My new project M50B32

[esoes06]

Block NV m50b25
89.6 crankshaft
87mm pistons
140mm rods
Double spring cylinder head
80mm throttle body
M54b30 47.7mm inlet camshaft
NV camshaft Exhaust 240/9
Ms41 tuned
Cold air intake
Headers Exhaust system
Lightened flywheel
Fan clutch delete
Electric fan cooling
+280hp Target...
Maybe later 272/252 camshaft
What do you guys think...

[pbonsalb]

Those are long rods. Can the pin go high enough in the piston to allow them with the S52/M54B30 crank?

[M3poseur]

With that crank/140mm rod combination, Valve/piston contact is imminent.

[esoes06]

Those are long rods. Can the pin go high enough in the piston to allow them with the S52/M54B30 crank?

Pistons special production. Compressor height calculated

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With that crank/140mm rod combination, Valve/piston contact is imminent.

Pistons are special production. My next goal is to use 145mm rods or 143mm rods

[5mall5nail5]

Is the bottom ring unsupported?

[esoes06]

Is the bottom ring unsupported?

I dont understand

[pbonsalb]

Your piston pin might be so far up into the piston that the lowest piston ring is around the hollow shell. Maybe that is OK. I assume you looked into this issue already and decided it was. Many of us have figured out the rod to piston ratio is theoretically not ideal for high rpm but it’s never been an issue and people have been building these engines for 25 years.

[5mall5nail5]

Your piston pin might be so far up into the piston that the lowest piston ring is around the hollow shell. Maybe that is OK. I assume you looked into this issue already and decided it was. Many of us have figured out the rod to piston ratio is theoretically not ideal for high rpm but it’s never been an issue and people have been building these engines for 25 years.

Yep - just not a fan of unsupported or suspended rings, even if just the oil ring. Sure, rod ratio can do wondrous things but 135mm has not really proven to ever be the (reasonable) limiting factor on these engines.

[someguy2800]

You just use a groove lock spacer below the oil control ring and it works just fine. I make almost all my M50B30 pistons with the wrist pin going through the oil ring groove and it works great. I’ve made S52 pistons for customers with 140mm rods and also 138mm Honda B18c rods.



https://youtu.be/-6_25L5U8y4

[someguy2800]

I don’t think you will meet you goal of 280 hp with the cams you are using and stock head and intake manifold. Probably like 240 whp. To make 280 whp with stock head and intake will probably require 280+ degree cams

[Hofmeister]

not far off whats in my car right now. And i can tell you its not a 280whp build, not without crazy compression and fancy gas. 280 crank feels more like it.

[someguy2800]

If you want to get fancy you can also do a pin button like this. It's only like $10 per piston from wiseco.

[M3poseur]

^^^^^^^
How long will add to lead time for something custom like that usually?

[esoes06]

The summary of the situation is the S50B32 clone. Rods length and piston diameter and crank s50b32 consistency

[esoes06]

I don’t think you will meet you goal of 280 hp with the cams you are using and stock head and intake manifold. Probably like 240 whp. To make 280 whp with stock head and intake will probably require 280+ degree cams

The intake manifold air intake will be 80mm. And 80mm throttle body. S50b32 rods 139mm. I'm going to use 140mm. S50b32 pistons 86.40mm. I'm going to use the 87mm. S50b32 crankshaft 91mm. I'm going to use 89.6mm. The two engines are also very similar. It's different just camshafts. Calculations show +280 hp. Previously the 86mm piston 140mm rods crank 89.6mm result in 270 hp. And the standard absorption is manifold and throttle body. The engine will be built and dyno tested. I will share the results here. Combination of 47.7mm inlet camshaft and valveless suction eccentric Exhaust. I think it's a successful setup.

[esoes06]

not far off whats in my car right now. And i can tell you its not a 280whp build, not without crazy compression and fancy gas. 280 crank feels more like it.

