How safe is 7000rpm on the FS with stock internals?

[fc3sboy]

weak rods

if those engines threw a rod because they were running a stock ECU then that's to be expected because when you hit the rev limiter, you run lean and all sorts of shock forces are put into the bottom end from having the combustion happening off and on again over and over

i beg to differ. the car had a piggy back with the rev limiter gone.

 

[LordWorm]

TheMAN: cool about FS-ZE... are you sure the rods are the same as the FS-DE? has this been 100% checked as certain? Curious thats all!

fc3sboy: proper tune on the piggyback? i'll be going full microtech, tuned to be VERY safe at WOT and high RPM... i'll also be going to a far thinner oil, and oil cooler at least to help defend against explosions...

If it can be confirmed that the FS-ZE is indentical internally to the FS-DE and its just a case of tuning it to be safe at 7k, i'll do it...
otherwise i think i'll go for a 6800 RPM soft cut and hard cut at 7000 to be safe.

The eventual goal is to drop the stroke and go for 9k - but thats a long way off, and i need the block to survive long enough to get that kinda treatment

 

[TheMAN]

yes the whole bottom end is the same, only the pistons are different

 

[Gen1GT]

You definitely won't have a problem with the valvetrain. There will be no valve float. The BP has hydraulic lifters, and it can rev to 7800RPM safely.

What you need to consider, is that the FS makes absolutely no power above 7000RPM.

 

[Focus]

You definitely won't have a problem with the valvetrain. There will be no valve float. The BP has hydraulic lifters, and it can rev to 7800RPM safely.

What you need to consider, is that the FS makes absolutely no power above 7000RPM.

Please explain this conclusion you have come to.

BP and FS are two different motors. FS has solid lifters.

 

[Maz2001MP]

yes the whole bottom end is the same, only the pistons are different

TheMAN is correct. Essentially the whole block is the same except for the piston compression. The head should be the same also except for the different camshafts which probably would allow the engine to make more power above 6,500 rpm.

Im sure the exhaust manifold and intake manifold differ also. If the car is left NA then you should have no problems with a 7,000 redline on the engine from what I know with proper engine management although it wont make power without supporting modifications (proper flow from IM,EM, head, cams, etc.)

The FSDE had a 6,500 redline so it can retain as much down low torque as possible for daily driving, otherwise I'm sure the bottom end and head could handle the extra 500 rpm's but would it be worth it without atleast throwing some JDM cams to support that rpm (our cams suck high rpm as is).

 

[Maz2001MP]

Please explain this conclusion you have come to.

BP and FS are two different motors. FS has solid lifters.

Hydraulic lifters in theory would make less power than a solid lifter and seem to be slightly more suited to higher rpm applications. Here is some friendly info for everyone.

quote from the vette forums:

"As always there's more to it, but in a nutshell:

1) The lifters are called "solids" because there are no springs or hydraulics in them - nothing that will compress. Solid lifters do have oil passages in them, and may even be made up of multiple pieces. In fact solid roller lifters have a wheel and needle bearings.

2) Hydraulic lifters are subject to this thing called "hydraulic intensity" which limits how quickly the cam can open the valve without "collapsing" the lifter mechanism (which would be detrimental in terms of performance). With a solid lifter, the cam profile can be more aggressive and can accelerate the valve off the seat and open it fully more quickly, resulting in "more area under the curve" (more valve opening during the same period) than is possible with a hydraulic. This is why solids will make more power, and you can turn them more rpms because the hydraulics can start to have problems at high rpms. Because of the difference in ramp rates on the camshafts, in general it's not wise to put hydraulic lifters on a solid lifter cam, and vice versa.

Dan"

 

[Maz2001MP]

The high rpm problem we have is mostly due to high piston speeds, installshield can tell you about that one.

 

[TheMAN]

TheMAN is correct. Essentially the whole block is the same except for the piston compression. The head should be the same also except for the different camshafts which probably would allow the engine to make more power above 6,500 rpm.

Im sure the exhaust manifold and intake manifold differ also. If the car is left NA then you should have no problems with a 7,000 redline on the engine from what I know with proper engine management although it wont make power without supporting modifications (proper flow from IM,EM, head, cams, etc.)

The FSDE had a 6,500 redline so it can retain as much down low torque as possible for daily driving, otherwise I'm sure the bottom end and head could handle the extra 500 rpm's but would it be worth it without atleast throwing some JDM cams to support that rpm (our cams suck high rpm as is).

the intake manifold *is* different, people have known that for years... I have that on my car and it definately flows way better than the USDM s***! the exhaust manifold is also different... it's a 4-2-1 cast iron design similar to the ones found in the 626s with the FS-DE

 

[LordWorm]

What you need to consider, is that the FS makes absolutely no power above 7000RPM.

eh? not even with a tune, cams set up to do the job, custom tuned header etc?

 

[twilightprotege]

btw, i have gone to 7250 in competition

 

[Gen1GT]

eh? not even with a tune, cams set up to do the job, custom tuned header etc?

Yeah, you could tune it to make power up there...