Metal Working! Fitting, Machining, Welding, Sheet and General Metal Fab

SummitFever

Eats Squid
The shim sealing surface area sound be as small as possible to lessen the breakaway force. What you don't want is a shim to piston interface that resembles "ringing" two gauge blocks together. I have on occasion used an ultra thin small diameter shim under the face shim to reduce this break away force.
 

fjohn860

Alice in diaperland
The shim sealing surface area sound be as small as possible to lessen the breakaway force. What you don't want is a shim to piston interface that resembles "ringing" two gauge blocks together. I have on occasion used an ultra thin small diameter shim under the face shim to reduce this break away force.
Definitely makes good sense.

Bit of a shakedown ride tonight, I'll see how it feels, though I'm a fair ol' gronk when it comes to minute adjustments or suspension feel.
 

ozzybmx

taking a shit with my boobs out
For sure.

The preload step on this piston is partly what makes this damper average at best. So can't hurt to have a tinker. Most of my inspiration come from a mtbr thread on this damper.
It's been something I've want to have messed with for a while, I'll get there some day.

Cant be too hard, damper harsh, squeeze more fucking oil thought the hole :p
 

Flow-Rider

Burner
Does anyone do it in Australia? This and Cryo treatment seem to be all the rage in the US for engine internals but I couldn't find anything in Australia that matched the description of WPC/micropeening with ceramic and secret herbs and lubricants.



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Lots of places cryogenically treat cranks in Australia, and many highend cars have it done factory.
 

Flow-Rider

Burner
But what about WPC?

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You usually only get conrods shot peened but that's like standard rods, A lot of the high end performance rods like "I beams" already come with a surface treatment so you generally don't touch them, or might void the warranty. It's something you need to work out between the engine builder and rod manufacturers. You can ask for certain treatments done by the rod manufacturers if they offer them. They'll usually have a recommendation for how much horsepower they're good for.
 
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Oddjob

Merry fucking Xmas to you assholes
You usually only get conrods shot peened but that's like standard cast iron rods, A lot of the high end performance rods like "I beams" already come with a surface treatment so you generally don't touch them, or might void the warranty. It's something you need to work out between the engine builder and rod manufacturers. You can ask for certain treatments done by the rod manufacturers if they offer them. They'll usually have a recommendation for how much horsepower they're good for.
Is re-using rods and pistons out of an upgraded engine a no-no? I.e. lunatic friend in the US offers me a custom GT30 twin turbo setup and Manley Turbo Tuff rods and pistons for a steal.


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Flow-Rider

Burner
Is re-using rods and pistons out of an upgraded engine a no-no? I.e. lunatic friend in the US offers me a custom GT30 twin turbo setup and Manley Turbo Tuff rods and pistons for a steal.


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Depends on the mileage and if the motor they come from has been flogged hard. You'd want to get them crack tested and check the big end bore for out of roundness and the wrist pin bushes are still good. Also measure up the pistons, sometimes it is cheaper to buy them new. Manley rods are shot peened from new. You also want to check that the pistons are standard sizing and not oversized, and will be a direct fit to your engine.
 
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Dales Cannon

lightbrain about 4pm
Staff member
Your engine builder should do all these checks automatically and if he doesn't find a new engine builder.
 

Oddjob

Merry fucking Xmas to you assholes
Depends on the mileage and if the motor they come from has been flogged hard. You'd want to get them crack tested and check the big end bore for out of roundness and the wrist pin bushes are still good. Also measure up the pistons, sometimes it is cheaper to buy them new. Manley rods are shot peened from new. You also want to check that the pistons are standard sizing and not oversized, and will be a direct fit to your engine.
Well put it this way. He built the engine, took the car to the drags once, decided he wanted more . Pistons are the middle of the three sizes on offer so fingers crossed.

I will tell the engine builder that I want a dead flat torque curve from boost to red line, and see if we can increase red line up to 8-8.5k rpm. This will better suit sprints, and hopefully avoid turning the gearbox into confetti.

Your engine builder should do all these checks automatically and if he doesn't find a new engine builder.
Engine builder will be Croydon Racing Developments. They have built some truly demented projects, see

I on the other hand just want an ordinary looking R35 that thinks it's a Veyron.

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Flow-Rider

Burner
Well put it this way. He built the engine, took the car to the drags once, decided he wanted more . Pistons are the middle of the three sizes on offer so fingers crossed.

I will tell the engine builder that I want a dead flat torque curve from boost to red line, and see if we can increase red line up to 8-8.5k rpm. This will better suit sprints, and hopefully avoid turning the gearbox into confetti.



Engine builder will be Croydon Racing Developments. They have built some truly demented projects, see

I on the other hand just want an ordinary looking R35 that thinks it's a Veyron.

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I'm guessing you mean they're oversized pistons which means you'll need to get the engine block 'bored to size, which will mean it might not need it in the first place, and you'll have one less rebore out of the engine block.

You can detonate an engine on a dyno and damage the piston skirts in one run, even though I can't see any scuff marks in those pictures but that's all it takes in the engine world and I've seen many fuckwits do this shit on dynos over the years. You're literally buying this stuff blind without 3rd party checks, it would want to be less than half of new retail for me.

Your engine builder should do all these checks automatically and if he doesn't find a new engine builder.
Too late once you've bought them from overseas and the guy doesn't want to give you your money back.
 
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Dales Cannon

lightbrain about 4pm
Staff member
I'm guessing you mean they're oversized pistons which means you'll need to get the engine block 'bored to size, which will mean it might not need it in the first place, and you'll have one less rebore out of the engine block.

You can detonate an engine on a dyno and damage the piston skirts in one run, even though I can't see any scuff marks in those pictures but that's all it takes in the engine world and I've seen many fuckwits do this shit on dynos over the years. You're literally buying this stuff blind without 3rd party checks, it would want to be less than half of new retail for me.

Too late once you've bought them from overseas and the guy doesn't want to give you your money back.
It's @Oddjob money so that is ok. :D
 

komdotkom

Likes Bikes and Dirt
Well put it this way. He built the engine, took the car to the drags once, decided he wanted more . Pistons are the middle of the three sizes on offer so fingers crossed.

I will tell the engine builder that I want a dead flat torque curve from boost to red line, and see if we can increase red line up to 8-8.5k rpm. This will better suit sprints, and hopefully avoid turning the gearbox into confetti.



Engine builder will be Croydon Racing Developments. They have built some truly demented projects, see

I on the other hand just want an ordinary looking R35 that thinks it's a Veyron.

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I don't know if I'd spend the money to get CRD to build the engine and then use second hand parts. Pistons and rods are fairly cheap. The other guy to speak to is JHH.
 

Oddjob

Merry fucking Xmas to you assholes
I don't know if I'd spend the money to get CRD to build the engine and then use second hand parts. Pistons and rods are fairly cheap. The other guy to speak to is JHH.
True. But the Asian in me just can't pass up a good deal!!!

The Manley Platinum Series lightweight pistons seem to come in three sizes for the standard 95.5mm bore to match the different OEM tolerances. See:


I'm not aware of anyone else doing this, not even Cosworth, Tomei or HKS.

A full set of the Manley rods in Australia is $3,000, the pistons are another $2,000. I picked up the full set for $1,100 USD, so about $1,700. If the pistons work out (I'm sure the rods will) that's a lot of change I can put towards other bits of the car.

Edit: AMS Alpha pistons come in three sizes too.

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