Oil Pump Question...Seized?

[BuGsBuNnY]

The car is a dry sumped Megabird.

The scenario:

Was at Cadwell last weekend. On the last lap, the car vibrated quite a bit on high revs. I took it easy on the next one and was ready to go in the pits to check everything over. Oil pressure warning light comes on, shut engine, get towed back.

On investigation at the pits, the belt that drives the dry sump oil pump had snapped.

Got towed home, ordered new belt. I tried firing up the engine and everything sounded as it should. Put the belt on and everything sounded extremely stressed, like a bag of nails. stopped the engine immediately, removed the belt, tried it again, engine sounds perfect.

On further investigation, the new belt lost two teeth.

Am I correct to assume the oil pump is seized? The original belt was in very good condition so that fits in with the theory of a seized pump. I cannot move the oil pump cog by hand, dont know if thats normal or not. Is it a common fault? Has anyone come up with it before?

Cheers!

[Terry Everall]

Sounds like the pump has seized -But Why???

take it off and strip down to see if any "bits " are in it or if pump itself is knackered. Ring PACE pumps for advice

[JeffC]

Re-sealed my pump couple of weeks ago, As advised I spoke to Niel at Pac..

pump should turn by hand  

the pump is a b******* to get off the car you will take some skin off      but  very simple to take apart  and  not a lot in there to go wrong really ?

hope you get it sorted.

Jc

[longshanks]

I've heard of this happening before... I think Malc (Crash Override) had it on his 'bird... IIRC WF said it was probably due to contamination in the oil (swarf or something) being pulled into the pump from the sump   . I'm sure he'll be along shortly to clarify. He came up with the idea of fitting a gauze filter to the scavenge ports to ensure this couldn't happen again.... however I'm yet to be convinced that the Pace pumps don't just seize of their own accord....  The problem is proving it!

Looking on the bright side, I think you've had a fairly lucky escape not  to end up with a hole in the side of your engine!!!

I'm very nervous about exactly this problem as I'm just finishing off my Blackbird build!!!  

[BuGsBuNnY]

Thanks lads.

Spoken with Mr. Walker who confirmed that the pump should turn by hand and suggested a closer inspection...

Need to take it off tonight... Its been a while since my knuckes grown the skin back so I need to take it off again...

Oh how I hate dropping the engine oil!

On the same note, I would love to get rid of the belt driven pump due to the crank seal always weeping a bit of oil and annoying me.

Is an electric one a viable option or would it create problems of its own?

[Crash Override]

Yep had this problem with mine as Graham said, 100 miles into having it on the road. I noticed no oil pressure so shut of straight away and luckily I was at low revs. I've heard of sumps filling with oil and at high revs it breaking the crank. Pump would not turn by hand and the drive pulley had striped a load of teeth off the belt. Sent the pump back to pace via the factory and they said it had a piece of ali in the rotors that jammed it. Factory got pace to repair it as I did argue the point that the dry sump system has no protection for the scavenge pump.

Posted up on here about it at the time and DanB gave me Pics and instructions on what he had done with his in regards to fitting oil strainer filters in the sump to protect the scavenge pump. It works a treat I've done 14000 miles since including trackdays and still on original replacement belt.

If Dan doesn't pick up on this thread himself give him a pm and mention me and see if he wouldn't mind sending you the pics, mine are on old laptop and can't retrieve them.

Malc.

Edited to add: never had the crank seal leak.

[Terry Everall]

The Busa engines running tts dry sump systems have either gauze filters in the end of scavenge pipes ( but thses are so fine that dirty oil can clog them) or a sump pan plate with gauze in it to filter out any "bits"

[BuGsBuNnY]

Found the culprit. The pump is divided in three "areas" the one closest to the cog is where the problem is. Nothing to do with oil etc. I am totally unfamiliar with the terminology around those bits so I have a couple of pics. I am hoping I can replace that bit only or that the guys at PACE can fix it for me. Will give them a ring tomorrow. However, what caused the problem in the first place is a bit worrying because I haven't got a clue...

Here goes:

[Libell]

Yep had this problem with mine as Graham said, 100 miles into having it on the road. I noticed no oil pressure so shut of straight away and luckily I was at low revs. I've heard of sumps filling with oil and at high revs it breaking the crank. Pump would not turn by hand and the drive pulley had striped a load of teeth off the belt. Sent the pump back to pace via the factory and they said it had a piece of ali in the rotors that jammed it. Factory got pace to repair it as I did argue the point that the dry sump system has no protection for the scavenge pump.

Posted up on here about it at the time and DanB gave me Pics and instructions on what he had done with his in regards to fitting oil strainer filters in the sump to protect the scavenge pump. It works a treat I've done 14000 miles since including trackdays and still on original replacement belt.

If Dan doesn't pick up on this thread himself give him a pm and mention me and see if he wouldn't mind sending you the pics, mine are on old laptop and can't retrieve them.

Malc.

Edited to add: never had the crank seal leak.

Here is a pic on my filter in the sump for protection of the scavenge pump. Working well at least this far ( 1450 km) It was supplied by Neil at pace

[longshanks]

Bugs,

From the pics it looks like the rotor has been rubbing against the end of the pump casing....   have the bearings in the pump gone?  

Could it be possible that you had the belt too tight, causing excessive side load on the pump bearings?

[moomin]

QUOTE

If Dan doesn't pick up on this thread himself give him a pm and mention me and see if he wouldn't mind sending you the pics, mine are on old laptop and can't retrieve them.

I've done this mod to mine - loads of pics on my build diary.

moom.

[BuGsBuNnY]

Bugs,

From the pics it looks like the rotor has been rubbing against the end of the pump casing....   have the bearings in the pump gone?  

Could it be possible that you had the belt too tight, causing excessive side load on the pump bearings?

Belt could turn 90 degrees as per Westfield's recommendation so really dont know but I dont think so.

Pump is on its way to Neil at pace so will wait what happens when he has a look at it.

Those of you who put the filters in, is it just a slot in job or do you have to machine a groove so that the filter sits in the sump?

[moomin]

QUOTE

Those of you who put the filters in, is it just a slot in job or do you have to machine a groove so that the filter sits in the sump?

Probably easiest explained in pictures for what I did (same as DanB and Malc) - look at my build diary from 24th January 2005... click here

moomin

[Libell]

Those of you who put the filters in, is it just a slot in job or do you have to machine a groove so that the filter sits in the sump?

Yes some machining , I let a local machine company do the work for me . It didn´t cost much . I know that Pace can help you with this job . The "advantage" of my/pace way of mount the filter is that you dont have any extra parts in the sump that in worse case could come loose an do some damage . Like in Moomin´s way of mounting . (But maybe it isnt a problem) . I also notice that moomin and I have different filters (sizes of the holes in the net).

I hope everything solves in the best way  

[BuGsBuNnY]

Both ways seem safe enough for me but both involve removing the sump which I would love to avoid. I will speak with Neil and weigh any available options.

Thanks very much guys, your pics and commentary has been extremely helpful!