brian crower 280 cams and bc springs rev limit??

[BMGTZ]

well since the idiot hackers have caused the loss of a few posts and mine was one of them. I will put this up again.

my new engine in the white car is run in now and has had a basic tune......and yes it could be better, but that will come. I will do cam timing adjustments then to get more mid range.....turbonetics t61 and boost doesnt happen till about 3800......then gets to 17 psi pretty fast. It has an oringed block with a std type head gasket so for now that is enough boost.

question is what sort of revs have people seen as safe limits with the BC 280 cams and valve springs?

its seems like its only just got going at 6500... and with 8300 rev limit its still pulling hard. what experience have people had past 8500......is 9000 too much.

the motor hasd all the usual bits .........arp this arp that. forged pistons/rods.

your "informed" advice is appreciated.

 

[Liberoz]

Are the cams set at actual TDC? if your not running adjustable cam gears you will find that not all after market cams are at TDC when bolted to a stock cam gears. putting in bigger aftermarket cams with adjustable cam gears and with out a true TDC positioning on the cams will only unleast a minimal amount of power output they are capable of with without fine tuning.

 

[BMGTZ]

they are timied as bc suggested. however the turbo is somewhat on the large side so it has a bit of hole down low. I do have adjustable gears and will "try" to tune for a bit more down low using them to vary the cam timing. No point having adjustable gears otherwise.

however i am mainly interested in max revlimit of this setup.....as in not wanting to blow the bugger up trying to find out.

brian

 

[Liberoz]

Have you ever set the TRUE TDC of the cams before rocker cover was put on ?? This can only be true setting if done with a magnetic based gauge to the cam!

 

[BMGTZ]

the cams were set up to the specs as given by bc. with a degree wheel and a dial gauge. however rather than cam timing discussion, which I will alter anyway.... I am interested to find out a practical rev limit.

 

[Liberoz]

8.5

 

[JC evo1]

im revving to 8.5 with the BC springs and crower retainers with S2 cams, the BC 280 are a bit less agressive so you shouldnt have any problems going at least 8.5.

 

[BMGTZ]

thanks mate will try that....and see how it "feels". I kinda thought it should be ok to run it to 8300/8400 and limit at say 8500...8700

anyone running harder ? and what gear are you using

 

[VR-4Squid]

I've heard stock oil pumps don't like sustained periods of >8krpm.

Water pump and alternator also don't like to spin that fast, but a smaller crank pulley will sort out that.

With those issues sorted there's no reason you can't rev it past 9krpm, though you'll want to inspect/replace the bearings, etc frequently if your going to be pulling those sort of revs.

 

[BMGTZ]

I've heard stock oil pumps don't like sustained periods of >8krpm.

Water pump and alternator also don't like to spin that fast, but a smaller crank pulley will sort out that.

thanks for that info. I had thought of a smaller pulley but wanted to keep the balancer. Oil pump is a std one too....so I guess 8.5 is it.

 

[brisvr4]

Actually you would want a bigger pulley wouldn't you?
Bigger = slower revolutions?

 

[Muzz66]

Actually you would want a bigger pulley wouldn't you?
Bigger = slower revolutions?

Def not, the pully must be smaller to lower axillary's revs.

 

[brisvr4]

Bugger, I was thinking about it the wrong way!