S54 Port & Polish and/or Other Cylinder Head Work

[Feffman]

Fellow E46 drivers. Does anyone have before & after dyno number for a ported & polished, de-shrouded or any other cylinder head work for an S54?

Doing this is no small endeavor and I'd like some practical proof one way or another. Picture for affect. Thank you in advanced.

Feff

[Slideways]

I spy some CSL exhaust valves. I think the S54 head is known to flow really well, so I'd spend that on other things. You'll probably have to contact Lang in SoCal to see if he has any before and after dynos. There is also the dyno thread and I think two other forum members posted about their stage # cylinder heads.

[Speed Monkey]

CSL valves…. I don’t know why I remember this, but on M3F a zillion years ago, there was a fella whose handle was M3Dragon, or something similar. He recorded his findings after having those exhaust valves installed. I seem to remember he provided a positive subjective statement. As far as flowed heads, maybe try and call that fella who runs that “race” shop in Lake Forest, Cali. He sells flowed heads.

[CrisSilberGrau]

Most of the experienced S54 engine handlers my side of the world, mention that the intake side of the head is above average from factory, its the exhaust where you can make "gains". Valves etc I have no info on.

[Cronenberged]

Lang uses Dinan for the port work. I would also reach out to Chris (PTGs Engine builder) http://www.fletchermadehorsepower.com/fmh-store2.html and see what he recommends.

[Tbonem3]

Well if you are going to, better have cams, airbox, larger injectors, maybe dinan or DIY bored TBs.

[digger]

Fellow E46 drivers. Does anyone have before & after dyno number for a ported & polished, de-shrouded or any other cylinder head work for an S54?

Doing this is no small endeavor and I'd like some practical proof one way or another. Picture for affect. Thank you in advanced.

Feff

On an S50b32 with similar port layout to s54 there is 20cfm gains (260 to 280) on the inlet side with std valve size and about 40 gain (260-300) with 0.65mm o/s . Unless you make good gains on the intake side you are not going to realise good power gains as its easier to get it out than get it in. big gains on exhaust cfm do not translate to power gains and can often hurt the torque of the engine.

At the end of the day you need to do what the engine combination needs as far as airflow requirements, it is not somehting that can be assessed in isolation. A stock engine doesnt demand (how much the piston is trying to pull) 280-300cfm so probably wont be able to utilse it like a 3.5L turning 9000rpm would

[cornerbalanced]

You probably know, but head work provides diminishing returns beyond cams. The factory S54 head flows extremely well. There isn’t much room for improvement on the intake side. Decent room for improvement porting the exhaust side, but will it net noticeable gains? Unlikely.

I have been researching this matter a lot as I’m considering doing the same. Was pretty much told by everyone I spoke with that unless I’m FI, I’m not leaving much on the table by not porting/polishing/doing major head work. Perhaps down the road if I do cams, E85, airbox I’ll find value in building the head and porting it.

I’d wager a lot of money you won’t mind much data on this subject. Not many S54s are running around with a ported and polished head to begin with. Fewer did proper before & after dynos—and of those few, surly they did more than just a port and polish (most likely cams) … thus making the data useless in this circumstance. Hope I’m proved wrong.

[CrisSilberGrau]

You probably know, but head work provides diminishing returns beyond cams. The factory S54 head flows extremely well. There isn’t much room for improvement on the intake side. Decent room for improvement porting the exhaust side, but will it net noticeable gains? Unlikely.

I have been researching this matter a lot as I’m considering doing the same. Was pretty much told by everyone I spoke with that unless I’m FI, I’m not leaving much on the table by not porting/polishing/doing major head work. Perhaps down the road if I do cams, E85, airbox I’ll find value in building the head and porting it.

I’d wager a lot of money you won’t mind much data on this subject. Not many S54s are running around with a ported and polished head to begin with. Fewer did proper before & after dynos—and of those few, surly they did more than just a port and polish (most likely cams) … thus making the data useless in this circumstance. Hope I’m proved wrong.

Basically what I've been told. I went from OEM -> euro header -> CSL -> SSV1 -> Cams. In thinking in two years time engine out refresh i will explore options like this and document.

[bigjae46]

Stash1? I know he has done a lot of S54 testing and work.

Over the years I can remember instances where head work ends up hurting power. Hasn't been many because there are so many pitfalls and challenges to make the endeavor not worth the risk. Tuning might be a challenge for example.

But it's been said that it couldn't be done before...I'd be interested to see the outcome.

[digger]

Stash1? I know he has done a lot of S54 testing and work.

Over the years I can remember instances where head work ends up hurting power. Hasn't been many because there are so many pitfalls and challenges to make the endeavor not worth the risk. Tuning might be a challenge for example.

But it's been said that it couldn't be done before...I'd be interested to see the outcome.

The real issue is finding someone competent.