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Excessive oil burning, oil jets, stuck rings, acetone
I tried to cram as many search words as I can in the title.
Backstory: * ~29K miles since rebuild (summer 2012) with new 84mm JE pistons and rings, Mtuned rods, bearings, the whole nine yards.. * >2K miles on the head with brand new everything - valves, springs, seats, guides, you name it. * Progressive port water injection * MP62 supercharger / TDR IC * Replica Gibb 4 into 1 header, resonator, Borla muffler. No cat. 2.5" Daily driver, driven fast, two track outings on the engine. I noticed the car was using some oil about a year or so after the rebuild. Didn't think much of it. Boosted engine and all. Then, it started getting worse. I was adding about a quart between oil changes. (less than 3K miles) That got progressively worse. Up to 4 quarts between oil changes. Got to a point where I was shooting blue smoke every time I got on the gas. I would be cruising, and I would give it gas to either pass someone or get ahead of them, and there would be smoke all over. And, in the past few months, oil consumption was up to a liter in about 200 km (~120 miles). Whoa. I never let the engine starve, carried oil in the trunk and always topped it off to be safe. And, it bothered me. A lot. I would start the car, keep the idle high, and as the idle climbed smoke would be billowing. Red lights were a smoke show. The engine had power, and performance did not suffer, tho. So I started searching. Had to be the rings. "New" rings I had taken all that time to seat properly. My search pointed at oil jets as a possible culprit. I have JE pistons which are quite similar to Wisecos with the oil drain ports on the lower lip of the oil control ringlands, and the jets supposedly shoot their load right between those rings, overwhelming any "control" function. Anyway. I borrowed a leakdown tester, and promptly found out the second "percentage" gauge on the tester is busted. I used it anyway. The idea was to at least to pinpoint where the leak was, and screw the percentage for now. I know it drinks and farts oil. All four cylinders leaked past the rings. No noise/hissing at intake or exhaust, no bubbles or anything at the radiator neck, but plenty at the oil filler neck and the dipstick. Funny thing, if I put the oil cap back on while listening through the dipstick, it just gurgled for a while. I did a comp test, too. Results were within 1-2 psi of each other, and pretty much identical to a previous test I had done back when the engine was fresh and healthy. So, top rings are good. Must be the oil control rings. They could be stuck for all I know. After all, I DID read about how oil from the jets getting between the rings could turn into varnish, harden and cause the rings to stick. As the next logical step, I poured liberal amounts of a homemade penetrant into each cylinder (about 1/2" deep), rocked the engine back and forth a bit, put the plugs back on and left the car to sit overnight. That could maybe, possibly, free up the stuck rings. If they were stuck indeed. BTW, homemade penetrant is a 50/50 mix of Dexron 2 ATF and acetone. Long story short, after I cleaned out what little "penetrant" was left in the cylinders the next day, I ran the engine to burn off the remaining ATF and get it up to temp to change the oil. I used Mobil1 10w60. Then I took the car out for several test drives. Holy crap. The car does not smoke. Well, almost does not smoke. I drove for 45 miles, and saw smoke 3, maybe 4 times. And, I was trying to get it to smoke, by flooring it, driving in high RPMs, the usual smoke producing things. Checked the oil level, just fine. It should have gone down on the dipstick by now. So, I am somewhat happy that my diagnosis was correct (oil control rings are the culprit), but also bothered by the fact that I need to pull the engine again. Here's the plan: Pull engine, check PTW clearance, hone cylinders, install new rings, REMOVE the oil jets, break engine in again, profit (not). I already have 84mm pistons and I do not want to shell out big bucks again if PTW clearance is unacceptable. If it turns out to be too much, I will just sleeve the block. (Can't find a block here, and block sleeving is cheap, like less than $100.) PTW clearance should be 0.002953". That's what the engine builder had told me. I already ordered a full engine gasket from Fel-Pro and a set of JE rings. Will keep you guys posted about how things unfold. This thread will not be be updated frequently, I need to find the time to tear the engine, do the break-in, and accumulate miles to get meaningful results. Just posting this here to keep open records, provide info for others and approach this in a logical and scientific way with your input. Hope your does not smoke like mine |
Nice diagnosis and trial, I have spare blocks, but I noticed you're in Istanbul. Didn't that used to be Constantinople?
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How's this penetrant work?
