Oil pump failure

[TWOpointFORliter]

Made my first ever passes at the shootout this year and after my 3rd run I started leaking oil inside of the timing cover. Thought I pushed the oil pump seal out so I parked the car till I could get it back home and tear into it.

Well after getting it tore down I found that not only did I push the seal but the shaft was not centered and eating into the front case. This is a very expensive long block built by a very reputable shop and had a brand new front case/oil pump. I never double checked their work on the timing side of the engine but one would assume they knew what they were doing for setting proper tension on the belt. Engine has about 5,000 miles, 6 passes at the strip and a few dyno pulls.

My question is can anything cause this other than improper belt tension?

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[DrewmHolland]

definitely belt tension, the extra friction just killed it

 

[1990TSIAWDTALON]

It appears that they didn't know everything about a 4g63 engine build. That belt had to be way too tight to wear out the oil pump housing bushing.

 

[curt-s]

Damn, one of those things that make you wish you could go back and take a picture of the tensioner clocking prior to teardown.

 

[LaserRS92]

Good job this weekend on your first 10sec pass, I talked to you right after you made it back to the pits and found the oil trail. Hope you can get this fixed quickly and get back out there.

 

[TWOpointFORliter]

It appears that they didn't know everything about a 4g63 engine build. That belt had to be way too tight to wear out the oil pump housing bushing.

I won’t directly name the shop but I’m pretty sure they’re listed in my vehicle profile.

Good job this weekend on your first 10sec pass, I talked to you right after you made it back to the pits and found the oil trail. Hope you can get this fixed quickly and get back out there.

Thank you sir. I’ve been going to the shootout for a very long time as a spectator and this was by far the best time I’ve ever had. Already have the parts ordered to fix it and I’ll see how deep into the 10’s my driving can get me on street tires.

 

[LaserRS92]

I'll let you know once I have some edited photos. With the harsh sunlight and it being black I'm doubting my skills at the moment. haha

 

[TWOpointFORliter]

I'll let you know once I have some edited photos. With the harsh sunlight and it being black I'm doubting my skills at the moment. haha

I would appreciate that very much. I’ve found 3 photos of my car so far in all the shootout albums I’ve gone through. Happens every time I go to a cars and coffee too. Pictures of every car but mine haha. I really wanted a picture of it at the starting line but I only ran on Friday so I doubt there is one floating around out there. Next year!!!

 

[TWOpointFORliter]

Still trying to figure out something besides belt tension that could have caused this. Been doing a ton of searching through old threads and I did come across another post where someone had this happen multiple times. They even tried setting the belt tension “loose” but it still happened.

The engine builder told me the rear balance shaft journal was damaged so I couldn’t use the “race balance shaft delete” and was stuck with just using the stubby shaft for that block. What’s the limit for the stubby shaft in terms of engine torque output (I made 634 on a mustang dyno) or rpm’s (8200 rpm’s in the 1/4). Seems like a lot to ask from a shaft that just rides on a thin film of oil and not an actual bearing.

I’m about to put it all back together with a different case but I’m worried it’s just gonna happen again. Was told by multiple people at the shootout to rebuild an old oem case because they have repeatedly found casting flaws and cracking in the newer cases so that’s what I’m doing.

Anyone have a 7bolt FF oil pump? I’ll pay over market value for one!!!

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[EC17PSE]

If the rear journal is bad then then replace the inner BS bearing and run a race shaft. This will help the loading more vs a stubby shaft. The stubbys are also generally used for straight cut gears also. While it works for both the concensus is long shaft helical, stubby for straight cut.

No matter what shop done it you should always inspect the work. Some big shops over the last few years have had all kinds of slip ups and it might not be specifically down to care but anything from not checking, new guys or an off day in the shop! It happens and will continue to happen till the end of time. Its just precaution on your end to final check its correct and questions before its used.

All you can do is new case it, replace rear BS bearing, race BS and time it again perfectly for the granade pin free moving once set and left. Of course clear your oil and pan out and if you got an oil cooler replace that now to! Do not re use the oil cooler once any debris have gotten into the oil and once it comes out it will eat the bearings again.

 

[steve]

Which stubby shaft?

 

[mitsubishikid]

Which stubby shaft?

I'm thinking the same thing... lets hope it's not the knockoff with the missing oil groove.

 

[TWOpointFORliter]

Which stubby shaft?

The oem stubby shaft. I have never even considered for a second using cheap parts for this car. Right now I’m considering paying $1000 over new price for a FF oil pump.

After talking to a member on here this morning I believe the cause of failure is because they used a 2.0 belt instead of a 2.4 belt which can’t be tensioned properly without modifications which were not done.

 

[bastarddsm]

Unless the tensioner was bottomed, you CANNOT put to much tension on the belt. NOT POSSIBLE. The tensioner sets the tension.

This was likely lack of oil. Are you logging oil pressure? The oil pump is the first to show signs of distress when it has a bad oil supply.

You also need to check bearings now.

 

[jdxnc]

Unless the tensioner was bottomed, you CANNOT put to much tension on the belt. NOT POSSIBLE. The tensioner sets the tension.

This was likely lack of oil. Are you logging oil pressure? The oil pump is the first to show signs of distress when it has a bad oil supply.

You also need to check bearings now.

^This.

Low oil pressure or oil starvation are the most likely culprits. Even on a 1.5-6 60' you can see oil pressure drops on these cars. I have the "kiggly" modded oil pickup tube and always run a QT over the full line on the dipstick and see zero pressure drop on low 1.4 60's.

