A few sr questions...

[So Make Like]

I just finished a rebuild; main & rod bearings, thrust washers, piston rings, head gasket, valve stem seals and a light valve job. I finished "my" break-in period of roughly 1300 miles with no problems. I changed the oil 5 minutes after start up, 50 miles, 500 miles and 1000 miles with conventional 5w30. I took it on a long, hard drive one night on the freeway and found an incredible amount of knocking afterwards. I changed the oil again and found a lot of "glitter" on my magnetic drain plug. Not quite shavings or flecks, but the consistency of graphite powder. Along with that, there was a ridiculous amount of fuel in it. It was almost like brown water and it reeked coming out. The dipstick smelled of straight fuel as well. I used 10w40 synthetic with a thickening additive to no avail. The bearings are done.

1. Can I just reuse my rings? (1300 miles on OEM rings)

2. Is fuel alone capable of doing this to bearings?

3. Any personal stories of this sort of thing you can tell me for my own benefit of learning?

Thanks guys.

[So Make Like]

Any feedback?

[Kingtal0n]

This happens all the time. You need to build a few of them (or get lucky) before they stay together.

Whats a rebuild cost? Then consider the possibility this happens and the entire engine block is un-usable because metal shavings have clogged tiny orifices, making the re-use of the block an enormous risk, even with "proper" cleaning up.

Better off sourcing a used long block most of the time. If your power goals exceed the factory limitations of the OEM internals it is far cheaper, and more reliable to install a larger more capable engine.

Usually it goes like this.
1. build an sr20
2. 400 miles later it fails
3. re-build the same sr20
4. put it for sale "going in a new direction, selling a freshly build sr20det with forged internals with 80 miles"

furthermore this is why I never buy used parts related to oil flow such as oil relocating kits.

Figure out how the fuel got in there, are you sure it is fuel? injector O-ring? bad ECU? accidentally ground the injectors?

[Dboyizmlg]

I think what Kingtalon is trying to say is this.
-sell your engine and get some money back.
-buy a bigger better motor ex:RB, 1J, 2J some thing along that road that can handle more power and be more reliable.

It's kinda funny but I agree with Kingtalon.
If my engine had rod knock, toasted a piston, or bad rings, etc.
I would buy a used clip instead of rebuild.

[angel mkiv]

Dam I just rebuilt my sr20 and am hoping it lasts.. Please update this thread when you find out the problem..

[Arrowking]

Did you actually check clearances before you built it? It takes more than just throwing forged parts at an engine for it to run and produce reliable power.

[Prok0]

It could be an issue with improper machine work or improper assembly.

Even with a good amount of fuel washing past the rings it should not cause bearing failure unless it as borderline ridiculous, and even then I dont think that alone would cause the failure.

When I first built my SR and fired it up I had some issues causing it to run pretty rich, the oil smelled strongly of fuel, and after I got those issues sorted out the motor still ran strong for 40k+ miles.

I would say pull the motor, disassemble everything and take it to a competent machine shop, have them inspect the crank/main caps/rods and see if there was any damage to them, if there is see if its repairable, if there isnt have the whole assembly cleaned thoroughly, buy some new parts, and toss it back together.

I would recommend a new ring set, as its only 100-150$ generally for OEM or CP/JE/etc. and if your rebuilding it you might as well do it right.

[Moore]

what was our oil pressure like? 5w30 is light. I would agree with the might as well but likely you can reuse the rings

[RalliartRsX]

Were you not using break in oil during your break in??

Typically new bearings will "shed" material during breakin, and if they get lodged in between the crank and the bearing, that usually means the bearings will be scored and the bearings will be destroyed in a few hundred miles at best (which it sounds like is exactly what happened here)

[So Make Like]

It could be an issue with improper machine work or improper assembly.



Even with a good amount of fuel washing past the rings it should not cause bearing failure unless it as borderline ridiculous, and even then I dont think that alone would cause the failure.



When I first built my SR and fired it up I had some issues causing it to run pretty rich, the oil smelled strongly of fuel, and after I got those issues sorted out the motor still ran strong for 40k+ miles.



