Dodge Challenger Forum banner

61 - 80 of 115 Posts

·
Registered
Joined
·
876 Posts
Discussion Starter #61
If anyone has done this before let me know what you think. Also let me know if I missed any areas that should be blended. I just wanted to smooth all of the radius turns and blend into the gasket.


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
876 Posts
Discussion Starter #62
So, I've never ported and polish heads myself but I think the polishing part is pretty important. I could be completely wrong about this though and I'm a few beers deep, reaching way back to my engineering college courses.

If the surface is rough, if will cause the air to spoil or tumble, which will cause a localized increase in pressure.

If you want to increase the velocity of the air, you go from high pressure to low pressure. The bigger the differential, the faster the air moves.

So, if you're going boosted, with super high pressure entering the heads, maybe it doesn't matter as much. But the higher the pressure delta between intake (high pressure) and combustion chamber (low pressure), the better.
Thank you for this it’s bit of information. I will have to buy some polishing compound and go to work on these heads as well. Which isn’t a bad thing.


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
74 Posts
On my 460 BBF I kept my intake ports rough and my exhaust ports polished.
Is there a reason?

Again, I'm not smart on this from an engine build stance. Hell, I'm not even that smart to begin with.

But, polishing both makes sense to me. Air entering the throttle body (high pressure) flowing to the low pressure combustion chamber (should be pulling vacuum essentially). Again, the bigger the difference (pressure decrease), the larger the increase in fluid velocity (Bernoulli principle?).

Same concept on the exhaust stroke. But that's just basic fluid dynamics, there may be plenty of real world considerations I'm not aware of.

However, air flow over a rough surface will tumble and create a high pressure area. This is why airplanes get de-iced on the wings. The ice build up changes the flow of the air over the wing, creating a higher than desired pressure on the topside of the wing, which decreases the wings ability to create lift (smaller pressure delta between top side of wing and bottom side of wing).
 

·
Registered
Joined
·
876 Posts
Discussion Starter #65
I can see the advantage to polishing the exhaust side. Especially in my case. This should help the air flow more smoothly thus spoiling twins easier. As for the intake side that will be receiving forced air so it really won’t make a difference one way or the other. I’m sure slight differences may be realized. But I can over come those by turning up the boost IMO. Side note once I get the block back. I’ll post up some new picks. Currently I don’t have much to post. Still need to finish up the passenger side head.


Sent from my iPhone using Tapatalk
 

·
Registered
2015 RT 5.7 M6
Joined
·
7,584 Posts
Is there a reason?

Again, I'm not smart on this from an engine build stance. Hell, I'm not even that smart to begin with.

But, polishing both makes sense to me. Air entering the throttle body (high pressure) flowing to the low pressure combustion chamber (should be pulling vacuum essentially). Again, the bigger the difference (pressure decrease), the larger the increase in fluid velocity (Bernoulli principle?).

Same concept on the exhaust stroke. But that's just basic fluid dynamics, there may be plenty of real world considerations I'm not aware of.

However, air flow over a rough surface will tumble and create a high pressure area. This is why airplanes get de-iced on the wings. The ice build up changes the flow of the air over the wing, creating a higher than desired pressure on the topside of the wing, which decreases the wings ability to create lift (smaller pressure delta between top side of wing and bottom side of wing).
Leaving intake rough helps with fuel atomization (not a direct injection engine so fuel still hits the port surfaces). Polishing the exhaust...at least my train of thought...helps keep carbon build-up from attaching to rough surface.
 

·
Registered
2015 RT 5.7 M6
Joined
·
7,584 Posts
Even hot rod mag talks about being careful not to polish passages that carry wet fuel.

" Be careful about polishing surfaces that are likely to carry wet fuel flow. A rougher (like a quality cast finish) can actually be an advantage. "
 

·
Registered
Joined
·
74 Posts
Even hot rod mag talks about being careful not to polish passages that carry wet fuel.

" Be careful about polishing surfaces that are likely to carry wet fuel flow. A rougher (like a quality cast finish) can actually be an advantage. "
Thanks, that was a really good read!

