S54 Stroker build

[M/Anthony]

You do realize that it's a bit silly to build a motor to rev that high and have shorter gearing just to get it up there, when you could prioritize the midrange and have a motor that is 'faster' in the real world and MUCH more reliable?

All of this sounds cool for bragging rights but it will be deemed a waste of money one way or another once you're on the other side of this build... you'd be much better off in every regard by just getting a GT3.

Is there really a way to get midrange power out of the S54 besides slapping a turbo on it? I could run stroker kit but that really isn't the best way to in terms of reliability.

[ethan]

You do realize that it's a bit silly to build a motor to rev that high and have shorter gearing just to get it up there, when you could prioritize the midrange and have a motor that is 'faster' in the real world and MUCH more reliable?

All of this sounds cool for bragging rights but it will be deemed a waste of money one way or another once you're on the other side of this build... you'd be much better off in every regard by just getting a GT3.

Or a Corvette or LS-swapped-anything by your logic. Still, agreed 9000rpm on an S54 in an HPDE context isn't pragmatic in the slightest.

[ethan]

Is there really a way to get midrange power out of the S54 besides slapping a turbo on it? I could run stroker kit but that really isn't the best way to in terms of reliability.

The good Supersprint stuff, a quality CSL airbox conversion, no more than 288/280s, a fresh set of valve springs in the head, and no more than 8300rpm on the limiter. That's a good, reliable HPDE S54 build right there. Runs an almost stock CSL tune on a stock MSS54HP - easy. Want a little more? Go from 11.5 -> 12.0 compression by way of pistons and keep running 93. Do an 0.25-0.5mm overbore while you're in there for the fresh cylinder walls (moreso than for the displacement.)

Stroker? Yeah, maybe if you've spun a rod bearing and need a crank anyway and already have to rebuild the bottom end. Probably not worth the cost, but I bet Lang's solution is better in reliability terms than we're giving it credit here.

If you need more than that, you're going to want to have a really good plan figured out - one which you've had verified by race engine builders not just us forum trolls.

[Speed Monkey]

Steve Dinan has a new gig it appears, and he is offering up this - a 3.3 liter S54.
https://carbahnautoworks.com/product...ngine-rebuild/

[M/Anthony]

The good Supersprint stuff, a quality CSL airbox conversion, no more than 288/280s, a fresh set of valve springs in the head, and no more than 8300rpm on the limiter. That's a good, reliable HPDE S54 build right there. Runs an almost stock CSL tune on a stock MSS54HP - easy. Want a little more? Go from 11.5 -> 12.0 compression by way of pistons and keep running 93. Do an 0.25-0.5mm overbore while you're in there for the fresh cylinder walls (moreso than for the displacement.)

Stroker? Yeah, maybe if you've spun a rod bearing and need a crank anyway and already have to rebuild the bottom end. Probably not worth the cost, but I bet Lang's solution is better in reliability terms than we're giving it credit here.

If you need more than that, you're going to want to have a really good plan figured out - one which you've had verified by race engine builders not just us forum trolls.

I'm awaiting a response from Lang Racing. Will sleeve and bore the engine while we're there, what about bumping compression up a slight bit to run 12:5/13:1, and run E85, since I have a pump 5 miles away. Would that harm mid-range power and increase the top end? And to clarify, I want the valve train to be able to hold 9000rpm and as stout and well built as I can get.

[r4dr]

Steve Dinan has a new gig it appears, and he is offering up this - a 3.3 liter S54.
https://carbahnautoworks.com/product...ngine-rebuild/

That's a lot of money for tens of horsepower at the wheels. Keep in mind those dyno graphs are done on 100 octane gas. A 4.10 rear end and smaller diameter tires are way cheaper!

[Obioban]

The good Supersprint stuff, a quality CSL airbox conversion, no more than 288/280s, a fresh set of valve springs in the head, and no more than 8300rpm on the limiter. That's a good, reliable HPDE S54 build right there. Runs an almost stock CSL tune on a stock MSS54HP - easy. Want a little more? Go from 11.5 -> 12.0 compression by way of pistons and keep running 93. Do an 0.25-0.5mm overbore while you're in there for the fresh cylinder walls (moreso than for the displacement.)

Stroker? Yeah, maybe if you've spun a rod bearing and need a crank anyway and already have to rebuild the bottom end. Probably not worth the cost, but I bet Lang's solution is better in reliability terms than we're giving it credit here.

If you need more than that, you're going to want to have a really good plan figured out - one which you've had verified by race engine builders not just us forum trolls.

