Zac28

UPDATE POST HERE ​​https://ls1tech.com/forums/generatio...l#post20472871
Video of noise after bent pushrod issue here https://ls1tech.com/forums/generatio...l#post20472555

Trying to get an idea of what caused a bunch of bent pushrods. Since the swap it has only been idled and taken around the block enough to burp coolant and trans. Its never seen past 3k rpms, if even that. I will also mention that it turned over with no issues while on the stand.

After the new top end build I was getting some loud valve train noise on passenger side. I pulled 3 pushrods that had no pressure on them to find they were all bent. I havent turned the motor over to pull the rest of the pushrods but I'm guessing they are all the same. My initial though was I math'ed wrong and got too long pushrods. After rechecking length with pushrod checker I came up with the same numbers as before. With everything measured in overall length I got @ zero lash 7.380 + .060 preload = 7.440. I'm running pushrods with an overall length of 7.435. So my next thought is PTV, which I didnt measure because to me seems like to be just a simple LS2 with a cam, so I wasnt too worried.....and maybe I'm paying for that now

Engine is a stock bottom end LQ9, TBSS intake, 92mm TB with 799 heads, cammotion dual springs/pushrods, Morel 7717, stock MLS gasket, RPM Max rockers (which are stock arms with trunnion upgrade) and custom cam (216/224 .604/.604 114 LSA -8.0 overlap). Heads were purchased locally (sort of) from a guy who works at a machine shop. He said they were milled .020 but after some measurements it appears thats not the case. The short version of that story is measuring from the valve cover to the deck they averaged 4.751 and factory (from what I've always been told/seen) is 4.750. See my other thread about those with pics here https://ls1tech.com/forums/generatio...ce-height.html. Based on those measurements I assumed the guy lied and they had only been resurfaced enough to clean the gasket material.

So what do you guys think…if the heads really were milled .020 and I was running that cam with stock gasket, would I be running into PTV issues, or have others done more "aggressive" cams with the same setup and no issues?
I cant see in the cylinder to check for any piston/valve impact yet, new borescope should be here tomorrow. Until then I'm just scratching my head. When the rest of America wakes up I'll reach out to my cam guy and see his thoughts.

Shtstr

Could be a list of different things that caused this.
from the Morel lifters that have really bad reviews to a set of valve springs that have a high seat pressure. Providing you didn't use thick wall chrome molly push rods.
as std thickness push rods would bend under the higher spring pressure load.

Zac28

The morels having really bad reviews is news to me.
The pushrods and springs are from cam motion. Rods are 5/16 chrome moly .080 wall and came as a kit with the springs. I'd be surprised that they'd sell incompatible components but I've been surprised before.

Che70velle

iTrader: (6)

You list Cammotion dual springs. Do you know the part number for the spring package? Install heights? What retainers and locks? Sounds like coil bind to me.

Zac28

VSK142201 is the part number for the springs kit.... springs, locks, seals and seats. 1.780 is advertised installed height. All was purchased with the cam as a kit.

Zac28

The coil bind comment got me thinking so I did some math - bind is listed as 1.070. Installed height listed as 1.780...so 1.070-1.780=.710 - .080 for bind gap and I "should" be safe to run .630 lift. Does this sound right? Sounds like I'll need to verify actual installed height.

Update -- Got to check during lunch and the installed height is spot on so if my math checks out then I shouldnt have a binding issue. That leads me back to PTV clearance but again I feel like theres others running setups with more potential for contact issues.

TrendSetter

installed height should be measured, i wouldnt go by the spec in the catalog for that.
if it was shimmed up a bunch to narrow that down it would have a lot of spring pressure which could be a problem.
did you assemble the heads or did you buy them done? the parts could have been mixed and matched. different retainers can have an effect on coil bind and seat pressure.

Zac28

During lunch I got to check installed height and its spot on with advertised. I bought the heads with stock valves/springs but I am the one who put the dual spring kit in.

TrendSetter

are you able to check seat and open pressure?

Zac28

I maybe able to find one but off hand no.

I just spoke with the guy who spec'd my cam and he says he's never had and issue with these pushrods and surprised they bent at all. He said if anything he figured they would have broke. He's thinking its something internal binding and I'm leaning towards that more and more. I am borrowing a bore scope today to get a peak inside but I'm 99% sure the heads are coming back off no matter what.

