Porting a 24v head

Got Milk?

Got Milk?

One hook at a time
Joined
Feb 12, 2008
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952
Blew another head gasket last week, and had to pull the head. While it is off the motor I was thinking of doing some more porting to the head. I would like to try to do myself, and was wondering if anyone had measurements, cut-away diagrams, pictures, or tips of where to grind, and how much to grind. Thanks in advance,
Will M.
 
when you put the head back on, surface it to make sure it is flat, get a marine head gasket and copper-spray both sides
 
The head is O-ringed now and is going to be fire-ringed, and should be checked to see if its flat at the machine shop. I am just looking for porting information, but thanks for the input anyways.
 
Depends on how far you want to go - the casting is pretty decent as far as core shift/flash/sand bumps go, so it's easy enough to clean up to a good surface finish.

It's hard to screw up the swirl characteristics of a 4-valve head, so the inner & outer exhaust ports, the siamesed intake ports and bowls (including removing the guide bosses) can easily absorb 24 hours of labor... just get extra-long carbides & polishing dremels, excellent lighting and be ready to flip the head 47 times before you're done! :hehe:
 
why do you think it blew the HG? whats your timing set at? were you driving it or did it happen on the dyno?

I retorqued mine last weekend and cleaned the block good, haven't seen any leaks yet.
 
MAXTORQ said:
Umm NO , install it dry . There is a reason why that gasket is kinda gummy. Only a MLS should you ever do this on.
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copper spray enhances the seal on any head gasket. I have never had a problem with using copper on non-mls gaskets. My buddy's been running 35+psi on his Eagle talon with a stock headgasket w/ copper spray
 
tj, I was making a hard run down the road to test fuel pressure and when i pulled back home the entire back of the head was leaking oil. Pulled the head saturday and the whole back of the head gasket had blown. Dont know why it blew? I pulled the truck two weeks ago, and it went down the track just fine with no problems or leaks.

As far as the porting goes, the bottom of the exhaust port has a flat spot cast in it. would it be wise th try and grind it out?
 
The floor of the port is the slowest as the gases rush to the top of the port and ride along there. Reshaping and polishing the top of the port gives the most gains.
 
Got Milk? said:
tj, I was making a hard run down the road to test fuel pressure and when i pulled back home the entire back of the head was leaking oil. Pulled the head saturday and the whole back of the head gasket had blown. Dont know why it blew? I pulled the truck two weeks ago, and it went down the track just fine with no problems or leaks.

As far as the porting goes, the bottom of the exhaust port has a flat spot cast in it. would it be wise th try and grind it out?
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damn that sucks. i been keeping any eye on mine pretty close, i checked and re-checked the back of the head when i had the tranny out last week and the only signs of oil i can find were from my leaking valve cover gasket. i just hope i dont have to pull the head again. but ill find out for sure on april 4th whether its gonna hold or not.
 
sinfulcoin said:
The floor of the port is the slowest as the gases rush to the top of the port and ride along there. Reshaping and polishing the top of the port gives the most gains.
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that makes sense, the gases should be riding the top the hradest. So spend my time polishing the top of the ports. thanks
 
getblown5.9 said:
damn that sucks. i been keeping any eye on mine pretty close, i checked and re-checked the back of the head when i had the tranny out last week and the only signs of oil i can find were from my leaking valve cover gasket. i just hope i dont have to pull the head again. but ill find out for sure on april 4th whether its gonna hold or not.
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Brett and I spotted some wetness on the right rear of the motor, but i just figured keep and eye on it this season:bang I am kinda glad to take the head off, so i was able to see the condition of my pistons and walls. They look good to go for another season. Hope your head holds better than mine lol.
 
right rear as in passenger side or right side when you are looking from the front?
 
http://www.devilscastle.net/cummins2003-2h.htm Check out this work on a 12v. I couldn't find my pics so I tried to find the next best thing. Porting is best done with a flow bench to get them all equal. As XLR8R said its really hard to mess up the swirl on a 4valve head. I went crazy on mine. Boost at same fueling went down 13psi. The difference in spool was crazy as well. This engine is in my brothers truck now with an HX40 on it. Cheap 500hp build that will last forever.
 
sinfulcoin said:
http://www.devilscastle.net/cummins2003-2h.htm Check out this work on a 12v. I couldn't find my pics so I tried to find the next best thing. Porting is best done with a flow bench to get them all equal. As XLR8R said its really hard to mess up the swirl on a 4valve head. I went crazy on mine. Boost at same fueling went down 13psi. The difference in spool was crazy as well. This engine is in my brothers truck now with an HX40 on it. Cheap 500hp build that will last forever.
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Wow thats some nice work done.

On a side note I see your from Morgan City, I been down there one time 5 years ago, helping out people put on a boat race on the lake down there.
 
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