[cmitchell17]

Originally Posted by KingLT1

I have used Manley's in the past and the advertised length was spot on with my Digital Caliper. Either way measure the pushrod you order with the digital caliper to make sure it lines up with your measurents taken and everything should be fine. It's what I have done in the past with no issues. Some companies will allow you to swap out pushrods to a different length if they haven't been installed and ran.

I have the TSP 7.8in which I measured with the calipers at 7.796.

I am with you 100%, I already invested in a degree wheel with mounts and a dial gauge, another dial gauge with a magnetic mount, soft springs to help check PTV and hold the valves, and some other stuff.

I also sent a message to cam motion and filled out one of their cam recommendation forms.

I am in the process of using dynomation and running some scenario engines. I've been using the iterator function on there that basically brute forces a cam profile and iterates until it finds the largest integral horsepower or torque area through a predefined RPM range.

So far I found that it keeps selecting very high duration cams with massive amounts of overlap (like 30-40 degrees+), even when you try to optimize in say the 2500-6500rpm range and not pushing it like (4500-7000, which would be more of a optimal scenario).

I am missing the intake and exhaust port minimum cross section, I estimated the max cross section from pulling the intake manifold and using the specs I got from the C7 and C8 Corvette power point publications.

Since I have the heads off I am going to try to take one into the QA department at work and maybe I can set it up on the CMM, hopefully we will have a probe to curve around into the ports. I tried using snap gages and they are extremely difficult to use.

While I am on the topic, I want to narrow the range of cams when simulating by taking out the rougher idling stuff. Does anyone have a intake closing or exhaust opening degree number where lope starts happening? I know its more the relationship between the intake and exhaust, but I can only input the 4 individual valve events.

[95 imp]

Originally Posted by cmitchell17

So TSP is saying "falling out", I guess that means literally falling out of the seat. I don't think mine have fallen out of the seat? I think #7 failed and the others are starting to fail from being burned. Now I guess the burning could be from bad machining, valve float/bounce and having constant combustion hot gases escape, or something else.

Intake valves usually do not burn. They always have cool air/fuel running past them. It's the exhaust valves that burn.

[KingLT1]

Originally Posted by cmitchell17

I have the TSP 7.8in which I measured with the calipers at 7.796.

I am with you 100%, I already invested in a degree wheel with mounts and a dial gauge, another dial gauge with a magnetic mount, soft springs to help check PTV and hold the valves, and some other stuff.

I also sent a message to cam motion and filled out one of their cam recommendation forms.

I am in the process of using dynomation and running some scenario engines. I've been using the iterator function on there that basically brute forces a cam profile and iterates until it finds the largest integral horsepower or torque area through a predefined RPM range.

So far I found that it keeps selecting very high duration cams with massive amounts of overlap (like 30-40 degrees+), even when you try to optimize in say the 2500-6500rpm range and not pushing it like (4500-7000, which would be more of a optimal scenario).

I am missing the intake and exhaust port minimum cross section, I estimated the max cross section from pulling the intake manifold and using the specs I got from the C7 and C8 Corvette power point publications.

Since I have the heads off I am going to try to take one into the QA department at work and maybe I can set it up on the CMM, hopefully we will have a probe to curve around into the ports. I tried using snap gages and they are extremely difficult to use.

While I am on the topic, I want to narrow the range of cams when simulating by taking out the rougher idling stuff. Does anyone have a intake closing or exhaust opening degree number where lope starts happening? I know its more the relationship between the intake and exhaust, but I can only input the 4 individual valve events.

Can't really help there as I have never got too involved with valve events. I always just trusted a reputable name to spec the cam.

Originally Posted by 95 imp

Intake valves usually do not burn. They always have cool air/fuel running past them. It's the exhaust valves that burn.

With DI fuel sprays directly into combustion chamber so the intake valve doesn't get the cooling effect from fuel but it still sees some air cooling. I do agree it's normally an exhaust valve that burns up.

[NA18CamaroSS]

Reading through this thread is very informative. I was already leaning towards a more conservative cam, and this unfortunate motor has sealed the deal for me. I have never seen valve seats chip like that before, intake valve seats no less. Bent valves, burned and broken exhaust valve seats, sure. So sorry to the OP for your troubles.

[L78toLT1]

OP, what do your guides look like? From the pics, it looks like the radial position was not being controlled i.e. when closing, it appears the valves never hit in the same place twice. I would check the guides. It's possible the side load imparted by the rocker may have worn the guides causing the valves to walk around radially and beat up the seats.

[6spdhyperblue]

Not to highjack, but tsp has their own cam grinder. Where are the endurance lobe line? It looks like they have like 4 cams from 2013.

Secondly, I wonder if hardening the seats for E makes them more brittle. A trade off from gm and was ok within their oe and gmpp cam. Again another reason to run soft ramps.

[KingLT1]

There are several variables at play here. Only thing further I can add is to go back and research through the evolution of cam installs on LS engines and apply that to your LT build. The valve trains are nearly identical between gen 3, 4, and 5 small blocks. Almost all of the research applies here.

Just going to throw some key points out there to consider when planning a H/C build.

-Stock rocker arm builds should stay at or around .600 lift. Once above .630 lift they begin to side load the valve and cause valve guide wear. This was common on 15 degree LS heads. Not sure if 12 degree LT heads allow more lift with a stock rocker or not?

