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Well it looks like low oil press. I dont see any real scratches like from metal particles. And i dont see any "hammered" local areas.

U could take a long thin drift/punch and try and see if that steel ball is missing. I believe u have to knock it out from the top of block on rear "china wall". The ball comes out on the rear main saddle in a hole next to the bolt hole on drivers side (i think) when block is right side up or other side when upside down looking at the saddles. But i does look more like low oil press or lack of oil.

Now no oil at all would have seized things up and melted/welded some brg material.

Dont know what to say of the better condition rod brgs other than just a matter of time for them also. Rods maybe a little less loaded. Who knows - but im sure someone here will claim they do. U did say the rods ran a tigher 0.0015" clearance. But that wont explain the 0.0025" gap on the rear main - it looks the best.

Have to ask did u use "fresh" plasti-gauge"?? It tends to dry out in the tool box over time - sorry dont know the self life myself.
 

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Hope you didn't cheap out on the dial bore gage.The cheap ones only measure to 0.0005" which is worthless when checking engine parts.

You need a bore gage that truly measure down to 0.ooo1" They cost more.
 

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this is why guys just building an engine or two should let a machine shop do the measuring.

the proper tools to do this stuff dont pay for themselves until you've built quite a few engines.

then after you've used them, you need tools to calibrate your tools

I have used plastigauge quite a few times, though, but to use it properly is a real bitch.
 

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Discussion Starter #25
Im getting a better quality bore gauge. Thanks for the insight.
What is TIR? Sorry dont know what it means
yeah the plastgauge was fresh. I tried getting measurements with my calipers and mics but wasnt really the best tool for the job but I do know how to use them well. I worked In a machine shop and did QC work so I know how to use them. Im pretty confident in my measurements. Thats why im asking about other possibilities other than to loose or to tight of bearing tolerances.
I did notice the very rear cam bearing was not pressed all the way in. The oil hole was barely open to the galley. Like ony about 1/3 of the oil hole was open. But the cam and bearing looked okay. But it kinda looks like the oil was possibly passing between the bearing and block towards the back of the block. But cant really confirm that I will drive out the cam bearings to check. And from what I have read says the rear main is feed right off the pump right after the filter and all others are feed after the cam. May explain why the rear main isnt really bad. But dont really explain the front main. But guys im just asking for ideas. I know it may very well be my measurements were off. But is there something else wrong with either the block or something else.im already gonna have the block line honed and checked by another shop.
 

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Ok dude i did some research for as i see your trying hard to find this answer. And i read theres really no bad way to install cam bearings other than having the holes lined up with the oil galley holes. What im saying is u dont want the cam brg holes to line up with the galley feed holes - can create a backpress - but this would only affect the cam brgs and not the mains or rod brgs. U want the cam brg holes at 'bout 2 o'clock from the feed holes to ensure the oil flows in the block grooves around the back of the brg and do that oil wedge thing once on the cam journal. But i dont think the hole alignment can affect the main press - only a large cam to brg clearance would drop press.

The more i read on this ball plug the more it could be the problem. The Chevy Power manual says without that plug (on a bowtie block its a regular metal plug rather than a ball) the engine will loss oil lube to the mains and not live/survive. TPIS says that also. Im think'n w/o the ball (plug) u would still read good press but oil would no longer be forced into the main gallery.

U really need to check the ball/plugs is there. U need a long small dia drift to knock it out from the top of block.

Now a bad/large TIR (total indicator reading) could cause that damage but the second check for that TIR is the turn by hand method which u said it passed. U could retest TIR now but maybe in a set of V-blocks.

Bore gauges are cumbersome to me because i rarely use them and have to relearn how to take and how many readings to take. Theres some handling methods to get the right orientation needed to taking a correct reading. Good luck to u.
 

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Now a bad/large TIR (total indicator reading) could cause that damage but the second check for that TIR is the turn by hand method which u said it passed. U could retest TIR now but maybe in a set of V-blocks.
Total Indicated Runout...not total indicator reading. With something as big as a crankshaft this is typically done in a lathe between centers with a dial indicator. Putting something this heavy on v blocks will scratch surfaces that shouldn't be scratched.

