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Haha. I had to borrow those gloves because I forgot mine and you had to have gloves when driving there =)
Acki: The oilpump was almost brand new, and I dont think that was the problem since it became much better after I changed to a thinner oil.
The guy I was talking to said that the only engine he knew that used 10-60 oil was the BMW M5 V10 engine.
About Gearbox/diff mods: Its all stock so far except for the diff/gearbox mounts that are almost solid. Stock driveshafts/joints too. So far Ive wrecked 2 driveshafts (due to way low rpm and fully releasing the clutch) and while the first driveshaft snapped I also broke the sprocket that locks the rear diff so att first I thought that the diff was crap too but when I opened it it was fine!
Yes, too thick oil, high revs, cavitation can appear.
Audi UrS4 Avant 2.5 20vt - twincharged - Project
Audi 80q B4 Sedan 2.2 20vt - Daily user
BMW 320d Touring e91 M-Sport - Daily user
BMW 740iA e38 - Project
I use 2 years in my car mobil1 10w60 and my rev limiter is 7900rpm no problems at all.With new engine I will use 20w60 and rev limiter will be about 10000rpm .You lucky if your driveshafts and cv joints holding.My start break with only 300hp
I only know something about an steel wheel for the oil pump.
High revs only when the oil pressure dropped or together with higher load?
Something at the conrod bearings (weak crankshaft or block).
The CroMo oilpump gear doesn't help if you get oil starvation or cavitation. It should hold better against high rpms. The stock gear have been raported to break in pieces quite easily. Then again I know that the stock gear have been used with 8500-8600rpm limiter without problems. The CroMo gear costs ~130 euros so it's not a too expencive upgrade if going with the stock pump.
Audi UrS4 Avant 2.5 20vt - twincharged - Project
Audi 80q B4 Sedan 2.2 20vt - Daily user
BMW 320d Touring e91 M-Sport - Daily user
BMW 740iA e38 - Project
Cavitation signs I never saw in any engine.
I only know it out of books at Conrod bearings.
How ever, his bearings are seized so the supply (as the pressure) was bad.
Oil pump should have enough power to hold the pressure also when some sprayers are always open (hot idle should then be an issue) or something else has a too big oil consumption.
Oil pump snorkel blocked? Oil filter bad? Too less oil in the sump?!
I had seen cylinder heads where the oil wasn't able to flow back into the sump. That would explain why thinner oil made the issue better.
But than the hydraulic lifters maybe got too much oil?
Head gasket with limiting bore for the oil supply was used (most engines have this element there - unfortunately I'm not a 5 banger junkie).
Or changed engine position? Angle of the block?
Cavitation can happen in the pump if it's trying to suck but the oil isn't flowing fast enough to the gears. But thick oils can also have other issues, just like you told, they may not flow back to the sump fast enough from the head. The oil level drops and then in a hard acceleration the oil left in the sump moves to the back of the sump, and the oil pickup suck air... 700hp/8000rpm what happens if the bearings get air..?
Audi UrS4 Avant 2.5 20vt - twincharged - Project
Audi 80q B4 Sedan 2.2 20vt - Daily user
BMW 320d Touring e91 M-Sport - Daily user
BMW 740iA e38 - Project
Never saw it at oil pump. Sometimes at water pumps but the wheels are design that no cavitation is present.
Sucking air is different from that, clear.
Bubbles are pressed together and will expand.
He used thinner oil, not thicker.
However we will see what he will do next.
700hp durable - is a lot of fun. I'm not sure if a 900hp step makes sense.
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.You lucky if your driveshafts and cv joints holding.My start break with only 300hp
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