Stroker build gone wrong - low oil pressure

[mveltre123]

Hey everyone,

As the title suggests I just completed my stroker build and very shortly after the initial cam break in, now have low oil pressure. Hot pressure was around 40 during the break in and test drive, and dropped to around 10 at idle. I have already verified these numbers with a mechanical gauge, the gauge read slightly higher in both scenarios. After assembly and before install I primed the oil system with a drill and saw over 60 psi with the same gauge. All parts I used during this build were supplied from Russ. Everything measured out perfectly, main bearings clearances at .002 and rods at .0015. I've pulled apart the oil filter and most of the media inside was covered with a coating of metallic glitter type flakes, with a few larger chunks in the housing. I've attached photos below. Russ was the first person I called immediately after this happened earlier and he thinks I've most likely wiped a cam lobe or a bearing. I absolutely respect his opinion and advice but was looking for as much input as possible on what might have caused the situation. I am extremely hesitant to pull the motor and do this job again, as I found that I've sacrificed most of my free time and time with my friends/loved ones to complete this build for the past few months.

As I said before any help or input is greatly appreciated!

[Cheromaniac]

Premature wear of the cam lobes, lifters, or cam.bearings is indeed a possibility. What engine oil did you use for the cam break in? Did you use cam lube for the installation or ZDDP additive?
You might want to pull the oil pan to inspect the rod/main bearings on the no.6 cylinder (rearmost). If those bearings look OK, it's likely the others are too.
You'll get a good view of the cam lobes while the oil pan is off too, and check the oil pump pick-up screen.

[optmaxx]

No knocking could be a good sign that you caught it in time. Low oil pressure could be caused by rod or main bearings failure too, which can be replaced by dropping the pan and without removing the engine; rod bearings being the easiest one to do vs main bearings.

Was your cam the pin and spring type?

[mveltre123]

Thanks for the replies guys. During the initial break in I was running comp cams break in oil in 10w-30, then changed it to conventional Castrol 10w-30 with redline break in additive. Was using a wix filter for both. The cam I installed was a thrust plate style vice the spring and pin which I believe is better at controlling cam walk. Going to pull the pan tonight and inspect all the breaings for wear. Also going to pull the valve cover and check the pushrods for up and down play to see if I've damaged the cam. I will report any findings.

[mveltre123]

Alright so I've pulled the pan off and fairly quickly discovered that cam bearings #2 and #3 appeared to have failed. You can see them oozing out bearing material in the photos I've attached. I also pulled the cap off rod #6 and the bearing was pristine so I'm sure it's safe to say the other main & rod bearings are safe as well. Going to start disassembly this afternoon. What does everyone recommend to prevent this from happening again? With cam bearing failures being a common thing based on my research, I'd absolutely hate to tear down and rebuild the motor again just to have those bearings fail again.

[Randy Bobandi]

cam bearings #2 and #3 appeared to have failed.
What does everyone recommend to prevent this from happening again? With cam bearing failures being a common thing based on my research, I'd absolutely hate to tear down and rebuild the motor again just to have those bearings fail again.

Cam bearing failures are virtually non-existent for this engine. The cam tunnels were line honed with the bearings in place during the original assembly process. As a result, each cam bearing had .0005"-.002" of material removed from the 4o'clock-8o'clock position. If you still have your OE cam bearings, you'll notice that they've been machined. This can be tricky when installing an aftermarket camshaft. Some aftermarket journals can be smaller than OE, some larger than OE. I would suspect that the cam you installed has slightly larger than OE journals, or it's bent. Cams can be bent easily in shipping. Another cause could be if the cam bearings were not installed in the correct locations, but I'm sure you're well aware that each cam journal is a different diameter and each cam bearing is as well.

So there really two things to look at; camshaft straightness and cam bearing oil clearance. To prevent it from happening again, you'll have to get out the micrometers.

[Cheromaniac]

Cam bearing failures are virtually non-existent for this engine. The cam tunnels were line honed with the bearings in place during the original assembly process. As a result, each cam bearing had .0005"-.002" of material removed from the 4o'clock-8o'clock position. If you still have your OE cam bearings, you'll notice that they've been machined. This can be tricky when installing an aftermarket camshaft. Some aftermarket journals can be smaller than OE, some larger than OE. I would suspect that the cam you installed has slightly larger than OE journals, or it's bent. Cams can be bent easily in shipping. Another cause could be if the cam bearings were not installed in the correct locations, but I'm sure you're well aware that each cam journal is a different diameter and each cam bearing is as well.

So there really two things to look at; camshaft straightness and cam bearing oil clearance. To prevent it from happening again, you'll have to get out the micrometers.

This!

[mveltre123]

cam bearings #2 and #3 appeared to have failed.
What does everyone recommend to prevent this from happening again? With cam bearing failures being a common thing based on my research, I'd absolutely hate to tear down and rebuild the motor again just to have those bearings fail again.

Cam bearing failures are virtually non-existent for this engine. The cam tunnels were line honed with the bearings in place during the original assembly process. As a result, each cam bearing had .0005"-.002" of material removed from the 4o'clock-8o'clock position. If you still have your OE cam bearings, you'll notice that they've been machined. This can be tricky when installing an aftermarket camshaft. Some aftermarket journals can be smaller than OE, some larger than OE. I would suspect that the cam you installed has slightly larger than OE journals, or it's bent. Cams can be bent easily in shipping. Another cause could be if the cam bearings were not installed in the correct locations, but I'm sure you're well aware that each cam journal is a different diameter and each cam bearing is as well.

So there really two things to look at; camshaft straightness and cam bearing oil clearance. To prevent it from happening again, you'll have to get out the micrometers.

Thanks for the feedback Randy. Once I finish disassembly I'm going to bring the block to the machine shop and have the new cam bearings installed. I'll have them check out the cam for straightness as well and measure the journals. Is there a certain oil clearance spec I should have the shop shoot for with the new bearings, in the event that my aftermarket cam journals are different sizes than stock? I want to do everything possible to prevent this from happening again.

[Randy Bobandi]

Is there a certain oil clearance spec I should have the shop shoot for with the new bearings

I would just ask if they have they ability to align hone cam tunnels, then insure that each bearing housing is perfectly round and each journal has .002" of oil clearance per the provided camshaft. Not all machine shops are equipped with line honing machines.

[dwg86]

Cam walk caused by pin is too short (pin and spring). The later model timing cover doesn't have a "bump" on the inside for the pin to ride on. I made a solid pin with about .005 camshaft endplay with the timing cover and gasket installed. I removed the rear cam plug and used a dial indicator to measure end play. I put a slight crown on the pin end where it would contact the timing cover.

Silverxj (member on this site) went through this same problem. He only fixed it when he had a custom later model cam ground and went back to the cam retaining plate a link style timing chain. I think cam motion ground his cam. Comp cams sells 1 cam for the 1999-2006 block. part # 163-201-5
https://www.compcams.com/xtreme-4x4-205 ... -2006.html

[dwg86]

I'd also only use lifters made in USA.
https://johnsonlifters.com/