R33 Rb30 Conversion

[mr_rbman]

i've got a pretty heavy one in there now, so i'll keep that in there til it dies then i'm not too sure what i'm going to go for, still want driveability though!

I'll use the rb25 runners and the the rb20 plenum then, that sounds the most practical and easiest.

[rukus]

hey.. sorry if this has been asked b4, but for the guys that have already done this, how much did it cost you all up?

[Cubes]

http://www.skylinesaustralia.com/forums/in...s&highlite=cost

[Abo Bob]

I'm sorry guys but I can't seem to work out how to search just in this thread. Nor can I seem to download the thread as a whole to search on my computer. And When I go to print view it only shows about 100 posts.

Anyway. I have a couple of questions.

Has anyone done this with a NEO RB25 head yet? Is it possible?

Do I have to remove the strut brace in my GTT to fit this?

It looks like I need a rebuild and I'm keen for some more torque.

EDIT

I found the search this thread button sorry guys. It seems the R34 RB25 head is pretty much the same. Has anyone actually used it though?

[someonestolecc]

It looks like I need a rebuild and I'm keen for some more torque.

<{POST_SNAPBACK}>

Don't forget to factor the cost of a manual conversion

[Cubes]

Abo Bob,

The Auto would work really well with the auto I think. I had planned on it. UNTIL I changed plans and plan to not use the car as a daily driver once I finish uni, more so a bit of a fun car. Its not worth selling it.

With regards to spool and response.. You would have roughly the same spool/response with the RB30 and a XR6 Turbo as the RB25 with a GCG VG30 highflow setup.

GCG VG30 comes on hard around the 3800rpm mark with the RB25, The XR6 turbo comes on hard around 3800rpm with the rb30, but obviously with more torque and acceleration off boost. The XR6 turbo apparently makes a solid 10psi a shade over 3000rpm. 10psi from that huffer is still a reasonable amount of airflow = power.

Linear = traction.

Its 100% the way I'm going now. I'm sticking the vg30 turbo on for a few months then at the end of the year will hopefully find a well priced xr6 turbo and bolt it on.

Hope my spool estimates are correct.

Edited September 16, 2005 by Cubes

[Abo Bob]

I already have a GCG highflow. I think the RB30 would work well with the auto too.

I do take it to the track though. Will stock RB30 rods be ok?

[someonestolecc]

I wasn't saying get a manual conversion from any *need* but more so from a fun aspect

[Cubes]

Stock rods with constant track use would make me nervous at 300rwkw+.

No worse than the rb25. If anything better as the rb30 rod has a better r/s ratio, more leverage (piston weight won't hurt the rods as much) and as there is more leverage there is less rod side load.

The rod fly's up and down the bore straighter. If that makes sense.

Edited September 16, 2005 by Cubes

[Abo Bob]

Got it.

What about piston speed? That would be increased wouldn't it?

Do you guys use ordinary cast pistons rather than forgies to keep the piston weight down?

Is there any weakness that is shown up by piston speeds that are too high?

I think I know what I'm asking but I might be wrong.

[Cubes]

Forgy's sitting on top of a rb25 or 26 rod is worse than one sitting on a rb30 rod.

Piston speed isn't really an issue. Its all about the rod to stroke ratio.

The RB30 rod length is 152.7mm

The stroke is 85mm.

Thats a rod to stroke ratio of 1.79. Rather nice.

The RB26 rod to stroke ratio is 1.65 from memory.

The mechanical stress is less with the longer rod length. There are two reasons for these results.

The primary reason for these results is that the profile of the instantaneous velocity of the piston changes with rod length.

The longer rod allows the piston to come to a stop at the top of the bore and accelerate away much more slowly than a short rod engine.

This slower motion translates into a lower instantaneous velocity and hence lower stresses on the piston.

Another strong effect on mechanical stress levels is the angle of the connecting rod with the bore centerline during the engine cycle.

The smaller the centerline angle, the less the side loading on the cylinder wall.

The longer rod will have less centerline angle for the same crank angle than the shorter rod and therefore has lower side loadings.

Visualise it.

http://www.sportcompactcarweb.com/tech/0104scc_ssbbpart7/EDIT: Here's a nice little link to help.[/url]

At the end of the day the rod to stroke ratio doesn't make 'that' much of a difference to integrity, more so the lesser friction.

Balancing the motor to 2grams or less will also help it hold together better at high rpm.

I've been told usual street performance balance is 4grams, factory 12grams and race 2grams. Mine was apparently done to 2grams.

Unsure if thats overall 2grams or individual as even the smallest nut had been touched.

Edited September 17, 2005 by Cubes

[DYNOBUSTER]

i have a grampa 1 owner 97k engine and it is unfortunatly a S1 block and it doesnt have the oil drain but worst of all it doesnt have the alternative twin cam idler area on the front of the block

I know if you dont have the machined face you can smooth it over with some devcon type of thing (I have the MOROSO epoxy used for building up intake ports etc just for this purpose) but I was thinking of this idea

you know how you drill and tap a new position for the tensioner above the water pump whats stopping you from drilling and tapping a new hole on the other side like my pic

and my engine guy balances my engines to .01 of a gram (ChrisMiltonED)

Edited September 16, 2005 by DYNOBUSTER

[DYNOBUSTER]

do you think this method wouldnt have enough control over the belt and cause it to vibrate and perhaps cause damage

and are the RB30det engines a free spinning engine IE if the belt broke/fell off would the pistons hit the valves?

