First Time Engine Build. Rb25/30 Neo Advice

[sky30]

Some thing else to think about, obviously to late for josh now, but by blocking a oil feed to the head you doing two things 1) creating uneven flow in the head ( not really an issue ), 2 ) creating an air pocket in the block under the plug ( can be an issue )

I am running two 1mm restrictors and a idle while looking through oil cap there is a good solid flow of oil coming out of the cam bearings

And while I'm here IMO a 3" exhaust on a 3.0 is to small, on my 2630 I went from a 80mm jap exhaust which had no restrictions in it ( I checked ) to a twin 3" in to single 4" and the difference is night and day, it is better every where

Did it make much more power with the exhaust? And is the wastegate plumbed back in?

On my 26/30 i have a 3.5" dump to 3" at mid car, dropping the exhaust half way so it was just 3.5" dump pipe only made 3kw more power on dyno. My exteral wastegate is vented to atmosphere so takes some pressure out the exhaust.

[KiwiRS4T]

And while I'm here IMO a 3" exhaust on a 3.0 is to small, on my 2630 I went from a 80mm jap exhaust which had no restrictions in it ( I checked ) to a twin 3" in to single 4" and the difference is night and day, it is better every where

At what point is 3in not enough? What power are you making now? I am making 314awkw and have wondered if a bigger exhaust would help although most say 3in is enough for 350kw.

[XKLABA]

Did it make much more power with the exhaust? And is the wastegate plumbed back in?

On my 26/30 i have a 3.5" dump to 3" at mid car, dropping the exhaust half way so it was just 3.5" dump pipe only made 3kw more power on dyno. My exteral wastegate is vented to atmosphere so takes some pressure out the exhaust.

I am running twin GT-RSs with internal gates, CES comp series split dumps so wastegates are plumbed in, and this is the exception, if the waste gates vent atmo then you can get away with a smaller exhaust

What power are you running ATM ?

[XKLABA]

At what point is 3in not enough? What power are you making now? I am making 314awkw and have wondered if a bigger exhaust would help although most say 3in is enough for 350kw.

I have made 458kw @28psi at all 4, IMO on a 3.0 with gates plumbed in once you pass 300kw at all 4, so a bit more for RWD, then the 3" starts been a restriction, now its not a case of 300 its fine then 301 its a massive restriction, at 314 I don't think it would make much difference, certainly not enough to warrant changing it, over 350 it would really start getting worth it though

If you get to 400 with a 3" on a 3.0 then your pushing it really hard and would gain a fair bit

I know people can make by power with a 3" but then you can blow a golf ball through a length of garden hose if you blow hard enough, the bigger exhaust just allows the motor to do it easier

[sky30]

I am running twin GT-RSs with internal gates, CES comp series split dumps so wastegates are plumbed in, and this is the exception, if the waste gates vent atmo then you can get away with a smaller exhaust

What power are you running ATM ?

Yea i would agree the internal wastegates would need bigger, but would think 3.5" would be near big enough.

Mine made 434rwkw through the full exhaust 3.5" to 3" rear half, 436rwkw with it just the 3.5" dump.

What rpm you get 20+ psi with the rb30 and gt-rs?

[XKLABA]

That's interesting and the difference an external wastegate/screamer makes, have you got a graph with both runs on it ?

Be interested to see the difference, would also like to know what would happen if you had to plumb the wastegate back in

What fuel are you using ?

I have a graph posted in the RB30 thread, its says about 5k is full boost but the RPMs aren't scaled right cause of the big tyres I have on the car, from driving I'd say full boost is around 4500, I haven't checked it yet

[iruvyouskyrine]

Hopefully I should be right, exhaust isn't particularly restrictive haha

[XKLABA]

LOL, no restrictions there

What's funny though is if you undo it at the V clamp it will be quieter

Nice peice of fabracating work

[iruvyouskyrine]

Yeah I'm pretty happy with it. I don't want to put it on the car to be honest, it's too beautiful!

Exhaust was made by Dann at NitroDann fabrication in Hetherbrae NSW. Top bloke to deal with!

[iruvyouskyrine]

Okay, went to put coolant in today and as i was filling it up i noticed that there was water leaking from the water pump. I had a look and thought that i must have just missed putting a bolt in, strange but sometimes you do miss stuff. Went to put a bolt in but it feels like there is no provision in the RB30 block for a bolt to go in. I should note that i am using a standard RB25DET NEO water pump, not the RB30 one.

So i started having a look here for info and the RB30 guide says "R33 RB25 water pump have a slightly different bolt up pattern" which i take to mean that this bolt is usually left out. Some more searching led me to a few people who leave this bolt out with no issues at all with water leakage, but i was getting them with just pouring into the radiator!! system was not even under pressure. Some people have said they just tap a thread into the water pump and put a bolt in there and liquid gasket it in, which sounds not too bad to do, but probably not ideal.

