R33 Rb30 Conversion

[Bl4cK32]

wouldn't it be better to get it welded? Wouldn't want to risk it coming away and floating around.....

[[SweN]]

Can someone tell me the alloy cement for blocking the VCT hole in the head is called? i need to buy some tomorow. the one that expands with alloy?

i got the impression from a pic i saw on here, near the bottom, that you can use a screw, and maybe just putty for good sealing??

[the phantom]

I just tapped the hole and used a socket head grub screw with a bit of loctite to be sure it never leaked....done 50000km in it and havent had an issue....

[Sydneykid]

Hi guys, I haven't drop in on this thread for a while.

Steve, asked how extra power causes dropped valves?

What happens is the extra boost holds the inlet valve open if the valve spring isn't strong enough to close it. It stays open long enough for the piston to come up and hit the open valve.

This either breaks the head off the valve instantly and then proceeds to smash it around the combustion chamber. If it doesn't break the head off, it bends the valve stem which holds the valve open and the piston then proceeds to hit it until it does break off. All this happens at 100 times a second at 6,000 rpm and makes an awefull mess of piston and head.

So having suitable valve springs is definitely a good idea.

Somebody asked about having to remove the head to change valve springs. You actually can change valve springs with the head on. We use a leak down tester and fill the combustion chamber up with compressed air. Then you can compress the valve springs enough to remove the collets, the retainers and the old springs and replace them with stronger springs.

On the dynosaur V8 Supercars we use a "special tool" (curved screw driver). Stick it in the spark plug hole and hold the valve closed. Then change the valve springs as above. We can't use compressed air cause the dynosaurs have only 2 big valves per cylinder, so they need monster valve springs. RB's with 4 valves of smaller individual size have much more sensible spring rates that don't soak up as much horsepower either.

Hope that helps

[Cubes]

So the big question is.. are the NA RB25DE Valve springs strong enough to handle the 300rwkw or say up to 20psi of boost?

While you are there Sydneykid.

I've noticed that in no. 5 combustion chamber both of the exhaust valve seats is sitting a little higher than the head. i.e you can run your finger along the combustion chamber and your nail will grab the edge of the valve seat. One is worse than the other.

All of the other valve seats are sunken in to the head where as it appears No 5 sits above the head. No 6 Sits flush with the head.

Darren or Bl4ck32 has the same head and he said all of his are sunken in to the head. My head has been rebuild, ported polished with quite a bit of work down to the exhaust's bowl area. The Inlet valves have been de-shrouded.

Looking at it I can imagine the valve seat getting to hot due to its edge being exposed and heat concentrating on it. Is this a problem?

[Bl4cK32]

Actually, just had a real close inspection. One exhaust valve on #6 is sitting flush with the surface of the head. All others are sunken slightly.

[Steve]

Originally posted by Sydneykid

Hi guys, I haven't drop in on this thread for a while.

Steve, asked how extra power causes dropped valves?

What happens is the extra boost holds the inlet valve open ......

Boost I understand, but power I dont? What boost pressure do you recommend upping spring rate?

Cheers

[GiJOr33]

For those going with aftermarket pistons. Do you get domed or dished pistons? Cos i worked out that 6cc domed pistons will mean that you get a compression ratio of 9:1. It also means that you don't have to spend big modifying the RB25DE cylinder head and only have to machine it 0.5-1.0mm.

That's with a 1.2mm head gasket and 87.5mm bore.

[[SweN]]

GiJOr33, i think its been said a few times that the 8.3:1 cr is pretty good for this hybrid engine. so i dont think many ppl have actually gone and bought domed pistons (if you can even get them.. i havnt seen any for the rb30)

i personally will be going for forged pistons with valve cuts and leaving it at that. might deck the head slightly when i get other work done tho.

on another note:

a friend of mine was speaking to an engine rebuilder today and mentioned that i was looking into the rb25/30 hybrid. basically the guy said "its one of the stupidist things you can do. the block twists up, and its just been born form the stupid aussie mentality that bigger is better. if it was so good the japs would be doing it."

anyone think there is any truth to what he said?

1. its an american mentality

2. the japs DO do it, but they get 3ltr built engines (or so ive been told)

so what about the block twisting up. havnt seen it mentioned at all, and i dont believe it. any one else?

[Steve]

Originally posted by [sweN]

on another note:

a friend of mine was speaking to an engine rebuilder today and mentioned that i was looking into the rb25/30 hybrid. basically the guy said "its one of the stupidist things you can do. the block twists up, and its just been born form the stupid aussie mentality that bigger is better. if it was so good the japs would be doing it."

anyone think there is any truth to what he said?

