dirtbag

iTrader: (2)

I have collapsed lifters in 3 different locations on 3 separate times now with the 224R cam. Preload has been set correctly (tq'ed to 22lbs), checked my pushrod length with an adjustable PR length checker, used LS7 lifters, tried a high volume ported oil pump (oil pressure has always been fine), checked lifter bored for marring (fine), even tried bigger springs (using .660 scoggin dickey double springs), and even checked my lifter trays for fitment.... Lifters stay tight in the trays. Why do I keep collapsing lifters? Is it the XER lobes causing me these headaches? I'm really getting sick of pouring all of this money into this POS if it's gonna keep happening. Any suggestions would be appreciated. Thanks guys.

FYI I have gone through 3 cams and 3 mushroomed lifters in 3500 miles.

Che70velle

iTrader: (6)

Has this happened every time with ls7 lifters? If so, it's time to upgrade to better lifters.

StangBanger317

I have a 228R cam with no problems. It must be your lifters. Although there is no reason LS7 lifters should be failing with that setup

soundengineer

iTrader: (16)

sounds more like a valvetrain control issue...
thousands of 224 cams on XER lobes with no issues like that....
lots of cams on more agressive lobes with no issues...

need more data

What rockers? stock or aftermarket? and what ratio if aftermarket.
224r.. from who.. there are several 22R cams now.
What retainers, what install height on the springs, with or without shims
have you verified that the springs are actually good?
Dimater of the middle of the inner spring? and size of valve guide?
were they Chamfered before install or just stuck on there
What pushrods? hardened or stock? and what length and what diameter
how much preload on the lifters and how did you measure the preload?(easier question would be from zero lash with the lifter on the base circle...how many turns till 22ft lbs of torque on the bolt.)
What Heads? milled or unmilled?

Lots of things can contribute to a lifter collapse... including something as simple as friction from an improperly installed or improperly clearanced part

and I'm not saying you are necessarily doing anything incorrect... but perhaps theres something small you have missed somewhere...so we need more details.

dirtbag

iTrader: (2)

I guess I should have explained the specs more in depth in the OP.

What rockers? stock or aftermarket? and what ratio if aftermarket.

Stock LS1 Rockers

224r.. from who.. there are several 22R cams now.

Texas Speed and Performance 224R .581/.581 224/224 114lsa

What retainers, what install height on the springs, with or without shims
have you verified that the springs are actually good?

PRC .650 lift double spring kit - titanium retainers, viton valve seals, no shims, springs were brand new out of the box so I did not verify they were good, I just installed them as is out of the box.

Here are the specs off of Tick's website:

Install Height: 1.800"
Closed Spring Pressure: 145lbs @ 1.800"
Open Spring Pressure: 450lbs @ 1.150"
Maximum Spring Lift: .650"
Coil Bind 1.080"
Spring Rate: 469lbs/in

Diameter of the middle of the inner spring? and size of valve guide?

The diameter of middle of inner spring is not supplied, and I do not have the size of the valve guide available... I would assume the stock size?

Here is the link to the exact product - http://www.tickperformance.com/preci...le-spring-kit/

were they Chamfered before install or just stuck on there

I did not install the valve guides - the previous time I have the motor built the engine builder installed them for me. I do not know if they were chamfered or not. I would assume they were installed correctly, though.

What pushrods? hardened or stock? and what length and what diameter

7.400" Chromoly Hardened Pushrods from Texas Speed and Performance, 5/16" diameter.

how much preload on the lifters and how did you measure the preload?(easier question would be from zero lash with the lifter on the base circle...how many turns till 22ft lbs of torque on the bolt.)

What Heads? milled or unmilled?

Late 853 LS1 Heads w/o the notch
Heads are milled 0.0075" and block deck is milled 0.0075" for a total of 0.015" of material taken off.
Head gasket was changed to a 0.040" Cometic MLS Head Gasket (stock is 0.052" compressed.... thus 0.012" thinner).
Cam base circle is 0.050" smaller than the stock cam (via cam card... I can post of pic of it if requested).
Stock PR length is 7.400", so 7.400+0.050-0.012-0.015=7.423" required @ stock 0.080" preload... I would like 0.065" preload so thats 7.423-0.015=7.408" PR length required.
I bought an adjustable PR length checker to be sure and 7.400" was right on the money for .060" preload.


