am_muscl

iTrader: (19)

So a member on here has a set of new Melling stock replacement LS lifters and I'm going to be putting a new 355 set up together n I'd like to replace my old stock lifters with something newer.

First off will they work with the car? Second, are they any better than stock LT1 replacements?

BlackBird87

iTrader: (6)

The lifters are the same. I don't know the quality of the melling one. But I do know you can get brand new ls7 lifters for around 120

myltwon

iTrader: (1)

as for lifters unless you're going with a very radical valvetrain that requires a more advanced lifter than the factory style, an OEM lifter will typically be your cheapest and highest quality choice.

robsquikz28

iTrader: (246)

I had a mellings in my old engine that easily saw 6700 rpm and had over 10k miles on them...I would say they are fine

Black94Z28

iTrader: (12)

Wheres your build thread? i know we took pics when I pulled your engine!

am_muscl

iTrader: (19)

the pics are still on the camera. the build thread will start as soon as I get the shortblock and we can put it in the car!! Tax return check should be deposited tomorrow. s60 and shortblock HERE I COME!!

defaultexistence

iTrader: (11)

Lucky Jerk!
i got audited this last year by the f'ing IRS on some missing paperwork from 08' and a divorce..so i owe em' 6,300 bucks..been paying $107 for about 5 months now and they absorbed my income tax return of $4,000 ...
i so would have moved to a place with a garage and built my motor...

AChotrod

iTrader: (17)

You can have the lifters in my short block, I have a new set of Comp pro mag lifters for my new build. Mine work fine and have 33k on them.

96capricemgr

iTrader: (1)

Originals are fine despite everyone's instance on wasting money to replace them.

AChotrod

iTrader: (17)

Exactly^^^ I got the new ones for free, If I didnt I would reuse the stockers no question.

qc97z

iTrader: (9)

I've got LS7 lifters in mine, they are running just fine. They're a good upgrade and are OEM quality.

96capricemgr

iTrader: (1)

Can you show any documentation that LS7 lifters are an upgrade?

Everyone says it but I have seen ZERO data to support it. IMO this blind assumption leads people to waste $120 or so on a useless "upgrade" that could have been better spent elsewhere.

If you have the money to do it all GREAT but most of us have a budget and I see a LOT of folks "save" $200 in the most critical place only to waste much more on crap like this.

qc97z

iTrader: (9)

Can you show that LS7 lifters AREN'T an upgrade?
Let me ask you this: if you were going to build a big, beefy motor to run lots of boost...would you use stock LT1 lifters, or would you get an aftermarket lifter?
In my eyes, the LS7 lifters ARE an upgrade FOR PEOPLE ON A BUDGET. They can be had cheaper than aftermarket lifters, and are more than likely an improved design over the stock LT1 unit. This is why the LS motor is a completely different design...it was ALL reengineered.

96capricemgr

iTrader: (1)

So now we blindly assume things are upgrades without any data to back it up?

Sort of like how everyone assumes the 5 pinion planetary for the tranny is an upgrade but they don't care to find out it is CHEAPER to build because the 4-pinions were forged and the 5-pinion powdered metal. They also ignore the 500rpm lower rating it has.

GM changes a lot of things for a lot of reasons, ultimate performance not being at the top of their list.

If you watch what I have said I am NOT saying they could not be an upgrade. I am saying that absent any data to support them being an upgrade people like you should stop BLINDLY pushing them on folks who have no reason to buy lifters atall.

AChotrod

iTrader: (17)

Jason you have free lifters in great working order, no worries or need to spend more money

WS Sick

I would like to see some data that says they are better as well, the first sentence of Caprice's post is the key sentence.

AChotrod

iTrader: (17)

how many failures of stock lifters do you see?

am_muscl

iTrader: (19)

mike you put my mind at ease, now I'm gonna sit back n watch the debate haha

qc97z

iTrader: (9)

So you blindly assume it's NOT an upgrade without data to back you up?

GM may not have ultimate performance at the top of their list, but they have the most important things in mind: Durability, dependability, and longevity. I know how engineering works at large corporations..because I am one of them.

I'm not pushing anything on anyone. I only stated that I happen to have LS7 lifters in my motor with no issues and it supports my setup. And it's reliably making a lot more power than you are. 'Nuff said.

I'd like to see some data that says they aren't better.

This is a debate that could go on and on. At some point, someone will eventually run some sort of test to prove one way or the other. But who has the equipment, money, and time to run a reliable scientific experiment? Probably none of us.
96Caprice's belief is that LS7 lifters are no better than stock LT1 lifters. I believe they are. Neither of us have proof. Logically, if you built a motor entirely of aftermarket high-performance everything (spare the block), you wouldn't use (or re-use) stock lifters.

wrd1972

iTrader: (12)

My 2 cents on this.

GM had a reason to create a new lifter for the LSx and we can only speculate what the reason is. Because the LTx and the LSx lifters have different part numbers, they can NOT be considered the same part. GM intended to control and track the stock of the two different lifters in question using the different part numbers. If it were simply a situation where a new manufacturer was creating the new LSx lifter for GM based off of the old LTx spec, you would still likely see a new part number again for inventory control.

When I rebuilt my motor, I decide to replace the 60K old lifters with brand new LS7 lifters that sold for $110 shipped. I then sold the used lifters to someone for around $75.00 IIRC. So for $35 I have piece of mind knowing the lifters are new.

I closely compared the LT1 lifter to the LS7 lifter even going as far as taking them apart and analyzing the internal parts. I only found one thing obviously different between the two lifters.

The "pushrod cup" on the LS7 lifter sat about .020" deeper in the body compared to the LT1 lifter. Another way of saying it, the machined inside diameter slot that is used to capture the retainer clip, was machined .020" deeper in the body. The overall size of the the LT1 and the LS7 lifter bodies measured the exact same. I completely believe that this change was intentional (reason can be debated) and not a result of acceptable machining tolerances.

I will speculate that this was done to make the LS7 lifter more robust as to reduce the chance of breakage at the end of the body where the pushrod cup and the retainer slot are located. I will further speculate that GM expected the LS7 lifter to endure more abuse from the higher performing LS platform so beefing it up would not hurt. I saw no evidence of anything else different with the lifter roller or other internal parts.

So IMO, if the LS7 lifter was actually redesigned by GM to be more durable compared to the LT1 lifter, IMO that would make it an upgrade to some likely little degree.

With that said, I agree that most folks would be fine reusing their existing lifters assuming they show no obvious signs, they fall within accepatble GM specs by measuring them with a micrometer and the rollers spin freely. I really doubt that the LS7 lifter performs any better than the LT1 lifter based on my analysis of the two lifters.