[Z06] LS7 Spintron Testing Request and Donation Thread
07-09-2014, 06:16 PM
#41
Safety Car
Thread Starter
Jason should have everything he needs expect for the Ferrea hollow stem valve. I will split the cost of the valve with you and send it to Jason if others want to chip in for the spintron fee.
I would really like to see the results of the Ferrea valve, PSI 1511, and Ti retainers with the torquer cam.
Thanks for all of you help Jason!
I would really like to see the results of the Ferrea valve, PSI 1511, and Ti retainers with the torquer cam.
Thanks for all of you help Jason!
07-09-2014, 06:25 PM
#42
Team Owner
I don't understand why anyone wants to go to the expense of spin testing the dry, hollow stem, exhaust.
The stocker weighs in the mid 70-gram area. An 85-g valve is going to need more spring pressure or a change in the cam profile to control–maybe not much of a change–but the difference could be enough to push valve motion to the limits of stability at the engine's rev limit.
Another issue I question about hollow-stem valves with no sodium in them. Whether the valve stem is metal, hollow-with-no-sodium or hollow-with-sodium filling, the stem is still the heat path from the valve head to the guide, to the head and then to the coolant.
With an "unfilled" or "dry" hollow stem valve, you replace metal with air which is a very poor conductor of heat compared to metal, so without sodium in the hollow stem, what are you doing to prevent the valve head from overheating?
The stocker weighs in the mid 70-gram area. An 85-g valve is going to need more spring pressure or a change in the cam profile to control–maybe not much of a change–but the difference could be enough to push valve motion to the limits of stability at the engine's rev limit.
Another issue I question about hollow-stem valves with no sodium in them. Whether the valve stem is metal, hollow-with-no-sodium or hollow-with-sodium filling, the stem is still the heat path from the valve head to the guide, to the head and then to the coolant.
With an "unfilled" or "dry" hollow stem valve, you replace metal with air which is a very poor conductor of heat compared to metal, so without sodium in the hollow stem, what are you doing to prevent the valve head from overheating?
Seriously, now ...............
Hib
Your point is very interesting. This is something that the spintron testing cannot account for. I readily admit I am not an engineer but others more inclined have pointed out limitations to this testing protocol. Your excellent point should be added to that list.
It seems likely that there is no perfect solution and that every setup has its benefits and shortfalls.
For me I'm sticking with the stronger benefit of the SS valves since they work for my daily driver/track car. And my personal experience of failed hollow valves but no such experience with SS valves.
Now let me put on my bathing suit and suntan lotion in preparation for a good flaming (not afraid of a little heat).
07-09-2014, 07:05 PM
#43
Safety Car
Thread Starter
^^^
Nobody better reply to this. Serious. Not the place. This thread is about spintron testing a new valve/components.
Nobody better reply to this. Serious. Not the place. This thread is about spintron testing a new valve/components.
Last edited by forg0tmypen; 07-09-2014 at 07:07 PM.
07-09-2014, 08:19 PM
#44
Team Owner
Would be interested in seeing a few different springs/etc tested to see the differences between a stock, beehive and a few duals. If pricing isn't bad for swapping some springs just to see the effect of different springs I may be down to throw some money in.
07-09-2014, 08:33 PM
#45
Safety Car
Thread Starter
Thought this was covered in first round of published tests. IIRC Jason used 3 different spring types with little other variables changed?
07-09-2014, 10:36 PM
#48
Melting Slicks
1. We have no price yet.
2. Jason has yet to agree to anything.
One thing at a time.
Once Jason commits to doing this then we can lay out what people would like to see as far as which setups they would like to see tested. Then we submit that to Jason and he gives us a price. Then we figure out how everyone will pay and which setups will make the cut. Dont forget to include the data aspect of the test as well. That will tack on some hours too.
First thing first... Is Jason willing.
2. Jason has yet to agree to anything.
One thing at a time.
Once Jason commits to doing this then we can lay out what people would like to see as far as which setups they would like to see tested. Then we submit that to Jason and he gives us a price. Then we figure out how everyone will pay and which setups will make the cut. Dont forget to include the data aspect of the test as well. That will tack on some hours too.
First thing first... Is Jason willing.
07-09-2014, 11:06 PM
#49
Melting Slicks
I also agree with Hib's point. Is there another lightweight exhaust valve alternative that does not have hollow stems (and without the extra expense of titanium)?
Manley used to make lightweight stainless valves that were substantially lighter than most.
Also, we have found that where the valve is manufactured is a good indication of the quality control measures used during the manufacturing process.
Do we know where the GM sodium filled exhaust valve is manufactured?
Do we know where the Ferrea hollow stem valve is manufactured?
Manley used to make lightweight stainless valves that were substantially lighter than most.
Also, we have found that where the valve is manufactured is a good indication of the quality control measures used during the manufacturing process.
Do we know where the GM sodium filled exhaust valve is manufactured?
Do we know where the Ferrea hollow stem valve is manufactured?
Last edited by Vito.A; 07-09-2014 at 11:21 PM.
07-09-2014, 11:07 PM
#50
Burning Brakes
07-09-2014, 11:27 PM
#51
Safety Car
Thread Starter
1. We have no price yet.
2. Jason has yet to agree to anything.
One thing at a time.
Once Jason commits to doing this then we can lay out what people would like to see as far as which setups they would like to see tested. Then we submit that to Jason and he gives us a price. Then we figure out how everyone will pay and which setups will make the cut. Dont forget to include the data aspect of the test as well. That will tack on some hours too.
First thing first... Is Jason willing.
2. Jason has yet to agree to anything.
One thing at a time.
