Port Matching Intake
 

I have my new Brodix HV 2001 intakes for my 509's. I'm curious what you guys thing about port matching the intakes. I've been digging into this that past few nights and general consensus from chevelles.com, yellow bullet, speed talk, etc is that you gain nothing by doing it. Seems that maybe if your spinning 7k, you might get a tiny gain (2-3 hp) but in general you will stay the same or maybe even lose power. The ports on my new intakes are around .10" +/- .05 narrower and the floors are the same amount higher than compared to the port matched runners on my Dart intakes. On the other forums, the general thought is if its less than an 1/8" leave it, and that there actually may be more of a benefit to the different size runners. That is, creating more turbulence, and greater velocity into the head. Before I spend the time port matching these, does anyone have an opinion on this? As of right now, I'm really leaning toward leaving them as they are.

The intakes you took off originally were off a LOT more than that.
If they are that close I probably wouldn't do anything either.
The dart intakes have smaller runners than the heads.

i have always believed it is better for the intake manifold port to be slightly smaller than the head,a pretty smart guy told me that years ago.

Are you exclusively fresh h20?

I agree about Dart intakes. Their as cast ports are really small and you pretty much have to do some work to them. Tomorrow I'm finally going to be able to set the intakes on the engines and I'll inspect everything with a scope. Unless I find something that doesn't line up right, I'm going to run them as cast. The actual quality of the castings are excellent. Much cleaner than other brands that I've had in the past.

Yes, 100% freshwater.

I have darts on a pair of tall decks, bought them used at a good price but required way to much work. I would never buy them again. i hear brodix and profiler are a lot better intakes to start. Darts my head porter match ported them and did some runner work, dyno engine then sent it back to him and he cut out cloverleaf design and blended it in, back on dyno and gained 27hp 23 torque.

So you gained 27 hp with the modified plenum work vs the stock design? I would be interested to see as cast vs. blended. I know with the Darts I had on my 454's they had a fair amount of casting flash in the runners and plenum, so I'm sure there would power to be gained by working on them.

I originally was going to go with the Sniper Jr intake but I was told they're not very good. Seems some guys love them and other don't. I know that JimV is not a fan of that intake. He likes the design of the Brodix HV so that's what I went with.

That's what it gained just from work under where the carb sits removing the cloverleaf, have no idea what port matching and runner work did. It is on 865hp 808tq nat aspirated so gains would be less in an engine with less air flowing but I think all those small gains can add up to 40 to 100hp. [ATTACH=CONFIG]567117[/ATTACH]

Something else that was cool is I gained 20 from velocity stack vs nothing at all, [ATTACH=CONFIG]567118[/ATTACH][ATTACH=CONFIG]567119[/ATTACH][ATTACH=CONFIG]567120[/ATTACH]

Going to have a velocity stack flame arrestor built. [ATTACH=CONFIG]567121[/ATTACH]

The guy who ports all our stuff leaves about a 1/16" "step" between the intake and head intake port as well.

I lined everything up today. When the boat goes to valako for the exhaust, I'm going to have him touch up the runners. There is enough of a difference that I think its worth a quick port match.

Where is Jim working out of these days. I need to have my tails modified.

I'm not sure, but I'm about to find out. Last I knew I think he was off 48th st. but that was a while ago. I know he moved since then.

West River Drive about 2 miles east of the ballpark.

My vintage B&M 420 intakes, matched up like chit to my heads. Both the Darts i had, and the EQ 320 heads. Probably because they were designed for the old GM heads. I ran them this way for a few years, but last winter when I switched to the EQ heads, It was just bugging my life.

I ended up using "splash zone" epoxy by zspar. I dug out some channels in the intake near the port exit. About 1/8th or so deep if I recall. Something for the epoxy to bite to . I then began shaping the port exit to match the head. Once I got it built up to where it needed, I gave the epoxy a coat of automotive clearcoat. Supposedly the epoxy is unaffected by gasoline, but alcohol and or methonal supposedly can eat at it over time. I was reluctant to do it, but after seeing guys like Darin Morgan doing it that way, I felt a little better about it.

Whether or not it did a single thing for performance, I have no idea. And, it was a royal pain in the azz doing it. But, it was winter, and what else is there to do.

This shows the mismatch on mine.. First pic is the intake, second is the head. Its not terrible, but could be better. The outside ports IMO are fine, its the outside edge of the inside ports that could be better. All of them are exactly like this. Joe- your's were off a lot and off on the wrong side. If you didn't notice a difference, it makes me think how much does this stuff really matter?

I changed alot of stuff last year. New heads, dropped compression a full point, added an intercooler, so who knows. Boat ran 88-89 with old setup, and 96 with new setup, same props just turning them faster. I obviously added a good amount of power to pick up 7-8mph on this old turd, but where exactly it came from, cant' say. I know its pretty much been proven, an intercooler adds about 25-30hp on a setup like mine. 30hp is only about 100-rpm or so. I gained 500rpm. I think most of that, came from the head swap.

Those old dart heads I had, really got a good butchering from the last shop that redid them. They flowed like chit on the bench. My current head guy showed me why, but not being a cylinder head expert, I take things like that with a grain of salt, until I showed several other pretty high end head guys pictures of those heads, and the valve job/seat work they did, not to mention the hardware and spring setup to be an abortion, basically, they said that guy should get out of the cylinder head business. Once I showed them the bill I got for that work, their comments even made me more sick lol.

You'll wanna have Jim port the intakes. I've seen some intakes where they were only opened to match heads however only went back into the intake runner 1/2" or so. (That can hurt velocity). It takes some work and measureing to make it worthy. I've yet to see any intake bolt on ready without some work unless hp isn't a consideration. Just ask Jim about some dyno sessions he's done with and without matching and spending some time on the intakes. You'll be having him do them. Most all the aftermarket intakes are designed to requires some work given all the different heads etc on the market.

On the flip side I had epoxied up floors on dart heads years ago and the expy let lose out of the intakes and noticed no difference however was a much lower hp 454 build. Plus dual plane intakes. We kinda thought it may have been a tumbling affect and was automizing the fuel perhaps better. Who knows but was interesting. But with your set up for sure do it. It's not just the matching.