Full throttle vs part throttle
08-08-2013, 05:05 PM
#16
Unless it's untaxed, then it's red.
Join Date: Aug 2009
Location: Damascus MD
Posts: 589
Likes: 0
Received 0 Likes
on
0 Posts
When I did my 3200 - just for fun I advanced the index +1 notch and started the truck. Ran terrible.
The. I retarded the indexing -1 notch and started it. Ran terrible.
I have my fuel screw in as far as it will go.
So I set it to stock indexing.
BC- are you suggesting that by going +/- one index mark I could get my pump set up so that I could actually find runwway? ( then back it off )
I even tig'd the fuel screw longer
The. I retarded the indexing -1 notch and started it. Ran terrible.
I have my fuel screw in as far as it will go.
So I set it to stock indexing.
BC- are you suggesting that by going +/- one index mark I could get my pump set up so that I could actually find runwway? ( then back it off )
I even tig'd the fuel screw longer
08-08-2013, 06:33 PM
#17
Registered User
Join Date: Jul 2013
Location: Media, PA
Posts: 16
Likes: 0
Received 0 Likes
on
0 Posts
IIRC, the 3200rpm governor-spring is a little longer than the stock/OEM governor-spring. With that, you either trim the new spring to match the former, so you can run the original indexing, or, you leave the new spring longer than the former, and take up the slack with reindexing the throttle bell-crank.
As I understand it, this is how the governor springs break down:
The stock Intercooled spring is a #386, and rated at 2600 RPM.
The stock Non-Intercooled spring is a#388, which is about 1/8" shorter than the stock intercooled spring, and rated at 2800 RPM.
The 3200 RPM spring (#366) Is the same length as the stock Intercooled spring, which makes it about 1/8" longer than the stock Non-Intercooled spring.
The 3800 RPM spring (#374) and 4200 RPM spring(#354) are both about 1/8" longer than the stock Intercooled spring... which makes them about 1/4" longer than the stock Non-Intercooled spring.
Someone please correct me if I'm wrong on any of this (which I may be).
-Hans
08-08-2013, 10:54 PM
#18
1st Generation Admin
08-08-2013, 10:58 PM
#19
1st Generation Admin
Yes, you should be able to. I'd back the fuel-screw out a little, after each index change so as to ensure it doesn't go full-throttle, and you're not prepared.
08-12-2013, 10:29 PM
#20
1st Generation Admin
There's another issue that will present with the same symptoms . . . . and I forgot to mention it. 
- Our dynamic injection event timing device is powered by case-pressure. In a nutshell, as engine speed increase, our injection event timing is advanced.
With larger injectors, there comes a point where they're large enough that they can effectively flow more than the vane-pump can move (WOT, high engine rpm, etc), and with that, the injection event -retards some as the case-pressure droops . . . . . till you let off the throttle some.
Sorry about that.
- Our dynamic injection event timing device is powered by case-pressure. In a nutshell, as engine speed increase, our injection event timing is advanced.
With larger injectors, there comes a point where they're large enough that they can effectively flow more than the vane-pump can move (WOT, high engine rpm, etc), and with that, the injection event -retards some as the case-pressure droops . . . . . till you let off the throttle some.
Sorry about that.
08-13-2013, 10:29 AM
#21
Registered User
Will it retard timing below the static timing spot or just make you lose all dynamic advance?
I'm really searching for an answer on the case pressure issue, and it seems there is a partial remedy but all the folks who have the answer won't share it openly on the forum. It's quite sad really.
Sent from my Galaxy SIII via tapatalk 2
I'm really searching for an answer on the case pressure issue, and it seems there is a partial remedy but all the folks who have the answer won't share it openly on the forum. It's quite sad really.
Sent from my Galaxy SIII via tapatalk 2
08-13-2013, 12:46 PM
#22
Unless it's untaxed, then it's red.
Join Date: Aug 2009
Location: Damascus MD
Posts: 589
Likes: 0
Received 0 Likes
on
0 Posts
08-13-2013, 03:41 PM
#23
Registered User
I'm wondering if they run a boost actuated valve that shuts the fuel return down at high throttle so all the fuel going to the ip stays in the ip, maybe keeping case pressure up a bit. I don't wanna pooch a pump if I'm wrong though. I have 2 but that's besides the point.
Sent from my Galaxy SIII via tapatalk 2
Sent from my Galaxy SIII via tapatalk 2
08-13-2013, 09:21 PM
#24
1st Generation Admin
I'm wondering if they run a boost actuated valve that shuts the fuel return down at high throttle so all the fuel going to the ip stays in the ip, maybe keeping case pressure up a bit. I don't wanna pooch a pump if I'm wrong though. I have 2 but that's besides the point.
Sent from my Galaxy SIII via tapatalk 2
Sent from my Galaxy SIII via tapatalk 2
- With 12psig input fuel pressure, the case pressure regulator set to 75psig @ 800engine rpm, has the case pressure level off to about 130 ~ 135psig @ 3200 engine rpm (no load / free-rev).
- Raising the input fuel pressure to 16psig has the 800rpm case pressure rise to 76psig, and rise to 140psig @ 3200 rpm (no load / free-rev).
- Adding to the above, clamping-off the IP's overflow restriction line presents with no difference at 800 rpm, but the case pressure rises to about 145psig @ 3200 rpm (no load / free-rev).
- Raising the input fuel pressure to 16psig has the 800rpm case pressure rise to 76psig, and rise to 140psig @ 3200 rpm (no load / free-rev).
- Adding to the above, clamping-off the IP's overflow restriction line presents with no difference at 800 rpm, but the case pressure rises to about 145psig @ 3200 rpm (no load / free-rev).
08-16-2013, 09:56 PM
#26
Registered User
Thought. If the return does so little is it really necessary to even have a return on the ip? Basically. Could it be blocked permanently or could that cause issues over the long term.
Sent from my Galaxy SIII via tapatalk 2
Sent from my Galaxy SIII via tapatalk 2
08-16-2013, 10:46 PM
#27
1st Generation Admin
The restricted overflow thingy provides a minimum volume of fuel flow through the IP case, for the purpose of cooling. Further, it works in conjunction with the IP case pressure relief valve (I've been guilty of incorrectly calling it a case pressure regulator) to maintain a given case pressure, at a given IP input-shaft speed . . . . . in order to provide a variable pressure source to drive the dynamic timing advance device.
Clear as mud.
Clear as mud.
08-16-2013, 10:47 PM
#28
Registered User
Thread Starter
Join Date: Apr 2007
Location: Southern New Jersey
Posts: 4,062
Likes: 0
Received 0 Likes
on
0 Posts
I would think that would cause the pump to get hot. I am pretty sure that the ve is cooled some what by fuel. If the fuel dead ends at the ve then there is no circulation to cool it. But it might be ok in a short burst.
08-18-2013, 12:20 AM
#30
1st Generation Admin
