Wiesco Pistons

[BigGun400EX]

I've herd some bad things about Wiescos 11:1 440 pistons are they that bad or is that just people talkin?

[dj416]

must be people just talkin. my freiend has been running one for about a year, i just put a 11;1 416 in mine and no probs with it either so far

[dj416]

must be people just talkin. my freiend has been running one for about a year, i just put a 11;1 416 in mine and no probs with it either so far

[Big - D Racing]

The problem with the wiseco 11:1 pistons is not with 416 kits, it is only with 440 kits (89mm). The problem is, that the true compression of the wiseco 11:1is more like 9.5:1 It is not a true 11:1, so if you go with a different brand that is a true 11:1 you will pick up a little more power and still be reliable. Many people don't run the wiseco because of this. If you contact Four stroke tech, they developed a true 11:1 wiseco piston, you can only order it from them though. The piston itself is reliable as every other brand, just the compresion is messed up on it.

[F-16Guy]

Do a search for "deck height". There was a really good thread concerning the true compression ratio of the 440 Wiseco piston, and good ways to compensate for it if you already have one. The thread is called "Have you decked the cylinder", you can learn a lot from it!

[Teufel]

I have used Wiseco for 15+ years they mfg an awesome product. I would be curious to know how those that say that the comp ratio of the piston is inaccurate actually determine that.. The piston is not the only factor effecting the ratio.
I built engines for BMW Motorsprots North America (M3) We used Dulador pistons ( at a cost of about $400 each). Probably the highest quality pistons available.
We still had to CC each piston in the block and cc each cylinder head and machine the piston accordingly to achieve the desired compression ratio.
So those of you that thing you can buy a spec. piston , slap it in and get achive the nominal ratio is baddly fooled.

:eek2: :eek2:

[F-16Guy]

I don't think anyone expects the exact CR specified when they just "throw" a piston in, but in this particular case, it's way off (according to the many people that bought them). Read through the thread I suggested earlier, it goes into detail. As far as my 87mm Wiseco, it was very close with no machining and stock thickness gaskets.

[Teufel]

So where were the pistons out of spec. and how was that determined? It just frustrates me to see people bashing a product when they don't have all of the information. It is always possible for a manufacturer to let a defective part out the door, no matter who they are, but to criticize the product line it's self is something different.

It's pretty easy to say " oh this product sux cause....blah blah blah.

I just have to keep reminding myself that the mean age on this board is 15 yrs old.......:eek2:

[F-16Guy]

Again, read the "decking" thread. To obtain the advertised CR, people with the 89mm Wiseco had to deck the cylinder, use XR gaskets, and/or shave the head. I think that the general consensus is that there should have been some amount of dome to the piston, when it is actually a flat top. I don't know from personal experience, but I'm not about to discount all of the very knowledgeable people that contributed to that thread. I run a Wiseco also, and I've had no problems, but I think the engineers may have overlooked something on this particular application. I think, overall, Wiseco makes an excellent product. The young guys that bash it are most likely not speaking from experience, rather just joining in with others.

[Extremeracer167]

I dont know, i only run Wiseco stuff, and my bike runs like a bat outta h#ll! I didnt even have to replace it after a full race season on it. Thing runs like a champ. Sure beats payin over $100 for some other brand.

[Big - D Racing]

Teufel you are wrong. It is way off of the given compression. And yes when I install a Je piston 11:1 with honeing the cylinder, it does put you at 11:1 or right about 11:1 you don't need to do anything else extra to it, just slap it in. Wiseco puts you no where close with their 89mm 11:1 You should contact Four Stroke Tech and talk to Mickey Dunlap. All he does is build engines. He'll tell you exactly how it is offand I don't think you can argue with him. He'll even tell you how to run a compression test to check your true compression for yourself. Wen you buy a 11:1 piston you shouldn't have to deck your head. Wiseco is a good piston and they do last. The only problem is their 89mm, it is a flat top design instead of a domed design. Many engine builders will tell you this, and that's why they don't use them at all. Look at all the major engine builders website such as TC, Sparks, LRD, Duncan, CT, etc. None of them run wiseco. The only company I know who runs it is FST because they developed a true 11:1 working with wiseco.

[Teufel]

Thanks for correcting me, I thought i knew what I was talking about....doh
Would you do me a favor , it would save me a phone call, tell me the steps that you used to determine what the resulting compression ratio was and how you came to find it was actually 11.1 when you installed your piston. :confused:



Oh and would you please tell me exactly which part of my post was incorrect :confused:

[F-16Guy]

Teufel, use this formula:
http://www.greatplainsas.com/icompratio.html
Stock compressed gasket thicknesses are:
head-0.025, base-0.018 (as per cometic)
Stock head volume=38cc
Bore=89mm, stroke=70mm
Wiseco 89mm piston deck height=0.043 (same as stock)

I came up with 9.44:1. Don't forget to add the gasket thicknesses to the deck volume.

[F-16Guy]

Any relation to Teufel's Nurseries?

[400MXer]

Actually Big - D, duncan, lrd, and CT do use wiseco pistons. lrd also uses pro-x and ct uses Ross. those are three heavy hitters in the motor building world and they use wiseco for most applications.

[Teufel]

Originally posted by F-16Guy
Teufel, use this formula:
http://www.greatplainsas.com/icompratio.html
Stock compressed gasket thicknesses are:
head-0.025, base-0.018 (as per cometic)
Stock head volume=38cc
Bore=89mm, stroke=70mm
Wiseco 89mm piston deck height=0.043 (same as stock)

I came up with 9.44:1. Don't forget to add the gasket thicknesses to the deck volume.


Thanks Bro, but I just wanted "big d racing" to explain it:devil
No I never heard of Teufel nurseries
The name is from one of my best friends who has long since past; a 120lb Rotti......
:cool:

[holeshot19]

my duncan pc2000 r engine uses weisco pistons in it i have to call out there and give them the serial number on it cause the tolarance are so tight on them.