So this is from my 6bolt road race engine. Ended the season with back to back wins. Motor was running strong as always. Never missed a beat. So decided that the motor should come apart after a bunch of abuse over the last few years. Everything looks good. Pistons and cylinders measure out perfect. Bearings are another story. I didn't get pics of all of them, but I did snag a pic of Number 4 rod lower bearing. Looks like cavitation to me. Just curious how that could happen. Run-down: 2.3 liter 6bolt. Moroso pan. Kiggly oil regulator. Still running the squirters although I did find a nozzle in the pan a while back. Turns out it was the number four squirter. Not that that would cause this issue. Curious what y'all think.

What bearings are they? Does look like cavitation/overloading.

bastarddsm said:

What bearings are they? Does look like cavitation/overloading.

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These are the ACL blue box. I'll take pics of the other bearings when I'm at my shop on Friday. They all have some degree of damage but not none have spun. This why post season teardowns are so crucial. Another 10 or so laps I'd have had a much more expensive rebuild bill.

Also, I run Brad Penn 20w50 and the Magnus rebuildable oil filter. This car only sees track time these days, but it did see street use in the early days of this build. I built this motor in '13. Since 2015 it's been seeing track and street time and this last year it's only seen track time.

What does the crank look like

How many rpms? That's an overloaded bearing.

gsxitement said:

Also, I run Brad Penn 20w50 and the Magnus rebuildable oil filter. This car only sees track time these days, but it did see street use in the early days of this build. I built this motor in '13. Since 2015 it's been seeing track and street time and this last year it's only seen track time.

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Get rid of the oil filter

Archer Fabrications said:

Get rid of the oil filter

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That oil filter is gold

The strokers dont do well with high rpm when it comes to rod bearings, what kind of oil pressure were you running? looks like a film failure.

I'm shifting at 7k. But have hot the limiter at 7500 a couple times trying to wind the gear out on. Oil pressure is around 85-90 psi at 7K. I'm doing the ofh mod to bring the pressure down. Was gonna delete the squirters, but may leave them in just as a pressure bleed. That oil filter has never given me an issue. This doesn't look like a starvation issue. Also crank looks perfect.

I see damage like that to the upper shells when using regular bearings over 500hp. Going to race bearings stopped it completely.

Overloaded bearings shed chunks just like your picture. If you are overloading the bottom shell like that I would switch to race bearings, and check your rod bolts for stretch.

donniekak said:

I see damage like that to the upper shells when using regular bearings over 500hp. Going to race bearings stopped it completely.

Overloaded bearings shed chunks just like your picture. If you are overloading the bottom shell like that I would switch to race bearings, and check your rod bolts for stretch.

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Yeah I'll do that. These were ACL Aluglides. It's worth noting this was the only bearing out of all 8 that looked like this. Number 4 lower rod. The rest showed wear, but no chunking like this. I'm thinking of going to the King Bearing. Also, the car makes about 450hp, but is a road course/time trial car, so the loading it sees is variable and sustained.

gsxitement said:

Yeah I'll do that. These were ACL Aluglides. It's worth noting this was the only bearing out of all 8 that looked like this. Number 4 lower rod. The rest showed wear, but no chunking like this. I'm thinking of going to the King Bearing. Also, the car makes about 450hp, but is a road course/time trial car, so the loading it sees is variable and sustained.

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Did you cut your filters when the motor was new? I cut the first 5 oil changes on both of my motor. Maybe im just paranoid.....Luckily ive been 0k

I would be interested in the out of round on the rod and that crank journal.

amsrn13 said:

Did you cut your filters when the motor was new? I cut the first 5 oil changes on both of my motor. Maybe im just paranoid.....Luckily ive been 0k

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I have the Magnus oil filter, I took it apart and cleaned it every oil change. I did have some junk in it stuck to the magnet.

motomattx said:

I would be interested in the out of round on the rod and that crank journal.

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Checking that soon. But the crank was polished before this build, and I'm running Manley I beam rods. I'm gonna measure everything, but I don't expect to find anything out of sorts.

gsxitement said:

I have the Magnus oil filter, I took it apart and cleaned it every oil change. I did have some junk in it stuck to the magnet.



Checking that soon. But the crank was polished before this build, and I'm running Manley I beam rods. I'm gonna measure everything, but I don't expect to find anything out of sorts.

