Broken oil pump

Ronnie Scott · 10-31-2010, 04:43 PM

Just pulled my roadster a part to find broken oil pump mellings m55 new style.
Motor is 400 inch motown block eagle crank, rods and wiseco pistons, soild roller cam and stefs pan.
This is the second pump.
First time no proplems this time crank spun 3&4 main bearings
My research has turned up, pump casting junk, arp dist. shaft not flexable, solid motor mounts and fluiddamper NG.

Any insight or help greatly appreacated.

Ronnie Scott
Super Rod 1918

Tim H · 10-31-2010, 05:07 PM

When you say new style pump ... ?There are numerous posts on the net regarding Melling's lightening of M55 pump castings and their subsequent recommendation to use a Melling Select Perf. pump with a number something like #10550 and 10551. Is this possibly related to your pump failure?
I have used solid mounts forever along with a Fluidampr on a 454 and never had a oil pump issue.

Ronnie Scott · 10-31-2010, 05:17 PM

Tim H.
I starting to find out that the warning that came with the pumps wasn't attached or I missed reading them.

Thanks,

Alan Roehrich · 11-01-2010, 11:17 AM

The only time we've had problems with a broken oil pump is when there is a balance problem (for example, a customer put an internal balance flexplate and/or balancer on an external balance engine, or the weight came off the flex plate). The Melling Select pumps are better pumps, and Melling just recently beefed up the base M55 casting. I've also had excellent luck with the Moroso blueprinted pumps. If you're spinning main bearings, you have some other serious problems going on, unless you accidentally made a pass after the pump broke and you had no oil pressure.

If you have a Fluidamper, find someone you hate and give it to them. Your clue that it (the Fluidamper) is going bad is the crank will break, or some other part will fail, such as the cam drive, and they all go bad because the viscous fluid fails and the internal weight welds to the outer housing (at that point it becomes a solid hub that is NOT balanced, and is not absorbing anything but your money). There's nothing wrong with ARP oil pump drives. Solid motor mounts will only cause a problem if there's a balance problem already, then they'll make it worse.

Ronnie Scott · 11-01-2010, 12:21 PM

Thanks Alan,
I have started my list to give the damper away. Maybe a lottery?
Thanks for the info.

don R · 11-29-2010, 12:15 AM

Maybe get a Moroso billet pump?

rod butcher · 11-29-2010, 08:00 AM

Ronnie
I sent you an email

Ronnie Scott · 11-29-2010, 05:27 PM

Thanks Rod,
Great information.
Will head in that direction. Thanks again
Ronnie Scott

10-31-2010, 05:07 PM	#2
Tim H VIP Member Join Date: Jan 2007 Posts: 1,039 Likes: 1,057 Liked 481 Times in 158 Posts	Re: Broken oil pump When you say new style pump ... ?There are numerous posts on the net regarding Melling's lightening of M55 pump castings and their subsequent recommendation to use a Melling Select Perf. pump with a number something like #10550 and 10551. Is this possibly related to your pump failure? I have used solid mounts forever along with a Fluidampr on a 454 and never had a oil pump issue. Last edited by Tim H; 10-31-2010 at 05:12 PM.

10-31-2010, 05:17 PM	#3
Ronnie Scott Junior Member Join Date: Oct 2008 Location: Mattapoisett MA Posts: 14 Likes: 0 Liked 0 Times in 0 Posts	Re: Broken oil pump Tim H. I starting to find out that the warning that came with the pumps wasn't attached or I missed reading them. Thanks,

11-01-2010, 11:17 AM	#4
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,068 Likes: 1,507 Liked 1,648 Times in 379 Posts	Re: Broken oil pump The only time we've had problems with a broken oil pump is when there is a balance problem (for example, a customer put an internal balance flexplate and/or balancer on an external balance engine, or the weight came off the flex plate). The Melling Select pumps are better pumps, and Melling just recently beefed up the base M55 casting. I've also had excellent luck with the Moroso blueprinted pumps. If you're spinning main bearings, you have some other serious problems going on, unless you accidentally made a pass after the pump broke and you had no oil pressure. If you have a Fluidamper, find someone you hate and give it to them. Your clue that it (the Fluidamper) is going bad is the crank will break, or some other part will fail, such as the cam drive, and they all go bad because the viscous fluid fails and the internal weight welds to the outer housing (at that point it becomes a solid hub that is NOT balanced, and is not absorbing anything but your money). There's nothing wrong with ARP oil pump drives. Solid motor mounts will only cause a problem if there's a balance problem already, then they'll make it worse. __________________ Alan Roehrich 212A G/S

11-01-2010, 12:21 PM	#5
Ronnie Scott Junior Member Join Date: Oct 2008 Location: Mattapoisett MA Posts: 14 Likes: 0 Liked 0 Times in 0 Posts	Re: Broken oil pump Thanks Alan, I have started my list to give the damper away. Maybe a lottery? Thanks for the info.

11-29-2010, 12:15 AM	#6
don R Member Join Date: Dec 2005 Location: Illinois Posts: 109 Likes: 0 Liked 0 Times in 0 Posts	Re: Broken oil pump Maybe get a Moroso billet pump?

10-31-2010, 04:43 PM	#1
Ronnie Scott Junior Member Join Date: Oct 2008 Location: Mattapoisett MA Posts: 14 Likes: 0 Liked 0 Times in 0 Posts	Broken oil pump Just pulled my roadster a part to find broken oil pump mellings m55 new style. Motor is 400 inch motown block eagle crank, rods and wiseco pistons, soild roller cam and stefs pan. This is the second pump. First time no proplems this time crank spun 3&4 main bearings My research has turned up, pump casting junk, arp dist. shaft not flexable, solid motor mounts and fluiddamper NG. Any insight or help greatly appreacated. Ronnie Scott Super Rod 1918 Last edited by Ronnie Scott; 10-31-2010 at 04:50 PM. Reason: spelling

11-29-2010, 08:00 AM	#7
rod butcher Member Join Date: Dec 2005 Posts: 252 Likes: 297 Liked 132 Times in 27 Posts	Re: Broken oil pump Ronnie I sent you an email

11-29-2010, 05:27 PM	#8
Ronnie Scott Junior Member Join Date: Oct 2008 Location: Mattapoisett MA Posts: 14 Likes: 0 Liked 0 Times in 0 Posts	Re: Broken oil pump Thanks Rod, Great information. Will head in that direction. Thanks again Ronnie Scott