The idea is to check if your crank is straight.
 

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Discussion Starter #29
Okay thanks for all the responses. I didnt check for run out. I didnt think it would be an issue cause it was new. But after thinking about it maybe it should have been checked. I will have the machine shop check it cause the crank needs to be turned. I will definitely check the check ball/plug to see what is going on. This is the help I need. I doubt the crank was warped but hey ya never know. But I wanna explore all of the possibilities. THANKS GUYS!
 

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OP

I noted the check ball in my initial reply. it drives out from the top and back in from bottom as the passage it goes in is tapered so it stops where it is supposed to. Confirm it is installed

the cam bearings that were installed wrong, IMHO, could have "contributed" to the oiling problem as the improperly installed cam bearings can cause oil to back feed

obviously check crank run out as mentioned. If you used plastic gauge..maybe the readings were not as accurate as you intended and the bearing clearances were a little tight.

For a stock spec bearing clearance a standard oil pump is fine. maybe just swapping in the higher pressure spring if you want. if going with wider bearing clearances a HV pump

I found this book helpful in detail about specifics of LT1/LT4 SBC and have used it several times for reference

[ame]http://www.amazon.com/Rebuild-Small-Block-Chevy-Engines-HP1393-ebook/dp/B004QZAZBO[/ame]
 

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Discussion Starter #31
Thanks for the recommendation of the book. I will get it on the way. Havent had a chance to check the ball/plug yet. I know my oil pump is a gm stock flow. But I think it had the white spring already. The part # 12555281 that is the casting number. Dont have the actual part oder number. Any ideas on what would make the oil system act as if it sucks the pan dry. Thats what im really concerned about. I have pulled the oil pump apart it looks great no signs of problems. I did find that there is a glue or loctite all over the rear cam bearing and what ever it is didnt even wear off the bearing surface. It was some hard stuff but didnt seem to hurt the cam. But may have ran into the oil passages at the back of the block. Im gonna remove the cam bearings myself and inspect it the best I can.
 

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. Any ideas on what would make the oil system act as if it sucks the pan dry. Thats what im really concerned about. .
from this side of the internet, just making observations/comments on what you "describe".

the check ball thing may be the cause..but if it is installed was it removed for block cleaning then re-installed as it should have been???

if not crud may have lodged/block a portion of oil passage that affected the mains more than rods during, what I assume, was hot tanking/cleaning of the bare block.

if ball is not there...than that would certainly affect oil flow within engine

did the use of plasti-gage, even with your best intent and careful use, provide clearance 411 that compared to a more accurate mic tool cause the bearing clearances of the center crank bearings to be to tight?? possible

did the wrong alignment of some of the cam bearings...and now the evidence of something (RTV??) on the rear cam journal block oil passage?? possible

Is the run out of crank beyond spec?? possible until that is checked

any one of the above or all combined seems to be what caused the failure. A standard flow oil pump with white spring will not "suck a pan dry"...and frankly other than internet postings that HV pumps do (not in my motor) I have not seen clear evidence they do...at least in motors with wider bearing clearances
 

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Discussion Starter #33
I plan to work on it tonight. I ask all the questions because I have another block. But this one is powder coated and is bored. But I am worried I may miss something. I have it scheduled to drop the block off with a different reputable machine shop early next week to be checked and line honed and new cam bearings. And the crank to be checked and turned. I am just wanting to get a head start on inspecting all of it myself cause I cant believe i didnt catch the cam bearings. "Really not happy with loctite/glue or whatever they used and got all over the rear cam bearing." Couldnt see it until I removed the rear cam freeze plug for inspection. I may post a pic of it. I plan to knock all the cam bearings out tonight. To see what i find.
 

