I have heard its true. I'm not an expert - can someone quickly edumecate me please. Thanks.

 

I'm no expert in this area, but after talking with Vince about the ported heads that DDM and ZZP have been producing for the LNF, it appears that you can actually ramp up the spark timing earlier in the RPM range, particularly in the midrange, due to a decreased chance of knock.

My guess for this is that if the engine's breathing easier in certain areas, then the load on the engine goes down, making it less prone to knock.

 

^ That's my understanding too.

OP, was your combustion chamber on the head ported as well? Changing the shape and overall size of the combustion chamber can cause the burning flame characteristics to change and might be enough to cause KR if something isn't right. Theory is that the altered combustion chamber is causing the flame to burn at a different rate or even become erratic - if it's a poor port job and there is an edge where a hot spot can be created, that would cause a KR issue as well.

Again, this is a theory and I've heard of it happening before on a specific Porsche motor.

 

My head isn't ported. Been offered a deal for a fully built ported head, and it's a good deal. I'm a little nervous that it might cause KR. I believe only the intake part is ported, not sure.

I thought that there might be a chance it affects the flow of air negatively, that there was alot of flow tests done on the stock lnf head to make sure the issue didn't happen. I guess i will have to research it more.

 

I would not let anyone without knowledge of the lnf do the ported head. There's marginal gain for doing the lnf head as compare to other makes as was told by Matt and Tim. My understanding was that you can't go too aggressive with it?

 

A ported head should flow more freely, decrease heat, and thus decrease knock..

 

^This.

If you look inside the intake runners of the head for instance, it's got some interesting stuff going on in there, I'm guessing for Direct Injection. If somebody who hasn't done work or R&D specifically on DI heads, I would turn them down, because you'll probably end up with problems. The LNF is a wonderful engine, but it's just so picky about some things, including the head.

If you're not into ZZP, I would look at DDM. They are big in the Solstice/Sky world, and I have heard good things about them as well. They seem to have done their homework.



Here's an example of a ZZP Ported head:

Check out the intake side versus the straightforward exhaust side.



Intake Side



Exhaust Side

 

I dont see how this can cause KR it should decrease it because there's more flow in the engine but its just my opinion

 

Yeah Stamina, that is exactly what I heard. The LNF engine is really picky when it comes to the head. I will have to do more research, thanks.