LLLosingit

iTrader: (4)

Was the cam degreed?

Zac28

Nope. Obviously I'm far from an expert, but I have never heard of a reputable LS cam grinder's centerline being off enough to cause an interference issue, especially on a mild build like mine. If it was off that much I would think it would be a tooth off, or close to it, which would be pretty noticeable. This motor was turned over by hand quite a bit with heads on and off. I never had any problems turning it over and I checked the dots a few times, they always lined back up at TDC.

Having said that, if it were off I guess degreeing it would have revealed it, and if thats my case, it would have saved me time and cash. Maybe I should look into buying the tools needed for it.

Jake Wade

Have you tried seeing how many turns on the rocker bolt it takes from zero lash to torque spec? Pretty sure it’s 22 lbs ft.
I don’t understand why you need pushrods that long. Stock LQ9 with OEM 799’s and GM lifters typically require a 7.375 pushrod.
From what I have read, the Morels do have a shorter cup height of around .025 but, require a little less preload, typically .040-.050 which is basically a wash. I would have thought around a 7.400 pushrod would be ideal.

Zac28

I torqued them to 22 ft lb. I did not count how many turns from 0 lash. I have heard people saying that you have to turn it half to full turn from 0 lash but I dont understand how thats a thing if you are using a torque wrench. Once the rocker is fully compressed on the girdle turning the bolt any more is not making rocker go down any farther, i.e. change the distance between rocker and lifter. Yes I know you have to have the rocker as far down as it will go to measure correctly but to continue turning the bolt is only stretching it or putting more pressure on it. Its not goin to change the distance between the rocker and lifter. Hopefully I explained that correctly...lol

Jake Wade

I am just trying to get a base line on how much preload you are putting on the lifter. Torquing to 22 lbs ft guarantees all the preload is in.

One complete turn from zero lash equals .078 at the lifter.

Shtstr

If the push rods are correct for the intended purpose and the springs aren't coil binding then the only thing left is the lifters.
Yes the Morel lifters have hi failure rates here in Australia and has been shown on many different build platforms here..

grinder11

iTrader: (1)

OP should invest in a decent, 1.000" travel dial indicator and suitable mount, and check how much lift you actually have. I ordered a custom cam from Futral/Cammotion a few years back. I wanted lower lift than spec'd on their off the shelf cam. I wanted .605"-.610" lift on both I. and E.. Fortunately for me, I worked as a Tool & Diemaker for many years, and decided to check the lift on a surface plate, using gage blocks and a dial indicator, before installing it. My lift worked out to be .650" I., and .640" E.!!! Back it went. Wasn't Futrals fault, but Cammotion's. All turned out well, but it never hurts to double check. What is puzzling to me is it turned over easily on the stand/bench!! Oil pressure in a running engine in this instance could only change one thing in the valvetrain, and that's the lifter cup position. You have to pull the heads, and check for bent valves. Check the piston reliefs for marks. Also, even though you may not be in coil bind on the valve springs, Che70velle made a good point on coil bind and/or locks/retainers/keepers. You obviously have interference somewhere. Maybe the retainers are hitting guides/seals, or??? Best of luck to you.......

Che70velle

iTrader: (6)

A 5/16 .080 wall pushrod isn’t going to bend from driving around the block at low rpm from too much spring. I don’t possibly see how the lifters could bend a pushrod either…maybe I’m wrong. Only time I’ve ever seen a pushrod bend was from either interference in the valvetrain somewhere, or at high rpm with a pushrod that was too small diameter. Your not running a lot of valvespring here, at least not enough to bend a pushrod at low rpm. I still say there is interference somewhere. Check PTV and make sure cam is installed correctly. Wrong installation or a cam that’s cut wrong, can cause too little PTV.

Zac28

Thanks for all the advice. I have a few decent dial indicators and can check the lift at the rockers to make sure its not more than its supposed to be. Last night I borrowed my brothers bore scope and didn't see anything obvious. It was hard to see and I have what I hope is a better scope coming today. Maybe it will show more but I'm pretty much planning on pulling the heads at this point after I do a compression check.

LilJayV10

iTrader: (39)

What timing chain/gear set did you use?