Iron head testing (update on post #65)

[Jerryl]

I am no expert but continually fascinated by air flow and ended up re-porting a TB professionally ported set of heads that disappointed me. Took me 6 months of studying , measuring and porting. I know I am crazy but love doing that stuff. Lol.

Anyway. . . . . The max flow is typically around 25-30% of seat diameter. It's about the curtain area. What that means is that there really is no need to have anything over about .520 lift and tax the valve train over very minimal gain.
Great stuff, lots to learn.

 

[V6sleeper]

Very interesting... hmmm Golf ball porting...

 

[TURBOELKY]

Right on point guys. And Jerryl, that was exactly the goal in what my machinist has me doing. Bring the flow numbers up as quick as possible and not worry AS much about max flow up to, although I do have a target. Gradually I have been able to bring the flow up and almost max out around .400" lift. As I said, I forgot my dang flow card from last night.

I'm glad this post has people's interest because you guys are obviously having fun with the same stuff! Any opinions, examples or help is welcome here

 

[~JM~]

I've been fascinated with intake & exhaust systems ever since I learned the concept of scavenging, flow & how to reduce resistance to flow. It's almost like free power.

A head porter once told me that the flow numbers in the middle of your lift range were the most important, as the engine spent at least twice (or more) the amount of time operating at that range than it did at max lift. He was also experimenting with reducing port area by filling (raising) the floor of the port to enhance velocity in a naturally aspirated application.

 

[TURBOELKY]

I've been fascinated with intake & exhaust systems ever since I learned the concept of scavenging, flow & how to reduce resistance to flow. It's almost like free power.

A head porter once told me that the flow numbers in the middle of your lift range were the most important, as the engine spent at least twice (or more) the amount of time operating at that range than it did at max lift. He was also experimenting with reducing port area by filling (raising) the floor of the port to enhance velocity in a naturally aspirated application.

Yup exactly. I mentioned it earlier on, a few posts ago about a lot of heads from the sprint cars coming in for repair after they had been waaayyyy over ported. A lot of them have the back side of the ports filled and re finished. I can take pics of examples next week if anyone wanted to see that. You would be amazed on how much material is added

 

[~JM~]

Here is one of the cool articles that I have saved. I hope no one minds that I post it up. If you don't like it, please let me know & I'll delete it.

 

[~JM~]

 

[~JM~]

Here is another interesting/controversial article: http://mototuneusa.com/think_fast_intake_porting.htm

 

[Mike T]

Larry Meaux is a proponent of the dimple ports and has done some back to back testing and found a small but worthwhile HP increase in doing so.

That's the guy......I still can't find his article/interview that I was referring to. The pattern is very appealing to the eye but there is also said to be boundary layer improvement as well as mixing.

I really need to read it again because I can't remember if turbo/supercharged applications were mentioned as benefitting from this. Seem as if 10-20 HP were the typical increases on dyno pulls for a N/A motor.

All of this may seem insignificant.... especially when were just blowing air through a set of heads but I think all of these little details in conjunction with forcing the air in would pay off exponentially.

 

[Mr.Spool]

All of this may seem insignificant.... especially when were just blowing air through a set of heads but I think all of these little details in conjunction with forcing the air in would pay off exponentially.

on the na cars I could see the gains but with forced induction I don't think it matters.i have seen junk heads make a ton of power with the right turbo/turbos pushing air through them.

 

[TURBOELKY]

Hey Mike, how far were you able to take this bump down? This is probably the worst thing that could have happened to the head....other than the valve size

 

[Mike T]

View attachment 280394 Hey Mike, how far were you able to take this bump down? This is probably the worst thing that could have happened to the head....other than the valve size

Sorry to see that. I'm not at the shop but I'll go later and install a valve as reference to measure from.

Just as a quick reference my throat should be around 1.646 so if your under that maybe its core shift. I was pushing wire (as a measuring device) through the water passages from the back side. This was to gauge thickness and identify areas that were getting thin.

 

[TURBOELKY]

I looked at all the spare heads I have and try all have that bump in there. I might put the sonic tester to it and see how much material is here or cut a head in half. That actually might be a good idea. I've seen cut heads on gnttype but their site is down?

 

[Mike T]

I looked at all the spare heads I have and try all have that bump in there. I might put the sonic tester to it and see how much material is here or cut a head in half. That actually might be a good idea. I've seen cut heads on gnttype but their site is down?

Oh wow! I'm glad your only dealing with the hump.....on my screen it looked like two hairline cracks as if you went through. I feel better now.

 

[TURBOELKY]

Oh wow! I'm glad your only dealing with the hump.....on my screen it looked like two hairline cracks as if you went through. I feel better now.

No lol. I was asking how far you took those humps down lol! No cracks yet

 

[Mike T]

This all I have at the moment I'll get a better shot tomorrow.

 

[TURBOELKY]

Hmmmm. Looks like you were braver than I was. That hump is right in the middle of all the good stuff, I'll work on it Sunday. Thanks for the pics.

 

[~JM~]

This all I have at the moment I'll get a better shot tomorrow...

That looks great !!!

 

[Mike T]

Hmmmm. Looks like you were braver than I was. That hump is right in the middle of all the good stuff, I'll work on it Sunday. Thanks for the pics.

You would think I'd remember if it was totally eliminated or not but I just can't say for sure. I'll get you a better angle.

Something else to consider.....your intake numbers are darn close to mine and you still have stock valves. So you have probably already found most of the flow.

That looks great !!!

Thank you...definitely learned a lot doing it.

 

[TURBOELKY]

Thanks Mike. I'm going to have to get busy finishing up this pair and stop playing so much on the bench. I am about ready to start assembling engine hopefully end of the month. Pistons should be in next week. Getting excited!!

I do plan on continuing on with the heads though. I've done some work on other heads at the shop and there's a lot of that work coming in. I need to keep at it. Plus I have a few buddies that need some decent heads.

Please do keep me posted on the pic of that area, thanks! I'm right on your heels!!