Hey guys--

I have a new rebuilt hp 300 with about 1,000 miles. From the beginning until now I watched the oil pressure go down from 30 psi at a hot idle coming off the freeway, to 10 psi. If I had not put in a high volume pump, I'm sure the pressure would be 7 psi or less at a hot idle.

I found, after about 10 days, that there was some gas getting into the oil. I could smell it, but could not see the level going up much. There was also some grit in the pan, but it seemed minor.

I swapped out the fuel pump, and the carb. But the psi was already down to 10 with the hv pump. It really bothered me. AND TO THE GUY ON THIS FORUM WHO SAID THERE WAS NOTHING WRONG WITH MY OIL PRESSURE: I found four out of six rod bearings were already showing copper, dude. On the mains only the thrust bearing was showing a bit of copper on the edges of the surface that contacts the crank.

My mechanic says that he suspects pollutants in the oil because most of the bearings show lines like scratches. But if that were the cause, the mains would also be damaged because they are first to get the oil. Something else that occurs to me: Is it possible that the rods are getting over torgued, thereby being deprived of oil, and so are 'cooking' a bit.

Or should I simply blame it on the gas in the oil? But that would certainly have caused the same symptoms with the main bearings.

Holy crap-o-la. I think I may have just solved the problem: The rods are torgued to a higher torque than the books calls for because I used ARP rod bolts. I torqued them to 50 psi as ARP suggested. But most of those bearings are showing copper, so something is wrong. It has to be the torque. That is the only explanation I can come up with. Maybe ARP gave the max. setting, and possibly my torque wrench is off a bit, so they are getting tightened beyond specs.

Both times the engine had Clevite 77 bearings installed.

Any feedback is greatly appreciated.

 

Ya know, it would be a lot easier to follow your disjointed story if you stuck with one thread, not four with only a little of the info in each one.
Now that I've wasted nearly an hour of my time tracking down your whole story, here's the rundown I see:
You had gas in the oil.
You didn't mention anything about the surface finish of the crank.
You didn't mention anything (even though I asked) about what your peak oil pressure was.
You dropped the pan on a brand new engine to put in a high volume pump without checking the bearings.
You never mention any noise, or other issues that would lead people to think you actually had a wear issue.

Next time you jump on me for giving you advise, think twice. Your oil pressure was well within specs, given the fragmented and incomplete info you gave. These engines, hell any engine is known to have lower oil pressure at idle than at cruise, and hot oil flows more easily so the pressure seems even lower. A new engine will put some debris into the oil, and the filter will get somewhat restricted. I run only Motorcraft filters, and on a newly built engine, will change the oil and filter at 500, 1000, and 2000 miles, in addition to running a magnet on the filter case to get any stray metal.

FWIW, I have built a few of these engines. My hi-po one was way more powerful than yours, and ran less oil pressure. I drove that truck cross-country, towing a trailer, and then drove it for two more years before I sold it to a guy who ran it for at least another three years.
Maybe it's different since I do ALL my own work, not just bolting together other people's work.
FWIW, if torque on the rod bolts made your big end smaller, I'll eat my hat. 55ft/lbs (not PSI, that's not a torque measurement) on a 3/8" bolt creates approximately 8500 pounds of clamping force. Your forged connecting rods have a yield strength of 75,000 to 80,000 pounds per square inch, so unless you "accidentally" applied about 650ft/lbs of torque to those bolts, that is not your issue.

Get out your micrometer, plastigage, and check the smoothness of the journals. Inspect, never trust, and you wouldn't be in this position.

 

"the rods are torgued to a higher torque...."


really?




Sorry but i agree with everything ford_six said.

 

if it was contaminates the mains should show some damage as well.if the rods were down to copper i would be checking the crank jornals for damage.7 psi at idle isnt great but its not low enough to cause premature wear/ the old screaming jimmy deisels would idle at 5 psi

 

By the length of your discourse, I can see that you really needed to make yourself feel superior. Good for you. Do you feel better now?

I came on this forum seeking knowledge from others more experienced. You did not offer an opinion as to my problems, only took the time to point out where I was wrong. How helpful.

Obviously there was a problem with my oil pressure. It continues to drop, not hold steady, probably due to the wear on the rod bearings.

If you took offense to my posting, that was your choice. I'm sorry.

 

All the crank journals still show the machining finish. I had the crank turned .010.

The engine runs at 55 mph at about 38 psi. When I first dropped the pan, leery that the pressure had fallen considerably to under 10psi coming off the freeway, I checked the mains and one of the rod bearing. They were already beyond the tolerances in the book, but I saw no damage, and the crank looked good.

At that time I put in a hv pump, and that raised the oil pressure to about 15 for about a week, and it slowly dropped to 10.

Fearing something was amiss, I dropped the pan again, and found 4 of 6 bearing showing copper on the rods.

I am thinking the gas in the oil did its damage and it should be fine now.

 

I wanted to show some photos of the bearings I changed. Should these be cause for alarm?

I have the new bearings in, with the hv pump, and am running 15/40 oil. As the engine warmed up of course the pressure dropped. Hot around town I have 14 psi, with the new bearings.

<a href="http://s659.photobucket.com/albums/uu316/bobbyrogue/?action=view&current=P1010261.jpg" target="_blank"><img src="http://i659.photobucket.com/albums/uu316/bobbyrogue/P1010261.jpg" border="0" alt="mains"></a>

<a href="http://s659.photobucket.com/albums/uu316/bobbyrogue/?action=view&current=P1010262.jpg" target="_blank"><img src="http://i659.photobucket.com/albums/uu316/bobbyrogue/P1010262.jpg" border="0" alt="rod bearings"></a>

The top photo is the mains, and the one just above is the rods.