I'm assuming you drained the oil beforehand and flushed after the penetrant? |
Originally Posted by thirdgen
(Post 1360391)
..., but I noticed you're in Istanbul. Didn't that used to be Constantinople?
Cheers to OP, I am glad you found a temporary solution to the problem. Very glad you tried to cram a bunch of search terms, will definitely help people in the future, giving a solid reason why they should remove the oil squirters on aftermarket pistons. |
I'm going to try this.
Getting rid of my squirters cut down my oil consumption by a bunch (about 1 quart every 2k miles down from 1 quart every 1k). Have supertech's with oil drain back holes. Also run an mp62 with 63mm and 140mm pulleys... 14psi @ 7200rpm. |
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My belief and experience. Most aftermarket pistons don't work well with oil squrters. The gas ports for the oil control rings are done wrong. Stock pistons don't have gas ports connecting between the underside of the pistons and the oil control rings. the oil pressure squirting on the underside of the piston goes out those gas ports and completely fills up the oil control ring groove.
I also think that ceramic thermal barrier coating the top of the piston works. I think it works better keeping the heat out of the piston than trying to cool the piston from the underside by squirting excess oil at it. Note the design of the pistons mazda put on the 323 GTR. 1) Compression ringland portion is cast Iron, Strength ready for all of it boost levels. 2) Oil squirters actually shoot into a hole routing it through a channel that pulls heat from the ringland portion of the piston. 3) Gas ports for the oil control rings don't go through to the underside of the piston, they go to the outside by the wrist pins. |
Originally Posted by bbundy
(Post 1360682)
My belief and experience. Most aftermarket pistons don't work well with oil squrters. The gas ports for the oil control rings are done wrong. Stock pistons don't have gas ports connecting between the underside of the pistons and the oil control rings. the oil pressure squirting on the underside of the piston goes out those gas ports and completely fills up the oil control ring groove.
Originally Posted by bbundy
(Post 1360682)
Note the design of the pistons mazda put on the 323 GTR.
1) Compression ringland portion is cast Iron, Strength ready for all of it boost levels. 2) Oil squirters actually shoot into a hole routing it through a channel that pulls heat from the ringland portion of the piston. 3) Gas ports for the oil control rings don't go through to the underside of the piston, they go to the outside by the wrist pins. 1. The cast iron ring grooves are added to prevent wear in the grooves, due to high cylinder pressure and soft aluminum, and to keep the aluminum from sticking to the bottom side of the ring when the piston gets hot. 2. Piston cooling galleries are the most effective ways of cooing the piston, and allows you to run really high in cylinder temps without melting pistons 3. Most oil ring drain features don't go all the way through the piston, just provide a small channel to drain oil from the back of the groove, and allows it to drain over the area of lots of space above the wrist pins As for OP, it could very well be stuck rings, and I hope your method works well, but have never heard of good luck using solvents or other products to get rings unstuck for long periods of time. There are lots of products out there that are supposed to dissolve the carbon, but I never heard that they work for long periods of time. |
Good info. Props
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Originally Posted by adryargument
(Post 1360424)
How's this penetrant work?
I'm assuming you drained the oil beforehand and flushed after the penetrant? There's some supporting evidence to the merits of this concoction, anyway. As for draining the oil beforehand, I didn't. I figured, by the time this mixture runs through the rings and into the oil pan, the acetone would be long gone. I waited for almost 24 hours before I did anything to the car, and the really thick goo left in the cylinders sort of proved what I had assumed. Of course I changed the oil afterwards. I have a special "tilted on the lift" procedure that gets pretty much everything out of the engine. (The car is tilted, with the pass side down, about 30-35 degrees and left there for at least 45 minutes for the last of the oil to run out)
Originally Posted by bbundy
(Post 1360682)
My belief and experience. Most aftermarket pistons don't work well with oil squrters. The gas ports for the oil control rings are done wrong. Stock pistons don't have gas ports connecting between the underside of the pistons and the oil control rings. the oil pressure squirting on the underside of the piston goes out those gas ports and completely fills up the oil control ring groove.
I also think that ceramic thermal barrier coating the top of the piston works. I think it works better keeping the heat out of the piston than trying to cool the piston from the underside by squirting excess oil at it. Note the design of the pistons mazda put on the 323 GTR. 1) Compression ringland portion is cast Iron, Strength ready for all of it boost levels. 2) Oil squirters actually shoot into a hole routing it through a channel that pulls heat from the ringland portion of the piston. 3) Gas ports for the oil control rings don't go through to the underside of the piston, they go to the outside by the wrist pins. That pretty much confirms my suspicions.