I started the tear down today to initially confirm my suspicions - a collapsed lifter at cylinder #3 exhaust valve. See the excessive play in the rocker and valve stem. I would guess around 0.125-0.250" roughly.



I then took out the pushrod and it was straight as an arrow. Next, removed a rocker from a few other locations as a control point for lifter compression. I could push down on the pushrod and the lifter would compress - even on the problem lifter. The lower pushrod height is probably becuase of a flat spot on the lifter roller . Bye bye cam lobe. This will be an expensive fix yet again.

So then the brainstorming began... what could be causing this issue?

1. Lifter is turning in bore due to a busted lifter tray. I did not replace these 1k miles ago while fixing this same problem as they were NOT wore at all and held the lifters in quite well. They are the LS1 style trays and not the LS2 revised versions.

2. Poor oiling due to a pinched O-ring at pickup tube. When doing the repair last time I took extra care to make sure this was 100% correct. I dropped the K-member and removed the oil pan first, then removed pickup and cleaned everything extremely well, including the pickup tube so no material was blocking the screen. Then, using a BLUE o-ring that came with my new GM High Volume Oil Pump I oiled the o-ring and put it on the pickup tube first. The tube went in pretty easy with a little "pop" once in and the pickup tube had enough grab to stay in there while I put in the bolt. Re-assembled everything and good to go. My oil pressure after using Castrol GTX dino oil 5w30 would be 50psi cold and 20-25psi hot (depending on weather... 70-80 degrees out and it would be 25psi, 100 degrees out it would be 20psi). This whole pickup tube issue worries me. I switched to 20w50 oil and the hot pressure was 35psi idle and cold was 60psi idle.

3. Incorrect pushrod length. Maybe I have the preload set incorrectly? Do you thing that I have too much or too little preload causing valve float at high RPM's - thus the roller on lifter is jumping a lobe and flat spotting?

Sorry for the long post, this whole ordeal is extremely frustrating and I would like to know the root cause for these repeat lifter failures.

Sales@Tick

iTrader: (3)

Interesting.

soundengineer

iTrader: (16)

with the adjustable pushrod.. did you measure 7.4 to zero lash?
or did you measure a lesser value or greater value? (for .080 preload you should have measured 7.320 at zero lash... for .060 preload you should have measured 7.340 at zero lash)

Math sounds correct, but lets be sure you measured correctly as well...

dirtbag

iTrader: (2)

I followed these instructions as the supplied instructions from Comp Cams were a bit confusing.

https://ls1tech.com/forums/showpost.php?p=8290983&postcount=9

I will test for correct pushrod length at ALL locations this time around to see if there is any variation in PR length requirement and take the average of the intakes and average for exhaust PR's and report back with the results.

Thank you again for the quick reponse.

soundengineer

iTrader: (16)

take a picture of the instructions from your comp pushrod length checker and post please....
lets make sure you did it correctly per their instructions.
also, I always physically measure the checker.. I dont count turns as Humans are inaccurate at counting turns usually.

vettenuts

iTrader: (4)

Couple of thoughts to throw into the mix. Not sure on your installed height, but the stock heads I have worked with usually set up with an installed height less than 1.800" so your seat value "may" be north of 145 lb. Your open spring force with that lift cam may be approximately 425 lb. Your pushrods may be flexing quite a bit and hammering the lifters due to these higher spring force values. (Every part in the valve train flexes but the pushrods can act as pole vaults with too much force and no increase in stiffness).

Don't overlook pushrod diameter as well as length as OD is the only real way to increase the stiffness of the pushrods. You may want to consider the Manton 11/32" pushrods when you sort this out as a replacement since they will usually fit stock heads. If the heads come off you could also open the pushrod holes for 3/8" OD pushrods.

