S54 Stroker build

[stash1]

^^^ Interestingly though, I don't believe that Callies has rods for the S54...at least not that I've heard? Also, for those not aware, Carillo came out w/a lighter weight rod (434g's) specifically designed for NA applications up to 400 whp.

Speaking of rods, anyone ever heard of these? https://www.hurricanerods.com/produc...139-53-21.html

[Feffman]

Interesting article from Engine Labs about connecting rod design type.

https://www.enginelabs.com/engine-tech/cranks-rods/connect-the-rods-i-beam-and-h-beam-connecting-rods-explained/

Feff

[Speed Monkey]

Symbolically - me dropping this info... 🤪

[digger]

I never thought of that before, thats good to note, it does make sense why not to go with stageed head builders. Thank you Digger, I will take this into account. How do u get bench flow numbers? is it reasonable to ask for them?

Whoever does the port work usually calculates flow using a flow bench just ask for them if they didn’t use one then ask how they know they did a good job.
Some background as to the textbook way to port IMO. some will just grind away willy nilly and pray for a good result.

Normally the flow bench test is firstly done in stock form to determine the baseline numbers and after modifications to compare the difference.

They apply a depression across the head (pressure differential) and measure flow at each valve lift increment e.g. 1 mm, 2 mm, 3 mm or 0.050" 0.100", 0.200" ,0.300" etc up to slightly past max valve lift.

The measurements are usually corrected to CFM at 28" water pressure differential standard but they should be tested at that same pressure or higher (not tested at 10" and corrected to 28" which is 1980’s and 90’s methods).

Unfortunately, a flow bench can be misleading as normally if you make it bigger it flows more, what you want is efficiency (velocity or flow per square inch). A well ported head flows better but a head that flows better doesn’t mean it is ported well if that extra flow is achieved by making it huge but inefficient.

Normally what they should do is start with the goals and the application. What size engine, how many rpm, how much hp, what powerband is required, what cams, street or race or something etc

Then the valve size in relation to bore is determined using rules of thumb and inspection of valve placement and other considerations for what can fit and what’s appropriate for the application. Do you need oversized valves? If the port and valve is big enough already to meet power goals then bigger simply makes it less efficient during operation even though on the flow bench it looks great. no use a port that works well on a engine at 10,000rpm if you are only gonna turn 8500

Then they machine throat of the port in relation to valve size with the valve job blending the throat size to the combustion chamber. this again depends on the application e.g. say 88-92% is a common throat % based on valve diameter (say 35 mm valve would have approx. 31-32 mm throat diameter) depending on what is used by the factory and whether new seats are being installed. The seat angles have to transition the port angle to the valve and into the chamber to diffuse the air smoothly The valves might be back cut to compliment the multi angle valve seat.

Then they size the minimum cross area (might already be the throat but sometimes its near the guide at the short turn radius is smaller if the casting is like that) and also the port entry may need to be changed to provide a taper. again the actual size depends mostly on maximum hp. Lower hp means less area is needed to keep the velocity appropriate.

Then they shape all the ports, the short side is reshaped to help the air turn and keep the air attached and not too fast and blended to the seat, same with the bowl its blended to the seat and throat. Basically, streamlining things without unnecessary material removal. The good porters will probably use a pitot tube to check for velocity at various locations to make sure they aren’t too fast or too slow and shape accordingly.

Sometimes the valve and port is already too big so its just a job to improve flow with minimum material removal to optimize efficiency. Like an S52 head flows 240cfm at 28” at around 12 mm lift , the engine even for 300 hp needs maybe 200 CFM only so its not working efficiently in stock form and why without vanos its got no bottom end torque.

A ported S54 with stock valves should flow up to 7-10% more than stock (which is 10% more power potential) and a slightly bigger inlet valve will flow around 15% more if done correctly. You only realize the full power potential gains if the engine is built with parts that support the extra flow meaning, cams exhaust, inlet runner length and so on all done to work together as a system.

