Rb25de (supercharged) Project

[Adriano]

Usually use a reed valve to stop the exhaust gas, like a 2 stroke reed valve.

[r33_racer]

Can you put a one way valve on there to avoid exhaust getting into the system?

Yeh I have a hydraulic one way valve im going to use. I just need to modify the spring so its weaker and easily opened as this one has a 0.5 bar cracking pressure. But the rest of it is heavy duty and about the right size.

[r33_racer]

I finished the breather can last night. It was a mission to put together and weld up.

Also milled the supercharger inlet bracket flat as it had warped from the welding.

There is the one way valve im going to use for the exhaust evac setup.

[r33_racer]

I got the motor/gbox out on saturday and the block stripped by late afternoon. I cleaned the block up a little and started abit of deburring of edges and cast marks and general loose crap. I picked it back up sunday after shipping the block, head and manifolds to work. More tools, more die grinders and burrs and most importantly more air supply! After about 6 hours of grinding the block ended up looing like this.

You will be suprised at how much casting shit is left in there attached in hard to reach or see places. Main spots I noticed were under the webs where they meet the sump rails and underneath the rails themselves. If you are building your motor, take to it with a die grinder and clean that up. I was quite shocked at just how big some of these flakes were and how loosely they were attached to the block.

Today I picked up a port and polishing kit from down the road. Cost me about 160bux, but it has a heap cartridge rolls, mandrels, extensions, rotary stones and buffs which is pretty well everything you need aside from some carbide burrs. I started after work with some basic port matching of the manifolds to their respective gaskets. While at it I got carried away and cleaned up the runners of the inlet manifold using my new tool set, 40 grit cartridge roll and extension. Took a while but it looks a hell of a lot better then the cast finish and its clean again. I also cleaned up the manifold entry behind the throttle body opening.

It went from looking like this

to something like this

That is pretty well it so far. Tomorrow will no doubt be more of the same! Its fun playing with new stuff.

[zebra]

I love doing stuff like that, but working with old cast iron heads, kills my equipment real quick

Really need a good quality Air die grinder.

You changing much with the engine or is it just a quick freshen up?

[Madaz]

looking awesome

will you blue print also or thats what gasket matching is

[r33_racer]

Yeh, anything ferrous kills equipment unfortunately. Sucks! Great thing about alloys, shit barely wears out at all. Carbide burrs last for almost forever.

Lol, funny you should ask, as Im changing abit actually. Doing the oil control mods properly, block restrictor for head, o ringing block and head if I can fit it in, getting the tunnel honed, bore torque plate honed, crank ground .010" under, some oiling system mods and I think thats it. Probably get piston tops and skirts coated as well.

Also decided to do the rest of the exhaust system in 4" to stop these nightmares im constantly getting of too much back pressure. Probs get that just jap cooling pro 100mm gtr cooler to replace my shitty damaged pwr 75mm gtr cooler.

The more I think about stuff, the worse this all gets!

[r33_racer]

looking awesome

will you blue print also or thats what gasket matching is

Im not sure I follow what you mean by blue print? The engine during assembly/machining or the head/manifolds?

Gasket matching/ port matching is just some light grinding to make manifold ports and gaskets aligned perfectly (or as close too) and then usually doing the head ports to suit as well. Normally you only match the inlet side so there is no restriction when air is trying to enter the motor. On the exhaust however, you want the gasket and manifold bigger then the exhaust port so any reversion will hit the edge around the port and do a u banger instead of trying to go back down the port and into the chamber. So ive matched my exhaust manifold to gasket and they are both bigger then my head exhaust port which I will leave factory size for that reason.

Hopefully that makes sense.

[Madaz]

yep by the sounds of it blue printing was only done on inlet side from your description and the combustion chambers

[zebra]

Yeh, anything ferrous kills equipment unfortunately. Sucks! Great thing about alloys, shit barely wears out at all. Carbide burrs last for almost forever.

Lol, funny you should ask, as Im changing abit actually. Doing the oil control mods properly, block restrictor for head, o ringing block and head if I can fit it in, getting the tunnel honed, bore torque plate honed, crank ground .010" under, some oiling system mods and I think thats it. Probably get piston tops and skirts coated as well.

Also decided to do the rest of the exhaust system in 4" to stop these nightmares im constantly getting of too much back pressure. Probs get that just jap cooling pro 100mm gtr cooler to replace my shitty damaged pwr 75mm gtr cooler.

The more I think about stuff, the worse this all gets!

Sounds good and is also why im leaving the Soarer alone haha.

[XRATED]

moroso evac fitting kit:

http://www.summitracing.com/parts/MOR-25900/

I'm putting on into my gts-t as we speak- h aha ha.

[r33_racer]

lol. Farkk, I could have gotten that instead. Ah well. If mine doesnt work I will get that kit instead!

moroso evac fitting kit:

http://www.summitrac...arts/MOR-25900/

I'm putting on into my gts-t as we speak- h aha ha.

[XRATED]

Are you putting your 'slash cut' fitting in the center of the pipe? I wasn't going to put it in that far, maybe 10mm in or so. I'm more worried about restriction than maximum velocity for vacumme.

J.

[r33_racer]

Lol yeh I did, I put it right after a reducer 4" -> 3" 45 cut in the centre. Thats how I was taught to do it as the best setup for maximum vacuum. Hopefully it wont be too much of a restriction.

[r33_racer]

So I finished my backyard porting job. Pretty well just cleaned up the ports and matched the inlet side. Polished the chambers lightly and roughed up the inlet with 40 grit. Did exhaust in 80 grit.

I have to admit, it took most of the week doing all that. It gets painful around the guides!

[r33_racer]

I made the EHPS pump mounting bracket this afternoon. It should mount nicely in the drivers side back corner of the boot.

So thats one little issue out of the way!

[Rolls]

Did you read up on porting? Apparently there is an art to doing it properly. I'd be too scared to do it wrong and have worse results.

Edited June 5, 2011 by Rolls

[r33_racer]

Did you read up on porting? Apparently there is an art to doing it properly. I'd be too scared to do it wrong and have worse results.

Yeh I did some reading and looked at what pictures I could find around the place to give me an idea on what to do. I didnt go reshaping ports or anything like that. I just matched the inlet manifold and head to gasket and just cleaned up the casting and machining marks. So all ive done is a clean up essentially. If you go and start opening up port sizes and messing with the shape then you could easily go backwards. But I cant really see any harm in what ive done.

But I will find out when its all going lol.

[Rolls]

Ah yep, can't go wrong just port matching. How did you do it just overlay the gasket and draw on it?

[Madaz]

your work looks great, i hope it inspires some people, it would me but i cant be bothered