Oil Pump Problems On Rb25/30

[«Cyph3r»]

Hi,

Posting up question for a mate.

He is running the following parts:

Balanced RB30 Crank w/ machine press fitted crank collar

Ross Harmonic Balancer

N1 Oil Pump

JPC Billet Gears

This is what it looks like after only 5000k's.

This siezed the motor completely. Once the oil pump was taken off it turned over.

Anyone had similair problems as this is the second set of oil pump gears that has been destroyed?

After the first time he fitted the balancer and upgraded to billet gears as he wanted to make sure it didn't do another oil pump.

Any suggestions on what could be the problem?

Cheers

Jamie

[jarrod83]

what sort of balancing was done on your crank/rods and pistons?

ive had a similar problem on my first pump, which was only a standard rb25 pump, standard balancer etc.. and shattered the pump in a similar matter, only the outside ring was also broken into about 9 pieces, but my oil pump continued to work for a few weeks after the time i think i broke and use to lock up every now and then.. which could explain the outside ring being in so many pieces

i have mainly had things suggested that youve already had done.. the harmonic balancer and billet gears, aswell as very good balancing, its hard to make out but your pump seems to have the same unusual wear mine has on the inner gear where it gets driven, as well what looks like heat marks, someone suggested to me that there may not of been enough clearance between the crank collar and the oil pump drive

The last thing i have had suggested briefly that i dont understand at all, was something about checking the clearance of the block for the oil pump, i think they mean making sure that the block that the oil pump sits against is flat, but i may be wrong

hopefully we can get some experts in here with alot more experience and point us down the right direction and maybe enlighten us to anything we may of missed

Jarrod

[todoom]

I had the same problem with my 25/30 i had the n1 on mine and the gears let go but did not damage the housing. I now have the JPC billet gears in my pump and one of there crank collars and i have done power cruise in my car with no problems. I do know that manual cars do brake oil pumps more often then autos as there is more on/off throttle with manuals and if u do bash the limiter more often then that doesnt help the gears. The fact that you have done 2 sets of gears tells me that there must be something wrong with the balancing of the engine or the balancer my not be for a RB30.

[Adriano]

Bent crank? How was the clearnace betwwen teh collar and the pump

Edited September 28, 2010 by Adriano

[mico]

geez it looks as if it was too sloppy a fit, and the crank has twisted almont all the way round in the pump. was it hard to remove from the crank ?

[STATUS]

i would be checking the crank collar. Check the gear on the collar for free play.

[ezy_09s]

Inner pump gear looks twisted ..and shows impact marks on the gear near where the collar on the crank drive is.

I think you should measure the run out on the crank snout.

[«Cyph3r»]

Thanks guys, I'll pass on the suggestions.

A bit more info:

Crank was balanced by someone that has plenty of experience.

Forged pistons and rods were used.

Both pump gears and the collar were bought from JPC to avoid possible issues with collar/gear tolerances.

When the crank was pulled they checked the grub screws on the collar to make sure the collar hadn't moved.

It was all still good and hadn't moved since assembly.

I have been told that it was hard to remove from the crank and that the collar had almost fused itself to the inner gear.

[r33_racer]

Perhaps the clearance between the collar and inner gear was too tight??? No expansion allowance maybe...

[T04GTR]

after the first blow up, was a new crank collar fitted? not a bunrnout/rev limmiter motr is it?

[mico]

what ended up being the problem ??

[«Cyph3r»]

JPC gears were binned, they looked rubbish for the money and will not use or recommend them again.

Suspect problem was the collar to gear clearance. Either way when JPC supply the gears and collar together there should be no issue when used on a balanced crank.

My mate had the crank built up instead of using a collar and then rebalanced, welded collar has been built up to suit standard n1 gears by a reputable machine shop in Brisbane.

[mico]

i hope mine dont break i just bought some. i think more survive than break, but the setup on your mates looked like very bad clearance collar/inner gear.

[r33_racer]

It always pays to double check....everything.