XXX Piston Porn

[Dannyh82]

My Wiseco ceramic coated 750 big bore pistons ready to go in. Video will be coming soon.

 

[kshansen]

My Wiseco ceramic coated 750 big bore pistons ready to go in. Video will be coming soon.

I should have taken a picture of the pistons I put in my 92 Sportster, also Wiseco but 1200!

Here's what one I took out looked like:

Wiseco rep. thinks timing was a little advanced, so I back it off a couple degrees.

 

[46th Georgia]

My Wiseco ceramic coated 750 big bore pistons ready to go in. Video will be coming soon.

Thanks! Now I need a cold shower!

 

[jay760]

Here's my low compression pistons

 

[46th Georgia]

My Wiseco ceramic coated 750 big bore pistons ready to go in. Video will be coming soon.

What's the compression ratio?

 

[jay760]

The strange thing with Wiseco pistons is there seems to be varying statements on the compression ratio, most stating around 10.5-1 where JE pistons also state they are 10.5-1 which Gary Hoos says he has measured but when you look at the dome on the JE piston looks like it's massive compared to the Wiseco this is
a standard JE piston for comparison

 

[46th Georgia]

The strange thing with Wiseco pistons is there seems to be varying statements on the compression ratio, most stating around 10.5-1 where JE pistons also state they are 10.5-1 which Gary Hoos says he has measured but when you look at the dome on the JE piston looks like it's massive compared to the Wiseco this is
a standard JE piston for comparison ngView attachment 218442

Man, you're making me contemplate doing nasty thing with assembly lube. Stop it!!!

 

[Dannyh82]

What's the compression ratio?

Not 100% sure yet but will be checking when I get my head back from machine shop.

 

[Dannyh82]

The strange thing with Wiseco pistons is there seems to be varying statements on the compression ratio, most stating around 10.5-1 where JE pistons also state they are 10.5-1 which Gary Hoos says he has measured but when you look at the dome on the JE piston looks like it's massive compared to the Wiseco this is
a standard JE piston for comparison View attachment 218442

Yea I have noticed alot of info. I am going to check it myself when head is back from machine shop so I know what I'm dealing with.

 

[hovel]

Here's what one I took out looked like:

What totally baffles me is that the racket from all the detonation apparently went un-noticed. What we're looking at didn't just happen suddenly.
Sportster engines are kinda noisy to begin with but, my goodness !!

 

[jay760]

Not 100% sure yet but will be checking when I get my head back from machine shop.

What are you having done to the head?

 

[Dannyh82]

What are you having done to the head?

Black diamond valves and bronze guides going in, gas flowed etc

 

[kshansen]

What totally baffles me is that the racket from all the detonation apparently went un-noticed. What we're looking at didn't just happen suddenly.
Sportster engines are kinda noisy to begin with but, my goodness !!

I agree I would have thought I could have heard something. Also the fact that it ran for 8,000 miles after the pistons were installed makes me wonder even more. And up to the instant it did make some strange sounds it seemed to run just fine.

I also have another Sportster that has over 117,000 miles on it since I got it new and 85,000 since being converted to a 1200 and has not had heads off since then.

 

[hovel]

and 85,000 since being converted to a 1200 and has not had heads off since then.

Even with diligent maintenance, the proper fuel and a spot-on tune-up, that is impressive !
A long time ago I rode an early 90's sportster, maybe a 'C' ? model with factory dual plug heads. That bike was FAST.

 

[bikefreakjon]

That doesn't look like detonation yes, it looks like part of the ring broke off and bounced around up in there for a while