Loss of oil pressure, crank walked forward into oil pump.

[trmin8ter03]

Hello everyone its been a while since I've been on the forums. I've been busy with life not much time to give attention to the cobra (got married).

Well a few months ago a few buddies and I were planning on going to the track. Took her out to do some test runs to make sure everything was OK. I did a 2nd and 3rd gear pull nothing crazy. After letting off I noticed the oil pressure gauge was was all the way down thought the engine died. I came to a stop and it was till running but knew something wasn't right. The engine was stumbling so I emmidiatley shut it down.

Towed it home and began pulling it apart to diagnose the problem. I was hoping maybe oil pump went out(melling oil pump) and it would be a easy fix. Of course things are never that easy. Once I pulled the oil pump I found the crank had walked forward into the back of the oil pump and wore away at it sending shaving into the main bearing. I'll try and post some picture soon as I can.

So I'm hopping the crank can be saved and just replace the bearings to get it back up and running.

Just for info I built the motor a few years ago.

Teksid block with Manley pistons.
Mods at the time the motor let go consisted of a #4 lower and upper Pulley. I was also spraying a 150 shot at the time oil pressure was lost. Any ideas as to what would of caused the crank to walk forward, has anyone ever seen this? I'm thinking the thrust bearing went out either first or oil pump let go causing thrust bearing to let go from no oil pressure.

I've been on the forums for quite some time and don't remember out motors having this issue. Of course, having the lower Pulley adds stress to the crank I'm leaning toward that being the contributing factor.

 

[jrgoffin]

The two-piece thrust bearings can be improved upon. If you go with King bearings, they have a version that is one piece. Then again, it could have been assembly error. Also, for anyone doing a build, a billet oil pump gear is something that should never be overlooked. See the build thread in the sig - a ton of info if you are going to start over.

 

[trmin8ter03]

Thanks for the great info. I'm going to try and just redu the bottom end I'm going to finish tearing it down and hoping the top end is good. The machine shop who did the work did a mediocre job. I don't think they had done many modular motor and mostly do sbc. I'm going to try and assemble it myself this time. Those main bearings deff look good hope you don't mind me messaging you for more info. Thanks again.

 

[trmin8ter03]

Well finally got around to reading the engine down to find out why I lost oil pressure. Found that the engine builder put the trust bearing on backwards. I'll post some pictures soon.

 

[R.D.P.]

Well finally got around to reading the engine down to find out why I lost oil pressure. Found that the engine builder put the trust bearing on backwards. I'll post some pictures soon.

Man that sucks. Shame of it is the place probably won't take any responsibility. If your 100% sure it's on them and they refuse to take any ownership, but sure to light them up on yelp & google reviews.

 

[trmin8ter03]

 

[trmin8ter03]

 

[trmin8ter03]

 

[trmin8ter03]

This is the second time I've had to pull the engine due to their incompetence. Back in 2010 when i first had them build the engine they installed one of the intake cams on the exhaust side and destroyed the valves. Had to pull the motor out. After some hazzle they did fix the head originally they blamed it on me. And now this.... This is supposed to be a reputable machine shop in my area. The motor lasted about 7k miles.

 

[SlowSVT]

No one is as stupid with bearing design and selection then Ford was with the mod motor. The thrust bearing arraingment in this engine sucks :smmon:

jrgoffin

Any full thrust bearing solutions for a Boss 5.0 iron block? It uses the 5.4 bearing set which gets the question: why are they different in the first place?

 

[trmin8ter03]

When installed correctly they work fine. I dont think ford design played anybpart in this failure. There are also upgraded thrust bearings such as king. I'm going to take the crank and bearing in to the machine shop tomorrow and see if they will do anything for me. It's pretty obvious it was their fault.

 

[jrgoffin]

No one is as stupid with bearing design and selection then Ford was with the mod motor. The thrust bearing arraingment in this engine sucks :smmon:

jrgoffin

Any full thrust bearing solutions for a Boss 5.0 iron block? It uses the 5.4 bearing set which gets the question: why are they different in the first place?

That I couldn't say, but since Ed was the one who turned me on to the one-piece thrust bearing, he may know. It's kind of annoying to buy an extra set of bearings just for the one, but in the end, it was well worth it. I had no desire to deal with the "Tinker Toy" (as Ed calls is) setup, so the new one is a no-brainer. Just put my first 15 miles on the car yesterday with the new engine and it is running incredibly well.

Here's a pic of them from my build thread at ModFords as an FYI (and you only end up using the upper shell). All the details are in there on the first page (link in sig).

 

[Blkkbgt]

That's terrible. I guess the assembler didn't understand that the grooves in the bearing are there to oil the crank not the block. Where in CA are you located and what machine shop did you use?

 

[SlowSVT]

When installed correctly they work fine. I dont think ford design played anybpart in this failure. There are also upgraded thrust bearings such as king. I'm going to take the crank and bearing in to the machine shop tomorrow and see if they will do anything for me. It's pretty obvious it was their fault.

I would not agree with this statement.

A separate thrust bearing will not provide the surface area of a full flanged bearing which will result in reduced film strength. This is nothing more then an cost reduction effort on Ford's part.

 

[SlowSVT]

That I couldn't say, but since Ed was the one who turned me on to the one-piece thrust bearing, he may know. It's kind of annoying to buy an extra set of bearings just for the one, but in the end, it was well worth it. I had no desire to deal with the "Tinker Toy" (as Ed calls is) setup, so the new one is a no-brainer. Just put my first 15 miles on the car yesterday with the new engine and it is running incredibly well.

Here's a pic of them from my build thread at ModFords as an FYI (and you only end up using the upper shell). All the details are in there on the first page (link in sig).

I broached this topic with Ed years ago and if I remember correctly there was an issue with the Boss 5.0/5.4 bearing saddle that poured some cold water on this mod like the tang location but I don't recall. I was hoping that perhaps you had some insights. At build time I get it figured out.

Congrats on the new mill. Nothing better then an engine that has been carefully assembled by the owner and being DOHC V8 with FI doesn't hurt either. My philosophy with regard to new engines is to be very distrustful of them as far as I'm concerned I'm just waiting for a component to fail, a bearing to seize, an assembly or manufacturing flaw to manifest itself and treat it accordingly as I work my way up to that 1000 mile mark. After that the whips & chains come out!

 

[SID297]

Legally, that shop is at fault. If they don't make it right then sue them in small claims court.

 

[trmin8ter03]

Well I made my way down to the machine shop and spoke with the manager. After showing him the crank and the destroyed thrust bearing he was very appologitic and did not argue the fact that it was installed incorrectly.
When I removed the crank, three of the main bearings were spun so I beleive the block will have to be replaced. He said they can fix the crank but I told him we should look into replacing it. I told him even a used crank would be better than trying to fix the rear of the crank and it needs to be grinded down. I just hope they can find another teksid block and forged crank.

 

[trmin8ter03]

I know it's been a while but here's an update. Got the motor back a couple months ago. Haven't put it in the car yet. We are installing it in my buddies Mach first. He got it with a blown motor and is planing on building into a race car. So to smog and register he's using my motor.

I was lucky enough to find a brand new kellog crank that was that was something MMR was reworking back in the day.

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[trmin8ter03]

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[SID297]

Good to see you got it back together. Did you replace the block as well?