High revving combos
10-02-2010, 04:55 PM
#21
Staging Lane
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Well you'd probably know better than me in that case. I just know I have seen some gnarley main and rod bearings on LSx engines that have seen prolonged high rpm usage. It's inescapable that friction is going to increase as you rev higher.
10-02-2010, 05:42 PM
#24
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I'm not so much scared of it coming apart, as I am of reduced lifespan and extra machine work, like from scored journals. If you don't care about some degree of reduced lifespan, I wholeheartedly endorse it! Nothing is more badass. Of course, like you guys say, a lot can be done to prevent that, and you don't have to run a stock shortblock anyway, right?
10-02-2010, 06:05 PM
#25
I'm not so much scared of it coming apart, as I am of reduced lifespan and extra machine work, like from scored journals. If you don't care about some degree of reduced lifespan, I wholeheartedly endorse it! Nothing is more badass. Of course, like you guys say, a lot can be done to prevent that, and you don't have to run a stock shortblock anyway, right?
all the resources are available for a hi rpm engine. my engine 7200rpm shifts when it had to. although i machined and assembled with quality parts and bearings. detailed and proper clearances. proper maintenance and used the correct oil grade and also have an engine oil cooler in place.
for valvetrain stabilty i used jesel rockers. engine is new new owners car now and it still sees hi rpm. prolly has round 45k miles now. who knows how much n2o has been thru it and hiway pulls and downshifts.
Once you hear those Rpms a V8 can never match that kind of scream
10-03-2010, 06:52 AM
#28
http://www.youtube.com/watch?v=hZyjRvUErZQ
car spun hard out of 1st....
The average piston speed on this combo at 9200 is less than the stock LS engines at 7200.
With a rod/stroke of 1.92 there should be little side loading of the piston.
The oil pump is an external 12gpm unit driven at .57 crank speed, oiling is not a problem.
Makes around 2hp/cube.
Dave
10-03-2010, 05:39 PM
#30
TECH Apprentice
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My engine isn't in the car yet, but it has seen 7500 on the dyno ... 4" stroke, 4.010 bore. With the new cam and intake, it will go to 9000. 6010 Box with truck coils
Hopefully soon.
Hopefully soon.
10-04-2010, 04:37 AM
#36
i need some advice if possible on this same thing. my setup has short gearing and i cant really alter it, so upping the rev limit will help me, but what would be safe with my set up?
i have a forged ls6 from WRE with stock (balanced) crank and wiseco pistons/carillo rods.
LS7 lifters, comp cams pushrods and retainers.
cam is very mild, 220/220 111 lsa with .550 lift, so not very high lift. peak power on the dyno was about 6300rpm, my rev limit at the moment is 6400 which it hits very quickly.
my worry is i am using stock ls1 rockers and ls1 heads. i havent yet done the trunion upgrade which i plan to do this winter. i have hardened pushrods in place but am using comp cams 916 beehive springs, not the 918s as the 916s suited the spring pressure required for my cam better on their advice, with it being a baby cam.
i intend doing the trunion upgrade over winter and might change the springs to something else, but i think 6500rpm might be my safest limit anyway bearing in mind the cam peaks at 6300.
headers are 1 7/8" and i have a GMP intake and demon carb, it revs out like lightening as the car is very light and accelerates like mad. i dont need more power, the car is fine as it is, but is 6500rpm safe on my setup or should i change the springs?
cheers
i have a forged ls6 from WRE with stock (balanced) crank and wiseco pistons/carillo rods.
LS7 lifters, comp cams pushrods and retainers.
cam is very mild, 220/220 111 lsa with .550 lift, so not very high lift. peak power on the dyno was about 6300rpm, my rev limit at the moment is 6400 which it hits very quickly.
my worry is i am using stock ls1 rockers and ls1 heads. i havent yet done the trunion upgrade which i plan to do this winter. i have hardened pushrods in place but am using comp cams 916 beehive springs, not the 918s as the 916s suited the spring pressure required for my cam better on their advice, with it being a baby cam.
i intend doing the trunion upgrade over winter and might change the springs to something else, but i think 6500rpm might be my safest limit anyway bearing in mind the cam peaks at 6300.
headers are 1 7/8" and i have a GMP intake and demon carb, it revs out like lightening as the car is very light and accelerates like mad. i dont need more power, the car is fine as it is, but is 6500rpm safe on my setup or should i change the springs?
cheers
10-04-2010, 10:29 AM
#37
If you're spinning that high then why didn't you purchase a larger cam that would continue making power higher? Personally I would run double springs just as a failsafe if the outer breaks you shouldn't drop a valve. Otherwise 6500 with good rod bolts isn't out of the question
10-04-2010, 05:15 PM
#40
If you're spinning that high then why didn't you purchase a larger cam that would continue making power higher? Personally I would run double springs just as a failsafe if the outer breaks you shouldn't drop a valve. Otherwise 6500 with good rod bolts isn't out of the question