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That's most of the problem. Using one of the heaviest rods on the market in a stroker that sees constant high rpm use.

donniekak said:

That's most of the problem. Using one of the heaviest rods on the market in a stroker that sees constant high rpm use.

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Yeah. I get that, but this was the only bearing really showing any kind of wear in this manner. Gonna go with King Bearings this time around. Have heard nothing but excellent things about them.

A big thing is when I built this motor, it was with a different purpose in mind. Mostly just a weekend street terror. But as my life has changed, the ability to go road racing has presented itself, and I'm gonna do that. I'm gonna build a proper road race engine soon, but for now, I need to rebuild this motor to last next season so I can run for a championship.

gsxitement said:

Yeah. I get that, but this was the only bearing really showing any kind of wear in this manner. Gonna go with King Bearings this time around. Have heard nothing but excellent things about them.

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When you are running parts on the edge of their capability any small issue that normally wouldn't be a problem becomes a problem. The localized low oil pressure from losing the squirter may have contributed.

Either way I never run heavy I beams in anything. It's either h beams or aluminum rods, no place for the super heavy rods in an engine that's either revving to 10k, or running a 4" stroke with a 1.5:1 rod ratio.

It's a known issue. It's recommended to roll in new rods bearings as part of a maintenance schedule with the heavy rods.

amsrn13 said:

That oil filter is gold

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That oil filter killed my motor in 400 miles

Not that it was @gsxitement 's issue. I just dont think they are better then oem or WIX but we have chatted bout it.

Archer Fabrications said:

That oil filter killed my motor in 400 miles

Not that it was @gsxitement 's issue. I just dont think they are better then oem or WIX but we have chatted bout it.

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Apart from the crappy magnet glue the chinese made filter works fine as i have one! It just needs to be tight to stop it from coming loose!

ec17pse said:

Apart from the crappy magnet glue the chinese made filter works fine as i have one! It just needs to be tight to stop it from coming loose!

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The seating o ring is too thin/small, spun the whole filter off, not the serviceable part. The whole thing.

Archer Fabrications said:

The seating o ring is too thin/small, spun the whole filter off, not the serviceable part. The whole thing.

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Thin? I think that part is fine really, i just have issues with the damn magnet glue myself , i think the return flap inside the top lid (red thing) it a bit weird and not great but it seems to work, but that seal you say has been fine for me and its not come loose once! I make sure its snug snug on the OFH though,

donniekak said:

When you are running parts on the edge of their capability any small issue that normally wouldn't be a problem becomes a problem. The localized low oil pressure from losing the squirter may have contributed.

Either way I never run heavy I beams in anything. It's either h beams or aluminum rods, no place for the super heavy rods in an engine that's either revving to 10k, or running a 4" stroke with a 1.5:1 rod ratio.

It's a known issue. It's recommended to roll in new rods bearings as part of a maintenance schedule with the heavy rods.

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Believe me, I get it. They are heavy rods. But as it stands, I cannot afford new rods at the moment. So I'm limited in my options. Pretty much my only option for next season is put in a better quality bearing. Eventually I'll build a correct road race motor that's more suited to the task. The whole road racing thing kinda snowballed more than I expected and now I have sponsorship money coming in for next season, so I'm gonna have to make do with what I have for now. I appreciate the input. It'll help me come up with ideas for the next motor. Either keep it 2.0 or so a 2.1 long rod, but I've read those are really expensive to build. I'm also not concerned with revving to 10K RPM. I'm fine with the 7-8K window.

Even if you only make power to 7500-8000 with a 2.0 the extra 1,000+ rpms of overrev will help a ton on a road course, especially with how these transmissions shift.

I would do exactly what you're doing for now. Check everything, race bearings, and run it.

Archer Fabrications said:

That oil filter killed my motor in 400 miles

Not that it was @gsxitement 's issue. I just dont think they are better then oem or WIX but we have chatted bout it.

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I know, i was referring to your situation when their oil filter removed your sack for u . Its a pointless mod imo

Archer Fabrications said:

The seating o ring is too thin/small, spun the whole filter off, not the serviceable part. The whole thing.

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Filters on modded 4g's need safety wire most of the time to stop them from backing off.