R33 Rb30 Conversion

[BIGBLOCKR31COUPE]

With your different compressor it would act differently to mine and come on later but stronger. A friend of mine had the 750HP XTR made for his R32 GTR. My back ribs hurt after a ride in his car. Nothing until 4-4.5k and then bbwwooooossssshh.................RB symphony. Gotta love the screamer pipe. lol

[Sydneykid]

Hi guys, extra 0.15 bar to make up for 0.5 lower compression ratio????

That sounds about the amount you would need to get the same combustion pressure, I have never tried it though. But I don't think that is the point, I believe the issue is how much longer does it take to get to the same boost, and then how much longer does it take to get the extra 2.2 psi.

You may find that the average horsepower is lower because you have to use that part of the rpm range. This is particularly noticeable after an upchange, where you get a hesitation in the acceleration while the rpm and thus boost gets built up again. Do this 3 times in 1/4 run and you have a big difference in ET and TS. Let alone in a circuit race car where you do 20 gearchanges per lap over 20 laps, the difference is half the length of the straight.

I think it would be interesting to look at the exhaust gas production (volume and velocity) of the two compression ratios, that may actually tell you more about the costs and benefits.

But that calculation makes my brain hurt, so time to stop.

[51jay]

I'm curious what does it actually cost to get an old VL block cleaned up inside and out and how clean do the water and oil channels actually come up.

I got a new series 2 VL block off Nick and at $450 it seems pretty good value and of course gets you off to a good start.

ps got an old block for the crankshaft etc cost $50

[Bl4cK32]

riceline, are u planning on using this thread as ur own personal diary?, or going to offer some info at some point.

As for the heads,

If it was not for the cam's on the 25 you would not tell the difference!

you'd have to be lame not to tell the difference between a sohc head and the dohc head.

[riceline]

I have got the motor out of the car... What i want to know does anybody know a way to get the harmonic balancer and clutch/flywheel assembly off the motor, The gearbox is still in the car. I'm thinking im going to have to get a motor shop to do it.

[BIGBLOCKR31COUPE]

Loosen all the bolts on the flywheel first and then jam a long bar between them to hold it still while you undo the balancer.

[dontfeelcold]

is it possible to machine the rb25det pistons to acheive 9:1cr without weakening it it anyway?

or can the block be machined a bit?

it seems worthwhile to have 9:1cr, seeing as the rb25det has this cr.

[scary]

OMG i thought this thread would never finish!

I am very impressed with all the helpful information supplied by all!

I am from the calaisturbo forums actually and i am considering the DOHC and turbo conversion to the series II n/a block.

Ive just got 2 questions;

1.

The thing that worries me the most is the VCT RB25de head... and in the DIY RB30det pdf file, it says

'The RB25de head from the R32 GTS non-turbo bolts straight up to the RB30e bottom end.' Just to clarify this, does this mean that NO drilling or filling or welding or whatever has to take place to get the head and block to mate well? So, if i used a R32 GTS non-turbo head, it will bolt straight to the RB30e without modification? Because if this is true, i am going out and buying one this weekend! :-)

2.

To get a turbo and RB25de head to work well for a daily street car, which aftermarket (stock?) ECU will handle all this? I havent read into it too much but cost is always a factor, so what do you guys recommend?

Thanx again and well done on an informative and llllooooonnnnggg thread ;-)

[Cubes]

The R32 GTS RB25DE head is a straight bolt up. You can use either the headgasket from the R32 GTS RB25DE VRS kit that costs $275 from Nissan (All top end gaskets, rocker cover gaskets etc) OR you can buy a RB30E headgasket for around $80 and use that.

There is no drilling or filling required.

Because you have a VL the only problem with running the engine is the CAS. You will either have to adapt the wiring loom/ecu from a R32 GTS and get it chipped or fit an aftermarket ecu with the required wiring adapted to allow the CAS to work correctly.

I went with the R32 RB25DE head as it is an easy bolt up in to the R32 GTS. If I were to go the R33 RB25DE/T head then I would have to frig around with an ecu that can handle the VCT, fill in holes and drill a new oil supply for the VCT.

The port size & valve size between the R32 RB25 & R33 RB25 heads are the same. The R33 RB25 appears to look bigger however it isn't as the R33 RB25 ports have a slightly different more open looking design around where the injectors sit. The ports are not bigger though. Use the RB25DE inlet manifold & plenum. The RB25DE injectors are the same as the RB20DET injectors.. 270cc's or is it 320cc's from memory. I think the R33's are 370cc's.

