Hello again from greece. Does some one know if the following items are the same between cima single turbo vg30det and z32tt. Acl main-rod bearings Z32tt oil pump-gasket Arp rod bolts. As you understand i tend to strength mv vg30det's bottom end. One rod bearing seems to be gone so if everything else (flywheel-rods)is ok, im gonna fit the above
Thanks again. You are my man... Any ideas why the oem bearings failed? The engine is stock, over 150000 km i quess, with a gt3071 at 1.1 bar. I didnt dynoed it but i believe its about 330+ rwhp. Is this power too much for the engine or its just the oldness of the engine?
would like to see the failures you have experienced. Its not uncommon to toss a rod bearing on these engines.
Not dynoed? What were your afr's (mixtures) showing? Id guess detonation if you cant answer above and id predict the piston tops might show the signs. L8r E
that power will not kill one of these motors, spun bearing will be a lubrication problem, or detonation i guess, but rings normally go first
These engines are almost certain to spin a rod bearing when lack of maintenance, overheating the oil and frequent abuse are combined.
Regular oil changes, never exceeded 5000km. I use oem oil filter at every single change. Redline 5w40 full synthetic is the oil i use. For the oil temp i don't have a meter but i never push the car continiusly. That's why i dont have an oil cooler. I never go at the track, and the bigest distance i make never exceeds 100km. It's a dailydrive car. As matter for the detonation, the car has been programmed at the road safe. Afr is at 11.5 and i use only 100+ unleaded. No overboost just 1.1 bar from the beggining. Generally i love my car and i treat it as my child. The only think i dont know is how the jap owner treat it
Errrmmm, you say its never been on a dyno...... How do you know these are running AFR's and at what rpm/load does that occur. Also, you dont need to be actually boosting to get destructive detonation. Not specifically saying detonation killed it but see where Im going with this? You "may" have just been unlucky. L8r E
when combined yes, but frequent abuse alone wont, Since the day i bought my zed i thrashed it without mercy and the bottom end has always been in very good order. Out of approx 20 VG's ive built, only one had thrown a rod, that was caused by a loose sump plug(another workshop) and no oil. so cant blame the car or the driver for that. Ive had maybe 1 in 5 rebuilds where stock pistons have shown cracks in the ring lands, broken rings and piston material chipped away. This type of failure is much more common in my experience. But i guess its just the luck of the draw
We are all just guessing here, get some pics up when you get a chance. AFR doesn't cause knock. Timing does, even if his afr was 30:1 doesn't mean anything unless it has too much timing. Out of all the VG builds I have done that have come in dead, I would guess 20, I have seen probably 6 with failed bottom ends. All of those have either been #4 or 6 big ends. Another 2 have very badly worn big end bearings, 2 have had cracked ring lands, 1 with a broken gudgeon pin, 2 with bent valves, 2 with bent rods & twisted crank, 1 with incorrectly resized small ends. The rest have been overheated to the point where they will not start. Allmost all the other rebuilds I have done, probably 30+ have been suffering the effects of overheating or worn intake valves. I can not honestly say I have seen a vg30de or tt that has worn out from old age, the all die from abuse, whether that be lack of care, bad tunes, over heating, overboosting, over revving etc. Every engine you pull apart tells you a story of how it's last few hours were played out.
I have an inovate lc1 wideband permanetly mounted in my car. That's why i know the afr. At full throtle it shows 11.4 11.5 from 3000 rpms till 6200. After 6200 till 7150 where my limiter is, the afr goes gently to 10.9. As for detonation when we tuned the car we used an external knock sensor, knocklite i thing, for being sure. The ignition map is the stock map with a litle retard at the midlle rpms
OK then Ill fall back on "You may have been unlucky". Occasionally, engines fail. Have the bearings actually spun or have they picked up on the crank and spalled up. Pix M8, They speak a thousand words. As drz400y has clearly stated, we are all purely speculating without visual info. Until then. L8r E
The 3rd cyl rod bearing is the one that failed. The bearing now has a bronze color with some scratches on it. All the other bearings had the same silver but all of them had signs of minor damages. The color is silver and litle scratches started to appear at some of them... Pics is coming. The crank seems to be in excelent condition. No scratches at all. Tomorow i ll have it measured just to be sure. If everything is ok what's your sugestion? Should i use oem bearings or acl? What about arp rod bolts?
Oil starvation. I would be getting all rods checked and resized, new ARP rod bolts, and checking the crank for size and heat stress. Bearings are a preferential choice for most, I use ACL race or King. That rod journal lost lubrication or never had enough lubrication. Could be pressure related, oil surge, wrong oil viscosity, lack of bearing clearance etc.