[Bl4cK32]

The belt wouldnt be going the way you showed i think. The one below the white one you placed is the std location for the bearing pulley.

If you did that you would end up with the belt running as shown below in my dodgy pic

BTW - thats a photo of my motor just after assembly. And while Milton does know his stuff, im glad i chose elsewhere to get my motor done....

ps- for the price a series 2 motor can be picked up for, it will save a lot of hassles in the long run. Jeezus, its like $100 for a short motor...why do people bother using a motor you have to drill and tap, or modify???

[Cubes]

Why not reverse the location of the tensioners?

Right side up high above the water pump, the left down low?

Interestering you mention Chris Milton Engine Developments, thats who we had do our head.

His price for the bottom end was too expensive for what I wanted.

I was only after a fairly stockish rebuild + a set of forged pistons, crank and rods machined for equal clearances, block crank and rod crack test and a nice heinz balance.

From memory the balance was around $400, thinking back now I'm also pretty sure Andrew sent the bits to Miltons for the balance.

Not too many ppls have heinz balancers.

Edited September 17, 2005 by Cubes

[DYNOBUSTER]

The belt wouldnt be going the way you showed i think. The one below the white one you placed is the std location for the bearing pulley.

If you did that you would end up with the belt running as shown below in my dodgy pic

BTW - thats a photo of my motor just after assembly. And while Milton does know his stuff, im glad i chose elsewhere to get my motor done....

ps- for the price a series 2 motor can be picked up for, it will save a lot of hassles in the long run. Jeezus, its like $100 for a short motor...why do people bother using a motor you have to drill and tap, or modify???

<{POST_SNAPBACK}>

ahhh ok

are you serious

and even if you have a S2 block to save you having to get a cam belt made of un-obtainium you have to drill and tap it above the water pump

and if thats a pic of your engine them you have had to drill and tap a thread for the tensioner so sadly you had to dill and tap and modify YOUR block

why the f**k did you bother <_<

and i have a quote to balance the full engine ie flywheel crank piston/rods and harmonic balancer for $180

this is what I have

$55 acid clean

$140 oversize bore

$186 balance

$100 face head and block

$40 micro finish crank

$252 shot peen rods

$108 resize rods (required after shot peening)

$130 ARP rod bolts

$1125 for Arias forged pistons (with moly rings, pins and locks)

$49 ACL race big end bearings

$89 ACL race main bearings

$66 for the cambelt

$240 for a pair of new belt tensioners

so $2580 for the bottom end

thats on the whole bottom end this is what its cost me so far

I was tempted to run a set of eagle H beam rods and I might on the next one I do but I figured the stock rods would be good enough for what I want to do with the engine

Edited September 17, 2005 by DYNOBUSTER

[Bl4cK32]

ahhh ok

are you serious

and even if you have a S2 block to save you having to get a cam belt made of un-obtainium you have to drill and tap it above the water pump

and if thats a pic of your engine them you have had to drill and tap a thread for the tensioner so sadly you had to dill and tap and modify YOUR block

why the f**k did you bother  <_<

<{POST_SNAPBACK}>

For starters, any rb30det is going to require another tensioner drill and tapped above the water pump (or the other method). I was referring to drilling and tapping new oil and water lines for the turbo, not the tensioner. Sorry for the confusion, just dont get too upset if you read it wrong.

$66 for the cambelt

$240 for a pair of new belt tensioners

<{POST_SNAPBACK}>

Cambelt is only $30 odd, and you can use 2 x rb30 tensioners @ $80 (ie $160 for the pair)

But why should i waste my time if you are going to take offence if i typed it wrong, or you read it wrong....get off it mate, we're here to help everyone. Im no keyboard warrior, ask if you get confused, cos it aint hard....

[Cubes]

Our bottom end complete not including bolting the head on set us back $3500 including Wiseco forged.

But then again we did have the crank and rods machined for equal clearances, or what is known as blueprinting those items.

Even still, you consider no forged pistons in your build, ~1400 for a rebuild seems a little too cheap. My bet is you will go to pick up the motor and you will be faced with a bigger bill. Just like Bl4ck32 was when he picked up his head.

I remember I received a quote from Miltons, listed what I wanted done and the price was up around 6-7k.

Edited September 18, 2005 by Cubes

[mr_rbman]

rang around a few importers about getting a series 1 oil pump off the rb25det and they all said they didn't know the difference between series 1 and series 2 so is anyone able to tell me?

[Bl4cK32]

id say the thickness on the drive...series 1 is the same as rb20det/rb30et and r32gtr

Edited September 18, 2005 by Bl4cK32