Makes sense about fuel atomization and having the most effective combustion event, for the health of the engine. Turns out that the rougher surface tumbling the air may be beneficial if it helps with the fuel atomization.

Guess I just assumed the fuel injectors already did a pretty good job at that.

Insert "The More You Know!" picture.

Dak, I'm still gonna hijack your thread for conversations like this during your build haha.
 

·
Registered
Joined
·
74 Posts
So, now I have to ask the question:

Is there empirical evidence that the fuel isn't atomized sufficiently straight from the injector? You'd think modern day fuel injectors would be pretty good.

If they do atomize sufficiently, I'd focus on air velocity. But I don't know because I haven't built an engine in a looooooong time.

Either way, based on that article, the squeeze might not be worth the juice (2%).
 

·
Registered
Joined
·
876 Posts
Discussion Starter #70
Atomization from the injectors really depends on the injectors you use. Remember all an injector does is spray fuel into the chambers it’s not participating in the mixing of said fuel with air.


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
876 Posts
Discussion Starter #71
IMG_3024.jpg

So I picked this Gem up from the machine shop today. There’s something to be said about quality work and timely service. I will certainly do business with these guys again.


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
876 Posts
Discussion Starter #73
That’s the goal for sure


Sent from my iPhone using Tapatalk
 

·
Registered
2015 SRT 392
Joined
·
2,714 Posts
ChallyTatum my man. I hear you with trust issues brother. Honestly I would run Spray again but it makes more sense long run to do a boosted application. The way I see it, pay more up front for life time of fun = Boost. Pay minimum now and continue to pay every time you want to play = Nitrous. I’m fortunate that the majority of this stuff I’m doing myself. So I can spend a little more on better parts.


Sent from my iPhone using Tapatalk
Having the turbo's is like having spray without having to refill the bottles (which gets Expensive). I had a 68 Camaro with a 540ci BBC in it and a 2 stage N20 setup that sprayed 400 hp. I had three bottles that seemed to have holes in them (it felt like that because the Nitrous was just gone after a couple of runs).

Controlling the power is nice too, especially with that E-Boost 2. where you can do boost by gear and other options. Great choice on boost controllers. It's one of the nicest ones before you start going to the high end C02 stuff.


Well that makes 3 of us, though I am the guy who does the bomb dropping haha. Never made it to AFG though, I always end up operating in Iraq/Syria.

Thanks to both of you for your service.
First and foremost, Thanks for your service (that's directed to all of the Military people in this thread and pretty much ANY thread)!

I'd guess by your screen name that you fly an F16. If so, getting out of that BEAST and into a car has to feel like you're going backwards.


So, I've never ported and polish heads myself but I think the polishing part is pretty important. I could be completely wrong about this though and I'm a few beers deep, reaching way back to my engineering college courses.

If the surface is rough, if will cause the air to spoil or tumble, which will cause a localized increase in pressure.

If you want to increase the velocity of the air, you go from high pressure to low pressure. The bigger the differential, the faster the air moves.

So, if you're going boosted, with super high pressure entering the heads, maybe it doesn't matter as much. But the higher the pressure delta between intake (high pressure) and combustion chamber (low pressure), the better.
You're right that under boost, it doesn't matter as much, but it still matters.

Anything that you can do to make an engine (think big air pump) make better VE, is going to help make more power per pound of boost. People tend to get caught up on making a certain amount of boost when they should think about how much power that you want to make. Boost is a measurement of restriction and you want to make as much power as you can on the least amount of boost (if that makes sense). If you look at a turbo compressor map, there is nowhere on it that asks you how much boost you want. It's about airflow and pressures because boost is going to be different for every motor and the turbo doesn't care.

If anyone has done this before let me know what you think. Also let me know if I missed any areas that should be blended. I just wanted to smooth all of the radius turns and blend into the gasket.

Sent from my iPhone using Tapatalk
You're doing Great! Nice job!

On the head, there is power to be made in the bowls and the pockets behind the valve (hence the term "pocket porting"). A good valve job is often overlooked too. Just don't get crazy with the carbide and you'll be fine. Do a little at a time because I've seen people get a bit over aggressive and go into the jacket, but since you're just cleaning yours up, you won't have to worry about that. There is plenty of meat left on that bone. :D

Atomization from the injectors really depends on the injectors you use. Remember all an injector does is spray fuel into the chambers it’s not participating in the mixing of said fuel with air.

