neverkickn
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Contact???
starting a "build" next month
- Thread starter 01stroked
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Contact???
BigAlsPSD
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:whs: As there are many who have installed 910's this would be useful information to know?
indyF-350psd
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yes....do share about the 910's....you got me ****tin' my pants right now...
PowerstrokeJunkie
Active member
You just have to shim them down to 1.500" and they will work 
BigAlsPSD
New member
You just have to shim them down to 1.500" and they will work
That seems really helpful too...if there is a known issue I would really like to know as I have put them in 3 motors and recommended them to many more. More information as to the preferred springs, and/or what the problem is with the 910's
He was kidding. You can only get them down to 1.750ish, any more you are going to get coil bind.
Here's a chart for everyone to look at:
http://www.compcams.com/technical/valvespringchart/216-06.pdf
If you look at the chart when running the spring right to the limit - seat pressure is only 134lbs. Now take the valve size and multiply it by boost or backpressure to see when the valve will lift WITHOUT the influence of a camshaft.
1.85ish (cannot remember exact size) X 70PSI = valve to piston contact on a motor that is not even running.
That PSI might seem a bit high for your average setup, but I know there are many people pushing stock turbos to that range of backpressure.
Honesty, I could care less what everyone else is doing, I would just like others to consider that 910's might not be the best option for anything other than a stock application.
Here's a chart for everyone to look at:
http://www.compcams.com/technical/valvespringchart/216-06.pdf
If you look at the chart when running the spring right to the limit - seat pressure is only 134lbs. Now take the valve size and multiply it by boost or backpressure to see when the valve will lift WITHOUT the influence of a camshaft.
1.85ish (cannot remember exact size) X 70PSI = valve to piston contact on a motor that is not even running.
That PSI might seem a bit high for your average setup, but I know there are many people pushing stock turbos to that range of backpressure.
Honesty, I could care less what everyone else is doing, I would just like others to consider that 910's might not be the best option for anything other than a stock application.
BigAlsPSD
New member
Understandable, thanks for the info. Mostly stock applications that I have installed them in.
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OSCS
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R
So are you saying that as long as the back pressure is kept in check the 910's properly shimmed will work? I'm still learning myself and was always told as long as your shims are correct and BP is under control they will jive.
MadDiesel73
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S467 all the way
01stroked
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So 907dave. What would u recomend for the spring
PowerstrokeJunkie
Active member
For your setup you'll be doing 910's shimmed will be fine. You wont be pushing more than 50 psi through either side of the turbo
Marty
New member
PM me on the fuel system I believe I have the wrong # for you.
OSCS
New member
This is what I was told.. With a gate and drive pressures in line 910's and proper shims should do just fine.
OSCS
New member
907DAVE...
the 910s work...not by luck...but because the numbers say they do, as well as our experience...
5500+rpm= on the engine dyno..127mph in the 1/4mile with 910s
recently pulled heads to replace a cracked piston...(from nitrous backfire last season)...not a mark on the piston(s) from the valve(s)...just a split down to the piston pin. Going back together with the same ol' 910s and our steel pistons this week.
The face of the valve is 1.675" (not 1.85")
the valve seat (where the boost/backpressure is actually acting on the valve) is only 1.618"(ie, the diameter where the valve seals against the seat)
soooo....
1.618" diameter x 70psi = 113.2 pounds trying to open the valve...
FWIW,
the factory valve spring specs are 71-79lbs of seat pressure @ 1.833" installed height, for both I&E valves.
so jusssst swapping in a set of 910's (no shims) would take you from 71-79lbs to @ 99lbs, again... with no shims. Shimmed to 1.78" (which is what we recommend for most street vehicles)..there is @125lbs of seat load...which would be more than safe enough for up to 75lbs of boost (or backpressure)...
With a stock camshaft, the valve lift is @ 0.390" (this includes the multiplication through the rocker arm)
with 910's installed at 1.75" (a number you chose as inadequate & requiring cool aid)...there would still be (an additional!) 1.36" of valve travel available BEFORE coil bind... (910 coil bind @ 1.280")...anyone running triple the OEM valve lift?
we do use different springs for different applications (without spring rotators, etc)...but to say that 910s don't work...cool-aid, etc...without explaining why is unnecessary, and not at all accurate.
the 910s work...not by luck...but because the numbers say they do, as well as our experience...
