BannedCR500Riders.com

it the high temps and high load with my high compression, I've ended up pinging quite a few times where I was not in a position to get off the throttle... clatter my way to the top, then take it mellow back to camp to fatten the thing up... That has happened to me a few times, if I had a cast piston, I would have demolished the thing by now.

I would say thats your issue, not the pistons. I've rattled my piston quite a few times..... no problems. But I hear what your saying.

ya, it is, I like to try to keep an efficient tune which sometimes ends up on the lean side. It sucks because the 2 main places I ride at have over a 2000ft difference and the temps can be quite different, so what worked at apex a month ago will probably be way off for whats good at dumont tomorrow...
The last time I rattled it good was when I was getting that mikuni dialed in at armagosa a while ago. It was bogging and I was getting ready to go back to camp, but I wasn't familiar with the place and basically followed justin up a huge wall of sand rattling the whole way up.. I was talkign to her the whole time "come on baby, hold on, I'll get you a richer needle, just get me back to camp...come on..."

dannygraves wrote: "come on baby, hold on, I'll get you a richer main, just get me back to camp...come on..."

Been there done that at dumont!

HAHA

MICK wrote:

AlisoBob wrote: Thats .07MM.....

EDIT: Holly shit I just realized something that you said Bob. Wiseco's recommends .03 in. Yes I doubt any piston can operate with less than that. I stand corrected.

LA LA LA LA LA, LA LA LA LA LA, LA LA LA LA LAA LA LA LA LA. DOO DOO DOO DO DO DO.

Ported&Polished wrote:LA LA LA LA LA, LA LA LA LA LA, LA LA LA LA LAA LA LA LA LA. DOO DOO DOO DO DO DO.

excuse me, .003

This just in from JFR Racing after reading Bob's post they heve switched ALL their race cars over to cast pistons

mynew cylinder has a pro x. so would it be ok for supermoto applications? is there a lot of load on the motor riding it on the street?

street is the lightest load, but will also see a lot of revs... you'll be ok...

pstoffers wrote:This just in from JFR Racing after reading Bob's post they heve switched ALL their race cars over to cast pistons

Lets see... a CR500 has about 145psi cranking pressure, and makes power to about 6500 rpm..

Yea, that most definatly needs a forged piston, no doubt. I stand corrected.

Put down the weed Paul..



Heres the specs on Chevy's baddest motor, found in the Z06 Corvette:

• Aluminum engine block with 104.8-mm bores and pressed-in liners
• Forged steel crankshaft with 101.6-mm stroke
• 6-bolt, forged steel main bearing caps
• Titanium connecting rods
• Cast aluminum flat-top pistons
• Racing-derived CNC-ported aluminum cylinder heads with 70-cc chambers
• 56mm titanium intake valves
• 41mm sodium-filled exhaust valves
• 11.0:1 compression ratio
• Composite manifold with 90 mm single-bore throttle body
• Camshaft with 15-mm (.591-inch) lift
• Dry-sump oiling system
• 7000-rpm redline
• 500hp/475lb-ft torque

Every part of this motor was carefully chosen. It just didnt assemble itself.

Titanium Rods and Valves....Sure.

Cast Pistons.... Right on.

Believe me, if forged pistons were better, this motor would have them.

Class Dismissed.

ford crate engine: 347ci- 450hp

forged pistons
forged crank
forged rods

http://www.fordracingparts.com/parts/pa ... Field=9934


and the GRAND DADDY

540ci hemi: 650hp-900hp mopar

4340 forged rods
4340 forged crank
forged lightweight racing pistons

http://www.mopartsracing.com/parts/blocks.html

AlisoBob wrote:

pstoffers wrote:This just in from JFR Racing after reading Bob's post they heve switched ALL their race cars over to cast pistons

Lets see... a CR500 has about 145psi cranking pressure, and makes power to about 6500 rpm..

Yea, that most definatly needs a forged piston, no doubt. I stand corrected.

Put down the weed Paul..



