Cryo treating internals

[spetz]

Is it safe/good idea to cryo treat stock pistons?

I was told, with cryod crank, shotpeened rods, cryoed rods, cryod pistons and molybednum coated piston skirts I could raise the rev limiter by a bit and the internals would be around 30% stronger?

[WhiteAP1]

cryo treating does strengthen parts,but i havnt heard of it improving performance, just reliability

[spetz]

Yeah strengthening is what I am looking for

Basically these are my car details:
Peak power 7500rpm
Peak torque 6000rpm
Redline 8100 rpm
Cut out 8200 rpm

These are stock figures, and the engine is not stock, so I am assuming that peak power and torque will be at higher rpm
I also want to do cams, which I am assuming will raise my peak power and maybe torque figure to beyond the engines cut out
So, basically I want to be able to raise the rev limiter
And I can not afford forged internals, and then engine is being rebuilt right now

So, I am looking at a cheaper version to be able to strengthen internals
I got quoted:
$120 to cryo crank
$10 per rod + $20 per rod to shotpeen, polish and crack test
Also, $10 per piston to cryo (but was recommended against this??) and $45 per piston to molybednum coat
At the same time, using stronger rod bolts etc

What are your thoughts??

[Slow96GSR]

http://www.onecryo.com/onecryo/motorsport-imssept98.htm

How far do you want to raise the redline? The real parts that need the the help are the valve springs, rods and crank. Now I don't know that you will be able to go up to 10k rpm with it but I can see 500-1k more. Hope that helps. We did a write up on here a while back but I couldn't find it.

[spetz]

Well 500-1000 is really what I was expecting/wanting
Valve springs of course will be done as well as larger cams and stuff

Rods were very skinny and weak looking. The engine is a 6A12 MIVEC and there was a 6A12TT as well, I was thinking whether those rods would be good to use but they are impossible to find :(

[Slow96GSR]

Ebay it or order an aftermarket rod set from a performance manufacturer. Another thing, and this is just to everyone not just you, but just because the valve springs say they can handle 10k rpms or hight doesn't mean they will or that other parts can handle that. Use common sense and remember the motor is only as strong as its weakest part. So if the crank can handle 9k, rods 10k, springs 10k+, and cams 9k I guess you shouldn't go past 9k rpms. Ok just wanted to put that out there. I know most of you know that but it's more for the noobs.

[spetz]

Not enough $$$ to be doing forgies or anything :(

Also, I am pretty sure 2 litre MIVEC that I have and 1.6 MIVEC run same conrods
The 1.6 MIVEC has 81mm bore (mine is 78.4) and redlines at 8500 and cut out is close to 9000rpm, and has a higher stroke that mine (Mine is 69mm)

Actually, 1.6 MIVEC has exactly same bore and stroke as B16

So, it seems the pistons might be the weak link?

[iamhappy46]

Cryo treating works well on the engine block as well.

I paid $7 per kg last time I got my engine parts chryo treated... It will improve power as you the engine will take a little more ignition advance and with stronger internals with the same mass, it can theorectically rev higher if the engine is balanced to perfection so it can handle the extra revs.

Chryo treating the pistons can cause problems with piston to bore clearances, as the chryo treatment process on stock pistons causes 'shrinkage'

I believe the 2L MIVEC V6 does slightly different rods to the 1.6 MIVEC but whether they are interchangeable is another story.

If your after rods, I suggest you contact PAR engineering in Sydney about them making a custom set to suit and they can make custom lightweight forged rods with all the important stuff done already. They can be contacted via www.gccorp.com.au

[exquisit]

where did every1 get their stuff cryo treated at??

[Slow96GSR]

U.S. location: http://www.onecryo.com/onecryo/motorsport-imssept98.htm

[spetz]

Iamhappy, where did you get this cryo treatment done? Seems cheap?
As $10 per rod, and each rod is just a few grams! That's the pricing I got

Also, I wont bother with block, Mitsubishi blocks have always been uber strong (cast iron for starters)
And this is an NA setup

[saxman]

before spending so mcuh money, why not dyno the motor to see if raising the rev limiter would really help given your current mods

[spetz]

THe engine is apart now getting rebuild
That's why I want to somehow strengthen the internals

I realise with stock cams that peak power will be before rev cut, but with cams it would be good to be able to raise the rev cut by a few hundred rpm so that say peak power is about 8300rpm or so