HV oil pump bolts kit disappointment.

[Tony Tee]

This isn't a big deal, but it's more trouble than it's worth. And I'm letting others know before anyone else buys this kit from Mega parts. I ordered a extended bolt kit for a big block hv oil pump on ebay from Mega parts. And 3 of the 4 main body bolts are short. It also comes with 2 small cover bolts. So I told Mega parts about the problem and I asked them to send me the correct size longer bolts. And the reply I got was, (we don't have longer bolts and file a return). I'm going to look for some matching longer bolts locally. Before I send the kit back. As you can see by these pictures, new bolts are the left, and my old bolts from a standard pump is on the right.
The standard pump with standard pump, all the bolts protrude the same amount.
the HV pump has the new bolts from Mega parts and you can clearly see that 3 out of the 4 bolts are too short. So buyer beware.

 

[dadsbee]

5 threads is plenty of engagement, unless your block had stripped outer threads.

 

[radical rob]

Got my bolts at the local hardware store

 

[hunt2elk]

You only need one longer than factory bolt when switching to the hv pump. Looks like you got exactly what you need.

 

[Tony Tee]

5 threads is plenty of engagement, unless your block had stripped outer threads.

Then these kits are not needed? And why didn't chrysler use shorter bolts from the factory? They could have saved millions buying shorter bolts for all the big blocks they produced! Maybe they should have shortened every bolt on every vehicle produced? But they didn't ! and this kit is wrong! And so its ok to short change quality and parts on every reproduced kit we buy nowadays? Heck no! So I'm putting the word out. And one more thing! If your block has boogered up threads it's most likely because someone used bolts that are too short! 4 to 5 threads on soft cast iron is not good

 

[dadsbee]

Sorry I tried to help you out... I'll add you to the list.

 

[Tony Tee]

Sorry I don't believe only one long bolt is needed. As all 4 bolts on the standard pump are all the same length into the block. And even if it supposed to be ok with only one long bolt. I'm not doing it. Remember! the standard pumps bolts are the same length into the block.

 

[70bigblockdodge]

Glad I saved myself all this aggravation by just going to the hardware store.

 

[Tony Tee]

Glad I saved myself all this aggravation by just going to the hardware store.

Hindsight is 20/20 I wish I was warned before I ordered this kit.

 

[hunt2elk]

The kit you bought will work fine and as far as I know is the same as every other hv bolt kit being sold. If you can't sleep at night because you think it is not correct, just go to the hardware store, get some longer grade 5 bolts , and cut them off to exactly the length you believe that you need....

 

[Tony Tee]

The kit you bought will work fine and as far as I know is the same as every other hv bolt kit being sold. If you can't sleep at night because you think it is not correct, just go to the hardware store, get some longer grade 5 bolts , and cut them off to exactly the length you believe that you need....

I said that in my initial post. But thanks anyway.

 

[dadsbee]

Pull out stress analysis is generally done with one or two threads. 1.5 times bolt diameter of engagement is another more "real world" tried and true analysis, which you have there. If you think a longer cheap hardware store grade 3 bolt is gonna make you comfortable, go for it.

 

[Tony Tee]

Pull out stress analysis is generally done with one or two threads. 1.5 times bolt diameter of engagement is another more "real world" tried and true analysis, which you have there. If you think a longer cheap hardware store grade 3 bolt is gonna make you comfortable, go for it.

I'll look for grade 8 bolts. It just seems incorrect that the standard pump has all for bolts going into the block 5/8 " deep. And the hv bolt kit has only the long bolt going into the block 5/8" deep and the other 3 bolts go in at 5/16"
I understand what you and others are saying. About having less threads is strong enough. But why are all 4 bolts on a standard pump going in deeper on all 4 corners of the std. pump and not on the high volume pump. No one has come up with a answer. Just look at the pictures in my initial post. Sure it might be ok on your engine. But not mine. The block has almost 1" of threaded hole there. Why not use it?

 

[Tony Tee]

Sorry I tried to help you out... I'll add you to the list.

I appreciate the comments. Thanks!

 

[Jerry Hall]

As the factory didn't use HV pumps, it was probably less expensive to buy all the same length bolts than mixed sizes.

 

[Tony Tee]

I just found out that 440 sorce has high strength bolt kit for the m63hv pump ( pictured ) with all 4 bolts extending out of the pump equally. They have 12 point bolt kits for the HV pumps as well, but not shown installed into the pump. Not all bolt kits are created equal .

 

[BSB67]

I haven’t purchased a HV pump since the 1980s, so I’m going from memory from long ago. I think the standard bolts at that length start to increase on 1/2” increments. So the available bolts are either a bit short or too long and you’ll need to cut them down. If your going to cut them, I suggest grade 5 verses grade 8.

If you really want to be disappointed, open up that Melling pump and take a close look inside.

 

[dvw]

Go to the store. Get bolts that replicate the factory depth of engagement. As I remember you may have to trim their length to get what you need. I don't put them in shallow either. Ever seen a head or main bolt the only engages 5 threads?
Doug

 

[70bigblockdodge]

I usually just put a split-lock washer in behind the stock spring on a standard volume pump unless turning over 6k on a regular basis. The lock washer usually will push pressure up ~ 60 psi.

 

[Tony Tee]

I finally got the chance and bought some longer bolts. Plus I noticed that the short bolts were grade 5 while the long bolt was a grade 8.
Not a good bolt kit . Thanks everyone for your help. Sincerely, Tony.