dburt86

iTrader: (2)

So I added some pre compressor nozzles (250cc X2) in conjunction with my 1 pre throttle body nozzle (1000cc X1) and I decided start dialing it in.

First pull, it's about 11.0 afr, 10lbs, 10-12 degrees on pump gas.

Mid pull, car lost some of its power. Figured it went way rich and needed to be trimmed out.

Pull over to look at the logs and the car is making terrible valve train noises.

Pull drivers rocker cover and found this. Every rocker that's not loaded by a cam lobe is this loose. All the lifters seem to be collapsed.

Towed it to the shop and checked the oil pressure, still 40ish at idle

Oil looks like lapping compound.

Thinking maybe it spun a cam bearing and killed oil pressure to the rest of the lifters?

Motor number 2 in about 2 months. Fml

3 window

iTrader: (1)

The cam bearings branch off the lifter oil gallies and get fed AFTER the lifters. Makes sure the cam retainer plate gasket is good (not too flattened out). A bad gasket would cause oil to leak past at higher pressures and cause starvation to the lifters therefore collapsing them.

sbcgenII

iTrader: (1)

The cups in the lifters should have come up with no pressure on them. Unless they are just beat up. Or you have another issue.

dburt86

iTrader: (2)

I agree. The thing that really gets me is how much lash there is.how could that happen?

Push rods are not bent. .080 chromoly

Forcefed86

iTrader: (4)

Filter full of metal?

dburt86

iTrader: (2)

Haven't pulled it yet but I can see copper bearing material in the oil in the head

So yea, probably. Lol

On the slim chance I wiped the cam out somehow, I put a dial indicator on number 1 push rod and got my full .571 lift (.342x1.7) so that's not it

I can see in the datalog that it happened right before 6k

3 window

iTrader: (1)

What pan are you running, what oil and how much?

dburt86

iTrader: (2)

F body, 7qts of 20-50

The best I can come up with at this point is that the lifter lost oil pressure and the insides that usually plunge seized in the lifter housing? Just grabbing at straws here.

Pistons and rods came in tonight for the forged motor so I'll probably tear it down this weekend and get a real failure analysts

Forcefed86

iTrader: (4)

Post lots of pics and let us know what you find. 50w is pretty thick for a tight tolerance OEM LS motor. Not saying it caused your problem, but may something u want to read up on and change.

Do you log oil pressure? Seeing a rash of motors munching bearings due to loss of pressure lately. I think an oil accumulator would be cheaper/easier/better than messing with a decent aftermarket pan. Then having to modify it for turbo drains. I still have pressure issues on hard launches with the fbody pan/improved racing baffle/and 8qts!

sbcgenII

iTrader: (1)

Seen a few ls motors running on 20-50 lately. Garbage as clearances and put together with air tools. Then just throw in 20-50 so you have decent oil pressure. This is from "pro" shops.

3 window

iTrader: (1)

I agree, I think 50w oil is too thick. These engine don't have losse tolerances unless they're set up that way by a shop.

SethU

About ready to call BS on this thread...

There's no physically possible way to achieve full lift with that much "lash", unless the base circle wore and left the lobe intact... unlikely.

Something is being left out of the story or it's a hoax. What cam is in there?

Maybe I'm just not thinking with all cylinders???

69-chvl

iTrader: (11)

Video shows a lotta slack in valvetrain. Wonder if a lifter turned sideways? Either way not good.

Fat Jesus 808

iTrader: (5)

We've seen DOD lifters that

dburt86

iTrader: (2)

I'm not sure what there's to call bs on? The video clearly islustrated a very real issue. It's not specific to 1 cylinder either. I measure lift and it seems right on the money

The cam is 228/228 with .571 lift. I'm showing about .342 (iirc) of lift, times that by the 1.7 lifter ratio and it's pretty close to the rated lift. (This is just a harbor freight dial indicator and a quick check)

The only cylinders that don't have that much lash is the 2 most rear cylinders

And all the valves with that much lash, you can't compress the lifters. Like they are already collapsed

The motor still runs, it just sounds like **** (as you would imagine with that much lash.)

As far as the oil, no real reason for it. This motor broke a piston about a month ago, I slid a new slug in, changed some of the rod bearings and dumped some thicker wieght oil in it so I can keep driving the car while my forged motor gets built.

Not syaing that's a good reason for the oil, but it is what it is.

I pulled the valley pan last night and couldn't see any of the lifters damaged or turned. I cannt see any of the cam bearings but that doesn't mean they are still good.

dburt86

iTrader: (2)

I don't log it but I should start. A quick pressure transducer wouldn't be hard at all and they are real cheap now a days

SethU

What specific cam?

If it's a TSP 228R... it has 0.600 lift, and your measured/calculated .571 would leave a deficit of 0.029... However, looking at the video there seems to be at least 0.125 (maybe even 0.250) between the valve and rocker tip. :headscratch:

The reason it makes no sense is, if the cam is junk, or if the pushrods are bent, or the lifters collapsed or otherwise wore in a way that opened the lash that much (anything more than 0 lash) obtaining full lift is impossible.

So, there absolutely is missing or incorrect information.

Double check the cam specs. I suspect a 228/228 cam is going to have more than 0.571" lift... If so, then the story starts to make sense.

Or... if you mistakenly measured the valve lift (valve side of the rocker arm instead of the push rod side) and got 0.342 (believable) you wouldn't multiply it by the rocker ratio. If that's the case and your cam really is 0.571 lift, you should have 0.229 lash between the rocker and valve tip... that also is believable in watching the video.

dburt86

iTrader: (2)

It's a speed INC tu1.5 and I'm measuring the lift of the push rod.

In any case, I can see the cam lobe that I'm measuring (valley pan off) and the cam and lifter look to be undamaged.

So even if I'm measuring it wrong, I can still see the cam lobe is fine and atleast the bottom of the lifter is still in tact.

I'm going to start pulling the car apart tomorow. Not sure if I'll get it all the way apart but we will see soon.

No one is more confused then me. I'd be way happier if a rod came apart. Atleast then I'd know what failed

SethU

Well shoot. If you are measuring and getting full lobe lift on the push rod end and the cam and rollers look good as far as you can tell... your lifters have collapsed and plungers are stuck down in their bores. Weird to have so many, but if you pumped some junk through them... who knows?

I look forward to the autopsy report and pics...

sbcgenII

iTrader: (1)

If it makes you feel any better by the time I got home from the dyno today my check gauges light was on for oil pressure. Going to throw some 20-50 in it and hope it lasts a few more weeks.