Originally Posted by cal_len1
(Post 1360738)
As piston design engineer, and can confirm that all of this is right.
As for OP, it could very well be stuck rings, and I hope your method works well, but have never heard of good luck using solvents or other products to get rings unstuck for long periods of time. There are lots of products out there that are supposed to dissolve the carbon, but I never heard that they work for long periods of time. Oh, I DO know my method is not a permanent fix. I just wanted to verify/confirm my suspicions and use this solvent as a diagnostic tool. Please read the bottom of my first post. That engine IS coming apart. |
Originally Posted by cal_len1
(Post 1360738)
As piston design engineer, and can confirm that all of this is right. We have had similar experiences at work, but logically it makes sense. Your oil rings already have a lot to deal with, and introducing tons more oil to them via piston cooling nozzles/inertia and those stupid holes is not helpful. I was super surprised that my Wisecos came with them, and immediately removed my piston cooling nozzles because of it (well that and they didn't fit). I'm of the opinion that they are not needed on engines any of us on this site would build, provided forged pistons are used, because we are not OEMs trying to make an engine last 250k miles. If you look at any plot of aluminum strength vs temperature, note that the material is very sensitive, and why the OEM engine designers would want to use oil squirters. However, with forged material, a there is a lot more margin due to the higher strength.
These comments are very interesting, because you just described nearly every diesel piston. 1. The cast iron ring grooves are added to prevent wear in the grooves, due to high cylinder pressure and soft aluminum, and to keep the aluminum from sticking to the bottom side of the ring when the piston gets hot. 2. Piston cooling galleries are the most effective ways of cooing the piston, and allows you to run really high in cylinder temps without melting pistons 3. Most oil ring drain features don't go all the way through the piston, just provide a small channel to drain oil from the back of the groove, and allows it to drain over the area of lots of space above the wrist pins As for OP, it could very well be stuck rings, and I hope your method works well, but have never heard of good luck using solvents or other products to get rings unstuck for long periods of time. There are lots of products out there that are supposed to dissolve the carbon, but I never heard that they work for long periods of time. |
Originally Posted by bbundy
(Post 1360904)
I work for Paccar. though I don't work much on the engines specifically as I do more structural analysis work. My current office space is across the hall from 4 engine test dyno cells and my window looks at the heavy truck chassis dyno byilding that has a climactic wind tunnel built around it capable of dyno testing at extremes of atmospheric temperatures and pressures. I see lots of heavy diesel engines torn apart on a regular basis.
Off topic: How do you like Paccar, my fiance is a big fan of bellingham, and I saw that they were in the area. |
Originally Posted by aidandj
(Post 1360915)
Can you get a miata engine on one of those dynos :)
Off topic: How do you like Paccar, my fiance is a big fan of bellingham, and I saw that they were in the area. |
I have a freshly built 1.8 that I plan to install soon. It also has JE pistons. Im getting the vibe I should remove the oil squirters while its still on the stand. It also has a BE pump and shimmed +1. What should I expect as far as difference in oil pressure with the pump and no squirters? Sorry if thats a noobish question. Are there many builds out there with pistons that have oil drain back holes having problems with oil consumption?
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My guess, and it is only a guess, is that it would not make a big difference.
Those jets only spray when oil pressure is above 40 psi, and the Miata does not have any more or less oil ports/galleries/restrictions/flow paths in its block and head design compared to other engines. I did read some accounts of engines with removed jets, and there was no mention of noticeably increased pressure. Just decreased oil temps. |
Not quite an apples to apples comparison but I've just had my motor rebuild with FM Wiescos , I had the squirters removed . Huge increase in oil pressure compared to my old motor. Some of the increase is probably due to new bearings but I'm crediting at least some of the increase to the removal of the squirters.
Originally Posted by Godless Commie
(Post 1361162)
My guess, and it is only a guess, is that it would not make a big difference.
Those jets only spray when oil pressure is above 40 psi, and the Miata does not have any more or less oil ports/galleries/restrictions/flow paths in its block and head design compared to other engines. I did read some accounts of engines with removed jets, and there was no mention of noticeably increased pressure. Just decreased oil temps. |
Thanks for the input guys. Still not too sure yet on if I want to pull them or leave them be. Seems it would make sense to remove them though.
