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Fresh 355 build. Very mild budget build. Forged pistons, and all ARP hardware in the bottom end. Stock crank and rods. Bottom end was built by a good local shop ( I know things happen).
Anyway, spun a rod bearing in the old engine. Bad enough to destroy the crank. Got another short block and had it rebuilt as mentioned. Old engine had metal all throughout. I cleaned the heads really good and has a new oil pump and pickup.
I'v put about a hundred miles on the new engine. Started off well. I' running a cc306, with 918'' and stock ported heads, gmpp 1.6's, hardened push rods. (Note) I have not really revved the engine out yet. Just a few medium throttle pulls just to see how it was running. The car feels like it has a huge lack of power (compared to my stock short block, same heads/cam). Idles fine and no weird noise. But is lacking power and I'm starting to hear a rattling noise. The noise sounds like vslvetrain but I'm having troube pin pointing it. Im leaning towards some bad lifters considering I reused the ones from the old engine. It was an after thought and didn't really thonk about the metal shavings possibly all through the lifters.
I pull the valve covers tonight and started inspecting. Then pulled the intake and rockers, push rods, and lifters. Visually they look ok. Rollers are ok. Is it possible for some lifters to hold enough pressure to idle fine and drive under light load but under a heavier load/more rpm they bleed out?
Im leaning towards the lifters but wanted some opinions. Also what's' a good lifter to shoot for. I read about the ls7 lifters bUT read some bad reviews
That's your problem right there your old engine spun the bearings and the trash circulated throughout your old engine. You should have replaced the lifters at the time of your new build, the problem you may have now is that any metal that was in those lifters has been circulated through your new engine which could end up causing bearing issues in your new engine.
Unfortunately, I've accepted that it was a rookie move. I'm hoping I can throw some new lifters in it and have everything else be alright. The oil looks clean and I don't see metal in the heads or valley. Maybe I'll have gotten lucky.
Idles fine and no weird noise. But is lacking power and I'm starting to hear a rattling noise. The noise sounds like vslvetrain but I'm having troube pin pointing it. Im leaning towards some bad lifters considering I reused the ones from the old engine. It was an after thought and didn't really thonk about the metal shavings possibly all through the lifters.
Is it possible for some lifters to hold enough pressure to idle fine and drive under light load but under a heavier load/more rpm they bleed out?
Im leaning towards the lifters but wanted some opinions. Also what's' a good lifter to shoot for. I read about the ls7 lifters bUT read some bad reviews
"rattling noise" is not what I would normally refer as coming from valve train/lifter...more a "tick or tapping" sound.
Generally a weak lifter will make a taping sound (that is actually the PR bouncing on it and RR at idle (lower oil pressure) but quiet down as the RPM increases pumping up the lifter vs a lifter bleeding down at high RPM
You could push the plunger in on each lifter and see if one, or more, collapse considerably easier than others
You can even take each one apart and inspect and clean (if there is in fact metal shavings in them from previous engine)
Check your oil/filter for any sparkles that may have migrated from re-used lifters. If there is evidence than pop a few rod/main bearings and check for scoring from debris
you should also rotate motor and look at the cyl walls while the heads/intake is off for any piston wall scoring if everything else is checking out
lifters, I now have Comp 850's. Been in the 383 since new about 35k mi now
If I had to get a set today I would consider Lunatti. Never used them but I have their springs which I feel are very well made
Based on several negative comments on the LSx ones, I would not use them
I wont be able to pull the pan without pulling the engine out of the car. The heads are still bolted on. I'll check the filter.
As far as the comp 850's. They seem to have mixed reviews. But also seem to be the best bang for the buck lifter. I don' want to spend a fortune but I need something that will handle the lift and rpm of the cc306.
Hopefully I can order some lifters this coming week and get it back together with no noise. (Fingers crossed). I'e heard rod knock before in multiple engines. This noise sounded very strange to me. Only happened on a 1/2 -3/4 throttle pull. Normal driving and idle was perfect.
I'e heard rod knock before in multiple engines. This noise sounded very strange to me. Only happened on a 1/2 -3/4 throttle pull. Normal driving and idle was perfect.
I had literally the exact symptoms as you. I thought it was a light rod knock. Sounded heavier than a lifter tick, lighter than a typical rod. Only happened at speed, and under moderate load. Accelerating from 50-60 on the interstate, part throttle. Around town I never heard it. Before you go crazy, buy a cheapo borescope from Harbor Freight, or rent one, and carefully examine each lobe on the cam. You can do this in-car quite easily once the intake is off.
For me, it was a bad cam. The divot you see here is what I suspect caused the noise. Why the sound only happened on the interstate and under moderate load is something for minds much sharper than mine to sort out.
I cut open my oil fiter and saw metal flake, which caused me to pull the engine and tear it down. Turns out the metal was from the rollers on the Crower lifters. I had all 16 delaminate on the roller-surface and that's what took out the cam. I will be running the GMPP 17120735 LT1 specific lifters.
I wasn't planning on getting the ls7 lifters but after some more research I figured I'd give them a shot. Ordered them yesterday and got them this morning. From the chevy dealer next door. I measured the cup depth and found .1 of a difference. I will definitely re check my push rod length. I got them for $177 with tax. I'll put them in tonight and see how it goes.
I've had the LS7's in my car for a year. I need to pop the intake and check rollers/lobes. I've heard bad things, but I heard crap about Comp R's as well and when I had those (the new style/thinner retainer ring) I never had any problems with retainer rings popping off.
Just make sure there is absolutely zero pitting on your lobes or you'll have the same issue all over again and it may end up being a very expensive fix.
How do you guys go about bleeding the lifters? I let them soak for about 10-12hrs or so. Will they pump up after startup? Looks like they are bleeding out after I installed them last night. I still have the intake off at the moment.
Also, does it matter to which direction the oil feed holes face? I read to the rear?
I've never worried about which direction where the holes face. Never heard that being anything of concern. Your lifters won't pump up unless there is oil pressure. Soaking them is fine, but when you adjust them you must understand the only resistance you may feel when finding zero lash is the spring pressure to keep the lifter cup on place, which isn't much. Best method is using an up/down motion on the push rod instead of a twisting motion to find zero lash. Far more consistent. Not to insult your intelligence, but you do know the how to's of making sure each valve is truly closed before adjusting?
No insults taken here. lol. Yes I do understand. Each lifter was fully seated at the bottom before adjustment was made and as soon as it made contact is where I locked them down.
I find with the poly locks just tightening those with fingers as I check PR for no up down movement. Then pre-load lash to the turn you want. I go 3/4 turn
I think I got the adjustment pretty darn close. I just noticed as I was rotating the engine over for the other lifters that as the lifter cam up the push rod sank in the lifter. I'll finish throwing it together tonight and start it up. Probably let it run and warm up, then recheck the rockers
I just noticed as I was rotating the engine over for the other lifters that as the lifter cam up the push rod sank in the lifter.
There's no way the spring pressure from the lifter can overcome your valve spring pressures, which is why the push rods are sinking into the lifter. When you feel you have valves adjusted and start the engine there'll be a hell of a clatter for a few seconds before the lifters can pump up. Listen closely to your valvetrain after about ten seconds to see if there are any noises that stand out. Valvetrain should sound much like a sewing machine without any one part making more noise than the other. Everything must be uniform.
03-02-2018, 08:26 PM
New 355, noise, possibly lifters? 