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from this side of the internet, just making observations/comments on what you "describe".

the check ball thing may be the cause..but if it is installed was it removed for block cleaning then re-installed as it should have been???

if not crud may have lodged/block a portion of oil passage that affected the mains more than rods during, what I assume, was hot tanking/cleaning of the bare block.

if ball is not there...than that would certainly affect oil flow within engine
IIRC If the ball is missing, oil will be pumped up the gallery and it would leak out under the drivers side head at the rear of the block. As i undertand it you would notice it missiing.

Mitch
 

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Discussion Starter #35
okay guys. here is what i found.. the check ball/plugs is in there and appears to be in the right locations.. I pulled the cam bearings.. they looked like they were starting to wear bad. I did notice the wear on the middle three were the worst.. they were installed at 6oclock holes lined up perfectly and the wear was at about 5:30-8:00 position.. like the oil was not really getting into the bearings but the rest of the bearing surface was not that bad.. The loctite or glue i found on the rear cam bearing appeared to be from when they installed the rear cam freeze plug. they got carried away with the stuff. It was not under the bearing. So I still have not found what may have caused this for sure.. I was wondering about the oil pump drive if it didn't seal in the block good could it cause an internal leak and create some of the issues i am having.. 'kinda doubt this one but read it on the internet" made me think about it. If the crank was warped would turning it fix the issue. " i will also tell the machine shop to check it' but i would like some other feed back and opinions.. Well guys thanks again..
 

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Wear on the cam brgs and main brgs is a oil press and or supply problem as a large total indicator reading would not affect/have anything to do with the cam brgs too.

I would look over the oil pump and oil galleys and all the galley plugs. I would brush out the galleys and internal oil lines.

Having drops in oil press at steady state cruise would indicate the pump has issues. Some thing with the spring or the pump drive or pickup is creating perturbations and press drops.
Some details to look at:
- oil pump case top/cover to gear clearance 0.002" to 0.004" where the closer to 0.002" the better.
- braze or tack weld the oil pump pickup to the pump - of course after setting oil pan clearance.

BTW u set the oil pickup to oilpan clearance didnt u?? This has to be done or u may well get a dry situation if pick up is too high over the oil level or restricted as forced against the pan bottom. U dont have to be honest to me but u should be honest to yourself and set the pickup to pan clearance correctly = 3/8". FYI i use playdoo or modeling clay to make an impression with bolth pan and gasket on to measure clearance.

I dont think u need to do anything fancy like porting the oil pump or rerouting the bypass.

Hope this helps and u can get it going again.
 

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Discussion Starter #37
Yeah the pickup was set right I used the playdough method too.im gonna double check oil pump. Already tore it down but but done a quick once over but still looking for the cause of the problem.
 

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Discussion Starter #39
Already checked the oil galley plugs and check ball all is good. All the galleys are clean and no signs of issues. Im gonna check the crank tonight if get the chance.
 

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I searched Google because I had a similar problem with oil pressure. I've got a SBC Dart block 427. I clobbered a large cobblestone while out one night and my oil pressure dropped to nearly zero because my oil pan crushed up against the siphon. It would hit 40 or so on throttle but was extremely low on idle. By the time I got home, my hydraulic lifters were clacking away on idle. I removed the pan and straightened it out and while in there, I replaced the oil pump with a Melling high volume pump. I also replaced the lifters on the top end. Everything "seemed" fine initially, but after about 100 miles or so, my oil pressure began to be erratic. With the new pump my pressure would be about 60-70 when cold and would settle in around 45-50. Suddenly, my pressure jumped to 100 (my gauge max) and I could only think that the gauge or sending unit went bad. From there it would vary wildly and my gauge eventually did go bad from the pressure I presume. It stayed at 100 even when shut off and would peg the needle when under pressure. When it would come down to 100 I am thinking it was really close to zero and my new lifters would start making noise and I could feel a difference in power as the lifters lost their height. I'm guessing I have a similar issue as described in this thread and have either spun cam bearings or at least something along this line. I will say that I'm disgusted and think my problem is rather bad. Any thoughts?
 
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