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Great info here all, thank you for sharing. Yet another thread proving that MT.net is the best site on the web.
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Originally Posted by 92dx
(Post 1361213)
Thanks for the input guys. Still not too sure yet on if I want to pull them or leave them be. Seems it would make sense to remove them though.
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Originally Posted by cal_len1
(Post 1361242)
It's possible your decision could be made for you when you assemble your engine. When I assembled my engine (non-FM Wisecos), the piston directly interfered with the piston cooling nozzle. They all would have broken off if I would have left them. I think Bob, Eric Anderson and others have shown you don't need them. However if you want it for the safe feeling, and can potentially deal with increased oil consumption, your engine will still work fine.
The JE piston skirts are clearanced for the squirters from the factory. Which is why I wonder if it is a potential issue to run the jets with pistons that have oil drainback holes, that they are made with clearance for jets built in. I want to make the right decision, but not end up with "high" oil pressure because of the shimmed pump and no jets..if thats even possible. That where I'm concerned really. |
So when removing the oil jets, do you just let them be have the bolt hole open, or do are you supposed to screw a bolt in. Sorry for the silly question, I'm just trying to do it right. Thanks
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Originally Posted by Micztor
(Post 1370869)
So when removing the oil jets, do you just let them be have the bolt hole open, or do are you supposed to screw a bolt in. Sorry for the silly question, I'm just trying to do it right. Thanks
Otherwise you'll have a very short lived engine - no oil pressure, fried bearings, mayhem... |
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Quick update:
Engine is out and disassembled, AND things look a bit grim at the moment. Bearings are bad. #4 rod bearing has flaked. The engine had a bad miss on #4 for a little while due to a collapsed valve seat. Everything in the head has been replaced since, but the damage is done I guess. #1 cylinder wall is scored. Pistons have scratched skirts. Crank needs polishing. And yes, oil control rings were pretty much gummed. Please stand by for massive photo dump... |
Mains:
https://cimg9.ibsrv.net/gimg/www.mia...b44acb782d.jpg https://cimg1.ibsrv.net/gimg/www.mia...9883889146.jpg https://cimg2.ibsrv.net/gimg/www.mia...50dceaa0fe.jpg https://cimg3.ibsrv.net/gimg/www.mia...2bcc585cdd.jpg https://cimg4.ibsrv.net/gimg/www.mia...adfe657954.jpg https://cimg6.ibsrv.net/gimg/www.mia...49d4da3334.jpg https://cimg8.ibsrv.net/gimg/www.mia...80ce43da36.jpg https://cimg9.ibsrv.net/gimg/www.mia...9c9df5244a.jpg https://cimg0.ibsrv.net/gimg/www.mia...acf8556f10.jpg https://cimg1.ibsrv.net/gimg/www.mia...72d447c0f8.jpg https://cimg2.ibsrv.net/gimg/www.mia...ebc8858984.jpg https://cimg3.ibsrv.net/gimg/www.mia...11b965d8e9.jpg |
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Scored #1 cylinder wall:
(Photographing the cylinder wall is tricky, I tried a few different angles) https://cimg8.ibsrv.net/gimg/www.mia...847e78a69e.jpg https://cimg2.ibsrv.net/gimg/www.mia...ac8a97aafe.jpg https://cimg3.ibsrv.net/gimg/www.mia...c405b6a280.jpg |
Awww man :(
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Pistons:
(I cleaned one, then remembered I should have taken a photo.. Skirt scuffing can be seen, too) https://cimg9.ibsrv.net/gimg/www.mia...a1f63a9dfd.jpg |
The block is getting custom sleeves.
There's no getting around those scratches. I am not buying bigger pistons. I have 84 mm pistons already. |
Aaand, this is how you take your engine to the machine shop all the way across town, the right way...
https://cimg6.ibsrv.net/gimg/www.mia...0d683eb3ab.jpg https://cimg8.ibsrv.net/gimg/www.mia...dc206e192c.jpg 500 ccs of smooth power... |
Wow, the bearings...
Did you have an oil pressure problem? Or starvation? Looks like debris in the oil as well. What oil were you using? |
I was using Mobil Super 3000 5w40
https://cimg9.ibsrv.net/gimg/www.mia...9c5a6f2a56.jpg I'm thinking about using Shell Helix HX8 from now on. And no, we do not have Rotella T6 over here. |
Also, I have a "shimmed" oil pump, and great pressure.
