge, two low head bolts for the rear position. I have run into this a few times on SBM engines, especially with a high volume oil pump. I asked why they didn't just put the bolts in the kit, and their reply was that if someone called it in, they get the bolts, otherwise...

 

[68 HEMI GTS]

I usually grind them down a little. No biggie. Just make sure they are even or above the nut.

 

[451Mopar]

After I posted, I forgot the new engine has a girdle. On the old engine, I think I did have to grind the bolt down.

 

[Steve009]

Thanks for all the replies guys. I contacted arp and they are sending me two studs that are 1/8” shorter. I told them a few people (you guys) have come across this issue and they admitted that they have heard it before. Well then why not adjust the kit? Anyways at least they are helping me out.

 

[ChargerST]

Good to hear that ARP is taking care of the issue (in your case). What's the length of the current studs and/or the new studs? Do you happen to have the part number for the new studs?

 

[Steve009]

Good to hear that ARP is taking care of the issue (in your case). What's the length of the current studs and/or the new studs? Do you happen to have the part number for the new studs?

I haven’t got the new ones in yet. They said they would take care of it. I’ll post the part number when it arrives so people can mention it when they order.

 

[dvw]

Even with short studs the seal retainer needs a little clearancing.
Doug

 

[ChargerST]

I haven’t got the new ones in yet. They said they would take care of it. I’ll post the part number when it arrives so people can mention it when they order.

did you get the studs yet?

 

[Steve009]

did you get the studs yet?

Apparently they are arriving Thursday. I’ll post the part number then. I told them I want 1/8” shorter on the fine thread side (nut side) so we’ll see what they send me.

 

[Steve009]

This is what they sent me. About an 1/8” shorter. I should have gone with 1/4” shorter but with double gaskets and a windage tray I’ll have the gap I need. Still had to grind a bit off the seal retainer as Malex suggested to clear the nuts properly.

did you get the studs yet?

 

[ChargerST]

Thanks! It seems the next shorter stud is 4.060" long - so 0.190" shorter than the stud ARP sent you. Will that stud work as well or is the 4.060" too short already?

 

[Steve009]

Thanks! It seems the next shorter stud is 4.060" long - so 0.190" shorter than the stud ARP sent you. Will that stud work as well or is the 4.060" too short already?

The ones they sent me still hit the pan slightly (without a gasket) so even shorter would be better then what they sent me. As I mentioned, with a double gasket and windage tray I’ll be fine. From what I gather these blocks were drilled at all different depths it seems and that’s why some experience problems and some don’t. If you were just using bolts back in the day that didn’t matter but studs make it an annoyance.