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its strange though because its only after wot pull and then within minutes its back to normal.
my collapsed lifter on my 2019 definitely misfired though, thats my other truck.
that's different when a dod lifter collapses you get no valve movement and a misfire, reg lifter collapses and you have lash and noise but valve still opens and cyl fires . I don't have a definite answer for you but I think it's lifter related . More preload may help . Would have to look it up but your all aluminum engine could be expanding enough from the extra heat of a hard pull to lose all preload and as it cools off preload is restored . Does it raise coolant temp during a pull ? Mine does . There are some guidelines when setting cold lash on mechanical lifter set ups that take into account the expansion of aluminum heads and/or blocks , don't remember the # but lash is reduced on the cold set up . Same applies to hyd stuff , preload will decrease as the engine heats up - aluminum heads and block having larger effect
Quick search shows that for an all aluminum SBC lash needs to be set .012 tighter on a cold engine, so if you had only .010 preload cold on 1 lifter it would stay quiet up to a curtain temp ( maybe your cruising around temp ) then you beat on it for a few secs and the temp goes up and the block& heads expand a bit more and bingo - no preload or even a touch of lash and some noise . On a 10 sec pass my ECT goes up 15-20° . If this all makes sense to you then the longer pushrods will fix it
If the valve work has been done well the pushrods should all be very close n length except for maybe a dual pattern cam with a smaller base circle on the exhaust lobes , then you may need longer rods on the exhaust
If the valve work has been done well the pushrods should all be very close n length except for maybe a dual pattern cam with a smaller base circle on the exhaust lobes , then you may need longer rods on the exhaust
my heads were professionally done by a local shop that has very high ratings and my temps actually never rise. I have a 4 core radiator will dual fans plus im on e85 so my temps are always fairly low. The highest I may see is 190ish. When I checked all my push rods lengths they all measured between around 7.2985- 7.3125 and the lifters call for .040-.080. The engine had been sitting a few days when I took the measurement so the lifters probably were pumped with oil but according to those measurements I was in speck with the 7.375 push rods.
my heads were professionally done by a local shop that has very high ratings and my temps actually never rise. I have a 4 core radiator will dual fans plus im on e85 so my temps are always fairly low. The highest I may see is 190ish. When I checked all my push rods lengths they all measured between around 7.2985- 7.3125 and the lifters call for .040-.080. The engine had been sitting a few days when I took the measurement so the lifters probably were pumped with oil but according to those measurements I was in speck with the 7.375 push rods.
Sorry I should have read all your # before- was tired . In that case you should have plenty of preload and I'm back to I don't know what's going on other than something going on with those lifters
Sorry I should have read all your # before- was tired . In that case you should have plenty of preload and I'm back to I don't know what's going on other than something going on with those lifters
yeh thats what im thinking too, the only thing I dont get about it is my tuner uses the same lifters all the time and never has issues. Im out of town but im heading back home now when I get there im going to look over everything and see if I can figure it out. Maybe ill take it for a spin and stay close to my house so when it makes the noise hopefully I can get home in time to pull the valve covers and see whats going on.
Are you logging oil pressure?
The lifters get fed first with oil pressure so if you're getting a drop it'll turn up there first.
Running extra oil isn't always the fix for that either, some guys still have issues still.
Oil could be sloshing to the back or becoming aerated, might be time to look at a dedicated pan setup or an accumulator.
Are you logging oil pressure?
The lifters get fed first with oil pressure so if you're getting a drop it'll turn up there first.
Running extra oil isn't always the fix for that either, some guys still have issues still.
Oil could be sloshing to the back or becoming aerated, might be time to look at a dedicated pan setup or an accumulator.
yes, I havent seen any drop in oil pressure. Keep in mind I do have a truck pan. Ive read they are actually pretty decent at preventing oil starvation. Idk if thats true or not though.
Man I dont see anything that sticks out, pulled valved covers spun crank bolt until each set of pushrods were on base circle. Loosened the bolts and re torque and everything gave me between 1 full turn and 1 1/4. Springs all look nice and tight. Even took a small screw driver and checked inside springs and there tight. Trunnion look good. Drained the oil and honestly it looked brand new but im going to go ahead and put new oil with the additive mentioned above. If that doesnt cut it then I guess ill schedule a time with my tuner to take it over there and put it on the dyno to see if it happened on the dyno.
Did a transbrake launch at a redline and didnt notice anything crazy so it must be highway speeds when its happening. I wanted to make a pull on the highway since i changed the oil, about 5.5 quarts came out of it and i put 6 3/4 in it and liqui molly lifter additive but there was alot of cars on the road and the truck gets pretty violent so I didnt wanna take a chance. See everything is normal at normal speeds.
I had a new set of lifters from gm do something like this. I finally got it to do it and not release, tore it apart and the cup part was getting stuck sideways at the bottom of the lifter and there wasnt enough pressure to un stick it. Found several others that felt sticky. Swapped them all out and never another issue. May not be your issue just my 1 time experience.
And you'll need to get it on a dyno and see if its still making power that high. I imagine the rpm isn't a problem though
I had a new set of lifters from gm do something like this. I finally got it to do it and not release, tore it apart and the cup part was getting stuck sideways at the bottom of the lifter and there wasnt enough pressure to un stick it. Found several others that felt sticky. Swapped them all out and never another issue. May not be your issue just my 1 time experience.