<a href="http://s659.photobucket.com/albums/uu316/bobbyrogue/?action=view&current=P1010263.jpg" target="_blank"><img src="http://i659.photobucket.com/albums/uu316/bobbyrogue/P1010263.jpg" border="0" alt="edge copper"></a>

Above is a closer shot of one of the rod bearings showing copper on the outside edges.

<a href="http://s659.photobucket.com/albums/uu316/bobbyrogue/?action=view&current=P1010264.jpg" target="_blank"><img src="http://i659.photobucket.com/albums/uu316/bobbyrogue/P1010264.jpg" border="0" alt="rod bearing showing copper"></a>

Anyway, that is what I have. I'm not going to change them again.

 

You have dirt or grit or something in there. Look at the striations on those bearings. You can keep running it, but not for long.

Sorry for the troubles--I don't wish to get in on the prior posts here, but I've seen what happens with an engine is assembled in a dirt storm, and that's what these bearings look like to me.

Good luck with it.....

 

Your crank wasn't polished, either.

 

I apologize to Ford_Six. You were only trying to help. It is impossible to diagnose a problem without seeing the engine, etc.

It does look like something went through the oil. I helped the mechanic assemble, and he wire brushed EVERY bolt, and was super **** about keeping things clean, but then I look at the bearings....

The only incident I can think of that may explain the 'grit' and striations in/on the bearings involved the cam bearings. I had problems with the second cam bearing, and couldn't get the cam into it. So I took it to the shop which did the work, and they reamed the edge of the bearing and sanded it with very fine sandpaper. But the engine was not washed after that, and those fragments may have been circulated through the oil, with a bit gasoline in the initial start.

The crank journals look mirror smooth.

Anyway, I have changed the oil 4 times now, and today changed all the bearings with the new oil change. I hope these new bearings will be okay.

 

I have been following this project on here and I sure don't want ruffle any feathers,it just seems like there are some good lessons to be learned.If anyone is going to build an engine,you have to be down right religious about cleanliness and thorough about specs and accuracy.There isn't 1 mechanic in 50 out there that I would trust on a rebuild,sad,but true.their "good enough"isn't mine.There is so much money and time in a rebuild that you have be 100% on every aspect of it.I have rebuilt motorcycle engines on my dining room table, several times in years back, because they were clean enough to eat off from,and that's the way it's got to be if you want anything good when you are done.There is a lot of work in just rebuilding a short block and a lot of people take short cuts and that's where they get bit.Did anyone hand clean the oil passages on this crank and block,were the rods capped, torqued and checked for round?Was the mains checked and line bored,if needed.Was plastigage used to check all the journals,was the oil pump pre-primed? I don't know,I wasn't there,but there is a lot to cover on a rebuild and if you are going to do it,you have to be thorough.There is a lot of high tech stuff out there that this old duffer (me) probably isn't up on,but good basic mechanic principals never change-If you don't know it,learn it,learn it all,do it all,and be surgically clean about it.

 

You're right!! It had been many years since I rebuilt an engine, so I hired it done. I had all the machine work done at a shop, but there were things I did not know about that needed checking, like checking the caps for round. All the oil passages were wire brushed and washed. I know the mechanic was super clean and obsessive about cleanliness. That's why we're both baffled.

The only place we didn't wash, was the Clifford valve cover. I washed inside and out with solvent, but I had it professionally polished, and inside the hole where one puts the oil in, is a plate. It allows you to pour in the oil, and is down about 1" from the top of the valve cover, so the oil hits it and flows in. Of course it also keeps oil from splashing out if the cap is removed while running. Well, it occurs to me that the polishers did not have a cap while polishing, and that plate could have gotten compound inside. I did not see it, and did not clean up there, so with the first oil fill, it got washed into the engine, and you can see what happened to the bearings.

All tolerances were checked. I am hoping that after four oil changes and new bearings, that the engine will now be fine...that all grit--polishing compound--has been filtered out or washed out with two pan removals and washes.

I hope my problems serve to help someone reading this.

 

I have not read the entire thread, or the other threads on this subject. Just shooting from the hip - one way for your rod bearings to get trashed like this without the main bearings being trashed is if you had the crank ground and then installed it without cleaning all of the oil passages. The passages could have been filled with debris from the grinding/polishing process. When running, oil flow would push all of that debris away from the mains and right into the rod bearings.

 

there was definately dirt in there right from the beginning. also, one of the products used in polishing aluminum, is acid. that is the 1st process, to clean it down to a surface, that will accept the polish. between the acid, the rouge, the polish, sand from the cam bearing, and possibly all your other tin[ chromed side cover], you may have just thrown a hand full of sand dust right in there before you even hit the key 1st time.now add gas in the oil to thin it and you have a real nice mess. there's been enough oil through there to wash everything down, so do like ford six said, change at 500, 1,000, 1500, and faithfully at 3,500 forever after, and you should be fine. I'm glad to see that it is on the right road to becomeing a memory, not a continueing saga.

 

I feel better now knowing what happened. I know everything was done correctly, because I paid the machinist and ordered the things done, and watched as the engine was assembled. That's why it was driving me crazy trying to understand what happened. I mean, the mechanic wire wheeled Every bolt and washed it!!

Anyway, I have great oil pressure now, HOLDING STEADY, and the truck runs like a brute with the new carb. I'm soon taking it on a trip to C. California, to see how it does....

Thanks to all who tried to help.

I changed the oil after the first day of running, then three times after that.