Oil change intervals are no more than 3-4K miles. |
Yikes, why do you think this happened?
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Originally Posted by ridethecliche
(Post 1376628)
Yikes, why do you think this happened?
The rest... I can't say. Bad oil filter? I'm using a local brand. |
Originally Posted by Godless Commie
(Post 1376631)
Flaked bearing is self explanatory. (See related post)
The rest... I can't say. Bad oil filter? I'm using a local brand. I guess this is a good reminder that I should swap out my oil and fuel filter over the winter... |
I've heard....but not seen first hand that a flaked and pitted bearing like that is the result of detonation hammering them. The other bearings are more indicative of trash flowing through the engine (most likely from the flaked bearing) I would very closely inspect the #4 piston for signs of detonation. The collapsed valve seat is another indicator of that cylinder being hot from detonation. I see that you're running a coolant reroute, normally not running one is why you only see this issues like this on #4, the back cylinder runs hotter due to lack of flow and is the first to detonate when running on the ragged edge. In your case maybe it's a lower flowing injector or just dumb luck that it's #4 this showed up on.
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Bad news keeps on coming.
I'll just leave these here.. https://cimg4.ibsrv.net/gimg/www.mia...430665f532.jpg https://cimg7.ibsrv.net/gimg/www.mia...804bc993ba.jpg https://cimg9.ibsrv.net/gimg/www.mia...55bda010bd.jpg https://cimg0.ibsrv.net/gimg/www.mia...8f587dd582.jpg https://cimg1.ibsrv.net/gimg/www.mia...077641bc01.jpg It is being repaired as we speak. Yes, it is possible to repair this. And no, I can't find a block. |
You want to find out how much it would be to import one? I have two block sitting here and you can have one for the shipping and import duty, land freight could not be that much...
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Wow, it cracked both sides? How would you repair this? I'd have a spare empty shortblock you could have for shipping.
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Once again, more proof that this is the best damned forum on the planet. Two offers for free blocks. Fuck yeah, Miataturbo.net.
Sorry man, that sucks. weird. |
Tried the dump a bunch of solvent down my holes trick. Started with a bottle of AC Delco X66P because I had it laying around. Followed it up with some acetone. I'll post up again in 5k miles to see if it made any difference.
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Sorry to hear about what's happening to Hakan.
Originally Posted by bbundy
(Post 1360682)
My belief and experience. Most aftermarket pistons don't work well with oil squrters. The gas ports for the oil control rings are done wrong. Stock pistons don't have gas ports connecting between the underside of the pistons and the oil control rings. the oil pressure squirting on the underside of the piston goes out those gas ports and completely fills up the oil control ring groove.
"Removing squirters, lower oil temps" Whoa, that would mean that same amount of heat is what, going from the piston to the block? Hotter pistons more prone to detonation. |
Car is properly back on the road, so first (cautious) update...
Engine and transmission cracks were expertly repaired. Block is sleeved, has ACL bearings and no oil jets. It has been almost a couple of thousand miles since first crank. 30 weight non-synth oil for the first two oil changes, and non-synth 10w40 till I hit the 1000 mile mark. I used Shell HX8 Ultra 5w40 after that, and have been driving/enjoying it since. The engine never once asked me where the oil jets were. Just purrs along nicely. One noteworthy observation involves oil temps. Seems like it runs just a little HOTTER. Like, 5 to 8 degrees (C) hotter than before. I am used to seeing 89-90C on the gauge, now I consistently get 95+C. Maybe that oil mist from the jets was cooling on its way down to the pan. I mean, that's the only thing I can think of. I left bearing clearances on the high side of the specs, so I'm getting 22-24 ish PSI at idle with a fully warm engine, but anything above idle is pretty high. I often hit 90 PSI during driving. Steady cruise at low rpm with warm engine is never below 60 PSI. Have not had the time to do a compression test yet. Engine is more responsive, but that is expected. I am happy to answer any questions I may have overlooked posting about. |
That is a lot of oil pressure. VVT pump? Shimmed relief valve or standard?
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Originally Posted by sixshooter
(Post 1418228)
That is a lot of oil pressure. VVT pump? Shimmed relief valve or standard?
It's a standart aftermarket pump: https://cimg8.ibsrv.net/gimg/www.mia...11ca30b3c6.jpg I just shimmed the relief valve with one washer. |
There is no way I would have shimmed the pump, those levels of high oil pressure are not improving anything, just wasting horsepower and raising oil temps. Given your oil pressure measurements I question why you're running a 40W oil, I don't think it's needed.