Currently there are 85.50mm pistons and 135mm rods. Standard intake manifold. There is a combination of 47.7 inlet camshaft and m50nv camshaft. Ms41 tune. Crank dyno result 245hp

[esoes06]

272/264 camshafts The combination M50b30 engine is the result of a dyno of 275hp. Within the scope of this project, the pistons are 87mm. Rod 140mm. Inlet camshaft zhp 47.7mm. Intake manifold air inlet 80mm and throttle body. Modified cylinder head. Double spring and large valves and port polish. using 284 camshaft this setup i guess +340hp

[Hofmeister]

Currently there are 85.50mm pistons and 135mm rods. Standard intake manifold. There is a combination of 47.7 inlet camshaft and m50nv camshaft. Ms41 tune. Crank dyno result 245hp

I have 86.4 pistons, 135 rods and 89.6 crank, american s52 stuff. same cams as you mention too, arp head studs and rod bolts, stock thickness headgasket. Also on long tube headers, m50 intake manifold, 3.5" MAF from a 540, chromoly flywheel. I dont think youre going to get to those power figures unless you destroke and start revving it out in the 8k+ region but im no expert.

[someguy2800]

Currently there are 85.50mm pistons and 135mm rods. Standard intake manifold. There is a combination of 47.7 inlet camshaft and m50nv camshaft. Ms41 tune. Crank dyno result 245hp

What did it make at the wheels? I think we are talking in two different ways. Do you want to make 280 hp at the wheels or at the crankshaft? What correction factor are you using to estimate the drivetrain loss?

The S50B32 cylinder head flows much better than an unported m50 head and also has a much better intake manifold and bigger cams.

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^^^^^^^
How long will add to lead time for something custom like that usually?

doesn't add any extra time

[someguy2800]

For an example of what bigger cams can do, this is a friend of mine with the US version of the S50. (Not like the European S50b30). This was 87mm bore, 86mm stroke, stock head, m50 intake manifold, and Cat Cams 282/275 solid lifter cams. The picture is hard to read but it made 284 hp and 260 ft lbs at the wheels.

[esoes06]

What did it make at the wheels? I think we are talking in two different ways. Do you want to make 280 hp at the wheels or at the crankshaft? What correction factor are you using to estimate the drivetrain loss?

The S50B32 cylinder head flows much better than an unported m50 head and also has a much better intake manifold and bigger cams.

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doesn't add any extra time

The power I'm talking about is not wwp. I'm talking about engine power. The cylinder head is machined. Large valves and double springs. Port polish. s52b32 power is limited. Because the rods are 135mm. Intake manifold narrow air ducts. Ecu software is stingy. I modified the s52b32 15 years ago. M50b25 suction manifold and ecu tuned. Dyno test result 265hp. A friend of mine in Poland rebuilt the s52b32 engine. Custom 87mm pistons 140mm rods m50b25 intake manifold m60b30 throttle body cold air intake and ECU adjustment. The result is 310hp power. S52b32 block and m50nv block are like twin brothers. And with better calculations and material is likely higher power.

[esoes06]

I have 86.4 pistons, 135 rods and 89.6 crank, american s52 stuff. same cams as you mention too, arp head studs and rod bolts, stock thickness headgasket. Also on long tube headers, m50 intake manifold, 3.5" MAF from a 540, chromoly flywheel. I dont think youre going to get to those power figures unless you destroke and start revving it out in the 8k+ region but im no expert.

135mm rods ile 6700rpm Good. More is waste. Because rods are shorter than 135mm. Long rods will be more useful to take advantage of high revs.

[digger]

Should be able to reach the goals with a factory rotating and reciprocating assembly E.g. good used or new oversized s52 slugs, 135 rod, 89.6 crank. No need to reinvent the wheel

[M3poseur]

I am eager to see what the final result will be. Good luck with your build. Please share your progress here with us.

[esoes06]

I am eager to see what the final result will be. Good luck with your build. Please share your progress here with us.

Definitely