rb25DE NEO with DET NEO pistons? Conversion build.

[NEO25T]

I did plan to measure the combustion chamber on the de neo head but simply forgot, i would expect them to cc the same as det neo.

I used the runners from det neo with a plazmaman intake, only because i already had it setup on a built motor in the car previously 

[NEO25T]

Det neo piston and rod top

De neo piston and rod bottom

[NEO25T]

Bit of hole hacking, notice how I didn't call it porting......

[Dil-Dog]

@NEO25T wow bro! never seen them side by side before... just by eye i can see that bottom piston (NA) piston is taller/longer then the top (turbo) pistons. 

[Dil-Dog]

@NEO25T did a CNC machine do that?

Edited August 5, 2019 by Dil-Dog

[NEO25T]

Bottom end assembled

Dodgy piston stop to tdc the engine to set cam timing

[NEO25T]

There us usually a oil bypass in the left hole, I removed it and plugged the hole and used det oil cooler warmer thingo 

[NEO25T]

Almost ready to go hurt some feelings, hopefully not mine this time lol

[NEO25T]

8 minutes ago, Dil-Dog said:

@NEO25T did a CNC machine do that?

Nah this was full budget this time round i just opened them up with die grinder, no machining done at all. I just cleaned and measured everything, light hone on the block, cleaned everything again, and again, slapped in some valve stem seals and threw it together.

[Dil-Dog]

@NEO25T wow bro that is really beautiful,  so did a cnc machine "port" your head to the bigger DET holes? what coil packs are you running? is that timing belt cover from a series 2, because it looks like the steel ones and not the plastic NEO ones? and LASTLY, for you catch can, what the fittings you used to fit in the standard holes in the valve covers? i know its AN but can you explain how you made it work, i would like to do the same as well

 

[NEO25T]

6 hours ago, Dil-Dog said:

@NEO25T wow bro that is really beautiful,  so did a cnc machine "port" your head to the bigger DET holes? what coil packs are you running? is that timing belt cover from a series 2, because it looks like the steel ones and not the plastic NEO ones? and LASTLY, for you catch can, what the fittings you used to fit in the standard holes in the valve covers? i know its AN but can you explain how you made it work, i would like to do the same as well

 

Nah it was all done by hand with die grinder, just traced the gasket. I didnt take many pics but started by knife edging the divider then slightly open the bowls to same size as the seats, smoothed the radius of the short turn and slightly opened the ports to same size as det head then just blended it out to the marks from the gasket, i dont think id like to see any flow bench results lol.

Those are r35gtr coils from prp.

Yeah its just a cover from a hydro 25 as i dont like the look of the neo ones, rb20 cam covers on it too.

I did weld fittings in the cam covers on the other motor but these ones um i forget.....

I think those are the standard nissan ones i cut and welded with -12 fittings, you can get them push in to an but the ones i seen were straight so you had to put a 90 degree hose fitting and they stuck up and i didn't like how it looked, ill take a pic if i remember in the next day or 2

[NEO25T]

Welds are pretty average but hasn't broken off yet lol

 

Edited August 6, 2019 by NEO25T
Add photo

[Dil-Dog]

@NEO25T Hey bro i really need a lil help... i am gunna message you directly 

[Dil-Dog]

Just an update for future readers and any one else who may be able to learn from this or wanna do the same.... it works, i put manely h beams and cp turbo neo pistons with acl bearings with no problems. The head cc/size is the same. It is possible to forge a de with det parts 

[X Drifter]

Hey all I’m just in the process of building another rb25de neo engine for my car as my current engine didn’t seem to want to make more than 300rwkw but made good midrange 250 at 4000rpm. I’m wondering if u have a before and after Dyno sheet I’m looking to do a freedy intake polished ports , h beam rods, port and polish head and polished chambers, det cams, ARP studs and aim for 370 to 400 I may have to do pistons but can’t find info on max power from a stock piston motor

[Ben C34]

45 minutes ago, X Drifter said:

Hey all I’m just in the process of building another rb25de neo engine for my car as my current engine didn’t seem to want to make more than 300rwkw but made good midrange 250 at 4000rpm. I’m wondering if u have a before and after Dyno sheet I’m looking to do a freedy intake polished ports , h beam rods, port and polish head and polished chambers, det cams, ARP studs and aim for 370 to 400 I may have to do pistons but can’t find info on max power from a stock piston motor

Why though? Get a different turbo

[X Drifter]

It has a hypergear gtx3582gen2 capable of 470rwkw on a rb25det, I don’t want any bigger

[GTSBoy]

Well, the DE ports are small, so they will become a restriction on max power long before they would on a DET head. It's not surprising that you start to hit a wall.

Your options are to use a DET head or spend some time/money in digging the extra metal out of the ports. I know which would be easier!

Freddy intake is neither here nor there as far as power is concerned. You will make the power just as easily with a stock plenum. So if you're planning to change it for power reasons, spend the money elsewhere.

[KiwiRS4T]

Look for a DET head. Apart from the flow the DE exhaust cam has 6.9mm lift the DET 8.7mm.