M50 Future Turbo rebuild internals

[BeauBatchelor2]

Hey guys,
Im from Australia and I understand the American market got some different combinations of parts than us but ill explain the situation and hopefully someone can help.

I have an m50b25 which is the iron block. The motor is going off for rebuild soon but need to decide on what internals I go with which is what I need help with. I have sourced myself an m52b28 crankshaft, rods and pistons. I will definatly be using the crank.

THE GOAL:
so motor is getting rebuilt and I want to make the most of quality parts while were in there but would it be suitable to replace the rods and pistons to a stronger alternative such as je, cp or eagle rods etc. I will need to stay around stock compression ratio as I will be driving the car N/A for a year or so, meaning I won't be able to drop comp by means such as lower comp pistons. I just want to make sure that I am using quality components that will allow for 450hp reliably once it is turbo'd. So other than the usual mls head gasket for dropping comp and arp head studs. Would it be worth going better rods and pistons?

Bottom line: will I need to go better rods and pistons for getting 450hp reliably while maintaining stock compression for a year and by dropping compression through head gasket.

Any help would be greatly appreciated.
My insta is beau_Batchelor so if you would like to get in touch feel free to message me there.
Cheers.

[E30s50dude]

Why not just drop the compression with aftermarket rods and pistons to 9:1 or lower? You should be able to drive the car either way N/A, especially if your going to boosted route later. I would just build it from the start for the peace of mind and reliability you want.

[wgknestrick]

Hey guys,
Im from Australia and I understand the American market got some different combinations of parts than us but ill explain the situation and hopefully someone can help.

I have an m50b25 which is the iron block. The motor is going off for rebuild soon but need to decide on what internals I go with which is what I need help with. I have sourced myself an m52b28 crankshaft, rods and pistons. I will definatly be using the crank.

THE GOAL:
so motor is getting rebuilt and I want to make the most of quality parts while were in there but would it be suitable to replace the rods and pistons to a stronger alternative such as je, cp or eagle rods etc. I will need to stay around stock compression ratio as I will be driving the car N/A for a year or so, meaning I won't be able to drop comp by means such as lower comp pistons. I just want to make sure that I am using quality components that will allow for 450hp reliably once it is turbo'd. So other than the usual mls head gasket for dropping comp and arp head studs. Would it be worth going better rods and pistons?

Bottom line: will I need to go better rods and pistons for getting 450hp reliably while maintaining stock compression for a year and by dropping compression through head gasket.

Any help would be greatly appreciated.
My insta is beau_Batchelor so if you would like to get in touch feel free to message me there.
Cheers.

If I were you, I'd build it for it's end goal without compromise. 1 year is nothing. Head gasket spacers are a compromise in the long run IMO and can expose you to oil leaks (my original S52 engine had both).

M50 with good tuning, good modern turbo, cut ring head gasket, rods, and 9:1 pistons is damn near bullet proof. You are going to blow way past your 450hp goal. My stock block (ARPs and HG spacer) S52 made 440whp on wastegate pressure/12psi and 93oct. My built M50 (2.9l) hybrid (with VAC cams) made 495whp, 12psi, and E85. Both on the same EFR 8474 turbo system. It shows you what you can pick up with cams and that your power goal is way low for you intend to do to your engine.

[dominator293]

Do it properly in the first place by lowering compression, why do the work twice? On a side note, i'd avoid MLS gaskets unless you have machined the block perfectly smooth, stick with a cutring gasket.

[BeauBatchelor2]

Why not just drop the compression with aftermarket rods and pistons to 9:1 or lower? You should be able to drive the car either way N/A, especially if your going to boosted route later. I would just build it from the start for the peace of mind and reliability you want.

Yea that really seems like the way to go. The only thing I was concerned about was making the car substantially slower than factory while it was N/A once I dropped the compression. I still want to be able to have fun N/A but if its not going to be heaps slower there is no reason why I won't do that. Would be nice to hear from someone that has driven around NA on 9:1 compression and what they thought of it.

- - - Updated - - -

If I were you, I'd build it for it's end goal without compromise. 1 year is nothing. Head gasket spacers are a compromise in the long run IMO and can expose you to oil leaks (my original S52 engine had both).

M50 with good tuning, good modern turbo, cut ring head gasket, rods, and 9:1 pistons is damn near bullet proof. You are going to blow way past your 450hp goal. My stock block (ARPs and HG spacer) S52 made 440whp on wastegate pressure/12psi and 93oct. My built M50 (2.9l) hybrid (with VAC cams) made 495whp, 12psi, and E85. Both on the same EFR 8474 turbo system. It shows you what you can pick up with cams and that your power goal is way low for you intend to do to your engine.

Cheers man, looks like building it from the start is the way to go. would you have a recommendation on what piston and rod combo?

- - - Updated - - -

Do it properly in the first place by lowering compression, why do the work twice? On a side note, i'd avoid MLS gaskets unless you have machined the block perfectly smooth, stick with a cutring gasket.

The only reason I was thinking not to drop compression via means of pistons was because I would still like to have fun in the car while its NA. Then once it camp time to turbo just do head gasket. But it really seems as though building to 9:1 from the start is the go. just wonder how much slower it will be

[dominator293]

It would be a little bit down on power (maybe 10kw?) but still not as slow as a 318i To be honest, the freshly built lower comp motor will potentially have more power than a 28yr old clapped out M50. Unless you're made of money mate, i'd do the low compression now, then save for a decent turbo build. No point spending all this money on an engine now then having to re-do stuff in 12months time. Just live with the small lack of power and feel the gains in 12mths.

[someguy2800]

A 2.8L with 9.0 compression will still make more power than a 2.5L with stock compression. I agree with the others, just get it over with.

[E30s50dude]

I have a 9:1 piston rod set up and I've haven't driven the car yet due to it being winter rn. I can say the motor feels just as responsive as it did on stock internals with the potential to be even better with my 6466 attached lol.