jclark10

iTrader: (1)

I figured I would post this and maybe someone could help me identify the cause. I have a 2017 Camaro that I put a TSP CNC'ed heads and cam (228/236 114-LSA .635/.635), Johnson 2116 lifters, thicker TSP pushrods, PAC dual springs, kooks headers and green cats, C8 LT2 intake manifold, and rotofab intake on.

I've put about 10-20k on it over the last year, did a 7.44@100 in the 1/8 then got a #7 misfire right after the run, limped it home and now this:




I don't think I will buy another Texas Speed product after this. I now see on there website that there is a disclaimer that supposedly GM LT1 cylinder head valve seats are known to "drop out" (whatever that means? not sure if it means they literally fall out or what) and that you should purchase their aftermarket casting instead of porting your stock heads like I did. Anyway, I am almost positive this warning and disclaimer was not there when I bought my heads. I know no one mentioned anything about it, they only mention about what can they sell. When I installed it, the TSP guy guessed on the pushrod length and I bought a checker to see if they were going to work once I received my new ported and milled heads. I remember them being a little too short when I was checking for lash at the rocker arm tips, but TSP said it was probably ok and they actually run less preload on their Johnson lifters than what they recommend. I was excited and trying to finish and I said ok and put it back together.

I think having the extra lash along with me revving it way too high (sometimes it would hit over 7300 rpms before the fuel would cut) and having .635in of lift along with a extremely aggressive ramp (because TSP likes to advertise how much HP their cams make and not how reliable they are) all contributed to float and bounce and pounded on the seat I guess until they burned through and the #7 cracked and fell into the cylinder. I also found #5 exhaust valve I think was bent as it was a little harder to remove.

Now I got to figure out how to pick up the pieces and clean up this mess, maybe just buy aftermarket casting (definatley not from TSP), maybe pull the whole motor and do a stroker, or what. Anyone ever see any failure like this?

Thanks

FFDP

iTrader: (2)

Slap the stock heads back on and run it.

Never personally seen that specific issue but seen it happen before on forums.

timharber

If its only one seat, just get it fixed and move on. How's your tune?

Tim

ZO6Ted

This happened to Choda, a member on here on his Camaro. It is becoming a known issue unfortunately. Choda's Camaro was north of 800 and turbo'd. Everyone on Camaro 6 forum is now recommending upgraded seats and valves on high hp rides. I just saw the Tsp disclaimer 2-3 months ago for the 1st time. I don't believe it's their fault actually but a problem with the LT1 factory castings under very hard use. I have only heard of this with LT1's not LT4's but it is for sure an issue now. Not sure about 5.3 heads.

jclark10

iTrader: (1)

So its all the seats, except #8, but all the seats are chipping. And these are my stock heads I got ported by TSP, so I have to either buy new ones or fix these.

I was just a pretty small cam and 100% E85 and 0 boost though? I mean I don't think this was hard use, but I do believe TSP makes cams to advertise the biggest HP number possible and gives no consideration to reliably or durability. I honestly don't believe any of these aftermarket companies really go about the process in a engineering or analytical way. I think they just throw stuff in there and see what happens and some stuff I don't even think they test some things sometimes or barely test at all. I mean after all they don't have to warranty any of their products so they have no incentive to care.

I take blame on myself too for thinking that I could run a big cam and think I wouldn't have problems, I kind of did expect problems, but never foresaw valve seat issues and especially intake valve seat issues. The worst part about it is, it wasn't worth it, I barely could even tell the difference between the cam and heads and no cam and heads. I think it helps show, the extra 10 or whatever horsepower you get from stretching your lift and cam aggressiveness is in no way ever worth it.

TXsilverado

iTrader: (19)

1) That is not a big cam.
2) So you're mad at TSP for a GM issue? TSP probably didn't realize that the valve seats were an issue until they saw a few come apart.
3) If your tune was correct, there is absolutely no way that you could not tell the difference between a stock engine and a heads/cam engine. 100mph in the 1/8 N/A is no slouch.
4) If reliability is your focus, leave the car stock and do not go to the track.

you keep referring to lash, but I think you mean preload. what preload figures did you come up with your pushrod length checker?

ZO6Ted

It doesn't sound like you did anything wrong unless it was the rpm. Likely that's what it was. But since you're Camaro go over to Camaro 6 forum and ask this question or just pm Choda. But please update here as well. Really sorry to hear sir.

jclark10

iTrader: (1)

So you're are perfectly right, I shouldn't be blaming anyone but myself.

When I first installed it a year ago, TSP sent me 7.8 pushrods as a first guess. I bought the adjustable length pushrod from them as well to check. I measured more than .050 the first time but it was hard to measure with. I called TSP and they told me they sent me the wrong tool, so I loosened the rocker and tightened it back up until I found where it made contact then measured it from there while on the phone with them. They said I would be ok with the 7.8 pushrods becuase in their supposed testing they found more preload than what Johnson recommended (.035+/-.010) worked better for them. My best guess is I had about at least .048 preload, which would be out of Johnson's tolerance range, but TSP said I would be ok.

I am not sure what the implications of too much preload be, when it looks like the failure is from not enough preload (lash).

jclark10

iTrader: (1)

I did make a post, I haven't heard it happening to anyone else though or seen it happening. From asking some other people who seem to know, it just looks like the seats got beat to death.

I had my extreme limiter fuel cut set at 7200, which the GMPP hot cam crate motor runs to 7100 extreme cut and that's with I think stock springs and stock non-afm lifters. So I figured I was safe, again I asked TSP their recommendation, and it was "we regularly run our shop test motor past 8500 rpms". I had heard rod bolts can be an issue on these GEN V's. I had bumped the limiter up to 7275, to buy me extra room to shift without hitting the limiter.

TXsilverado

iTrader: (19)

The adjustable pushrods checkers are tough to work with when the engine is installed in a car. I think you're looking at preload as lash, and it is the exact opposite. .48 lash would be on the loose side, but .48 preload is on the tight side. preload is referring to how far in you're pushing the plunger into the lifter. essentially the rocker tip is always in contact with the valve so it is zero lash. Those lifters have .093 total plunger travel so .048 preload should have been just fine. A lot of people prefer to run the preload on the tighter side in an attempt to reduce valvetrain noise. **** breaks when you push it hard. I recently had a timing chain break which is a pretty odd failure. it crashed valves in brand new aftermarket heads and beat up some forged pistons. Before that I broke a spring and dropped a valve. In both cases I can't blame the engine builder...Lick your wounds and build it back stronger, or I can help source you a Prius to drive