Engine/Transmission (1994 - 1998) Has anyone though of a 3.5 gsk?

[EGaskamp]

I got to thinking the other night about getting the 4k gsk, but I know you have to put in heavier exhaust springs for that and don't want to do that. But then I got to thinking why doesn't anyone come up with a 3. 5 gsk. That way you wouldn't have to strain your engine all the way up to 4k and install heavier springs but you could go past 3k without defueling. Just a thought. let me know what y'all think. Thanks



Eric

 

[JJW_ND]

Depends on the Pump...

Eric... how high can you rev your engine with the 3 GSK?



My would run 3400 really easy with the GSK. I would guess most 215 pump engines would. They 4 GSK hits 4K real fast on would will un past.



Older (smaller hp) pumps probably get more bang out of the 4 GSK. The later (larger HP) pumps probably can get enough with just the 3 GSK.



jjw

ND

 

[Reb.B]

big difference between a 95 and a 96. 94-95 has 160 or 175 pump. Both have no fill time in the cam of the pump(well not much atleast). 96 through 98 have 180 and 215 pumps which have good fill time. A 3K in a 94-95 barely makes 3K in rpm and a 4k in that same truck makes a good 3. 5 in rpm. A 96 and above truck when using a 3K will rev about 3450 pretty good and a 4K will rev between 3900 to 4100 rpm.

 

[JGheen]

I'm running the 3K and it feels like it doesn't defuel until after around 3000 revs, but I am just scared to take my engine anywhere past that 3000 redline mark on the tach. Just paranoia of a rod being thrown or something...

Maybe in a truck pull or drag race I would hit the 3100 or 3200 rev mark but, to me there is really no reason to go that high when probably in my application I am making no more power than I would be, say @ 2900. Have to dyno to find out.

 

[JGK]

JGheen,



Don't sweat the mid 3K revs. I can (and do) regularly go to 3400 to 3500 just getting on the freeway in a hurry.



The word is, these engines can go over 5K before they come apart.



JK

 

[JGheen]

Originally posted by JGK





The word is, these engines can go over 5K before they come apart.



JK

I believe it, but I would never take it that high. Thanks for the experienced advice on the revs though...

 

[EGaskamp]

So in my 95 would I need bigger exahust springs since it won't rev that high?

 

[edmeyers]

i've heard of engines (not the stock block) goiong well over 5k but have never seen this first hand. so i can not confrim cummins offical word is the engine will come apart @ 4300. on my stock engine i could hold the throttle down and you definatly felt the the govner doing its job 2900ish was max rpm i don't recommend doing this but i wanted to try it just once since my power upgrades i've not try that stunt again but mine is through feuling at 2800rpms

 

[JGK]

EGaskamp,



You need the heavier exhaust springs on the 4K governor kit due to the possibility of valve float as you get close to that number. Generally you're also burning more fuel, so the exhaust charge is larger and the valves will float if the springs aren't changed out for heavier ones. That's why, I believe, they aren't needed on the intake side.



JK

 

[JKouzez]

what about putting a 4k kit on an auto with my set up.