Hey i've got an olds 403 fresh build, engine has less than 5k miles on it. On my way to SC from PA, cylinder 7's exhaust lobe started going flat, i caught it really early. Outside of dropping the oil pan and just thoroughly cleaning everything, do i have to worry about the micro shavings ruining my engine?
I planned to pull my oil pump as well and make sure nothing made its way in there. As of right now im leaving the cam bearings in unless i see anything that would cause for replacement.
I'm not familiar with the Old 403 oiling system. Does it have a pressure relieve bypass? If ti does....Generally speaking...what usually happens is the cam starts to come apart, the metal particles clog the filter, the bypass opens, and unfiltered oil makes way around the motor doing damage to the bearings. Perhaps the only way to know for sure is to drop the pan and have a look at the main bearings, from there condition you can divine the condition of the other bearings. Have a look at you oil filter...cut it open with an exhaust tubing cutter and see how much metal is in there. If it's in the filter and the lobe is still mostly there you're probably OK. Take some of the oil and drop on a piece of paper or paper towel. As the oil wicks out the metal will be trapped in the grain of the paper, If you see a ring of darkness in the center, your oil was contaminated with metal shavings. The warm oil pressure can also be a clue, if its still as high as it was when the engine was newish then the engine may fine.
Yes oil pressure remained the same, no change. Now when i say i caught it early i mean really early, when i get the cam out i'm kind've expecting to only really be able to see the difference in lobes with my digital caliper. It may have even been a lifter, but i doubt it.
I'm not sure if this helps or not, but back when i built the engine i placed an additional rare earth magnet in the pan on the opposite end of the pan.
I'll cut the filter open and see what i can collect with a magnet, i'll run some oil through coffee filters to double check. I have to drop the pan anyways, while i'm in there i'll pull a cap and check. I've got ARP studs so at least i won't have to replace hardware, but i won't pull all of them because i don't want to have to set the thrust bearing from under the car.
If yall don't mind i have another question, how long should i wait after this cams break in too switch to synthetic oil? I switched right after break in last time, don't know if that had any effect on the cam or not. I do know it was either the break in, or me accidentally over lashing this lifter that caused this lobe to start going flat.
After cam break-in, I prefer to change just the filter, top off the oil level and leave the ZDDP heavy additive oil in for 500-1000 miles before switching to anything else.
Caught early is your best hope for the filter catching it all, along with the magnet...I've been able to do this with just a change to a new cam and lifters successfully. I just have a hard time recommending this approach to anyone, because it is a risk of failure again, so it's up to you if you want to take a gamble on it.
I replaced the pump just because I already had a new one, but saved the old slightly scratched one and put it in a beater a couple years later(it was a HV pump). I could have used it again in the newer motor if I'd wanted to, it was really not scored much at all.
I take it this is a Comp Cams camshaft, therefore it wiped a lobe. You might be OK, but it probably damaged bearings from the debrie going through the engine. Throw a new cam in it, new lifters, use a lighter oil and proper break in procedure and you might be OK.
I have always used a good diesel engine oil 15w40 and a pint to a quart of Marvel Mystery oil. Run that for a couple of hours, then drain refill with the same mix and replace the filter and run until service time. No high revs and no long runs at a constant RPM for first 500 miles. After that drive it like you stole it...........:thumbup:
Why not run roller lifters and cam on that 403? As I see it...it costs about 600$ more to run a roller cam and lifters as insurance against trashing your motor and the time and labor associated with it. Spend 600 now or possibly be in a bad situation out on the road and spend 2500+ later....Seem like an easy risk / reward judgment to me. What's the allure of a hydraulic flat tappet? Am I missing something?
Wow thanks for the feedback guys. icsamerica i would love to run a roller setup, but as OneMoreTime stated my pockets just aren't deep enough right now. Studebaker, yeah it's a comp cams cam and as much as i don't want to i plan on putting another set of cam bearings in it, if it needs them. Won't know till i crack her open later this week. F-BIRD i might give molyslip a try, i've been using lucas/comp cams break in additive up until now.
I'm a marine technician and i can get Yamaha 4M 10W30 at very very low cost, can you guys take a peak at the specs of this oil and tell me if it would be any good to run in my 403, or at least better than the mobil 1 synthetic oil i typically run after break in?
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