-Use good lifters with reduced travel for higher rpm builds that require heavier spring rates.

-Reduced travel lifters require more effort to achieve precise lifter preload and less tolerant of variances from one valve to the next. This often requires shimming rocker arm pedestals or custom length pushrods when using stock rockers. Gen 1 & 2 small blocks used fully adjustable roller rockers which made this a breeze. The reason why LS/LT builds typically do not use them because they add more weight over the valve. The stock rocker allows better valve train stability when setup correctly.

-Often times ported heads with valve jobs will often have slight differences in valve lengths across all valves. Usually it will be all intake are X and exhaust Y so you need to measure all valves when checking or proper pre load.

-Dual springs are commonly used for piece of mind but not always Ideal. Beehive are used for good reasons by OEM's. If you use duals make sure they are setup correctly.

-Early in the LS days everyone was using cam lobes that were high intensity race lobes(XER & LSK) in their street cars. Most of these builds did not have the proper valve train setup to deal with the rpm and lobe intensity. It was later discovered that smoother lobes with less jerk rate intensity were more stable and made more power. BTR found this out with a lot of spintron testing. Comp released a article not too long ago and their testing has found that there is no added benefit to opening the valves really fast...it just beats the snot out of the valve train for little to no gain.

[cmitchell17]

Originally Posted by L78toLT1

OP, what do your guides look like? From the pics, it looks like the radial position was not being controlled i.e. when closing, it appears the valves never hit in the same place twice. I would check the guides. It's possible the side load imparted by the rocker may have worn the guides causing the valves to walk around radially and beat up the seats.

I need to go inspect after work. I know from sliding the valves in and out of them nothing felt loose, except the #5 being harder to pull out than the rest because I think its bent.

What gets me is the pitting and knicks that start on the OD of the intake valve seat, this can be seen in all of the cylinders.

[jimadvig]

Originally Posted by Puddin

They Edelbrock heads also require you to use Kooks headers so if you have headers already I'd skip the Edelbrocks.

It's only the Victor heads that need special headers. The Performer use standard headers.

[jimadvig]

Originally Posted by Joshinator99

Only the Victor Jr ones I believe. Thought the Performer RPM ones used stock headers.

I’m enjoying my Mast Black Label heads FWIW. Nice product. Support is a little on the slow side unfortunately, but to be fair I haven’t needed any since I bought them.

Did your Mast heads come bare or fully setup with valves, springs etc? I also saw that they offer their own factory casting CNC'd ported heads. They don't mention anything about the issues that TSP warns about on their CNC'd ported factory casting head description. I would imagine these would have the same issues if running a high lift cam.

[oldman]

I don't recall much but I thought my Johnson lifters were like .045 taller vs the LS7 lifter. All I remember was with the new Cam Motion cam and Johnson lifters I had to buy all new pushrods vs TSP cam and LS7 lifters.

IMO the R for reduce travel lifters should be only used with adjustable rockers, that is how hard it is to set the preload. But I'm old and younger guys may say no issues.

You can NOT like can't just order off the shelf pushrods when you go heads, valves cams, lifters. You have to measure PERIOD. Sure the LS7 lifter may work as it has a lot of clearance... IMO you are just playing with fire if you go with LS7 lifters and off the shelf stuff and hope it will all work to 7000 RPM.

[radz28]

I think Katech released a video where they insisted LT-valve guides were pretty bad from the factory, like the LS7-problem. I haven't noticed that statement from anywhere else, but I'm no expert. I also find it strange TSP will still sell heads with issues they KNOW but don't correct. Maybe I'm not understanding that correctly, but I assume that a big player like that would take care of all the deficiencies, like it seems like a company like AI (apparently) does.

This just sucks though. I'm sorry for your troubles.

[cmitchell17]

Originally Posted by radz28

I think Katech released a video where they insisted LT-valve guides were pretty bad from the factory, like the LS7-problem. I haven't noticed that statement from anywhere else, but I'm no expert. I also find it strange TSP will still sell heads with issues they KNOW but don't correct. Maybe I'm not understanding that correctly, but I assume that a big player like that would take care of all the deficiencies, like it seems like a company like AI (apparently) does.

This just sucks though. I'm sorry for your troubles.

Yeah, I agree, I will not be buying anything else through TSP.

I took the #7 intake valve and inserted it into all the other intake valve guides on the head, they all went in fine and the same, they also all wiggled the same. Apparently, the LS7 factory valve guide check procedure has them use a dial gauge at an angle to check guide wear which seems really inaccurate. I have a dial gauge and mount but not sure if I could get accurate measurements myself.

[Puddin]

Originally Posted by radz28

I think Katech released a video where they insisted LT-valve guides were pretty bad from the factory, like the LS7-problem. I haven't noticed that statement from anywhere else, but I'm no expert. I also find it strange TSP will still sell heads with issues they KNOW but don't correct. Maybe I'm not understanding that correctly, but I assume that a big player like that would take care of all the deficiencies, like it seems like a company like AI (apparently) does.

This just sucks though. I'm sorry for your troubles.

While I do believe they should just stop selling the heads its really not Texas Speeds fault if the valve guides are bad because they are coming from the factory like that so if anything this is a GM issue again like the Ls7. Hopefully since their custom heads are available now they have resolved any issues that the stock castings have.