ported heads
 

does any of the big name companies sell a bolt on ported head with o-rings already cut etc?

im thinking im gonna drop alot of coin already to have my current head machine and modded...for roughyl the same cost can you get a head already machine, and mildly ported etc, then send my core in for exchange???

if anyone does sell them, how much do they run? i dont have the knowledge to port my own head, but for nearly the same price of having my head re-done ill go with a better version thats ready to install

Call Piers...he's got 'em. No idea what they want for a 24v head, but the 12v head wasn't cheap.

well im already looking at over $1000 for machine work not including the studs, and head gasket.

i figure if an aftermarket ported head can be had for under $1500 its worth it

Double that and you'll be closer.....but not quite there.

they are outside their minds

Ahhh, there is a lot of time and precision that goes into headwork. Most of the big guys have heads ready to go out the door, but they will charge you the whole ball of wax until they get your core in and confirm it is a viable one to replace the one they sent out the door. If they can't use it you get to tow the line on the $$$!

Just going to throw this out there....why would you port and polish a head when you are pressurizing the intake manifold with boost, all it will do is lower the boost pressure. and yes i know that boost is a measurement of restriction BUT if the intake manifold is pressurized then IMO your not gaining anything besides less restriction. and that may sound a bit stupid but unless your shooting for the 800+ mark then you really dont need it...and if you are shooting for that much hp then you need fire rings and not o-rings.

this is just my take on porting a forced induction engine, plz dont slaughter me over this one

jake

The easier you can get air into, and out of, an engine the better (more efficient) it will run. You will make more power, lower egt's, quicker spool-up, etc..

You don't port the head on a diesel for power. You port it for cooler EGT's, faster spool up, slightly more power, and a broader RPM range of power. Same goes for a cam. Not a lot of power gain but a broader, flatter curve and lower egt's.

[duhhh] ... is big blue drinking tonight. [duhhh] [laugh]

I'm with the other guys, I think porting/polishing the head makes sense, even on a turbo'ed engine. Air in, air out. I am going to have my head done when I go nuts with my truck, don't know with who though

on a 24v head that already flow good your wasting your money. first off the casting isn't very good to begin with and theres not alot of material to be removed. also all they can do is clean up the exhaust side without having to completely cutoff the intake runner. but thats jmho

You could probably get a stock head with o-rings and all the machine work done, new guides and whatever, without turning a core in for $1500.

well right now, using my head, getting a valve job (guides, seats etc), deck the surface, o-rings, gasket, and studs im looking at right around $1700 and being as ill never be running over 700-800hp (if this is done right) then ill never have to touch the head again.

the machine shop told me to bring the HG i'll be using so they know where to cut the o-rings. do i just get a stock replacement HG or do i need to get one that is .010", .020" over etc?? i need to get the HG before next week so i can take it to the machine shop. and is it easier to get it direct from cummins, or should i get it from the dodge dealer

I'd recommend a thicker HG. Since you're going for performance, any time you can drop the compression a little bit, do it. I'd go with the .020 over Marine or RV gasket. .020 shouldn't mess up the injector spray relative to the piston bowl much at all.

Porting a head for performance is almost always a good idea. But whether or not it makes $$ sense is entirely different. The sotck uncut will flow pretty well if you give it a cam with some stouter specs.

I have no proof, but I honestly believe that the CAM, not the HEAD is the biggest restriction to flow on the 24V engine. Only AFTER you have a healthy cam in there would I consider a ported head to be worth the $$.


There are a lot of machine shops out there marketing a service (to make money) that might not even be necessary for the vast majority of guys who get it done. Lots of shops are installing larger valves, which is pure BS on a 24V. The diameter of the valves isn't the flow restriction-- it's the LIFT and the head ports. With better lift, the stock valve diameter flows a LOT more, even with the stock ports.

My advice: if going with Helix 2 or smaller cam, skip the head porting. If going with H3 or bigger cam (if it exists-- Budda, Scheid maybe?), then go for the porting.

jh

where/how would i go about getting a .020 over marine gasket...and will anything else need to be modified to run it?

Cummins should be able to get them easily-- but will likely have to order unless you live near the coast (not a whole lot of inland Cummins marine engines).

AFAIK, no mods needed to run it, but I'd see if some of the bigger shops (Haisley, Scheid, etc) make thinner injector washers to drop the injectors back a little closer to the pistons.

jh

i live right on the chesapeake bay...lots of marine engines around. ill look up some of the local cummins shops and see if they have marine parts.

how much of a difference is .020 gonna make with the injector?

I'm guessing .020", but call a pro.... ! (Is that a "here's your sign", kinda thing?)

Just Jokin, GB, and sorry for the smart-aleck:)

Seriously, I'm not sure how much of a different it would make as far as smoke and such goes. Spray angle on an injector is matched to the piston bowl. Even slight changes in Spray angle affect how the fuel disperses when it hits the bowl, and can thus effect efficiency of burn.

That said, it's certain to be a LOT better than 370s in a 12V, and plenty of guys run those.

Maybe Don could whip up some sticks for you with a little deeper spray to account for the thicker HG. Try a PM to him and see what he thinks about the extra .020. It's probably much ado about nothing....

It's just a good idea to pay attention to the little things to make sure everything's playing well together.

jmo

Justin

well thanks for the help...i never would have thought about the spray pattern being different with a thicker HG.

ill talk to my parts supplier tonight about the marine gasket, and see if he can get one from cummins. should be a fun weekend pulling the head :(

Thinner washers are a no-no on a 24V. The connecter tube will have a hard time sealing if the injector drops down from where it should be. A changed spray angle (if anything) is what you would want.

thank you banshee...if its a matter of more smoke/a VERY SLIGHT difference in power then i dont mind the different spray pattern. i was thinking the change would result in much higher EGT's, or improper combustion or piston damage

Do they make a 24V .010 or .020 over. Every one I talk to says to use a modified 12V .10 or .20 gasket. I used a stock 24V gasket on mine, but my head only had to be decked .004. I would have like to of used a .010, but the local shop wanted more than I was willing to pay (over twice what a stock gasket was) and I needed my truck up and running.

the only difference between the 24v and 12v gasket is the size of the holes in some coolant passages. all you do is take a punch and make them bigger.

Possibly. [laugh] What I meant is that yes you might gain some power, but you don't port the head as a major power adder. You might gain a little but not like what you would on a gasser. You port the head to support the power you have and any power that you might add in the future.

Just ported the head on my 12 valve this weekend. If you have a die grinder, take a look at the tech page on Piers site for a reference as to where to remove material and just be very careful and take your time. Dad and I cut aluminum sheet to protect the valve seat, but we removed it at the end to blend the wall into the inner angle of the valve job. Most of the work is on the intake, but we really cleaned up the exhaust nicely as well. Probably not quite as good as what you'd get from Piers or a race shop like Ray-Mac, but after talking to a lot of guys about it, it should still be a huge difference. Just throwing this in there in case you're on a budget. -Josh

PDW offers the 12v marine gasket modified for the 24v engine.... We almost always go with the .020 gasket for a rebuilt head that has been o-ringed.

As for porting, it does have its place...... But personally I feel like it is one of the last items to be done on a motor. You $$ would be much better spent on a good cam that a port job.

Doug Smith

Yeah, I shoulda known that[duhhh] [duhhh]