PREDATOR-Z

Very valid point

soundengineer

iTrader: (16)

well thought out, but you are forgetting the fact that there are thousands of this exact cam in LS1's all over the world now.....many of which are on Stock Heads, and with 5/16 pushrods.....

there would be a lot more issues exactly like this if the problem was as simple as the pushrods

XER lobes are considered agressive, but they arent so agressive that they would cause this issue on such a small lift cam...
try the lingenfelter lobes....WAY more agressive than XER and none have that issue with smaller and medium lift cams

and we havent even gotten into the issues of running extreme lift and fast ramp rates on big durations in a serious race cam


once again...thousands of this cam and head combo out on the road with no issues....

dirtbag

iTrader: (2)

Time for an update -

I have been super busy with work and haven't had a ton of time to tinker the past few days, but have made some progress on the pushrod length issue. First off, a few posts up I have some incorrect information. There was a spare stock LS1 pushrod sitting around in my toolbox so I figured measuring it with a digital caliper would confirm the length - it ended up being 7.385" NOT 7.400". So, the math above is actually off by .015".

Progress wise, I removed all spark plugs and wires, accessories, and the lid assembly, serpentine belt and tensioner to get more room to turn the motor over and get one of the cylinders to where both valves were closed. The easiest one for me to access happened to be cylinder #2 on the passenger side. After removing the rocker on the exhaust valve and depressing the lifter by hand with the pushrod to bleed any excess oil out, I did a check measurement of the pushrod currently being used - 7.400" - good.

Next, I set the adjustable pushrod length checker a few threads shorter than the current pushrod as a starting point. After a lot of trial and error to get zero lash while the rocker was "snugged up", I found the perfect sized pushrod and measured with a digital caliper the spacing between the two parts of the checker. Since the checker is 6.800" long, I ended up with these results:

- Cylinder #2 Exhaust Valve = 0.4715 + 6.800 = 7.2715" at zero lash
- Adding in a desired 0.065" of preload, we end up with a 7.3365" pushrod.
- If we use a 7.350" pushrod, we would have 0.0785" preload.
- If we use a 7.325" pushrod, we would have 0.0535" preload



- Cylinder #2 Intake Valve = 0.4615 + 6.800 = 7.2615" at zero lash
- Adding in a desired 0.065" of preload, we end up with a 7.3265" pushrod.
- If we use a 7.350" pushrod, we would have 0.0885" preload.
- If we use a 7.325" pushrod, we would have 0.0635" preload



To the post above - good info, in fact you have sold me on a set of Manton 3/8" pushrods since the heads will be off anyway and can go to the machine shop. I'm also thinking of getting the heads milled about 0.015" more so the pushrods will need to be rechecked later.

Well it looks like we have solved the issue to why I keep wasting LS7 lifters! I was running equivalent to 0.1385" of preload. Since LS7 lifters only have an operating range of 0.000-0.100" preload, they were like solid lifters and I bet the valves were also not shutting completely, thus potentially down on power.

I feel pretty much like I shot myself in the foot by not verifying the pushrod measurements during the last build.

Thoughts?

Edit: One thing I forgot to add is if I'm really going to have to replace the cam again I'm strongly considering the Tick Performance Polluter V2. These guys are by far my favorite sponsor to deal with and always have plenty of good knowledge to spare as well as great customer service. I feel pretty confidant they make a killer cam package. Anyone try this cam yet? Haven't seen any dyno results from it yet on the board.

vettenuts

iTrader: (4)

I am running the AFR heads with the 8019 valve springs. I removed the 5/16" pushrods and installed a set of 3/8" double taper pushrods. The upper end of the dyno was much smoother and didnt' roll over as much as the smaller pushrods. The increased stiffness was adding stability. There was also an increase of 6 hp. I have exchanged some thoughts on this with Erik Koenig who has seen similar responses to stiffer pushrods on his dyno. IMO there is no down side to using the stiffer pushrods.

There have also been quite a few guys having issues with the new LS7 lifters and I still think that pushrods may be a contributor.