Sent from my iPhone using Tapatalk
I'd think that it also depends on fuel pressure and other tune related stuff too. I'd think that it'd be less of a problem on a Direct Injected engine because of how and where the fuel is injected.

That’s the goal for sure

Sent from my iPhone using Tapatalk
I know on the LSx cars that the sweet spot of manageable drivability is around 800 to the ground. Anything more than that was problematic for traction and stuff. At least that's what the Guys who made over 1000 rwhp said (and some were quite a bit over 1000 rwhp. Heading towards 1400 rwhp). I don't know any Mopar Guys making that kind of power, so I can't say anything about that.

Sometimes, with Big power, Big problems can come along for the ride!

Good Luck and Thanks for keeping us posted.
 

·
Registered
Joined
·
876 Posts
Discussion Starter #75
Wow FreddyG you read my thread. As a long time member of this forum I’ve learned lots of information from folks like you, Challytatum & Mcloud. The fact that you looked at my build honors me. I have to agree with you on nearly everything. Boost is simply a number. The most important aspect of boost is applying it to make power. While 1K Streetable HP is the goal. I’m happy with anything in the 8-1K range. Also I’ve heard of pocket porting but I didn’t want to take a chance on that or a valve job on this heads. Like you said I’m just trying to clean mine up and gain where I can from port matching. Next up for me will be the 6.1 intake. Then assembly. I’m hoping to get up some pics once I start reassembly. Thanks again for reading my entire thread and I look forward to any words of wisdom.


Jay.


Sent from my iPhone using Tapatalk
 

·
Registered
2015 RT 5.7 M6
Joined
·
7,584 Posts
Honestly Dak your post about doing a cam swap back in 2017 is what lit the fire for me doing the 6.2 swap.


Most of the info I provide is just info I pulled from other threads, books or searches through the FSM/web so I can't take full credit. Half the time I repost the info as it 1) helps me retain it and 2) it is easier to find it by doing advanced search under my username. :)

Anyways, really looking forward to the completion of your build.
 

·
Registered
Joined
·
876 Posts
Discussion Starter #77
I just reread that thread. There was a lot of good info and tips there. I wish I knew how to use Tapatalk then. I could have provided a lot better pictures to go with the write up. When I install my new cam in the 6.4. I’ll take pics and have someone help me link them to the thread as well.


Sent from my iPhone using Tapatalk
 

·
Registered
2015 RT 5.7 M6
Joined
·
7,584 Posts
Posting pics on this forum is a breeze...literally click on the picture icon below and just drag the image in. I wish posting vids were that easy.
993873


Even when using my cell phone I just click the picture icon and select from my camera gallery. Back in the day it was a royal pain to add images. Heck now you can just use the windows snip tool and hit cntrl + V and bam! Not that you need to know how to post images...just saying times are good now.

The biggest tips are damper tool, removing oil pump without dropping the pan (saw texts of it but never an image) and not to freak out when pulling the cam out is tight initially. Oh and don't slam it back in either. Lol I am a dork, you meant your thread. Yes there was a lot of good tips in there...one of the first that I linked to my browser bookmarks!
 

·
Registered
Joined
·
876 Posts
Discussion Starter #79
Bro you are far from a dork. Side note. If when this Pandemic is over and the MSHS goes to Kentucky. I would really like to meet up with you my friend. It would be an honor to hang out and grab a bite.


Sent from my iPhone using Tapatalk
 

·
Premium Member
Joined
·
776 Posts
View attachment 993821
So I picked this Gem up from the machine shop today. There’s something to be said about quality work and timely service. I will certainly do business with these guys again.


Sent from my iPhone using Tapatalk
Speaking of timely service, how long does it take your tuner to make a revision? I'm on a week and called everyday... Do I need a new tuner? I wish it didn't take years to learn to tune, this has been the pain point in all of my projects since tuing has been required...
 
61 - 80 of 115 Posts
Top