Many times we have seen that the 280/272s have more mid range and the same top end as the 288/280s.

[ethan]

Many times we have seen that the 280/272s have more mid range and the same top end as the 288/280s.

Yep.

[jbfrancis3]

Many times we have seen that the 280/272s have more mid range and the same top end as the 288/280s.

What about with increase in displacement? No longer as definitive I am guessing

[jvit27]

Is there really a way to get midrange power out of the S54 besides slapping a turbo on it? I could run stroker kit but that really isn't the best way to in terms of reliability.

A lower-revving stroked S54 will be more reliable than what you're asking for and hit most of your targets. You're stuck on this arbitrary 9000rpm redline that is sabotaging all of your goals. Given what you're asking, it's wildly optimistic and dare I say greedy. I'm glad Anri explained it so well because at the end of the day, you're expecting WAY too much out of what is basically an evolution of a 30 year old engine design. Forced induction even would be more reliable than what you're asking for. The most successful race-built S54's would not even meet these criteria.

Or a Corvette or LS-swapped-anything by your logic. Still, agreed 9000rpm on an S54 in an HPDE context isn't pragmatic in the slightest.

It's not logic - it's fact. If you want a streetable 9000rpm 6 cylinder that can run on pump gas, what other options are there?

[digger]

the mean piston speed is too high with even the stock stroke to have good reliability at 9000 rpm

9000 rpm and 91 mm stroke MPS = 27.3 m/s
9000 rpm and 95 mm stroke MPS = 28.5 m/s
9000 rpm and 97 mm stroke MPS = 29.1 m/s

Even pro race teams that develop endurance engines don't go that high 25-26 is normally upper limit. that is big cubic inch drag motor territory which get rebuild often. it can be done but it is just not going to be reliable if you spend a significant amount of time at those rpm especially since you arent designing the engine around that from a blank sheet

the main point is a big stroker doesn't need the rpm it makes the power at a proportionally lower rpm so 97 mm would peak at 94% earlier so instead of 8200 its 7700 rpm and so on

for those that dont know mean piston speed is also tied to mean port speed not just reliability. above certain mean port speeds the VE starts to drop off rapidly anyway making turning those kind of rpm often a waste of time and engine life.

[ethan]

It's not logic - it's fact. If you want a streetable 9000rpm 6 cylinder that can run on pump gas, what other options are there?

I totally agree with you. I'm just poking fun at your statement that we should:

prioritize the midrange and have a motor that is 'faster' in the real world and MUCH more reliable

Reminds me of the "torque wins races"/"BMW engines suck, swap in an LS" crowd m3forum used to have to educate in matters of taste not that long ago. "You just don't appreciate the high revving nature of BMW's glorious S54." And don't get me wrong - I'm a major proponent of this engine's character as justification for its expensive maintenance and lack of power relative to turbos and big displacement alternatives. Funny for me to be on the conservative side of a moar NA RPM debate for once.

[stash1]

I'm awaiting a response from Lang Racing. Will sleeve and bore the engine while we're there, what about bumping compression up a slight bit to run 12:5/13:1, and run E85, since I have a pump 5 miles away. Would that harm mid-range power and increase the top end? And to clarify, I want the valve train to be able to hold 9000rpm and as stout and well built as I can get.

Lots of good advice & recommendations in here, and I’ll add something else as well...I’ve seen you mention sleeving the block twice now. I’m not sure if someone suggested this to you, but it’s an added machining step/expense that’s totally unnecessary for an NA S54.

[M/Anthony]

Lets semi-start over,
I hear what everyone is saying and I also thank you for your input.
can we shift the build to scrapping 9000rpms as it will be impossible and dangerous
What if we switch to running a higher compression, but also increasing torque.
Going off what Carbahn and Mike run, increasing compression in displacement can be doable, his engine maxes his hp at 8100.
So then, I'm not saying stuff won't be custom and this and that. Making this engine reliable with higher compression and higher torque.
I still believe we can get a pretty aggressive build matched with a high diff ratio.

[M/Anthony]

Lots of good advice & recommendations in here, and I’ll add something else as well...I’ve seen you mention sleeving the block twice now. I’m not sure if someone suggested this to you, but it’s an added machining step/expense that’s totally unnecessary for an NA S54.

Since we'll be down there already there really isn't a negative to sleeving it, in case anything goes wrong we can just remove the sleeves instead of worrying about replacing the block. If it comes down to cost at that point, then we won't be sleeving the engine.