taJon

is it possible? maybe with a shorter stroke and light weight internals? Just curious. By shortening the stroke, would the 346 become a 327 or whatnot?

matt420c

i think the C5R can rev to that high, but im an idiot lol

mullenh

iTrader: (1)

it is quite possible but you will be out of the power band. I don't believe any heads have been made for +9000 rpm

landstuhltaylor

iTrader: (6)

w2w is running 8500

2001bluerata

iTrader: (2)

I'm pretty sure that the 5.3 is a 327, not for sure though. If so try and spin that sucker to 9k. lol

Lurius

iTrader: (7)

The CI size of the 5.3L is a little weird lol. Doing the math, it comes out as a 325, but more than half the manufacturers, and sometimes even GM claim that its a 323. I know one thing, if you doing a search on summit and tell it you want parts for a 325, mostly old gen 1 SBC stuff comes up.

Anyways, the stock 5.3L is 6k rpm red line, but many people are revving them up to 6200 with new springs and cams, and supporting mods, but I imagine you could get them to rev to 7000 just as easy as a 5.7L motor. Never heard one one higher than that.

-Lurius

Juiced

iTrader: (2)

It's going to take a hell of an expensive valvetrain to have it rev 9000+ rpm, with a billet crank, Ti rods super light pistong the bottom end couls take it, but those pushrods are going to be hating life.

Kraest

iTrader: (3)

No point.

You aren't going to make power that high with anything but the most expensive and race-orientated setup. Severely ported heads (nearing 400 cfm) along with a huge cam (280s/290s @ .050 with an inch+ of lift) and race-gas only compression 13:1+. High RPM-only motor all built with lightweight/billet everything, etc.

I believe Futral built one and had one for sale for around $20,000 that consisted of a 427 with heavily ported C5R heads, 13.5:1, gigantic 1+ inch lift cam, etc that made somewhere in the high 700 horsepower range @ 8500 rpm.

Mike

gold87TBI

iTrader: (12)

i rev my 5.3 to 6800 with not any problem its a full bolt on with a comp 228-230 on a 112 lsa and a ls6 intake and still feels really strong on top at that rpm range

LS1>girlfriend

iTrader: (19)

why? ive been picked on/criticized by import owners about having a 5500 stock redline. just say i dont need have to spin that high to make power

taJon

well the aurora indy v8 is based on the northstar 5.7 and its capable of 10,500 rpms. I know that its different, so mostly just curious for the LSx engine. Its not for the firehawk, something more unusual I guess.

I really would love it to sound like an indy car.

Y2K Z28

iTrader: (1)

I've read about gen 1 and big block engines being built to go that high so I'm pretty sure an lsX based engine could do it as well. In fact I recall reading about a bbc that made 1000 or so hp at like 8500 rpm a few years back in an issue of car craft. If memory serves they used a custom style valve train to deal with the pushrods hating life as mentioned above. Pretty sure they used a bigger diameter roller lifter and pushrod to compencate along with larger cam lobes or something. 9,000 rpms isnt all that high really. Some indy engines rev a lot higher. With the right crank stroke light rods and pistons and a bottom end girdle the block should be fine.

mullenh

iTrader: (1)

the problem is the heads would cost nearly $10,000 to flow enough for 10,000 rpm, the light weight crank is going to cost another $3,000 , etc...

GuitsBoy

iTrader: (4)

There have been a few exotic race motors in the mid 8000 rpm range making 700 - 800 rwhp N/A. If its not a highly qualified team or shop building the motor from scratch, dont expect to hit the mark. Most of the combination of parts you can readily purchase will add up to a till that wont make power past mid 7000, max.

staringback05

iTrader: (8)

put a honda motor in your car....then itll rev like that...."9500rpms & 130hp" what a combo

brad8266

iTrader: (23)

LOL

comp builder

9500 rpms will be very hard to reach, and very costly also!! The bore/stroke combo would need to be something like 4.185" x 3.25" to get you a 358ci that would breathe well to that RPM, with a killer set of 400cfm+ heads. We did some back to back dyno tests with a 4.0" x 3.635" combo for an IHRA race motor with a FAST 90mm intake and a Wilson billet bank intake, and the FAST falls way off at 7500+ rpms and the Wilson keeps running. Peak was at about 8200-8300 with class legal 210 cc heads. Also the valvetrain gets to be a little questionable even with the Jesel rockers because of the short pivot length available, you get an extreme amount of sweep across the valve tip.
Just some food for thought
Cory Mattson
Patterson Racing

Patrick G

iTrader: (14)

If you can sift through some of the comedy, there's some good tech here in this thread from the Advanced Tech section: https://ls1tech.com/forums/advanced-engineering-tech/598108-what-allows-engine-spin-8-000-rpms-stay-together-long-time.html

Cop Car

iTrader: (14)

7.0 block. 4.8 crank. titanium rods. forged pistons. LS7 heads. Solid lifters. hell of a nasty cam to rev that high. individual throttle body intake.

orangeapeel

iTrader: (18)

Yeah, why are you wanting anything that goes past 7k anyway?