[scary]

arhhh excellent thanx heaps for that -Joel- !

now i just need to do some research on and ECU!

hrmm, i wonder if a can just piggyback a LINK ECU onto the VLT ECU and perhaps that will run the CAS ok?

*waits for someones opinion...* hehehehe

Cheers

[Cubes]

You would have to some how get the wiring sorted so that the CAS will operate as the CAS is what keeps track of where the crank is so that it can fire the required coil/plug. The VL's use the old distrubutor which is a mechanical CAS, in other words the VL/T ECU hasn't got provision to fire coils etc as that is what the distrubutor kind of replaces. It spins with with the crank and sparks the required plug when the rotor button touches the bits in the dizzy cap.

That is where the problem lies. I'm sure the VL turbo calais boys would know the easiest cheapest way to get around the problem.

[riceline]

Hey guys motor is geting there very nicely.. just need to know about the timing belt.. I have the belt (dayco 94407) and have relocated the tenisoner stud... just need to know where the timing marks on the belt would be? and how many teeth from the bottom timing mark should i be putting the belt on at?

Just a few extra questions.

I am looking at geting new vaccume lines. Would you guys recommend it?

I know that the standard radiator will cope with the load but i also know that Try09 runs a VL radiator Is it much bigger than the skyline one? If it is im going to get one and give my skyline one to a mate with a 180..

[GiJOr33]

It looks like my engine build won't be ready in time for me to put in my car and have some fun. I head over seas in March for an unknown length of time so i'll probably sell my skyline (and all associated turbo equipment/mods). But i'll keep the engine and hopefully put it in a GTR when i get back

No point wasting the quality parts as well as time and effort put into the build. I'll just store it till i get home and unleash the fury then!

[riceline]

gijor33

Thats a shame man that you wont get to play with your new toy for a while. Be sure to keep on this fourm when you are gone just to see how others are going and what not.. Ill be sure to smoke up the rear's when out at willobank for you

I just also want to ask a few questions.. I know that I have asked them on the last page.. but not many people read back through the thread.

I just need to know about the timing belt.. I have the belt (dayco 94407) and have relocated the tenisoner stud... just need to know where the timing marks on the belt would be? and how many teeth from the bottom timing mark should i be putting the belt on at?

I am looking at geting new vaccume lines. Would you guys recommend it?

I know that the standard radiator will cope with the load but i also know that Try09 runs a VL radiator. Is it much bigger than the skyline one?

take it easy guys.

[51jay]

No timing marks on belt as far as I know, marks are on the top wheel with a reference mark on the front of the head just above it. re vaccume lines....depends on the condition of the old ones. Re radiator.... I don't know I would assume that as the RB25 developes more power in stock form it's radiator would be bigger capacity..... but don't quote me on that .

[JNR24]

Hi 51jay,

I would assume the oppisite as the RB30 motor has a bigger displacment than the RB25. Bigger displacement = more heat.

If your worried about cooling, this is what im going to be running with my RB30/25:

http://www.are.com.au/Rad/radiator_options.htm

[Cubes]

I've got a R33 Radiator shroud on my R32 GTS-T radiator, they appear to look the same size.

The RB30 VL radiator is massive compared to the Line radiators, I doubt it would fit.

With regards to the RB's I believe

displacement = more heat

is a fallacy.

[GiJOr33]

VVT and not using it...

If you don't want to use VVT (cam gear, or just don't want to hook it up) do you need to leave the big thing on the front of it? because when i undid the 4 little bolts oil came out, then when i undid the big bolt in it more came out. So i presume that if you decide to leave that bit off then you are going to have oil leaking out. So if you have a VVT head, what do you need to do if you don't want to use the VVT?

We've discussed how to hook it up, but we've never discussed how to disable it.

And also what head bolts do you use? do the normal RB25 head bolts fit?

[riceline]

you have to have a line to the head as the oil not only runs the VVT it also lubes up the cam bearing so your kinda stuck with it.. if you dont want to run it just pull the fuse i belive..

as for the head bolts a have the rb25 ones in and they work fine

[Spoolup]

If you dont want to use the vvt cam pulley you have to replace the cam shaft as it is designed only for the vvt pulley. Otherwise you cam just disconnect the solenoid.