Homemade Cummins Runner Intake

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Well as some of you may know I am building a 700 to 800 hp Cummins in my Chevy. I pulled the head off to get it decked and have o rings cut into it. While it was off I said why not do a port and polish? Well to get to the intake ports you have to mill the cast intake off of the head and either buy one that costs $1,200 or make your own! Being that I'm 17 and broke (lol) I had no option but to make my own! (Which I would've done anyways). The only thing I bought was the intake flange to build off of. Tell me what you think!Still working on it right now, just took a little break!Building a 94 crew cab Chevy long bed dually welding truck. Has a Cummins, Ford ZF6 transmission with custom made adapter plate, NP271, Dodge Dana 60 SAS, Chevy 14 bolt rear, 8 inch suspension lift, with 3 inch body lift. Check out my build thread!!
Reply:Nice looking stuff. Have you ever ported a head before? 800 is alot of hp
Reply:I have a friend who has done a few teach me and look my work over. Not flow tested but better than stock!Building a 94 crew cab Chevy long bed dually welding truck. Has a Cummins, Ford ZF6 transmission with custom made adapter plate, NP271, Dodge Dana 60 SAS, Chevy 14 bolt rear, 8 inch suspension lift, with 3 inch body lift. Check out my build thread!!
Reply:I was just looking at a 24 valve the other day and they got pretty good short turns. Except one of the ex ports. I haven't seen a 12 valve tho. Alot of the flow will be in the roof and the short turn and bowl if you know what that means. Also a good valve job helps alot
Reply:How straight is the intake manifold angle with the intake runner angle?manifold  Looks alot higher. There's a guy on YouTube called headbytes porting with about a 100 videos on just porting that should give you a good idea. Sonic checking wall thickness might be a good idea even tho that casting is probably thick you don't wanna punch a hole!and leave the floor like really rough. 36 grit or rough carbide burr
Reply:I read that on fuel injected and turbo engines you don't need to leave any part of the port roughBuilding a 94 crew cab Chevy long bed dually welding truck. Has a Cummins, Ford ZF6 transmission with custom made adapter plate, NP271, Dodge Dana 60 SAS, Chevy 14 bolt rear, 8 inch suspension lift, with 3 inch body lift. Check out my build thread!!
Reply:Got some more done!Man I wish I had a TIG and knew how to use it ahaha.Building a 94 crew cab Chevy long bed dually welding truck. Has a Cummins, Ford ZF6 transmission with custom made adapter plate, NP271, Dodge Dana 60 SAS, Chevy 14 bolt rear, 8 inch suspension lift, with 3 inch body lift. Check out my build thread!!
Reply:Depends where the injector is. The fuel will naturally fall to the floor at low rpm. Tig is the **** for that kinda stuff. What's the cross sectional area of the intake port compared to the manifold runner? Any taper?and don't wast any time trying to polish the chamber or ex port it will carbon over in 2 minutes. I guess you don't have a chamber lol
Reply:Originally Posted by motolife313Depends where the injector is. The fuel will naturally fall to the floor at low rpm. Tig is the **** for that kinda stuff. What's the cross sectional area of the intake port compared to the manifold runner? Any taper?and don't wast any time trying to polish the chamber or ex port it will carbon over in 2 minutes. I guess you don't have a chamber lol
Reply:U wanna keep your CSA at a constant taper on the intake side
Reply:I have no idea about engine modifications so I cannot make any suggestions regarding the overall architecture of the intake.I understand it is being made out of stainless, right? If so, I have had a decent successs using 1,6mm (about 3/32") stainless rods for corner welds on thin sheet. Telling by the pictures it looks more like a series of tack welds than continuous stringers. I understand you need this welds to be airtight... and I doubt you are going to make sucessfull airtight welds by making a series of tacks.Mikel
Reply:Well I decided to make it out of square tubing instead. Less chance of a leak this way. I did a test fit, it juuust hits the injection pump so I need to cut each one down a bit.Building a 94 crew cab Chevy long bed dually welding truck. Has a Cummins, Ford ZF6 transmission with custom made adapter plate, NP271, Dodge Dana 60 SAS, Chevy 14 bolt rear, 8 inch suspension lift, with 3 inch body lift. Check out my build thread!!
