Sonny
It’s all fun til the rabbit gets the gun.
20-50
Possible blown head gasket?
- Thread starter Sonny
- Start date
Sonny
It’s all fun til the rabbit gets the gun.
The rest look fine.
Moparnocar
Well-Known Member
They still have that curve on the bottom?
PRHeads
Well-Known Member
- Local time
- 11:50 AM
- Joined
- Aug 31, 2018
- Messages
- 1,856
- Reaction score
- 2,586
- Location
- So. Burlington Vt
In 32 years of working in this field, I have come across the situation where the lifter wasn’t turning, and it didn’t wipe out the cam........ twice.
They were both mild hyd profiles that were running modest spring loads.
They were discovered as part of the cam swap process, with no prior indications that there was anything wrong.
Both had been run for a couple of seasons.
Usually........ if the lifter stops turning....... it’s all over.
As you can see in the pic above, that lifter basically never had any rotation....... which normally results in immediate failure.
In the case of the cam that went with the lifter in the pic, it had inadequate lobe taper(.0005”), so it didn’t promote proper lifter rotation.
They were both mild hyd profiles that were running modest spring loads.
They were discovered as part of the cam swap process, with no prior indications that there was anything wrong.
Both had been run for a couple of seasons.
Usually........ if the lifter stops turning....... it’s all over.
As you can see in the pic above, that lifter basically never had any rotation....... which normally results in immediate failure.
In the case of the cam that went with the lifter in the pic, it had inadequate lobe taper(.0005”), so it didn’t promote proper lifter rotation.
Last edited:
Runcharger
Well-Known Member
10lbs at idle with 20-50 oil.
Agree that's kind of low for 20/50w. Think I have a high volume pump and sure I have full groove mains. Avg. clearance M/R .0023, C 75psl w 40psi with Shell 20/50w diesel oil. Engine needs to be disassembled, cleaned and clearances checked if there's nothing obvious wrong. Gallery plug loose in cam area, doubt it.
Wietse
Well-Known Member
Damn...i am getting 60psi mostly, when cold it would be 70-75 but i never seen it go below 60 psi with 20W50.
Mine does have an high volume Melling pump.
But really interesting if OP has more bad lifters, as stated it would highlight a faulty part or wrong oil if all are bad.
Mine does have an high volume Melling pump.
But really interesting if OP has more bad lifters, as stated it would highlight a faulty part or wrong oil if all are bad.
It has low idle pressure because the pump speed isn't great enough to provide enough flow to overcome the internal leakage. A high volume pump will help. As will reducing internal leakage. Loose lifter bores, large main and/or rod clearances are usually the major culprits. But there's nothing the matter with large bearing clearance. Or low idle oil pressure either for that matter. 10 psi per 1000 rpm will be fine.
Doug
Doug
When you pull it apart check if there is a plug in left lifter gallery. Maybe somebody had solid lifters and put a plug in.
Lefty71
Well-Known Member
Would you happen to know if the lifter bores were properly broached, AND the lifters checked for proper spin when the motor was built?? Believe it or not, i always check these myself, after the shop says the block is ready to build. Sadly, it does look like you should pull it down, check everything again and clean up. If it was just one bad lifter, it will drive you crazy, but you'll be good next time. At 8000 miles, everything was most certainly broke in, but i'm wondering, did the car idle a lot, with that low oil pressure?? Maybe grooved halfs only would be a better plan?? 20-50 should'nt really be necessary on a mostly street engine anyway.... food for thought to discuss with your builder.
Very sorry to see the damage Sonny. Did you ever state where the lifters were sourced? Maybe a flat one from the factory, or maybe it just wasn't spinning.
When I built my motor I checked every one for a dome and matched them to bores and checked for rotation.
When I built my motor I checked every one for a dome and matched them to bores and checked for rotation.
Sonny
It’s all fun til the rabbit gets the gun.
Comp cams.
This is one reason oil samples are good to work with. If a person changes his only every 8 thousand it will tell you of a problem or give you heads up to start looking at. Sonny if that was a bearing I would say it had zero rotation the lifter was stuck and the cam burned thru it. Having oil pressure like you do tells me not to idle it very long. You need to look at other things as you put it back together. As above has mentioned but again send in a oil sample from a new quart of oil to make sure that the additives are in there. Then take oil sample after 8, 000 miles and compare. Oil samples will tell the story.
HEMI-ITIS
STREETER on LI
- Local time
- 11:50 AM
- Joined
- Dec 14, 2008
- Messages
- 12,936
- Reaction score
- 17,795
- Location
- Long Island,New York
I wouldn't go 8k on an oil change.
Wietse
Well-Known Member
I think 8k miles on mineral type oils is not a good idea.
If the engine was build with using synthetic oil (clearances, materials) in mind, then you can extend the oil change intervals.
For a streeter that is, a racer would be a different story again i think.
Oil sampling works well, but you need to commit to it and do it at certain intervals to have some history to compare against and you will immeadiatly notice any abnormal increase in metals and you have confirmation on how long the additives as zinc are holding up over time.
If the engine was build with using synthetic oil (clearances, materials) in mind, then you can extend the oil change intervals.
For a streeter that is, a racer would be a different story again i think.
Oil sampling works well, but you need to commit to it and do it at certain intervals to have some history to compare against and you will immeadiatly notice any abnormal increase in metals and you have confirmation on how long the additives as zinc are holding up over time.
Wietse
Well-Known Member
Yes, but i am not going to that extend with oil sampling though.
I change the oil after the winter period, after it has been sitting still for that time.
If i get a change in winter time to drive i go for it and have it up to temperature for some time, starting it and letting it idle is definitly not good.
Then better crank it with the coil disconnected.
I have the heat to deal with like your winters it is hell on engines. But watching my trends I can always change as needed. Samples are very good on alot of different levels just like the racers spend time on weather track temp etc. It gives info to work with. Adjust or not to adjust that's why it works.
Similar threads
