TIII Exhaust valves, EGT's, Power, & Warpage

[BadFastGTC]

I have found a common problem with TIII exhaust valves being warped and wondered if the issue is related to high egt values, poor material, or some other factor. Three of the heads have been high boost cars, one was not leading me to believe possibly the material is the issue. I have found 50% of the valves warped. A few were not salvageable but most I could clean up. I have been porting more and more TIII heads with this issue. I have not seen this issue with my 8V heads, speaking specifically of my own car, I have egt values around 1425 at the top of 4th gear. Thoughts, feedback, input? None of these valves show any contact with anything.

I can get custom made valves if I had to, I can put copper-beryllium seats in, but those are expensive options.

[Pat]

I've had a few heads freshened by a local machinist I've had good luck with and never was told of this being an issue...but, maybe it's something he missed. Couldn't say for certain.

I've had bad guides/damaged stems and two heads from parts cars that had burnt exhaust valves, but so far, that's it.

[Lotashelbys]

On the valves you found warped are they the factory "Lotus" valves or the aftermarket valves? I was told that aftermarket valves are just spuncast and are a cheap stainless. The factory has some good inconel content in them. The best way to tell the difference by looking is in the center of the head the "casting dimple" is larger in the factory valves. I could get a pic of each of these valves so you know what im talking about....

[BadFastGTC]

38021Jackson,
I recall all the dimples are maybe .250" in diameter, but that is all I can tell you. I will look closer when I go back up the shop. I would like to see those both side by side if you would be so kind as to snap a shot of them. Thanks.



On the valves you found warped are they the factory "Lotus" valves or the aftermarket valves? I was told that aftermarket valves are just spuncast and are a cheap stainless. The factory has some good inconel content in them. The best way to tell the difference by looking is in the center of the head the "casting dimple" is larger in the factory valves. I could get a pic of each of these valves so you know what im talking about....

[BadFastGTC]

I found some of the same. The guides crumble if you breathe on them! Seals riding on valve stems, seals dried and hard, etc. I did find a bronze guide to use, but I must team the factory guide hole a few thousandths for them to work. No big deal for me. I would rather have the bronze anyhow. They are actually a manganese-bronze to be accurate.


I've had a few heads freshened by a local machinist I've had good luck with and never was told of this being an issue...but, maybe it's something he missed. Couldn't say for certain.

I've had bad guides/damaged stems and two heads from parts cars that had burnt exhaust valves, but so far, that's it.

[turbovanman²]

I haven't had any valve issues unless caused by me, lol.

My head guy put larger guides in, then we used a 4.6 seal that's held in with the valve spring.

[shackwrrr]

I found some of the same. The guides crumble if you breathe on them! Seals riding on valve stems, seals dried and hard, etc. I did find a bronze guide to use, but I must team the factory guide hole a few thousandths for them to work. No big deal for me. I would rather have the bronze anyhow. They are actually a manganese-bronze to be accurate.

Could you share where the guides came from?

[zin]

Were the aftermarket valves part of the "Dunn" re-pops? Or were they simply aftermarket replacements a cylinder head shop might by to replace damaged units?

Mike

[Lotashelbys]

Were the aftermarket valves part of the "Dunn" re-pops? Or were they simply aftermarket replacements a cylinder head shop might by to replace damaged units?

MikeNo usually the Dunn heads came un-loaded and they used the factory valves and springs and such. Im talking aftermarket SBI valves. They are not as strong as the Lotus valves for sure.


Hey Steve turn those valves around so I can see the heads lol! I will try to get you a pic of them side by side. I know I have a few heads with SBI valves in them.....


My local buddy that does my valvejobs uses bronze guides on everyone of the TIII heads he does also. The factory steel ones are always junk and do come apart easily even while running! He puts in a longer guide and used a "hat" style seal that the spring holds in place that takes place of the shim...

[BadFastGTC]

38040Here are the valve heads!


No usually the Dunn heads came un-loaded and they used the factory valves and springs and such. Im talking aftermarket SBI valves. They are not as strong as the Lotus valves for sure.


Hey Steve turn those valves around so I can see the heads lol! I will try to get you a pic of them side by side. I know I have a few heads with SBI valves in them.....


My local buddy that does my valvejobs uses bronze guides on everyone of the TIII heads he does also. The factory steel ones are always junk and do come apart easily even while running! He puts in a longer guide and used a "hat" style seal that the spring holds in place that takes place of the shim...

[rx2mazda]

38040Here are the valve heads!

Who's grandmother is holding them up for you?




















:lol:

[30 PSI SHADOW]

My local buddy that does my valvejobs uses bronze guides on everyone of the TIII heads he does also. The factory steel ones are always junk and do come apart easily even while running! He puts in a longer guide and used a "hat" style seal that the spring holds in place that takes place of the shim...[/QUOTE]


No Crap... you mean like this?38123

[turbovanman²]

That looks bronze?

[30 PSI SHADOW]

nope factory.

[30 PSI SHADOW]

this is what factory steel valve guides do to your engine when they fail...38138

[Directconnection]

was that an original guide that broke? Or, a recently replaced guide that broke?

[BadFastGTC]

Original


was that an original guide that broke? Or, a recently replaced guide that broke?

[shackwrrr]

Bring this back up, anyone know where to get the bronze guides? I an going through my TIII and I noticed tonight that one exhaust guide is dropped and moves up and down with the valve.

[MNmopar]

Jackson has a dude. he just put them in one of my heads.

[JasonFlood]

Could the higher than T1,2,or 4 EGT's be causing some of these problems? I remember a LONG time ago on a stock T3 the EGT's were in the 1700 degree range. If memory serves me the factory calibration runs 100% duty cycle on the injectors just to keep up. Then here we come uncorking the exhaust and uping the boost................

---------- Post added at 11:05 PM ---------- Previous post was at 11:03 PM ----------

Let me rephrase that....I was told after 5500 rpm and a certain boost level the injectors went to 100%

[4 l-bodies]

Hey Steve,
Masi 16V motors were also prone to having exhaust valves warped. Not sure whether it was from bad guides or bad exhaust guide material, so we replace both (lol). Mine had one out of eight warped. Rick D. has seen some warped in as little as 4K miles from new (on stock boost levels)!
Todd

[BadFastGTC]

Todd,
4k warpage is scary. These heads had guide issues, but not to the degree of wear I normally think the valves would be warped as badly as these. I know both of these were pushed a little harder than most. I will have to remember to bring a few to SDAC.

[RoadWarrior222]

Wow and I thought Maserati had almost nothing to do with those motors :D