many years ago that said you required 10psi for every 1000rpm. so for a 6000rpm limit you require 60psi. this was from chevy V8 literature from memory the VN s1 buick has 50psi standard, the VN s2 was upgraded to 60psi but still only had a 5000rpm limit. buicks tend to spin the bigends if rev'd much over 6000rpm. this would suggest a lack of oil so 50/60psi isn't enough. i just pulled my 50psi spring out and it was 2.8mm short. the difference between the 50 psi and 60psi spring is 1.4mm so 2.8mm short is a big difference. i'd suggest anybody who is fiting a cam with increased rev limit replace their oil pressure relief spring to ensure good oil pressure the ecotec which is basically a modified buick spins to 6000rpm and seems to have a max oil pressure in excess of 75psi. i've not heard of ecotecs spinning big ends? would like to hear from anybody out there with experience in regards to oil pressure requirments at higher revs/increased engine outputs.
Can you replace the Spring with the timing cover on the car? because i am looking into this how would i go about getting a better spring to increase oil pressure?
Had a spare timing cover laying around an the springs lenght was 62.8 so i will pull my other spring out of my car and see if its shorted, i have over head knocking sound on start up so i dope a engine flush and oil change along with a longer stronger spring will help abit.
to change the oil pressure relief spring oyu only need to remove the oil filter mount on the side of the timing cover. remove oil filter and then undo 4 bolts using a 1/2" socket, 3/8" drive. the 1/2" drive sockets are to big as 2 of the bolts are fairly close to the oil filter mounting surface. i would imagine any major automotive parts outlet store would stock the springs, if not try a engine reconditioning place. i certainly couldn't find one here in NZ, not even my local Holden dealership had em. Pub24/7 ended up sending one over for me:thumbsup:
So that spring i sent out works ok then immortaliy???I have sent another just in case its wrong. As i stated in immortality's my ride thread we use the same spring and relief valve for all v6's ecotech's oil pumps are slighty different but have same internals. I think 60psi @ 6000rpm isnt enough 80psi would be better but its a trade off as you dont want too much oil pressure as it'll pump it all to the top end and possibly drain your sump if it cant return it qiuck enough. Thats why some high revving motors i.e. burnout cars restrict oil to top end and make better drainage to the sump. Ecotecs have better oil drainage in the heads which is possibly why they run high oil pressure. Also another way to increase pressure is to shim up the relief valve like putting a metal of metal inside it to increase spring tension Be kneez i wouldnt use a 2nd hand spring as it could be stuffed better of buying a new one i doubt the cost much at all
yeah, i agree that with the the V6's 60psi doesn't seem to be enough, seems to be eonough on chevy V8's but they're a totally different engine. 60psi was the standard max pressure for the s2 VN V6 and they still spin bearings and throw rods (all be it with what is probably a tired oil pressure spring). i'm idling at 60psi cold or hot and seeing 75psi @about 2000rpm. i'm still running thicker oil then i normally do, a 25w50(older engine formula i had for 3.3 with stuffed bearings ) that i had sitting around and i'm only using it as a flush. will pickup my normal 10w40 this weekend and see what it does. for anybody thats interested, i've noted that my oil temp is 210degrees F or 99degrees C once it's completly up to running temp. it takes the oil considerably longer to get up to temp then the coolant. oil temp doesn't seem to move once it's up to temp even if the coolant is getting hot and the thermo fans kick in. the only way i've been able to get the oil nay hotter is to do a hillclimb @ sustained high throttle settings, although i won't be doing that again because the last time it got me a rahter large speeding ticket :bang:
been thinking some more about this, i wonder if this is also the reason some of the early home V6 turbo conversions ended in engine failures. from memory a few had spun bearings. tapping the oil supply for the turbo on a engine with possibly already a slight oil pressure problem seems like a sure way to see a engine blow with increased cylinder pressures/loads. some food for though for anybody doing a turbo conversion