I would say pull the motor, disassemble everything and take it to a competent machine shop, have them inspect the crank/main caps/rods and see if there was any damage to them, if there is see if its repairable, if there isnt have the whole assembly cleaned thoroughly, buy some new parts, and toss it back together.



I would recommend a new ring set, as its only 100-150$ generally for OEM or CP/JE/etc. and if your rebuilding it you might as well do it right.


I see. I'll more than likely disassemble it and take it all down to a machine shop to be assessed.

Were you not using break in oil during your break in??



Typically new bearings will "shed" material during breakin, and if they get lodged in between the crank and the bearing, that usually means the bearings will be scored and the bearings will be destroyed in a few hundred miles at best (which it sounds like is exactly what happened here)


I used an engine oil break-in additive and changed the oil frequently in fear of that happening.

This happens all the time. You need to build a few of them (or get lucky) before they stay together.

Whats a rebuild cost? Then consider the possibility this happens and the entire engine block is un-usable because metal shavings have clogged tiny orifices, making the re-use of the block an enormous risk, even with "proper" cleaning up.

Better off sourcing a used long block most of the time. If your power goals exceed the factory limitations of the OEM internals it is far cheaper, and more reliable to install a larger more capable engine.

Usually it goes like this.
1. build an sr20
2. 400 miles later it fails
3. re-build the same sr20
4. put it for sale "going in a new direction, selling a freshly build sr20det with forged internals with 80 miles"

furthermore this is why I never buy used parts related to oil flow such as oil relocating kits.

Figure out how the fuel got in there, are you sure it is fuel? injector O-ring? bad ECU? accidentally ground the injectors?


I understand what you're getting at, but I've grown to admire the sr20det, flaws and all. Impractical isn't an issue for this. Reliability is my current goal. Power can be addressed at a later time. And yes, I understand that a stock block will yield the reliability I seek. But in Hawaii, that isn't easily an option. It could be, though, given I had the money for a clip to be shipped and handled down here.

Maybe this just leaves me with leaving my motor in the hands of a machine shop?

[Kingtal0n]

I understand what you're getting at, but I've grown to admire the sr20det, flaws and all. Impractical isn't an issue for this. Reliability is my current goal. Power can be addressed at a later time. And yes, I understand that a stock block will yield the reliability I seek. But in Hawaii, that isn't easily an option. It could be, though, given I had the money for a clip to be shipped and handled down here.

Maybe this just leaves me with leaving my motor in the hands of a machine shop?

I never said ditch the sr20. I also love the sr20. I said if your power goals EXCEED the oem engine, go to a larger displacement.

Your power goals are < 350rwhp~ ? then keep the OEM internals sr20det...

.... Just DONT TOUCH THE INSIDES. The chances of you finding a "competent machine shop" in the USA that knows how to build one of these engines is very tiny. If you take it anywhere, take it to maxworx.

You seriously cant find an OEM longblock? there is nothing reliable about building an sr20det... unless you do it several time and figure out the weak links in the chain around each corner (after each failure decide why. Then re-build and try again). The problem with that is it STILL leaves you sourcing new long-block after long-block. Because for each time you wreck a set of engine bearings you leave yourself a much higher percentage chance of the NEXT rebuild failing due to oil passages containing metal debris. Next time out you think you have the bearings all set right... "this is it. I got it right this time" and you might be right. But then you wipe out a cam lobe because the oil tube above contains a .003" bit of material.

also what flaws does the sr20det have in your opinion?
I think the engine is fantastic; Its easy to maintain, easy to work on, easy to diagnose, it goes many miles with very little service, it comes with a turbocharger and piston oil squirters, parts are easy to find (for me anyways), its light weight, rear wheel drive, it drops right into any 240sx chassis, what more can you ask for!!

[DJ 21o3]

Fuel is definitely capable of killing bearings by tainting the oil and reducing its effectiveness. But I am rebuilding my SR currently and also curious how you ended up with so much fuel leaking by. What were your clearances before it was assembled?