One thought. You are measuring between the flats of the pushrod, or "overall length". Note that depending on the company you buy pushrods from, they may use "gauge length" for pushrod size. The difference is "gauge length" is approximately 0.017" longer. Trend, for example, uses gauge length and makes the pushrods for a lot of companies including Comp.

dirtbag

iTrader: (2)

Completely agree with you. Looking at my dyno sheet, you can see a slight drop off in power associated with some shakiness in the graph from 6100-6400. Might be the pushrods giving (typically one would think this is valve float).

They were measured from "End to End" as in from top of ball end to bottom of ball end. By gauge length, do you mean from edge of ball end (where the fillet begins on the main tube) to edge? It is a Comp Cams Pushrod Length Checker.

vettenuts

iTrader: (4)

As I recall, the gauge length is measured from a point on the ball where it is 0.140" diameter, so direct measurement is hard to do. The overall length is somewhat inaccurate as well because the oil hole diameter will determine where the flat surface of the end of the pushrod is relative to the guage length position. The number that is typically used to convert between the two is 0.015" - 0.017".

Hope this makes sense.

RonSSNova

iTrader: (3)

If your pushrod length puts you somewhere in the allowable plunger travel in the lifter, I doubt it is your problem.

Installing those heavy springs w/o measuring installed height is suspicious. They really need to be set to spec. If installed to short, you could be into coil bind. Maybe just barely, enoug to not bend the pushrod, but enough to stack the whole mess up eventually causing damage from loss of valve control.

Also confused on your term collapsed lifter. If the roller wheel is being destroyed and cam chewed up, that isn't collapsing. I am really not sure how a lifter would collapse and stay collapsed.

Because there are so many of these sized cams working perfectly fine, I think when you find the issue, it will be something simple.

Let us know what the other end of the lifter looks like.

Ron

soundengineer

iTrader: (16)

he said he's over .130
LS7 lifters are a max travel of .120

Highly doubtful he's in coil bind... he has a long distance to go before that happens... its a .588 lift cam with a .660 spring and no shims


too much preload = lifter compressed all the way = collapsed Lifter (meaning its not opening at all because of the preload)

when you compress a lifter, and basically turn it into a solid lifter... you will destroy the wheel, which in turn will destroy the cam...
if you get a solid billet cam, it will survive a little better, but eventually its still going to destroy the cam.


[QUOTE=RonSSNova;16762249]Because there are so many of these sized cams working perfectly fine, I think when you find the issue, it will be something simple.[quote]

it looks like it is something simple... he just measured and found out he has the wrong size pushrod, which equates to too much preload

I agree... it would be nice to see exactly what the end result is.. good education for people who dont understand what can happen if you make a mistake with measurements on install.

farmington

iTrader: (14)

way too much spring for that cam anyway. Needs a beehive. I never took the heads off of my car when I put in my 224r and used Comp 918 springs and factory retainers. They told me at Texas Speed to just use 7.400 pushrods which work perfect. Now he has taken .027 in length out with the milling and gaskets. Hmmmmmm. Should probably take spring off over bad lifter to look for signs of coil bind (shiny spots)

dirtbag

iTrader: (2)

The heads are going to machine shop when they come off for an overall inspection, clean up, and bronze valve guides if needed. Didn't even think about cool bind being an issue, thanks for the input.

0.008"-0.018" over the max travel depending on the location is enough at high RPMs to kill a lifter .

Worst part about this it is a simple mistake. Most people (like I did) think you can just buy a cam package from your favorite sponsor and install it in a weekend... A correctly built motor will not happen in this time frame.

If (and by if, I mean 99.9% sure) the cam is trashed, i'm exploring the idea of replacing the 224R with a Polluter V2. Still need to run the numbers to see if it will fit and do a PTV test with the current cam first. The motor has wiseco forged aluminium flattop pistons with -2cc valve reliefs so it SHOULD be fine. A 239/244 .63x/.59x cam is pretty huge though so we will see.

Regarding tear down pics of damaged components, I should get around to starting on Sunday and finishing by the end of next week. I'm only able to tinker a few hours at a time by myself it can take a while sometimes .

Called Manton today and they will be hooking me up with some 11/32" custom length pushrods. Those guys rock and have some pretty decent prices at $10/custom pushrod to boot.