[M/Anthony]

if youre paying upto a few grand for a ported head you want it done to suit the engine and its application not based on some prexisting shopping list. Honestly when shopping for a place to do porting id avoid the big name places that do alot of BMW stuff. you want a more specialized place that knows engines

I never thought of that before, thats good to note, it does make sense why not to go with stageed head builders. Thank you Digger, I will take this into account. How do u get bench flow numbers? is it reasonable to ask for them?

[M/Anthony]

I briefly talked with Chris fletcher, and he will end up building and speccing my engine out and it will be paired with an epic tune. I will ask him about head poritng etc. But he is doing my labor and speccing out. It will end up being a 3.4l stroker. I will email him this week to discuss specs, and I will regularly upload information and specs and why on this thread. Is there any questions I need to ask him when building this engine like hamronic damper, x part y part etc, whats the best option for x etc. ? I let him know it has to be in a car by december, but he is backed up which isnt a problem as time is on our hands.

[digger]

Why not someone that offers stages

if youre paying upto a few grand for a ported head you want it done to suit the engine and its application not based on some prexisting shopping list. Honestly when shopping for a place to do porting id avoid the big name places that do alot of BMW stuff. you want a more specialized place that knows engines

[stash1]

Why not someone that offers stages

I think what Digger is hinting at, is that "stages" are kind of a marketing thing w/port work...in that there are different areas of the head that can be ported separately (depending on ones budget). You will hear the terms pocket porting, intake/exhaust porting, fully ported, etc. to describe varying levels/areas of port work. When you ask someone to port a head, the machine shop should ideally address all areas of a cylinder head, and not just one or two. I believe that the reason porters use "stages" is because most folks aren't fully educated on what's actually involved in port work...and "stages" make it easier for people to wrap their heads around-lol. It's a budget thing for some folks too, and shops know this. Also, some porters don't like to discuss flow numbers either because it's such a crapshoot-kinda like dyno's. Most people don't understand what flow numbers actually mean, or even how flow data is collected/converted to meaningful numbers.

[M/Anthony]

The ATI comes with a pulley so youd hope so.
injectors for sure, not sure about pump capacity and longer term durabilty on E85. There are kits around.
There are single mass flywheel conversions around if you like a bit of noise and chatter, for a street car some forego the compromises.
Not sure there is a fully sorted carbon driveshaft on the market, seems like so many issues its hard to keep track.
For port work i would not go with anyone that offers stages.

Why not someone that offers stages

[digger]

does an ATI damper fit with AC?

I want to run e85, so what is needed to support?

Any good lightweight clutches?

Will run either epic or ssv1, and a y pipe paired to a Corsa exhaust

and a carbon driveshaft

The ATI comes with a pulley so youd hope so.
injectors for sure, not sure about pump capacity and longer term durabilty on E85. There are kits around.
There are single mass flywheel conversions around if you like a bit of noise and chatter, for a street car some forego the compromises.
Not sure there is a fully sorted carbon driveshaft on the market, seems like so many issues its hard to keep track.
For port work i would not go with anyone that offers stages.

[Tbonem3]

and a carbon driveshaft

[M/Anthony]

Porting work w/flow bench testing & assembly from a ‘reputable’ shop will run you anywhere from $1,500-3,000...depending on the depth of the porting work.

What do you mean by the depth of the porting work? I would assume a simple port and polish is sufficient enough

[stash1]

Porting work w/flow bench testing & assembly from a ‘reputable’ shop will run you anywhere from $1,500-3,000...depending on the depth of the porting work.

[M/Anthony]

apart from seals, gaskets, o-rings and similar pieces you'd probably want an ATI damper.
Would have to be close to needing higher flow injectors.
Also while you're in there clutch/FW etc
what about the exhaust and CSL style intake?

does an ATI damper fit with AC?

I want to run e85, so what is needed to support?

Any good lightweight clutches?

Will run either epic or ssv1, and a y pipe paired to a Corsa exhaust

and a carbon driveshaft

[digger]

apart from seals, gaskets, o-rings and similar pieces you'd probably want an ATI damper.
Would have to be close to needing higher flow injectors.
Also while you're in there clutch/FW etc
what about the exhaust and CSL style intake?