Reply:At least you got some fab practice in  how much boost you gona run? I would think over 80
Reply:Originally Posted by motolife313At least you got some fab practice in  how much boost you gona run? I would think over 80
Reply:Hey that's a lot of work for a 17yr. old,.................ahh to be young again! Now hurry up and finish this thing we want to see it run!!!
Reply:Originally Posted by BrianCHey that's a lot of work for a 17yr. old,.................ahh to be young again! Now hurry up and finish this thing we want to see it run!!!
Reply:Originally Posted by SteIn this the fuel is injected into the cylinder, so no need for it. But I matched the ports to the flange if that's what you're asking. Same thing on the exhaust side, I gasket matched the exhaust ports, matched the exhaust ports with the gasket, and gasket matched where the turbo bolts on and I will gasket match my turbo. I was going to set up 220 in our garage but I am moving out after the summer so I didn't. If I did, I would have a tig lol.
Reply:What turbos are you using? The intake looks good but why not just use the tunnel ram intake?
Reply:Originally Posted by Firemanmike69What turbos are you using? The intake looks good but why not just use the tunnel ram intake?
Reply:Originally Posted by SteYou have to mill the intake off to get into the intake ports to port them.
Reply:Originally Posted by Firemanmike69Correct but the tunnel ram is less than $300 and save you time and the as$ ache of building your own manifold and having to bend all the injection lines to fit
Reply:Originally Posted by SteBut I wanted to port my intake side, plus I wanted to do something different. I told my friends if I ever pulled the head I was doing this and they didn't think I was serious! Haha. It's a fun project doing this intake, I've learned a lot about fabricating stuff.
Reply:Intake runners are far to short. Ever hear of intake harmonics?The over all design is good, just runners are too short.Long story short if you make the intake runners long enough, you get free boost.Now you do have the issue of higher temperatures altering the value of rho, which has the effect of making the runners about 10% at 10psi of boost. Attached Imagesold Miller spectrum 625 Lincoln SP-135 T, CO2+0.025 wireMiller model 250 and WP-18V torchCraftsman 100amp AC/DC and WP-17V torchCentury 115-004 HF arc stabilizerHome made 4 transformer spot welderHome made alternator welder
Reply:I wonder what sled diesel puller intakes look like?
Reply:Originally Posted by mad welder 4Intake runners are far to short. Ever hear of intake harmonics?The over all design is good, just runners are too short.Long story short if you make the intake runners long enough, you get free boost.Now you do have the issue of higher temperatures altering the value of rho, which has the effect of making the runners about 10% at 10psi of boost.Originally Posted by motolife313I wonder what sled diesel puller intakes look like?
Reply:Here are some from google that I got ideas fromZZfab's:Random ones:There you can see that there isn't a lot of room to work with. This is the most precise thing I have ever made and it is a challenge for me. I only have a mig welder, chop saw, grinder, sawzall, drill, and drill press to work with haha.Building a 94 crew cab Chevy long bed dually welding truck. Has a Cummins, Ford ZF6 transmission with custom made adapter plate, NP271, Dodge Dana 60 SAS, Chevy 14 bolt rear, 8 inch suspension lift, with 3 inch body lift. Check out my build thread!!
Reply:The first and 2nd pic look like the runners have taper. Usually u want at least 1.5 degree taper up to around 7. But sense your manifold is so short I don't think it will matter as much. You know what CSA means?
Reply:Originally Posted by motolife313The first and 2nd pic look like the runners have taper. Usually u want at least 1.5 degree taper up to around 7. But sense your manifold is so short I don't think it will matter as much. You know what CSA means?
Reply:I figured you would now sense your building a manifold. It's length times width of the port in 1 givin area. The maximum is usually the short turn or the intake face. And the minimum is usually right above where the valves saets. And there's a average. U gota to do a little different math for a round port or one with big radius corners. Measure the CSA of the intake face area and see what that is compared to your intake manifold. I would think you would be raising the roof of the port by porting  and maybe widinging it also. Then make the manifold. You will wanna cc the ports it your gona do heavy metal removal to make sure there all the same it's very easy it will also tell you if you punched a little pin hole. You can also get the most acuurate CSA buy ccing and measuring the port length.
Reply:For fuel injection you can go like 3 or 4 maybe more times the volume of the motor for the plenum volume depending on your VE.
Reply:Make sure you thoroughly inspect the inside of the manifold for rogue MIG wire and spatter BBs when you're done. Just a little tiny bit of spatter or wire will do a lot of damage if it drops down into a cylinder.