Once Jason commits to doing this then we can lay out what people would like to see as far as which setups they would like to see tested. Then we submit that to Jason and he gives us a price. Then we figure out how everyone will pay and which setups will make the cut. Dont forget to include the data aspect of the test as well. That will tack on some hours too.
First thing first... Is Jason willing.
07-09-2014, 11:36 PM
#53
Burning Brakes
Expense of Testing
I don't understand why anyone wants to go to the expense of spin testing the dry, hollow stem, exhaust.
The stocker weighs in the mid 70-gram area. An 85-g valve is going to need more spring pressure or a change in the cam profile to control–maybe not much of a change–but the difference could be enough to push valve motion to the limits of stability at the engine's rev limit.
Another issue I question about hollow-stem valves with no sodium in them. Whether the valve stem is metal, hollow-with-no-sodium or hollow-with-sodium filling, the stem is still the heat path from the valve head to the guide, to the head and then to the coolant.
With an "unfilled" or "dry" hollow stem valve, you replace metal with air which is a very poor conductor of heat compared to metal, so without sodium in the hollow stem, what are you doing to prevent the valve head from overheating?
The stocker weighs in the mid 70-gram area. An 85-g valve is going to need more spring pressure or a change in the cam profile to control–maybe not much of a change–but the difference could be enough to push valve motion to the limits of stability at the engine's rev limit.
Another issue I question about hollow-stem valves with no sodium in them. Whether the valve stem is metal, hollow-with-no-sodium or hollow-with-sodium filling, the stem is still the heat path from the valve head to the guide, to the head and then to the coolant.
With an "unfilled" or "dry" hollow stem valve, you replace metal with air which is a very poor conductor of heat compared to metal, so without sodium in the hollow stem, what are you doing to prevent the valve head from overheating?
Currently, I do not have a dog in this hunt, in that I am running new GM heads with new GM valves and dual Pac 1208x springs. I do hope to change to the PSI beehive springs and the Katech Ti retainers at a later date. My cam is not a Torquer, but it has similar specs.
07-09-2014, 11:52 PM
#54
Safety Car
Thread Starter
I would donate as well. Jason can you tell us why the valve guides are wearing so fast in the oem heads? do you believe it to be a machining issue? I'm sure you guys have looked at these heads from top to bottom, what do you think is causing this? This is really Sad for such a great car. Sorry guys I'm not going to turn this into a valve debate. I would just like to hear what Katech has to say about it. I'll pay 500 for the cause Thanks
07-10-2014, 12:50 AM
#55
Team Owner
Its very unfortunate that some here think they are above others and that their cause is just and holy. I see several posters in this thread who were just over in the SS valved thread talking about everything under the sun but what the thread was about. Why should this thread be different than every other thread about these heads thats been started????? Is everyone from now on going to shut up in any thread that you state "Nobody better reply to this" ???????????????????
Please tell me exactly what part of my post was so offensive to you??
DH
07-10-2014, 03:10 AM
#56
Racer
Member Since: Oct 2005
Posts: 365
Likes: 0
Received 0 Likes
on
0 Posts
What engine acceleration rate is used to conduct the test? Or the machine can only hold the engine RPM constant while taking the measurements?
If the test can be done with an accelerating engine, I am willing to share the costs.
07-10-2014, 07:04 AM
#57
Safety Car
Thread Starter
Thats cool but I will respond to yours ..............
Its very unfortunate that some here think they are above others and that their cause is just and holy. I see several posters in this thread who were just over in the SS valved thread talking about everything under the sun but what the thread was about. Why should this thread be different than every other thread about these heads thats been started????? Is everyone from now on going to shut up in any thread that you state "Nobody better reply to this" ???????????????????
Please tell me exactly what part of my post was so offensive to you??
DH
Its very unfortunate that some here think they are above others and that their cause is just and holy. I see several posters in this thread who were just over in the SS valved thread talking about everything under the sun but what the thread was about. Why should this thread be different than every other thread about these heads thats been started????? Is everyone from now on going to shut up in any thread that you state "Nobody better reply to this" ???????????????????
Please tell me exactly what part of my post was so offensive to you??
DH
07-10-2014, 09:29 AM
#58
Melting Slicks
I would donate as well. Jason can you tell us why the valve guides are wearing so fast in the oem heads? do you believe it to be a machining issue? I'm sure you guys have looked at these heads from top to bottom, what do you think is causing this? This is really Sad for such a great car. Sorry guys I'm not going to turn this into a valve debate. I would just like to hear what Katech has to say about it. I'll pay 500 for the cause Thanks
That would be for another thread. Lets stay on topic.
07-10-2014, 09:42 AM
#59
Premium Supporting Vendor
It is a step test.
07-10-2014, 10:13 AM
#60
Team Owner
Howie I respect what you do for a living but on Corvette Forum...that's a different animal. And I don't want this thread to turn into Jason's last one so as soon as I see comments like yours, now that we have serious discussion going on, I'd rather put out the spark before it becomes a fire. If that happens then we won't be able to get anything done in here and lots of potential donations to what I feel is actual fact based unbiased research will be lost. So to sum up, if you want to see Jason run the hollow stem ferrea valve on the spintron or another combination I will add your name to the list of donors.
What I don't understand is, why didn't you direct your comment to Hib. He is the one who actually researches all this for a living. He is the one that stated that the test would be a waste of time, not me. In another current thread he stated that of all the options the valve you want to test is the "worse choice" available.
I would never and am not suggesting that the test should not proceed. If the cost is reasonable then I would chip in too. But if I did I would share the results with the entire community
DH