More or less my completed chamber. Now that I know what to do it'll take me a lot less time to do the others. I don't understand why it keeps posting the picture sideways. Annoying.
More or less my completed chamber. Now that I know what to do it'll take me a lot less time to do the others. I don't understand why it keeps posting the picture sideways. Annoying.
Looks good! Now to the throat and short/long turn areas under those valves, and straightening out those ports where needed.
Todd
Already did the ports. Just kinda cleaned them up, smoothed them but didn't change shape really.
The short turn area needs plenty of fixin. Flow is very low in this area, but very sensitive.Originally Posted by thedon809
Todd
The sensitivity part is why I didn't go crazy. Just as easy to make it worse as it is to make it better when you don't know what you are doing. I definitely fall into the don't know what I'm doing category lol.
Kinda like porting 2 Masi's from what I've seen...
Sort of. There are 64 holes alone to match port, then you have to port the darn things! The injector housings take a lot of time to port properly. Then of course you hope you don't hit water or PCV passages. That would suck to have to buy cores if you went through in a bad spot you couldn't weld up. They can't be cheap.
Look at the size of those secondary injector bungs! Covers up like 30% of the port. What were they thinking? No wonder these cars pick up so much HP from porting the intake tract.
Todd
Wow! That's some of the best pictures of those I've seen. I had no idea they were that bad. I presume that the reason they had one port smaller than the other was to try and induce a velocity difference between the 2 valves to get more swirl/tumble in the chamber? But yeah, easy to see why they can pick up so much.
The Masi isn't quite that bad, but it certainly can use some attention in the intake manifold. More than I initially thought, for sure!
Todd, how much does you typical swirl chamber job increase the chamber volume? I ordered a cheap volume checker but I'm just curious. What's the volume of a stock g head and swirl head? Dodge garage says the swirl is 6cc's smaller. I'm just kinda worried how much it'll lower compression.
So far, these are my weapons of choice. The bit that's on the die grinder will chew through aluminum in short order. Literally minutes to deshroud the valves 90%.
It really doesn't increase it as much as one would think. I would say maybe 3cc or so using stock valves. I say this because I almost always use a custom Manley valve that decreases the chamber due to the design style of the valve. They are much less concave than the factory valve, so I'm gaining some volume back on what I lost de-shrouding. Sometimes after .006-.010 surface cut, I end up being the same or slightly less than a stock swirl. So around 49-50cc after resurfacing.
On the g-head pictured. I removed a lot from the chamber. I ended up having a intentional .015 surface cut made to decrease chamber volume. On this head, I ended up at 57.8cc. Stock is about 1cc less. I aim for chambers and port volumes within .2cc of each other.
Here are stock NOS casting cc's for swirl and g-head.
Swirl
Chamber 50.4- 51cc
Intake 72.8-74cc
Exhaust 56cc
2.2 piston dish 14.5cc
2.5 piston dish 27.5
2.2 compression ratio 8.06:1 - 8.10:1
2.5 compression ratio 7.84:1 - 7.87:1
445 & 287 G-head
Chamber 56.6cc
Intake 84.2cc
Exhaust 59.6cc
2.2 piston dish 9cc
2.2 compression ratio 8.06:1 - 8.10:1
I know Steve Menegon typically uses a powerful electric grinder, I use a few different air powered die grinders. There is a huge difference in noise and vibration (or lack of it) when you get into some of the better die grinders. I won't use cheap die grinders anymore. As I've stated many times before, life is too short to port a cylinder head with a 1/8" Dremel (lol).So far, these are my weapons of choice. The bit that's on the die grinder will chew through aluminum in short order. Literally minutes to deshroud the valves 90%.
Todd
The Dremel is great for getting in the small areas that need just a little touch up and when you need more precision. This particular Dremel maintains the same RPM regardless of load. The blue point grinder works ok. The trigger is harder to smoothly control. Good that compression won't drop too much. Are the custom valves you get +1's or big valves?
Yes both. The g-head pictured used +1mm intake valves from MP. Nothing special there. I used them because I had them on hand. The MP exhaust valves were BV G-head valves (1.450") reduced in diameter to 1.430" so they would fit in stock seats.
Todd
Well, more or less done with my first ever attempt at porting. Thoughts and criticisms?
Hard to tell a # of things because I can't enlarge pick, but from the looks of it, you haven't reached the edge of the cyl yet, so some extra flow there for sure.
Did you have "throw away" valves dropped onto seats while you were doing the porting in chambers? Looks like a number of seats are nicked up, but again, hard to tell from pic if that's actually the case.
Need to get in there with some sanding rolls and smooth things out. You should finish up one chamber, smoothed, radius'd and as good as you feel you can get it. Then cc chamber, then rinse/ repeat.
Keep track of your #'s and you can go back and forth till they are all close.
Seats are just dirty and/or metal dust on them. That's the hardest damn part though. Not hitting the seats.
You mean radius this edge?
I do all the roughing out with a set of scrap valves in place to protect seats. Then when I'm close, I remove valves and use fine bit to remove hard edge of casting just outside of seat area and insure nice radius transition to head/ deck.Seats are just dirty and/or metal dust on them. That's the hardest damn part though. Not hitting the seats.
You mean radius this edge?
Again, hard to tell in pics but looks like a pretty straight transition (flatish) from outside of seat to head/ deck surface. You want a nice radius in there for flow Around valve.
Oh yeah. That bit is tough. I do have a set of junk valves I used that I ground thinner to make it a little easier to grind around them. Pic might not show it good enough but I tried to radius the chamber next to the seat as best as I could. I have another head that's junk that I will practice that part more. I did radius the edge from where I deshrouded the valves but I could do even more if it would be better.
I just realized my phone has a super macro mode and does close pics pretty good.
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