Also curious how the block was repaired. |
Originally Posted by patsmx5
(Post 1418413)
There is no way I would have shimmed the pump, those levels of high oil pressure are not improving anything, just wasting horsepower and raising oil temps. Given your oil pressure measurements I question why you're running a 40W oil, I don't think it's needed.
Also curious how the block was repaired. So, I just wanted to be perfectly sure, that's why I shimmed it with just one washer. Transmission cracks were simply ground and welded. I found a really good welder, he did a great job and I paid him about 8 or 10 bucks for the whole thing. Engine was tricky. I asked the welder (who is a machinist) to turn a solid steel bar that would fit perfectly in the bearing housings in the block. Think of it as a cylindrical crank, bolted in the mains. Then the crack was ground in a V and welded from both sides, and ground smooth to level the surface. I had him make that steel bar to prevent any distortion during welding. It worked like a charm, and subsequent line bore checking verified no distortion. That guy charged me 50 bucks. Sleeving the block and all the machine work came to about $250, including the crack repair. Hell, runs great now..Plenty redline runs so far. |
Originally Posted by patsmx5
(Post 1418413)
There is no way I would have shimmed the pump, those levels of high oil pressure are not improving anything, just wasting horsepower and raising oil temps. Given your oil pressure measurements I question why you're running a 40W oil, I don't think it's needed.
Also curious how the block was repaired. I don't think you need to change anything, but next time you tear into the engine, my suggestion would be to undo the changes. |
Originally Posted by stefanst
(Post 1418418)
What he said. Your high pressures are raising your oil-temp by converting your engines hp into heat.
I don't think you need to change anything, but next time you tear into the engine, my suggestion would be to undo the changes. I guess I could always un-shim the pump. Or, maybe go to 5w30... |
Originally Posted by Godless Commie
(Post 1418417)
To be perfectly honest, I bought an aftermarket pump because I was really pressed for time.
So, I just wanted to be perfectly sure, that's why I shimmed it with just one washer. Transmission cracks were simply ground and welded. I found a really good welder, he did a great job and I paid him about 8 or 10 bucks for the whole thing. Engine was tricky. I asked the welder (who is a machinist) to turn a solid steel bar that would fit perfectly in the bearing housings in the block. Think of it as a cylindrical crank, bolted in the mains. Then the crack was ground in a V and welded from both sides, and ground smooth to level the surface. I had him make that steel bar to prevent any distortion during welding. It worked like a charm, and subsequent line bore checking verified no distortion. That guy charged me 50 bucks. Sleeving the block and all the machine work came to about $250, including the crack repair. Hell, runs great now..Plenty redline runs so far. Do you know what sleeves were used by chance? If it were my car I would run 10-30 motor oil and go from there. That's easy to change and should drop the oil pressure some and increase the oil flow to the bearings. I run 10-30 in my motor on my car and have had excellent results for years, never had a bearing problem before. Have seen many boost and RPMs. I do run a large oil cooler for last few years though and I think that is a good idea if you are racing and boosting a miata to have a good oil cooler. |
Originally Posted by patsmx5
(Post 1418433)
That's cool how it was repaired, sounds like a soild repair. And cheap relative to our money! Just getting a machinist to make that steel bar you needed would have been 100-200 bucks here.
Do you know what sleeves were used by chance? If it were my car I would run 10-30 motor oil and go from there. That's easy to change and should drop the oil pressure some and increase the oil flow to the bearings. I run 10-30 in my motor on my car and have had excellent results for years, never had a bearing problem before. Have seen many boost and RPMs. I do run a large oil cooler for last few years though and I think that is a good idea if you are racing and boosting a miata to have a good oil cooler. |
Plugging the jets probably reduced the oil flow needs significantly, raising pressure overall. The relief is at about 60psi stock. 90psi creates excess heat, as mentioned. It also puts excess strain on the pump and may possibly cause additional wear, but that's speculation.
There's no reason to work it so hard. Flow protects the engine, pressure is simply a measure of the resistance to the flow. The main and rod bearings are not sealed and pressurized, but rather volume flow protected. |
Originally Posted by sixshooter
(Post 1418814)
There's no reason to work it so hard. Flow protects the engine, pressure is simply a measure of the resistance to the flow. The main and rod bearings are not sealed and pressurized, but rather volume flow protected.
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