1. its an american mentality

2. the japs DO do it, but they get 3ltr built engines (or so ive been told)

so what about the block twisting up. havnt seen it mentioned at all, and i dont believe it. any one else?

:whackit:

to expand, there are only 4 ways that I know of to increase the power from an engine

Forced induction

Increase revolutions

increase the number of cylinders

increase capacity

given everything else being the same, a larger capacity engine will always create more power.

If the 3L engine was so prone to twisting (god know how) - I am sure that guys like sydneykid who use one for the track, would be only too aware of that and wouldnt build as many 3L engines as he does.

Also John Munro and Kier Wilson, infact OS Giken are all morons cos they use 3L blocks. And I am 1000% certain that isnt the case.

[Cubes]

Lol... Its quite funny with what some people come out with.

I called a Jap Wrecker once and it turned out they did no imports.

No problems.. I said and he followed it with...

"If I had it my way all of those pieces of Jap crap would be at the wreckers"

I was actually kind of shocked and replied.. "Good on ya Buddy" and hung up.

Swen.. Let that bloke know that a lot of the HiPo Jap 800+hp RB's are 3ltrs. Takiara comes to mind.

[JNR24]

Originally posted by [sweN]

GiJOr33, i think its been said a few times that the 8.3:1 cr is pretty good for this hybrid engine. so i dont think many ppl have actually gone and bought domed pistons (if you can even get them.. i havnt seen any for the rb30)  

i personally will be going for forged pistons with valve cuts and leaving it at that. might deck the head slightly when i get other work done tho.

on another note:

a friend of mine was speaking to an engine rebuilder today and mentioned that i was looking into the rb25/30 hybrid. basically the guy said "its one of the stupidist things you can do. the block twists up, and its just been born form the stupid aussie mentality that bigger is better. if it was so good the japs would be doing it."

anyone think there is any truth to what he said?

1. its an american mentality

2. the japs DO do it, but they get 3ltr built engines (or so ive been told)

so what about the block twisting up. havnt seen it mentioned at all, and i dont believe it. any one else?

BAHAHAHAHHA

"block twisting up"....! :whackit:

How the f**k does a block "Twist up" ??

Why arent these blocks "twisting" on 9 & 8 sec VLs...??

tell him to check out the top 10 cars (Street drags) for calder-park racway.

EVERY ONE = Holden VL RB30, Hodlen VL RB30..... some ppl have no idear.

[[SweN]]

hahaha, just the respones i figured it would get

How the f**k does a block "Twist up" ??

the guy thats helping me with some car work at the moment used to build some small race engines, the blocks would twist cause there wasnt enough "metal" in them to take the abuse and heat they were receiving, only good for 3 races or something he said. but apparently they were cheap to replace or something so the team didnt care...

meh

[the phantom]

The R31/VL RB30 block hasn't got the integral 4WD sump mounting wings that the RB26 has for 4WD applications....

The Japs do perform this conversion....they resleeve an RB26 with taller cylinder liners and a thick deck plate with a longer stroke billet crank....i.e OS Giken 3.0 and others. Rumour has it that the RB26 block is structurally stronger than the RB30 however....

[Cubes]

Isn't it just the N1 RB26 blocks that are stronger?

[Guilt-Toy]

what power should be expected from a rb30det with vct pfc hks t04e supra fround mount intercooler malpassi adj fuel reg

I had 285bhp with a smaller VL t3 / t4 hybrid with the 25 (engine has done about 188,000km)

Would the turbo and bigger engine break into the 300's ??

[GiJOr33]

300hp or kw? it should do 300kw easy if you have the fuel supply to cope with it.

[OVL-747]

is that 300kw at the engine or wheels.

i dont think it will reach 300kw at wheels , and if he is using the standard computer , it wont have the ability to run a fuel system , to handle 300rwkw.

with that combo , id invest in a better fmic that the supra one.

should push 330hp at the wheels or so , good luck with it.

[Guilt-Toy]

i am using a Apexi PFC computer. & malpassi adj reg

[geordie]

Ok well i have read all 33pgs......very interesting. I got a r32 gts25, and i am feeling the urge for a turbo, so why not go all out and go for the 3ltr bottom end, considering my car already has the engine mounts and the preffered head for the conversion. Now.......what else can i retain, apparently my plenum is good for the job, i will need to upgrade my fuel system, injectors and fuel pump...yes???

As for the computer whats my best option, a r32 gtst??, or go for the power fc, my goal is 250+ rwkw. 300 would be sweet. Does the r32 puter have closed loop???

I also know before i start the conversion i will need, new diff, gearbox(rb25det), suspension and brakes, so dont mention them. And ofcause zorst. But atm i am just wondering what i can keep of my current engine to cut some costs for the all ready expensive conversion. I will need new oil pump yes??

Thanx in advance. Cheers