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RB30 block needed ASAP

ktech

By ktech,
in Engines & Forced Induction

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ktech Rookie

ktech

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Hi.

First of all, do anybody in here know if there are different deck height on the RB30 Blocks, like different models ?

Reason im asking is that I have a block here that has a 226,5mm deck height, and what other people tell me is that stock is 230.5mm

im looking for a new block, since this block keep messing things up and going out of straight.

So any info is appreciated, and let me know if someone has anything available.

Kenneth

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Rusty Nuts Experienced

Rusty Nuts

Posted
Posted
7 hours ago, ktech said:

First of all, do anybody in here know if there are different deck height on the RB30 Blocks, like different models

No, they are all the same. If you have a crazy deck height, your block has been molested by a previous owner trying to fit 25 pistons to it.

ktech Rookie

ktech

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6 hours ago, Rusty Nuts said:

No, they are all the same. If you have a crazy deck height, your block has been molested by a previous owner trying to fit 25 pistons to it.

Really, you think someone has machined 4mm off the Deck, thats crazy. I been wondering since day 1 why it was so short.

Anyway, yes im in Denmark and you might be right shipping gonna be alot :(

Rusty Nuts Experienced

Rusty Nuts

Posted
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Yes I really think the deck has been machined down that far, its lucky they didn't strike water jacket. This would certainly reduce block rigidity. You probably only have a couple of mm of solid deck surface. Sorry brother.

ktech Rookie

ktech

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1 hour ago, Rusty Nuts said:

Yes I really think the deck has been machined down that far, its lucky they didn't strike water jacket. This would certainly reduce block rigidity. You probably only have a couple of mm of solid deck surface. Sorry brother.

That might be the reason also why the mains keep getting out of straight. 

Its been line bored at least 2 times. Last time it cost a 94mm spool crank after only 10 miles. Just had it in the cnc machine again and its gone in the mains again. 

Rusty Nuts Experienced

Rusty Nuts

Posted
Posted
24 minutes ago, ktech said:

That might be the reason also why the mains keep getting out of straight

Absolutely. When I built my 30/25 I had the mains checked for line boring and my guy said not worth it the block was straight. The crank was also only linished and also checked out straight, the bores still showed the original hone marks top to bottom. The engine had travelled 150,000 km, and from talking to other builders this is not uncommon with these blocks. they were obviously very well cast and machined using excellent materials.

Rusty Nuts Experienced

Rusty Nuts

Posted
Posted

If you are running a 94mm crank throw what is the piston compression height and rod length. Asked a couple of mates and consensus was you can't remove 4mm from deck without hitting a cylinder parting. Apart from the proximity of the water gallery running just below the deck on exhaust side.

ktech Rookie

ktech

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6 hours ago, Rusty Nuts said:

If you are running a 94mm crank throw what is the piston compression height and rod length. Asked a couple of mates and consensus was you can't remove 4mm from deck without hitting a cylinder parting. Apart from the proximity of the water gallery running just below the deck on exhaust side.

I had custum piston made to fit the spool crank and rods, so i didnt notice from the beginning that the block was actually 4mm to short. I did wonder why Jeremy at JE piston told me that stock Deck height was 230.5mm. I was sure that there had to be different kind of blocks, since i could not imagine anyone that stupid to remove 4mm from a Block.

Anyway, i need a new one and i will need to order new pistons to fit the new block, and this time hope that it will stay straight. 

In case Griffin dont want to sell the one he has, do you know where to look up those kinda blocks ?

 

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