Heres the specs on Chevy's baddest motor, found in the Z06 Corvette:

• Aluminum engine block with 104.8-mm bores and pressed-in liners
• Forged steel crankshaft with 101.6-mm stroke
• 6-bolt, forged steel main bearing caps
• Titanium connecting rods
• Cast aluminum flat-top pistons
• Racing-derived CNC-ported aluminum cylinder heads with 70-cc chambers
• 56mm titanium intake valves
• 41mm sodium-filled exhaust valves
• 11.0:1 compression ratio
• Composite manifold with 90 mm single-bore throttle body
• Camshaft with 15-mm (.591-inch) lift
• Dry-sump oiling system
• 7000-rpm redline
• 500hp/475lb-ft torque

Every part of this motor was carefully chosen. It just didnt assemble itself.

Titanium Rods and Valves....Sure.

Cast Pistons.... Right on.

Believe me, if forged pistons were better, this motor would have them.

Class Dismissed.

Put the glass pipe down






















This ones for you Bob

As long as my bike runs I could care less what type of piston is used
but for the record mine is a Wiseco.

think this motor has ANY cast parts?

MICK wrote:

Ported&Polished wrote:LA LA LA LA LA, LA LA LA LA LA, LA LA LA LA LAA LA LA LA LA. DOO DOO DOO DO DO DO.

excuse me, .003

Better check those Wiseco instructions again. They call for .004

I had time getting my guy to go less than .0035 so he came in at .003504. From the looks of it, the piston, .0037 would have been better.

100hp honda wrote:think this motor has ANY cast parts?

That has allot to do with a CR500...

100hp honda wrote:ford crate engine: 347ci- 450hp


540ci hemi: 650hp-900hp mopar

Garbage motors , when compared to the Z06 motor....

AlisoBob wrote:
That has allot to do with a CR500...

And a Z06 does?

Iggy I went and got my Wiseco box when I thought about what Bob said. It's sitting at my feet now and says .003 in (.076 mm). I was all jacked up because I interpreted my notes from this spring as metric but they weren't measured as such. I was wrong. Bob was right.

100hp honda wrote:think this motor has ANY cast parts?

no sir.. however it DOES have a crewmember with a SIC mullet

this is just one of millions of articles that can be found regarding cast vs forged. ironically, it says what bob has been saying all along.

For the average joe with stock engine and pump gas= cast piston is best

For all other aplications= FORGED



http://www.lcengineering.com/TechNotes/TechNote41.htm

Great thread!!! you guys are killing me! LOL..... some folks pay for this quality of entertainment.

I have no CR500 piston experience to pass on other than stock. But I do with sleds. That is another application so I won't go there. (I use cast in all my sled motors )

Danny, have you ever run a Clippard power jet? I have run them for years in sleds and they are a godsend. If you are not familiar with them, they operate like the Mikuni power jet but are a valve that is adjustable with fingers. Dennis Packard uses them on all the Lectrons I get from him. If you want to try one, I can hook you up as I have a few whipped up.
BTW I saw a prox piston go real cheap on ebay this week

MICK wrote:

AlisoBob wrote:
That has allot to do with a CR500...

And a Z06 does?

The Z06, while capable of very high performance, was also designed to be a low maintenance, daily driver.

Sounds a lot like a CR500.

ellett wrote: The Z06, while capable of very high performance, was also designed to be a low maintenance, daily driver.

Sounds a lot like a CR500.

The C-130J Super Hercules was also designed as high performance medium lift cargo air frame with a reduced flight crew and maintenance cost...Also sounds shockingly similar to a CR500.

I don't see that applications other than single cylinder two strokes apply here

I am not suprised at Chevy's choice of cast. We are talking about a daily driver N/A car designed for pump gas; totally ok with a cast piston. I am totally surprised they went with Ti valves however, with the longevity in mind!!

When you are talking BOOST forged is the only way to go.

As far as Hp I disagree with the "cast seals better do to less sidewall clearance" since forged are run looser because why?? THEY SWELL MORE, so when they are hot and running then end up with the same (roughly) sidewall clearance as a cast piston. But I totally agree they beat the shit out of the themselves and the bore when they are "cold".

A forged piston is lighter and stronger, lighter means more power period...but forged is way over kill on anything less then a highly modded abused engine...