Concerns about Supertech pistons
#22
The distance from the top of the ring to the top of the piston is 0.2800" on our 9:1 pistons.
There's a potential difference in the alloy as well. Supertechs use 4032 alloy, ours are the stronger 2618.
I can only comment on the Wisecos that we carry. They're made to our specs and design, other shops will have different pistons. Ours will work with all Miata engines other than a +1 intake valve on a VVT engine. No need to special order for 1999 engines, that's a rumor I hadn't come across before. Personally, I like having at least a 9:1 compression ratio as any lower gets doggy off boost. I used to have a 323 GTX, if you got caught off boost in that thing in front of a truck you were dead meat.
As far as I know, none have suffered the same failure as these Supertechs did.
There's a potential difference in the alloy as well. Supertechs use 4032 alloy, ours are the stronger 2618.
I can only comment on the Wisecos that we carry. They're made to our specs and design, other shops will have different pistons. Ours will work with all Miata engines other than a +1 intake valve on a VVT engine. No need to special order for 1999 engines, that's a rumor I hadn't come across before. Personally, I like having at least a 9:1 compression ratio as any lower gets doggy off boost. I used to have a 323 GTX, if you got caught off boost in that thing in front of a truck you were dead meat.
As far as I know, none have suffered the same failure as these Supertechs did.
#23
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Thanks for the measurement Keith. I'll check it on one of the Supertech pistons when I get one out of the motor. Unless, someone around here has a set sitting around that they have not installed, and are willing to take a quick measurement.
To paraphrase 'The Wolf' (ninja edit for correctness)
"If I'm curt with you it's because time is a factor. I think fast, I talk fast and I need you guys to act fast if I wanna get out of this. So, pretty please... with sugar on top. Measure the ******* Supertech piston..."
That is one of my favorite movie lines, had to use it eventually.
So Keith I just want to be sure I understand this correctly... A +1mm oversized valve is only a problem with the Wiseco piston on a VVT motor, correct? I am non-VVT so I should be OK then.
To paraphrase 'The Wolf' (ninja edit for correctness)
"If I'm curt with you it's because time is a factor. I think fast, I talk fast and I need you guys to act fast if I wanna get out of this. So, pretty please... with sugar on top. Measure the ******* Supertech piston..."
That is one of my favorite movie lines, had to use it eventually.
So Keith I just want to be sure I understand this correctly... A +1mm oversized valve is only a problem with the Wiseco piston on a VVT motor, correct? I am non-VVT so I should be OK then.
Last edited by ZX-Tex; 08-18-2009 at 01:28 PM.
#24
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Thanks for the measurement Keith. I'll check it on one of the Supertech pistons when I get one out of the motor. Unless, someone around here has a set sitting around that they have not installed, and are willing to take a quick measurement.
To paraphrase 'The Fox'
"If I'm curt with you it's because time is a factor. I think fast, I talk fast and I need you guys to act fast if I wanna get out of this. So, pretty please... with sugar on top. Measure the ******* Supertech piston..."
That is one of my favorite movie lines, had to use it eventually.
So Keith I just want to be sure I understand this correctly... A +1mm oversized valve is only a problem with the Wiseco piston on a VVT motor, correct? I am non-VVT so I should be OK then.
To paraphrase 'The Fox'
"If I'm curt with you it's because time is a factor. I think fast, I talk fast and I need you guys to act fast if I wanna get out of this. So, pretty please... with sugar on top. Measure the ******* Supertech piston..."
That is one of my favorite movie lines, had to use it eventually.
So Keith I just want to be sure I understand this correctly... A +1mm oversized valve is only a problem with the Wiseco piston on a VVT motor, correct? I am non-VVT so I should be OK then.
#28
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OK well this concerns me too because the used engine I bought with supertech pistons was all messed up. The mechanic said that the engine looked like it was detonating and the tops of the pistons were eaten away. The belfab rods are apparently just fine though. I will try to post some good pictures of the pistons but now I will probably replace them with fm wisecos.
#29
chokeasphyxia, then that's a good reason to buy the FM Wisecos. They fit the 99 heads no problem
Remember that we don't sell the same Wiseco pistons that Wiseco does. They've been modifying their own design and moving closer to our specs over the years, but it's not the same piston and you can only get ours from us. So when I say that our Wisecos will work with every Miata head except a VVT setup with +1 valves, that may or may not apply to Wisecos available anywhere else. I don't know.
Again, this is true for the FM pistons. Not necessarily all Wisecos. But yes, it is true for the FMs. All of our built motors go out the door with +1mm valves, it would be a little foolish for us to build pistons that wouldn't fit with them
By the way, I just updated the picture on the FM site to show the current 1.8 9:1 design, as it's our most popular piston.
Remember that we don't sell the same Wiseco pistons that Wiseco does. They've been modifying their own design and moving closer to our specs over the years, but it's not the same piston and you can only get ours from us. So when I say that our Wisecos will work with every Miata head except a VVT setup with +1 valves, that may or may not apply to Wisecos available anywhere else. I don't know.
So Keith I just want to be sure I understand this correctly... A +1mm oversized valve is only a problem with the Wiseco piston on a VVT motor, correct? I am non-VVT so I should be OK then.
By the way, I just updated the picture on the FM site to show the current 1.8 9:1 design, as it's our most popular piston.
#36
I'd recommend checking clearances with any VVT head with +1 intake valves.
#38
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Good thing you asked a third time - because I double-checked with some of my coworkers. Turns out we increased the valve pocket size a bit, so they do fit now. The current FM pistons do work with a +1 VVT. It's an interference engine so keep that in mind if you decide to break a timing belt.
I'd recommend checking clearances with any VVT head with +1 intake valves.
I'd recommend checking clearances with any VVT head with +1 intake valves.
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#39
sux! i have wiseco's in mine. only they are LOW compression - 8.2 ccr if i remember correctly. anyway's why are you running 20psi? you goin' to the drag strip? i usually run 12psi daily. 15psi is all that i've tuned up to, but it's maxing out my 550cc injectors at that boost. only ran that a few times to play around with some friends. at the track i only run 9 psi. sometimes 10psi. and that's pretty fast if your turning like you should. dogged many porsche and vettes at that boost, especially on smaller tracks.