And you'll need to get it on a dyno and see if its still making power that high. I imagine the rpm isn't a problem though
im trying to visualize what your saying? So the lifter was actually spinning a bit or you mean it was hanging up as its moves up and down? That interesting maybe thats whats happening. Did you go back with the same lifters? If not which lifters did you use? Its definitely still making power at 7200, it pulls hard all the way through. Im definitely going to get it back on the dyno though. Its a close friend of mine so he won't charge me to use the dyno.
The innards of the lifter. The plunger piece that holds the pushrod tip was getting stuck down in the bore. They were acdelco lifters and were replaced with more acdelcos. Just happened to get a bad batch I guess.
That was in a customers stock truck. In my play cars i have always used ultra power brand from rock auto and never had an issue. They are the cheapest ones on rockauto
The innards of the lifter. The plunger piece that holds the pushrod tip was getting stuck down in the bore. They were acdelco lifters and were replaced with more acdelcos. Just happened to get a bad batch I guess.
That was in a customers stock truck. In my play cars i have always used ultra power brand from rock auto and never had an issue. They are the cheapest ones on rockauto
ah ok I see, thats crazy you buy the cheapest ones and have no problems. I tried to buy decent ones and its giving me hell. Im torn between do I try and change out whatever bad lifter it may be or do I change them all out for a more high performance brand. Was considering putting linked lifters but honestly I don't see where at my power level I should have too. I havent dyno the new engine yet but my old end was 760 wheel shifting at 6800 with a truck cam so im assuming im somewhere close to 800 wheel.
I have found the cheaper parts most of the time are rebranded of other brands. They even share the same part numbers, like the lifters are the same number as mellings. I have gotten cheap cam phasers for Fords that are identical to Ford phasers but the Ford part number has been ground off. It is a gamble, maybe they are culls from the bigger brands or just sold to another company to be rebranded. They have a good warranty though, some times its worth the gamble for us, some times we would rather get it from the OE. But even the OE has bad batches
Edit- again your issue may not be the lifters, but from your description the valvetrain seems suspicious
I have found the cheaper parts most of the time are rebranded of other brands. They even share the same part numbers, like the lifters are the same number as mellings. I have gotten cheap cam phasers for Fords that are identical to Ford phasers but the Ford part number has been ground off. It is a gamble, maybe they are culls from the bigger brands or just sold to another company to be rebranded. They have a good warranty though, some times its worth the gamble for us, some times we would rather get it from the OE. But even the OE has bad batches
Edit- again your issue may not be the lifters, but from your description the valvetrain seems suspicious
I notice that when I looked on the rockauto website, the mellings lifters i have are jb2079 and some of the others have the same number. Honestly it has fo be the lifters. The heads im using are the same heads i had on the old motor and ive never had a problem with them. Everything in the shortblock is brand new and it definitely doesnt sound like bottom end. The only thing new in my valvetrain is the lifters. I had the same 7.375 pushrods in my old motor. My cam is different but my measurements are good so it really all points to the lifters.
Putting a parts list together in case I have to pull the heads. What do yall think about these parts?
#1 Smeding performance gaterman ls/lt link bar lifters
#2 pac 1207x-16
#3 BTR SMALL BORE HEAD GASKET - 3.950" BORE - .055" THICKNESS -
#4 considering changing valves too, should i while im in there? I may not need all these parts but if i do this is the route im considering, open to ideas.
#5 also planning to add full exhaust back on the truck while im at it, the fender exit gets old quick. My plan is 4 inch to the axle with a diesel muffler and turn down or possibly out the side behind the tire.
I'm away on vacation but had some time and wifi so decided to check in on you guys. Was thinking about your situation and the very many hyd and solid lifters that I've set up . Never have I set that much preload, maybe on something completely stock . With your spring pressure I doubt you ate getting pump up but depending on actual cam profile , high rpm and possibly high oil pressure it could happen to a point where something is making contact and causing noise accompanied by a misfire. If you had a set of .050 shorter pushrods that would be a cheap and quick experiment. That would put you at what , about .020 - .030 ish , won't stop pump up but far less of a change if it happens. Just thinking here 🤔
Putting a parts list together in case I have to pull the heads. What do yall think about these parts?
#1 Smeding performance gaterman ls/lt link bar lifters
#2 pac 1207x-16
#3 BTR SMALL BORE HEAD GASKET - 3.950" BORE - .055" THICKNESS -
#4 considering changing valves too, should i while im in there? I may not need all these parts but if i do this is the route im considering, open to ideas.
#5 also planning to add full exhaust back on the truck while im at it, the fender exit gets old quick. My plan is 4 inch to the axle with a diesel muffler and turn down or possibly out the side behind the tire.
The lifters look like good pieces, those or the genuine LS7 lifters ICT Billet sells. (6) Gatorman Hydraulic Roller lifters | Yellow Bullet Forums
I run the BTR .660 drop in springs, been to 7,500+ rpm many times without issue.
Gaskets are good.
If you're looking at valves, I'd just go a step further and look at some TFS heads, I wouldn't spend the money on upgrading valves in factory heads for a boosted application.
I'd still run some sort of cutout if going full exhaust, honestly, I'd just straight pipe it too instead of running a muffler.
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