MachinistOne

Anything is possible, the pushrod will rub agaist the guideplate as it goes through it's motion, the worse the geometry the more side-load on the guideplate as it tries to keep everything in-line. No matter how good your geometry is I would not use those guideplates after seeing the hardness measurement.

roughneck427

Agreed i concured with wild when he first had the problems i had the same as well.I was going to do the case hardening deal but didnt want to risk the hardening flaking off if i didnt do it right and contaminating my motor.I just went with isky adjustables and mocked it up with two bolts on a gm plate and tack welded them came out nice no probs.I checked my valvtrain in the first as others stated that was the problem i had the correct wear pattern on the valve stems with a sharpie pen.

evilundisguised

A case is not a coating, so it shouldn't flake off... that being said, I would still prefer a hard base material to a hard case where there is the possibility of wear.


wrd1972 - Rockwell testing won't be ideal for characterizing a case-hardened part... since this grabs my attention at a materials guy, I could gather some microhardness data and create a case depth profile if you're willing to sacrifice one of your plates. I'm interested to see how well your treatment actually worked - where did you get that procedure from?

wrd1972

Its a fly by the seat of the pants recipe of my own design, no real research was done. The 1 step process showed good results so I figured 3 steps would be even better. I read that the more times you perform the process the better but I stopped at three dips in the powder and 1 dip in the water.
Please PM me your address and I will send you a plate.

Stoopalini

Apologies for resurrecting this post, but I'm curious what the outcome was from the hardening and testing of the plate.

I recently removed my heads due to a headgasket problem, and noticed all 8 of my guideplates have wear from the pushrods. This is after aprox 25k miles since the install of the 1.7 rockers and GMPP guideplates.

2 reasons why I like the GMPP plates are the valve spacing and the notches for the LT4 valvecover supports.

WRD1972, have you since checked the setup again? Any wear on the pushrods?

I spoke to a heat treating shop, who said they can harden these for me, but their concern was the pushrod would start to wear instead. He also said he cannot do the hardening without knowing exactly what kind of metal he is dealing with, and how hard the pushrods are. So he wants me to bring him a guideplate and a pushrod so he can test each to determine where the guideplate should be.

To do this, would be very cost prohibitive ... I don't want to spend $300 on 8 - $4 pieces! The $300 includes 2 material tests, and the hardening.

Can one of the machinist on this thread tell me what I need to know to have this guy harden them to the correct level?

If I end up using a different plate, anyone know if the ISKYs have the notch for the LT4 valvecover supports?

Thanks guys,
Thomas.

2QUIK6

I was planning to use the Trick Flow plates next time around, these to me look to be exactly the same shape as the GMPP ones so hopefully the clear the LT4 covers ok because thats what I have as well.
http://store.summitracing.com/partde...8&autoview=sku

These are the plates recommended by Lloyd and several others if you do not want to weld up the ISky adjustables.

My GMPP plates on my truck have 60k miles on them and there is probably about .050-.075" wear on many of them, they did not look good.


I'm wondering about wrd1972's comments on the Comp PRo mag rocker being defective??? Any news on that or why you thought that?

evilundisguised

Just like you said, you need to know the material of each and the heat treat/hardening condition of the rods.

96capricemgr

I think a big part of why the GMPP plates are wearing is they are not really RIGHT, they are closer than the other non-adjustale stuff, but not truely right. Not arguing the hardness I believe they are soft, but the spacing of off and that is I believe where the sideload is coming from.

I swapped mine out earlier this year, 8-9K miles and there was wear, I replaced them with Iskys.

Stoopalini

Interesting thought, but if I remember correctly, mine are worn on both sides. I'll have to double check when I get the heads back from the machine shop, but I'm pretty sure both sides of each guide show wear. If it were unusually high side loading from the angle being off, wouldn't the wear only be on one side?

With the information in this thread (Mild steel which should be between 30 - 35 rockwell c), the local heat treating facility said he could harden the plates to the proper level for $75. I'm tempted to bring him 16 plates to have some extras, as he said the cost would be $75 regardless of the # because of their small weight. For that matter, maybe bring him 32 and sell the other 3 sets to help pay for the hardening?

Another thought: if the hardness is not right and if the angle is also wrong, why aren't the stock application of these plates having a problem? Didn't LT4 motors come with these plates installed from the factory?

Thomas.

wrd1972

Wow, this is an oldy but goody.
The GM plates that I "garage hardened" had nearly 8k miles of use on my old motor with Comp chromeoly PR's. When they were removed for an engine rebuild a year ago there was not even a minuscule amount of wear. The PR's had just the normal blemish.

I am now using the same GM guide plates on my new motor which has 2K miles or so. I pulled the valve cover a few months ago for the sole purpose of checking the guide plates which again did not show any wear period. I am no metallurgist but I am convinced that there is absolutely no doubt the hardening process worked.

The root cause for the wear on my older plates excluding the fact they were NOT hardened was bad PR geometry. The worn slots showed up to .070" of wear. The one plate which had the severe wear that caused the rocker to fall off the valve was most likely not a bad Pro mag rocker, I do find it odd that 15 slots had similar wear and 1 out of 16 was severe.

I cant comment on a hardness of these plates but I will say this. If I dragged a file across the unaltered plate it would cut the metal and make a deep sound. After being hardened the file can not cut the metal at all and makes a completely different higher pitch sound. I intended to send a test plate to machinistone for grading but I ended up tossing my test plates.

97s10ondubs

Hmm, i just looked at my guideplates and they all show that side wear. I know the geometry is right b/c i used a checker spring and adjustable pushrod and used the sharpie on the stem to get the right pattern. Are the trickflows hardened? From the summit link it looks like they are just mild steel.

wrd1972

It appears that the Kasnit #2 can not be purchased any more, I am glad I stashed some away a few years ago. I have forgotten the reason that the Kasenit #1 would not work, I am sure someone told me that but I cant stand on it.

The small cans of Kasenit #1 are under $20.00, maybe someone can give it a shot. Here is some good info I found after a newer search:
http://www.piehtoolco.com/en-us/dept_626.html

Stoopalini

Thanks for the update. How did you determine bad pushrod geometry as the cause? When I set my valvetrain up, I did the sharpie test, and determined I needed a 7.150 length rod. With the shorter pushrod, the wear pattern was centered on the stem.

Is there another method which can be used to check lateral alignment? And if it is out, how do you correct for it?

Thanks again,
Thomas.

wrd1972

I did the sharpie test.

The left valve shows the 7.050" length which centers up the pattern, the right is the 7.200" that shows the pattern way off towards the header side.


The 7.200" PR's which were obviously too long are what caused the majority of wear on my old guide plates IMHO. The rocker geometry on my new engine is dead centered with 7.000" PR's.

Note that the photo shows the test with LT4 springs, I did the test with a super light test spring also and got the exact same results.

2QUIK6

I saw that too, but according to Lloyd they are, as this is what he recommends in thread below.
https://www.camaroz28.com/forums/sho...d.php?t=559807