5500+rpm= on the engine dyno..127mph in the 1/4mile with 910s
recently pulled heads to replace a cracked piston...(from nitrous backfire last season)...not a mark on the piston(s) from the valve(s)...just a split down to the piston pin. Going back together with the same ol' 910s and our steel pistons this week.
The face of the valve is 1.675" (not 1.85")
the valve seat (where the boost/backpressure is actually acting on the valve) is only 1.618"(ie, the diameter where the valve seals against the seat)
soooo....
1.618" diameter x 70psi = 113.2 pounds trying to open the valve...
FWIW,
the factory valve spring specs are 71-79lbs of seat pressure @ 1.833" installed height, for both I&E valves.
so jusssst swapping in a set of 910's (no shims) would take you from 71-79lbs to @ 99lbs, again... with no shims. Shimmed to 1.78" (which is what we recommend for most street vehicles)..there is @125lbs of seat load...which would be more than safe enough for up to 75lbs of boost (or backpressure)...
With a stock camshaft, the valve lift is @ 0.390" (this includes the multiplication through the rocker arm)
with 910's installed at 1.75" (a number you chose as inadequate & requiring cool aid)...there would still be (an additional!) 1.36" of valve travel available BEFORE coil bind... (910 coil bind @ 1.280")...anyone running triple the OEM valve lift?
we do use different springs for different applications (without spring rotators, etc)...but to say that 910s don't work...cool-aid, etc...without explaining why is unnecessary, and not at all accurate.
4duggan
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Relieved , thanks Dave @ Swamps
01stroked
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Alright thanks everybody... I've decided to drop to a 100 percent nozzle instead of the 200s
Thanks Dave!
I am just speaking from bad experiences:
First experience was on my stock motor with roughly 130k. Installed 910's to 1.80 and was running 50psi and roughly 60psi BP. When that motor tossed a rod I found some pretty notable contact.
Second motor received .010 shorter pistons, the thicker Cometics, 910's (again set to the 1.80 height) and everything else set to factory clearances . After I blew the *** out of the Cometics the first time I hit 60psi I found that EVERY exhaust valve hit. BP's were in the 80's as I was in the process of dialing gates.
That motor received Fire Rings and 910's shimmed to 1.75 per recommendation. Next time I ran the truck I broke multiple rocker arms....
The motor then came apart and received a set of Crower springs set to 1.90 and never had a problem sense.
Only makes sense that the springs was the culprit, right?
I am just speaking from bad experiences:
First experience was on my stock motor with roughly 130k. Installed 910's to 1.80 and was running 50psi and roughly 60psi BP. When that motor tossed a rod I found some pretty notable contact.
Second motor received .010 shorter pistons, the thicker Cometics, 910's (again set to the 1.80 height) and everything else set to factory clearances . After I blew the *** out of the Cometics the first time I hit 60psi I found that EVERY exhaust valve hit. BP's were in the 80's as I was in the process of dialing gates.
That motor received Fire Rings and 910's shimmed to 1.75 per recommendation. Next time I ran the truck I broke multiple rocker arms....
The motor then came apart and received a set of Crower springs set to 1.90 and never had a problem sense.
Only makes sense that the springs was the culprit, right?
what was your PISTON PROTRUSION on the first/second/third engine(s)??
obviously if your pistons are sticking up gawd knows how much over stock specs...then no amount of valve spring can prevent that...
but that isn't the fault (nor could be corrected by/with a different) spring..
did you measure PTV clearance on any of these engines???
(edit edit) did you measure/record the valve recess(es) on any of the valves during assembly?
obviously if your pistons are sticking up gawd knows how much over stock specs...then no amount of valve spring can prevent that...
but that isn't the fault (nor could be corrected by/with a different) spring..
did you measure PTV clearance on any of these engines???
(edit edit) did you measure/record the valve recess(es) on any of the valves during assembly?
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