Piston Modification

[Anonymous]

Hi all,

Just a quick question for you's. I currently have a set of forged hightop pistons to suit the 200 rods on the 250 crank. What i am wondering can you have them dished by a machine shop for compression reasons and if so would it reduce strength etc. I have contacted a few mobs but are unwilling to do it incase they stuff it up.

 

[xctasy]

Geeze. Townsville. What the heck you building a car in Townsville, son. Almost as silly as funky Dunedin....

I reckon, because of your location, people are either not worthy of your intellegience, or this isn't there staple diet. Unless the forging is a trim kind with insufficent thickness built into it, get it profiled via Autocad at a CNC/CAD/CAM mechanical engineering outfit, and have it machined to the correct surface roughness average.

I don't know where, though. If I was selling it, I'd make tripply sure I got a machinist who deals with this.

We've got guys down here in the deap south, like Denco Engineering (1987) LTD:

(sicko free add for britten engine builders, ralph, :nono:

419 Tuam St Christchurch Ph (03)381-2111 Fax (03)381-2069 who import Ross blanks, and cut the bleading daylights out of them.

Here are some suppliers you may consider calling:-

http://www.planet.net.au/~alexst/parts.html

Best bet? Talk to Brads Speed Shop - 221 Parramatta Rd Granville 2142 NSW (02) 637 4199.

Since your not a normal V8 guy, you actually know what you want, these guys should cut you some slack, and name a supplier.

My TRW's were cut down to the base of the trough, to almost 1.45" depth. A no brainer, with a 25 thou chamfer to clear the hard edge formed. They started with a blue print comp height at 1.531", almost 2 mm shaved off. The forging wasn't the best, race grade kind, but it is tuff as. Forged pistons can swollow throttle screws and valves whole, and then get alloy welded, and live to fight another battle.

 

[addo]

AFAIK, Brad's is long gone.

 

[xctasy]

your crapping me. Am I out of touch?

(don't answer that)

 

[CobraSix]

your crapping me. Am I out of touch?

(don't answer that)

Come on...must you really ask?

Slade

 

[xctasy]

He he he he. Time to slice off my frontal lobe as a means of restraining my wandering mind, my beloved web-site provider.


:idea: Back to the parking lot with you, and leave your 2V detached so I can steal it later.

And you need some forged pistons. :!: 200's dont need dishes in the pistons.

 

[Anonymous]

At the minimum get in there with a grinder and knock those rather sharp edges.


-=Whittey=-

 

[SuperMag]

Call the manufacturer and find out if you can do that. Pistons are shaped and thickened in some areas with expansion characteristics in mind. If you go mill off the crown, you might still have sufficient strength, but have it go oval (or worse) in the bore when it heats up...

 

[Anonymous]

SuperMag is right.
Some forged pistons, TRW for instance, are designed to be removed. Others , lighter ones, are not.

John

 

[Lazy JW]

At the minimum get in there with a grinder and knock those rather sharp edges.-=Whittey=-

Were you referring to Tags pistons or Execute's lobotomy?

Joe

 

[Anonymous]

At the minimum get in there with a grinder and knock those rather sharp edges.-=Whittey=-

Were you referring to Tags pistons or Execute's lobotomy?

Honestly, I don't even know.....


-=Whittey=-

 

[Anonymous]

Thanx for the reply's.

There are a few places i havnt tried yet so i will see how i go.

Cheers

Simon