10:1 Pistons GP?

[cribbj]

Anyone interested in doing a GP for 10:1 forged pistons from Ross?

These would be just like the last GP. Designed for the early motor, with stock rods, and probably 0.010 or 0.015 oversize, etc.

I've had a couple of PM's from guys who wanted to know where I'm getting my 10:1 pistons, so apparently there's "some" interest in higher compression pistons.

I don't have any idea of pricing at this point, but we were able to get the 8.5:1's for less than $700 US last time.

Let's hear from you if this sounds interesting?

John

 

[turboteener]

Please stay away from Ross. The quality is not there. I would call Wiesco or CP and get them to make you something. They can handle the work and the quality is much better.

 

[rdm20fan]

Chris and I had a small failure with the Group Buy Ross pistons. We actually noticed a problem with the piston not being relieved by the exhaust valves, and thought about making our own relief, but we figured that Ross makes performance pistons all day long, and that they probably new what they were doing. So we didn't remove the material around the exhaust valve cutout.

Ross left a very sharp 3 sided edge with the cut away they did for the exhaust valve.
This lead to a hot spot, and melted part of the piston away.
We are looking at trying to relieve the rest of the pistons ourselves so that they can be reused, but I don't understand why Ross would have done this.
Toyota relieved this material from the stock pistons, I wish Ross would have followed Toyotas Lead.

Chris can probably explain this better then I can.

 

[Anaema]

isnt that partly your fault? you should have known that would happen. but still, its a bad mark of Ross' part.

 

[cowboy bebop]

That's very interesting, rdm20fan. So when we go to install the pistons, we will need to machine the pistons a little furthur. It's a shame that piston damage occured for anyone, but it's good to have this new knowledge.

Eric

 

[chrisman]

hi guys,, yes,, the small sharp edge got hot enough to melt on one of the pistons.. and yes toyota releived/removed the area on thier piston....the piston is still "useable" and we still have good compression in that cylinder.. but it is obvious that the "sharp edge" that was there , is there no more.. what exactly happens?,, well from what i have seen and heard it sort of vaporizes.. it gets hot enough that it eventually melts away..
problem being,, if it gets hot enough to ignite the incoming gas mixture,, you have a problem..and im pretty sure it was hot enough to ignite the incoming gas mixture..
that being said,, im am not telling everyone to worry, and remove thier pistons if they have already installed them--but, i will say that if you have not yet installed the pistons,, you should seriously consider removing the metal/sharp edges i am talking about.. one of the main reasons we decided not to was the fact that these were "balanced" from ross,, and removing any material could upset the near perfect balance..
one also important fact is that we were running 93 octane gas,, and pushing 17 pounds of boost thru the engine--all still without pulling any timing.. this , of course, creates very high cylinder pressure and heat--also coincidentally, power..
so,, i will try and summerize,, nobody should think that ross makes a bad piston,, it is probably as good or better than most.. but even forged pistons can get hot, and are not indestructable..
i still want to look at a few things--first i will check flow on the injectors going to that cylinder,, make sure i wasnt getting a lean condition to thta cyl only.. that could be a cause of this particular problem.. as a matter of practice,, i will probably check how all the injectors flow,, and compare to each other..
anyway,, i am wriiting a bunch,, it seems i forgot that this is somebodys post--sorry for jacking the thread.. i will start my own,, and get a few pics online to show/explain..

 

[cribbj]

Thanks for the clarifications Chris.

Assuming this gets resolved OK, is anyone else in the market for 10:1 pistons, or is it just me?

This is just to get a show of interest to see if a GP would be worthwhile.

John

 

[Lextreme II]

I am running 18 psi and i dont have any problem. I bondo the heads and pistons sample to Ross to make it.

 

[chrisman]

its not anything ross did,, its something i did not do.. --i will take a pic or 2 to help describe what i mean..--but its getting late,, so il do it tomorow..