Would you pay $630

[MR. X]

Thanks. You brought up a good point. Here they are.

PISTON SPECS FOR .030 OVER PISTONS

2.2 2.5
COMPRESSION RATIO 8:01 7.8:1
COMPRESSION HEIGHT 1.600 1.365
ALLOY 2618 2618
WRIST PIN DIAMETER 0.912 0.912
PIN MATERIAL 4130 4130
DOUBLE SPIRAL LOCKS
THEORETICAL VOLUME 11.34 21.78
WEIGHT IN GRAMS 439.5 401

[speeduphoria]

whats the dish volume?

[MR. X]

On piston designs, I work from the CR back. The dish volume is calculated not specified. On dished pistons the dish volume will change slightly from smaller to larger diameters. The program will give us the dish volume accordingly. Check out this link and you can plug in your own numbers.

http://www.diamondracing.net/cocalc.htm

Here is an example for the 2.5

COMPRESSION RATIO CHART
# of Cyl. 4
Bore 3.4750
Stroke 4.0900
Rod Len. 5.9400
Gskt Bore 3.540
Comp. Gskt .0680
Block Deck Ht. 9.3620
Top ring down 0.300
Chamb. Vol. 55.0
Dome (-) Dish (+) 24.00
Piston / deck 0.008
Calculated Values
Total Volume 727.90
Cylinder Volume 635.68
Clearance volume 92.22
Gasket volume 10.96
Top ring volume 1.01
Deck volume 1.24
Piston top land 3.437
1/2 Stroke 2.045
Comp. Ht. 1.369
Cubic Inches 155.16
Compression ratio 7.89

[MR. X]

Some one wrote that I had no class with what I said about other manufactures pistons. I am a straight shooter. What I meant to say is that most of the engine parts out in the TD and sport compact market is what the manufactures want to sell. They are production pieces. Allof my engine parts are built to my specs and not what is easier fot the manufacturer. Yes, many big names run the other manufactures pistons and they work well. Refer to above post. I do not try to sell parts telling clients what they want to hear. You can put perfume on a pig, but all you have is a nice smelling pig.

[speeduphoria]

Quote:

Originally Posted by MR. X On piston designs, I work from the CR back. The dish volume is calculated not specified. On dished pistons the dish volume will change slightly from smaller to larger diameters.

So you've never measured the dish volume and are assuming they are correct for the CR stated?

[MR. X]

The dish volume is irrelevant. It is calculated, as I said before, after all the relevent numbers are plugged into the equasion. It is the compression ratio that is relevant. The volume will be found out when you measure BDC volume or 1/2in down fill volume. This would be done to find out actual compression ratio when the engine is mocked up or assembled. Measuring the dish volume of the piston would be futile. It is different for all different diameters of pistons ie; std .020, .030, etc. I want the engine built to a specific compression ratio. Of course, your cylinder head volume also has alot to do with this. As of late we have been working with a 55cc head volume with very good results. I want to do some dyno work with 50cc head volumes to see if more gains can be made.

[median]

I see no issue in bashing cause its not really bashing....they do have there different consistancies....I have delt with only one brand I would pre-machine a block for, and thats cp...but hey, to each there own...I still dont consider it bashing.

[Ondonti]

I dont see how it is bashing to say that Venolia keeps better tolerances on their pistons then JE and Wiseco. Maybe he shouldnt have said they suck but he could basically say the same thing in nicer language.

My machine shop puts JE's in their Top Fuel car so I dont think they worry to much about lack of tolerance or using a piston that has silicone in it.

[crazymadbastard]

Looks like the new price is $499 for them pistons on Mr-x site. Tolerances are nice and tight too. My question is about the turbonetics swing valve, is that correct that it is for a 3in exhaust and a comptetitor to the TU one?

[Ondonti]

Isn the turbonetics one a stockish size...like 2.5"?

[Timmay2]

I guess everyone here makes custom pistons for a living???

Lots of work goes into it = $.