Just wondering what peoples thoughts are on this, should i pull it off and put a RB30 water pump on? Wanted to run the NEO pump as it is apparently the best water pump for RB as it flows well at high and low RPM and is anti cavitation.

[Simon-S14]

most people just use an RB30e pump which works fine.

i have in the past used rb25 pumps and filled the hole with sikaflex, zero issues also. It sounds like yours wasnt installed correctly as even with a bolt out it shouldnt pour water out like that. there's still a sealing surface on the pump and block, did you use the gasket? i never use gaskets i clean the block thoroughly and use proper sealant and then mount the pump

[iruvyouskyrine]

I used permatex liquid gasket, same thing i used for my thermostat housing and sump etc. I think the issue is i didnt quite use enough of it and without that bolt it isn't quite sealing properly again the block. I'm thinking of just machinig up a bit of tapered alloy and then filling the hole with liquid gasket, and hitting the alloy in for an interference fit. I think that should get it sealing properly.

I do have 2x spare RB30 pumps here that i can put on if that doesnt work but ideally i would like to run the neo pump.

[XKLABA]

Interesting, I used an N1 pump with just a gasket and no leakage and it uses all the bolt holes

[iruvyouskyrine]

So.

Put some shitty Shell 10W-40 that cost me $16 (half price at supercheap) in it and cranked it over a fair bit beforehand to try and get some oil circulation through the engine. Just running on my old map (25, ID 1000cc, 98 ULP, Hypergear SS2) but now using E85 i cranked it over and it fired up first turn of the key! Sat there idling for a little bit and it was missing but after about 30 seconds it sat idling perfectly, but any application of throttle caused it to choke up and almost stall, like there is no AFM connected. Surprised it started on E85 really.

During all this i was so excited that it didn't grenade itself on start up that i forgot to look at the oil pressure guage. Started it again and the guage was reading zero. Fck. Took turbo oil feed off and there was plenty of oil coming from there. Wondered if i had hooked the oil pressure sensor up backwards, and sure enough i had!

Started it again and i was getting between 55-60 PSI on 10W-40 on cold start/idle, is this value about right? Didnt leave it running long enough to get warm as i want to adjust the tune for E85.

Anyway, im stoked that it lives (for now) haha. Will do a compression test soon so i can get a baseline and try and guesstimate my static CR.

[iruvyouskyrine]

Should mention that i am only using this oil for startup and will be changine it very soon. Will be running Penrite full syn 10-tenths racing 10W-40.

[Simon-S14]

flat spotting when cold on e85 is gonna happen with no tune. you'll find that once warmed up it will run much better. this is something that once tuned, wont be an issue.

comp test wont give you any real guide for CR

50-60 psi on cold start is a tad low. what pump? RB30e? is the relief valve spring bumped up a bit? and also how accurate is the gauge

[iruvyouskyrine]

flat spotting when cold on e85 is gonna happen with no tune. you'll find that once warmed up it will run much better. this is something that once tuned, wont be an issue.

comp test wont give you any real guide for CR

50-60 psi on cold start is a tad low. what pump? RB30e? is the relief valve spring bumped up a bit? and also how accurate is the gauge

Yeah standard RB30E pump shimmed up with 2 washers (3mm) exactly as you suggested. Its a SAAS gauge, and i have no idea if its accurate or not, it worked on my last engine but once again i never knew if it was accurate. Might buy a mechanical guage and see what that reads.

Edited August 27, 2014 by iruvyouskyrine

[Simon-S14]

could be 10 psi out.. FWIW mine is around 70psi from dead cold at idle which drops to around 45psi after a few mins idling

[iruvyouskyrine]

After talking to a respectable member on these forums about oil he has said;

Stay with a 40 weight, if oil pressure looks low go for a 50 weight. Point being the lowest oil weight to get to the pressure you need. You want to see 10 psi per 1000 rpm so if you see 75 psi hot or even 80 PSI at 7500 rpm your safe. Dont stress about pressure at idle or very low RPM, there is not enough force to break the oil film but you still should have some good pressure.

So that gives me a bit of hope. Still using the shitty run in oil so i can go back and switch my good oil for a 50 weight if need be. Will get a mechanical gauge onto is ASAP before i start it next.

Thanks for all the info/help simon, been great being able to learn from someone so experianced!

[r33_racer]

Was about the say you could just put a 50 grade oil in there and that will help bump it up. However that will all drop once it gets hot and thins out which is normal so no need to worry the first time you give it a good hard run and find the idle pressure sits a lot lower.