h2.4

rs machine can cut grooves for circlips in those.

Spawne32

iTrader: (3)

Any idea how much something like that costs?

DDTECH

holy...lol

h2.4

No I dont. Dave at Rsmachine just gave us the option. We ended up going a different route though. I thought it was something like $80 for a set. I'm not sure on that price though, it was a while ago that we had talked about it.

Spawne32

iTrader: (3)

So updates updates updates....

- RSmachines 84.5 pistons on the way, selling the YCP set (cheaper and easier)
- head is going out for machine work this week, then onto the flow bench.
- block is 25% back together again
- Precision 3431E is on its way in the mail :D
- SPA bottom mount manifold is on order

turbo pics courtesy the marketplace add from which it was purchased

turbohatch96y7

iTrader: (15)

hey what kind of ball hone didyou use? can you post a pic?

Spawne32

iTrader: (3)

http://www.ebay.com/itm/3-1-2-Engine...bef63c&vxp=mtr

sorry i dont have any pics of it in my garage, but thats the exact one i bought, off ebay as well, and then the cylinder wash brush. You have to use fast strokes with it and dont exceed 1200rpm on your drill. Typically i was doing about 2 strokes (up and down) per 1 second, maybe slightly faster, for between 5-10 seconds. It WILL open up your bore despite what some have said that 400 grit is too fine for it to make a difference. I took about .002 off with about 15 seconds of use using tap magic (cutting oil).

Spawne32

iTrader: (3)

http://cgi.ebay.com/ws/eBayISAPI.dll...m=230912822119

the size of the hone will vary depending on your bore size, these were both for a 84-89mm bore.

turbohatch96y7

iTrader: (15)

cool thanks im ordering up the hone right now.

Spawne32

iTrader: (3)

make sure you buy the right size for your bore

turbohatch96y7

iTrader: (15)

do you own a dial bore gauge? im looking at the fowler digital gauge. its 188.00 shipped and goes up to 6" and reads down to the 0.0005

Spawne32

iTrader: (3)

i actually bought this one two weeks ago, works great

turbohatch96y7

iTrader: (15)

Thats the other option im debating.
Its between those two. I like the digital one a little better because you can measure the bore, set the gauge at the size you want. then it tells you when you're over or under.
The only downside im seeing is its a bitch to set up and you need the tutorial that comes with it almost everytime you use it.

rich7777

Sounds good Spawne. I think I should start charging for MY stud idea .

What is that turbo capable of ?

rich7777

Sounds good Spawne. I think I should start charging for MY stud idea .

What is that turbo capable of ?

Spawne32

iTrader: (3)

according to precision, 545hp lol

• 57mm inducer compressor wheel
• "E" compressor cover 3.0" inlet/2.0" outlet
• 57mm exducer T31, 76 trim turbine wheel
• Turbine housing options:
- T3 .63 A/R with 4 bolt discharge
• 360° journal bearing system

TheShodan

iTrader: (14)

That's to the crank. Subtract about 20% to get a more accurate "whp" capability.

Those are 56mm/75mm exducer ("57" trim) equivalent.

Spawne32

iTrader: (3)

So if i didnt mention it before, I had to order a set of RS machines pistons designed for floating pin rods, maching costs on the YCP's were too high to warrant using them vs the price for just buying another set. Since no one has been as dumb as me and bought two sets of CAST pistons back to back like this, I decided to take a look at the rs vs ycp and see just what was different.

As far as I can tell the RS machine has a slightly higher dome then the YCP pistons. Actually, looking at it now, i would describe this as a decent amount more compared to the YCP. Looks to be a +2 or +3 cc dome. Piston height appears to be exactly the same, and the second ring land is only a HAIR larger then the YCP, negligible difference.

I think the biggest difference here comes with the skirt. Aside from being fully coated rather then just teflon coated on the sides, the skirt is actually thinner on the RS pistons. Another noticable difference is the under side of the dome. As far as I can tell the dome is slightly thicker then the YCP, but I cant measure this directly. I can see a significant amount more material around the valve relief areas compared to the YCP pistons, and the RS pistons have a spark plug quench pad as well in the center of the dome.

Spawne32

iTrader: (3)

I wanna say that the YCP's are based on the P73-A0 dome and the RS machines are based on the P73-00 from what i can tell.

Spawne32

iTrader: (3)

and the moment of truth...new piston to wall clearance is....


.0020-.0015!!! PERFECT

Spawne32

iTrader: (3)

and we are back in business again...heres some comparison pics, you can see the dome height differences

EsotericImage

iTrader: (8)

ahh, back to boost i see..

replied in your FS thread

rich7777

Nice ! I bet you'll never make that mistake again lol (it was an easy me to make). At least you got to do a hands on experience though.

Did those RS pistons come with a spec sheet ? If so what did they recommend ?

Spawne32

iTrader: (3)

no spec sheet, im going with just outside the service spec limit on these. As far as i know they are designed to be OE replacements, so you follow OE specs.

blackeg

this thread is an amazing source of first hand information with lots of info for the diy engine builder.

now ive used ycp and rs machines pistons in the past on various engines but never had them together at the same time. the side by side pics are fantastic. really goes to show how short the skirt is on the supertech's. i also wish there was a way to know pretty precisely how much of a difference in thickness there is in the center of the piston under the dome.

spawne, im really thinking about buying that dial bore gauge since i started honing my own blocks. how easy is it to make estimations between the .0005 graduation? easy to tell the difference between say .0016 and .0018? being able to make a solid estimation is a great reason to pick up this gauge over say a digital one that runs out of decimal places.