My Rb30 Block Prep

[deep_space]

hello everyone. i am slowly building an rb30 for my gtst. i decided i want to get good power but be as reliable as possible too. so i am doing some hours (read lots) of work to the block.

flattening all of the casting marks on the internal walls, i am also going to redrill the oil drains and smooth the larger oil drains. here are some pictures for you

[urtwhistle]

you did exactly what I did. its amazing the amount of loose casting there is on there

[johnbarry88]

I spent hours doing this to my block and unless you are going to put 750+bhp their is no real benifit, although it may help in the long run..

[urtwhistle]

I spent maybe an hour if that, with a tapered burr. I mainly focused on removing the burr's from where the casting joints had not been removed. Its by no means polished but just a quick sweep across the surface removing the loose crap.

[r33_racer]

lol nice. I did the exact same thing to my rb25 not that long ago but I spent about half a day or more doing mine.

[urtwhistle]

screw that lol, My theory was that if it hasn't come off in 15 years of abuse and or a quick sweep than it sure as hell ain coming off with the oil washing past it. although yours looks alot nicer than mine

[r33_racer]

I agree with you there, but I get abit anal when doing stuff like that and when some bits looked out of place or not as nice as others I just had to keep going until it was satisfactory. A little ocd sometimes....If I had more time I would have gone over it with the cartridge rolls and got it proper smooth lol.

[brlucas]

Can I ask what the benefits are from this?

Is it basically the prevention of the casting marks coming off and causing damage?

I want to give it a crack prepping this bottom end I have soon, (lots of research to do still).

Edited September 14, 2011 by brlucas

[r33_racer]

Can I ask what the benefits are from this?

Is it basically the prevention of the casting marks coming off and causing damage?

I want to give it a crack prepping this bottom end I have soon, (lots of research to do still).

Yeh prevent loose casting flash from coming off and clogging the oil pickup screen. Also helps oil return as it slides down the walls back to the sump. When coarse it holds alot of oil. But it will also strengthen the block, be it an immeasurable amount by removing stress risers from the rough finish along the casting joints.

But most importantly the inside of your block looks nicer! lol.

[brlucas]

When I had the motor apart there was indeed a lot of oil along the side-walls!

Seems to be an interesting thing to do though. And looks good too

[deep_space]

r33_racer what did you use? i have spent bloody hours on it and i am no way near finished. i am using a crappy electric die grinder with stones, i am trying to get the smoothest finish possible.

i am aiming for a fairly high horsepower engine with as much reliability as possible. i want to use a dry sump setup too to erradicate all oil problems. with a gt4094 turbo on top

[urtwhistle]

Use a die grinder with either a round or taper burr

[r33_racer]

I used air die grinder with a big round burr for the open areas and then a smaller round burr for getting into the tighter areas. Also, if you are using an air die grinder get yourself a regulator if you dont already have one that lets you adjust the airline pressure. Set it low, like around 30-40 psi so you can just hold the trigger flat out and it will maintain a usable speed. Makes it alot easier on your fingers since you end up doing it for hours at a time. I got a rubber band and held the trigger down that way. You may need to play with the air pressure as all die grinders are different.

Obivously make sure the burrs you are using are for steel, not ally too.

[zebra]

I did a Small block v8 with a cheap electric die grinder...took days and the shitty stones were gone after about 10 mins...worst part of not living up in QLD anymore is the lack of all my Dad's tools haha

[r33_racer]

lol yeh i know what you mean there. Id be screwed if my old man didnt have a shed full of tools!

[zebra]

Got a set of 6" 302 rods to do next...cost = nothing but means they should hang together at 6500rpm and be stronger than the cheap chinese H beams

[brodielezgt]

Good old tafe bonus awauy helps out with that.make sure you get all the castings off the water pump inlet.

[Stoney85]

Years ago, when i rebuilt my old L series for my datto 1600, i read through the book on "how to maximise the potential of your L series" and one area it focused on was block prep, basically doing what has been done here, but going one step further and actually painting the internal walls of the block, so that the walls are completely glossy, allowing the oil to drain back to the sump as quickly as possible, probably more important in a race engine 20-30 years ago, running minimal baffles and a small capacity sump as opposed to todays standards, but never the less an interesting insight as to what extent builders went to.

I did it all to mine, and it really didnt take much longer to do with the right tools.

[MRHD66]

Looks good mate

[GTR260]

i spent a few hours on a rb30 block i have plans for, drilled the hole for the relocated tensioner, half drilled the drains to 8mm (need a longer drill bit if anyone knows where to get one) drilled the main bearing oil galleries out to 7mm, drilled the plug out of the main oil gallery so i can clean all the swarf out & also enlarge that a lil bit. pics are showing the difference between the standard size oil gallery and modified