 

[TWOpointFORliter]

Unless the tensioner was bottomed, you CANNOT put to much tension on the belt. NOT POSSIBLE. The tensioner sets the tension.

This was likely lack of oil. Are you logging oil pressure? The oil pump is the first to show signs of distress when it has a bad oil supply.

You also need to check bearings now.

No I am not logging oil pressure but I will after this. This happened after the first time I ever took the engine past 8000 rpm’s not sure if that’s related but I’m guessing I need to look into some oil pickup mods/baffles at this point?

I do plan to check the bearings while it’s all apart.

^This.

Low oil pressure or oil starvation are the most likely culprits. Even on a 1.5-6 60' you can see oil pressure drops on these cars. I have the "kiggly" modded oil pickup tube and always run a QT over the full line on the dipstick and see zero pressure drop on low 1.4 60's.

Can that mod be done to the 2g pickup tube?

 

[steve]

The oem stubby shaft. I have never even considered for a second using cheap parts for this car. Right now I’m considering paying $1000 over new price for a FF oil pump.

No offense intended just trying to cover the bases here.

 

[EC17PSE]

No I am not logging oil pressure but I will after this. This happened after the first time I ever took the engine past 8000 rpm’s not sure if that’s related but I’m guessing I need to look into some oil pickup mods/baffles at this point?

I do plan to check the bearings while it’s all apart.

High revs the oil pump stuggles and airates. Its an issue with the design. Baffles will help sloshing but not the high rev problems. The ff pump would be a good way forward if you plan to rev high and support your needs

 

[TWOpointFORliter]

No offense intended just trying to cover the bases here.

No offense taken. I completely understand how cheap dsm owners can be. I treat this car better than I do my first born. Haha

 

[bastarddsm]

High revs the oil pump stuggles and airates. Its an issue with the design. Baffles will help sloshing but not the high rev problems. The ff pump would be a good way forward if you plan to rev high and support your needs

No. If you keep the pickup in oil, it does not have these issues.

OP being that you have a stroker motor there is a good chance the extra stroke is creating extra windage which keeps oil out of the sump. I'd consider a crank scraper. Seeing who built the shortblock and how much you probably paid, I'd think all these bases would be covered....

 

[EC17PSE]

No. If you keep the pickup in oil, it does not have these issues.

You would think that but as the evo guys have found out that the gears can only push so much volume before it gives in, like the waterpump does its the same effect just with oil. The oil pressure drops the higher the revs so this is part of the main issue. While 8k should be fine so something else might be part of the problem along side it perhaps.

Due to the revs its spinning pretty much at its designed limits in a stock motor so 2.4 might be altering these limits lower down perhaps since 2.4 usually run lower revs at least from what I see on builds and those that are race engines ( as in circuit ) they mostly run drysump for the 9k+ revs.

Alternatively using an ER oil pump gear will slow it down some giving a better margin for safety but the gear design is the 4G63 achilles heal in the systm for high revs. Pretty much all of the evos i know or see racing in the high revs have ditched the stock pump long ago. Its being looked into mostly for the side loading to stop eating the case but also keep the gear straighter. There was bracing designed for this gear but its been a while since they came about.

 

[TWOpointFORliter]

Looks like they got a little warm so I’m thinking Kurt was right on with the oil starvation being the cause. Now I have to decide if I want to roll some new bearings in or pull the engine and send it off to Buschur to get sleeved so I don’t have to worry about the cylinder walls cracking that the 2.4’s are prone to doing. Or just give up on the 2.4 and go back to a 2.0 decisions decisions

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[jdxnc]

You would think that but as the evo guys have found out that the gears can only push so much volume before it gives in, like the waterpump does its the same effect just with oil. The oil pressure drops the higher the revs so this is part of the main issue. While 8k should be fine so something else might be part of the problem along side it perhaps.

Due to the revs its spinning pretty much at its designed limits in a stock motor so 2.4 might be altering these limits lower down perhaps since 2.4 usually run lower revs at least from what I see on builds and those that are race engines ( as in circuit ) they mostly run drysump for the 9k+ revs.

Alternatively using an ER oil pump gear will slow it down some giving a better margin for safety but the gear design is the 4G63 achilles heal in the systm for high revs. Pretty much all of the evos i know or see racing in the high revs have ditched the stock pump long ago. Its being looked into mostly for the side loading to stop eating the case but also keep the gear straighter. There was bracing designed for this gear but its been a while since they came about.

In my opinion the 1g straight cut gears handle RPM better than the helical gears found in the later 4G63's. Here's a log from my car to near 9500rpm, oem 6 bolt pump/straight cut gears and ported oil relief hole, otherwise it would be well in excess of 100 psi.

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[motomattx]

That looks like an oem front cover but can you 100% confirm that it is oem? the knockoffs from China are getting better and better. An over tight timing belt will generally whine at idle, did you notice any whining when it was at idle? Those bearings look like they had shrapnel ran across them, likely from the metal shavings from the pump failure. So was that oil track though the pits from your car? I had heard it was from a Honda.

 

[EC17PSE]

In my opinion the 1g straight cut gears handle RPM better than the helical gears found in the later 4G63's. Here's a log from my car to near 9500rpm, oem 6 bolt pump/straight cut gears and ported oil relief hole, otherwise it would be well in excess of 100 psi.

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Why they worried about noise for and went to helical is beyond me, they must of seen it flowed better being straight cut and should of kept it. Some of the evo guys have gone to the straight cuts.