[SvartKatt]

Hello, I am in the process of assembling an engine for my S40 based on a 2.5l B52544T2 RNC turbo block and crank, rods. It is going to be a NA build, and I want to keep my compression ratio up around 10.3 - 10.5:1 (stock NA) rather than the turbo 9.5:1.

Can I use my stock '04 B5244S pistons with the 2.5l block,crank, and rods to do this?
Does anyone have the critical piston dimensions for the 2.5 and 2.4l 5cyl. engines
( pin center to crown height, dish volume, etc.) that I need to complete my build?
I'm not looking for forged pistons, just a decent set of OEM or aftermarket D grade slugs
to wrap this up. Thanks!

 

[Facusan]

That doesn't look like the correct PCV for a RNC block. What car that block came from?

 

[Facusan]

Here's some info I got from VIDA:

 

[LukeFlynn]

That's not gonna work, PCV ports are incorrect, and cooling system is different. You can see the casting on the block for where RNC thermostat housing would be. This is an RN P2 block. Theoretically with a lot of work and adapting mounts to it, you could make it work, but not well.

 

[LukeFlynn]

It looks like you've already bored out that passage, but the large difference between the crankcase vent system is bound to cause fuel trim issues, and you will need to modify the RNC intake system to work with this. The fuel trim issues would concern me, because there are basically NO tuning options for this specific Denso ECU

 

[dunn53338]

“


Sent from my iPhone using Tapatalk

 

[SvartKatt]

That doesn't look like the correct PCV for a RNC block. What car that block came from?

Thanks for your interest in my project. It came from a '04 S80. B5254T2. It was a RN block, but I've made some modifications. I'm retaining the oil separator and pan mounted oil filter from the S80, but using the RNC style NA cylinder head and coolant outlet/thermostat housing. (This required drilling out the cylinder wall inside of the thermostat boss on the block to make it active) here are pictures of my modified block, with an '04 S60 head I am using. I guess I could call it an RNM engine :>)

 

[SvartKatt]

It looks like you've already bored out that passage, but the large difference between the crankcase vent system is bound to cause fuel trim issues, and you will need to modify the RNC intake system to work with this. The fuel trim issues would concern me, because there are basically NO tuning options for this specific Denso ECU

I just bought a PCV diaphragm valve from an Audi engine which I plan to try first.

here is the intake I will use.

 

[SvartKatt]

It looks like you've already bored out that passage, but the large difference between the crankcase vent system is bound to cause fuel trim issues, and you will need to modify the RNC intake system to work with this. The fuel trim issues would concern me, because there are basically NO tuning options for this specific Denso ECU

Hello, here are pictures of the intake manifold and PCV diaphragm valve (from an Audi) that I plan to use.

 

[Facusan]

Ok, with the thermostat location issue now solved, I'm wondering about the motor mount locations. I know on the P1 vehicles the timing belt side mount bracket is bolted to the cylinder head, that shouldn't be an issue at all (hopefully.....) since you're using an RNC head. The driver side mount bracket is bolted to the transmission case (which I'm guessing you will be using a P1 transmission. The only one remaining is the torque mount, which, IIRC the bracket is bolted to the block. Are those mounting points available on the RN block?

Another thing I'm thinking is how the ECU will react to the "extra" air the larger displacement engine draws through the stock MAF. Hopefully it will able to adjust the fuel trims within the normal parameters and without triggerin a lean mixture DTC. But if it does, I guess you could try using T5 injectors, which they have a higher flow rate. Yes they work in 2.4i engines, I tested them on mine for a couple days.

This is a very interesting project, I'll be following this one!.