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Port Matching Intake

Old 05-06-2017, 07:39 AM
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Going to have a velocity stack flame arrestor built. [ATTACH=CONFIG]567121[/ATTACH]
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Old 05-06-2017, 08:38 AM
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Originally Posted by mike tkach
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.
The guy who ports all our stuff leaves about a 1/16" "step" between the intake and head intake port as well.
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Old 05-06-2017, 07:55 PM
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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.
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Old 05-06-2017, 08:26 PM
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Where is Jim working out of these days. I need to have my tails modified.
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Old 05-06-2017, 08:29 PM
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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.
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Old 05-06-2017, 09:35 PM
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West River Drive about 2 miles east of the ballpark.
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Old 05-07-2017, 08:49 AM
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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.
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Old 05-07-2017, 08:59 AM
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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?
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Last edited by endeavour32; 05-07-2017 at 09:02 AM.
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Old 05-07-2017, 09:19 AM
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Originally Posted by endeavour32
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.
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Old 05-07-2017, 10:02 PM
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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.
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