ooooooooooooooooooooooooooooooooooooooo

 

Yes... Everyone....wonder why?

 

Solid inserts is why.

 

Are you saying inserts are wrong in these heads? Everyone uses them...

 

I am sayin solid inserts are wrong. Heli-Coil wire type inserts will not do that. I have posted many proven facts regarding Heli-Coil inserts. Do a search using "Heli-Coil". Should still be on here. Several people continue to disbelieve my info. I have seen several thousand Heli-Coil inserts installed in much tougher conditions than a Lightning and never seen a failure like you and several others have experienced with solid inserts. I quit preaching the benefits of coil type inserts because nobody was listening. It was always "my tuner only uses brand-x solid inserts so they must be the best". Once more failures like yours start cropping up (and they will) perhaps people will be interested in listening.

 

I understand completely what you are saying and believe that my failure had something to do with the inserts... I'm just surprised that we do not hear more of this...

 

Your about to.....I'm on a campaign against stainless steel spark plug inserts and valve springs

 

JUst an FYI I'm trying to get ported new style (03+) 8 thread heads for my replacements..NO INSERTS...It's very hard because I do not have a core and 99% of the vendors still have the 4 thread spark plug that they insert...Wish me luck..

 

Jeff there's nothing wrong with and insert....just not Stainless Steel and I know Bill will defend them but in the case of THIS CYLINDER HEAD....they dont work. But like I said....nothing wrong with the inserts just make sure they are copper or aluminum. You have to have the heat transfer and Stainless is very bad at heat transfer.
Personally I would have them put copper inserts in it and I wouldn't think a thing about it.
Dale

 

I working all angles Dale and thanks for the info... Maybe I should find out what inserts were in my heads that were damaged......Maybe JDM will chime in...

 

Dale,
In a solid insert I agree 100% that stainless would not be a good choice. However in the coil type inserts the heat transfer is so much less than a solid insert it's not an issue. We participated in a couple of test session with one of the engine suppliers to the IRL series. They had similar concerns. I can't get into the specifics other than to say after the tests heat transfer in no longer on their concern list. Several insert materials were tested and the 18-8/300 series stainless was by far the most consistant. Granted we did not test aluminum or copper based alloys. For their application they need the stregth of the nickel based alloys.

 

Holy Rod-Knockers ! That sucks goodluck with new ones. BTW Does anyone have part#s for the 03 heads with more threads on them ?

 

Jeff's inserts are titanium. Steel inserts wouldnt even cause this kind of problem, spark plugs are steel. I have seen this on stock heads with out inserts, happened to Rob 02 once.

JimIII

 

If you want to look at just the heat transfer/thermal conductivity of the materials we are talking about.....You can throw a blanket over Titanium and 300 Stainless Steel....they are within a few percent of each other but they are both down about 1000 % from aluminum and you don't even want to know about Copper.....its off the chart percentage wise. In other words Stainless Steel has the ability to dissipate heat about as well as a ceramic tile off the space shuttle, well not quite but you get the drift.

If you look at the way the spark plug is situated in the 2V head....over half of it is facing towards the sun...so to speak. The type of material used in the insert WILL make a difference in this application. You have to be able to get the heat out of the plug and back to the cooling system or the plug becomes a glow plug in a nano second.

Bill...on the type of cylinder heads you guys did testing on is no way comparable to what we have here. On a well designed 4V head the plug sits in the center of the action and there are no hot spots. The heat can travel from the plug tip in all directions...on this 2V head that is not the case.
Dale

 

Dale,
I am not questioning the thermal conductivity of stainless at all. On a thermal chart as well as galvanic chart stainless and aluminum are at oposite ends of the spectrum. Where the advantage comes to play is in the design of the insert itself. As you know a Heli-Coil in it's simplists terms is a spring. It is a single piece of formed wire. The diamond shape of the wire and the space between threads has an incredible ability to dissapate heat. The company we tested with went as far as to heat several types of inserts in a controlled enviornment. They recorded the amount of time various insert styles and materials came up to temp. Once the goal temp was reached they timed and recorded the cooling rate. From there they went "live" engine testing. Nondisclosure agreements keep me from exact details but their equipment measure the combustion temps in several locations. Also EGT's, spark plugs, and several other temps were monitored down to .xx degrees.

Again you are correct in their application is not an apples to apples comparison however the cylinder pressures and temps we saw would melt a Lightning to the ground. LOL. The real fun is destructive testing. several engines running at max rpm for hours on end. Makes the airport seem like a quiet library. Any way after all the testing was done there was no significant differnce in combustion efficiency, temps, or detonation between a plain aluminum head and a head containing the Heli-Coils. What they gained is a plug hole that no longer ejects plugs and a greatly increased service life of the heads. Prior to this heads were cut up and destroyed after each event. Now they will be able to refurbish and re-use.

What is gained by using aluminum or copper inserts? What type of copper alloy are you looking at? Berrylium, Phosphous Bronze? Dale I enjoy your objective opinions. It's quite refreshing from the normal banter on here.