Cylinder head porting

[Don M]

Ok,



I am getting closer to pulling the motor now more than ever. I have about 200K in miles and the 5th gear just squirted out of her again. So I figure I'll pull the whole mess and rebuild it all.



The 5th gear updaye from standard is going in and a southbend clutch as well... the poor stock one is really starting to slip now. .



While I have it all out I want to go into the cylinder head and port it. I have spoken with Piers H. and several other guys about it.

But I have not found out yet what the trick port job is yet.

Being from a kinda sorta racing background I know you can screw a cylinder head up with the wrong port job. I am aware of the frickin bolt hole through the number one runner as well. What's everyone doing for that?

Porting the cylinder head is going to drop the velocity some but being forced air inducted it will probably loose boost but the EGT's should drop more then a few degrees too.



So... . whats the hot ticket?



Don~

 

[HoleshotHolset]

I'm really hoping that someone responds to this..... I want to port/polish my cylinder head as well.....



Matt

 

[Don M]

Matt,



yeah I think that the porting will be the hot ticket. Polishing is normally for the really high RPM engines like the gassers. But the cummins is direct injected so fuel delivery is not to worry. A good polished intake and exhaust runner would do wonders for effeciency. The exhaust side would help EGT's a fair amount as well.



Like I said earlier, the overall boost would go down with the same set-up if you opened up the intake side alot but the gains in effeciency would combat any boost loss. I would also say the low end power would suffer as well. The high end side would be better though. Trade off kinda thing. Kinda like the HX-40 vs. the 35. Give a little here take a little there.







Mild porting might not hurt the low end at all.



All these questions and no answers yet. This is the reason I am trying to get input on the head work others have done and thier experience in power loss and gains and so on.



Im pulling the motor and trans in the next few weeks to do all the work. The wife is gonna freak when I use her Mercedes to chase parts with. Last time I got grease in it. hehe!





I have decided to go all out with the truck in the next few months. I was kicking the idea around about getting a new 24 valve and selling the 12. NO way... . I am going to build a stout 12 valve that is easier to tweak and does not run on the newer computer technology. Plus the 12 is almost paid for.









Don~

 

[HoleshotHolset]

I hear ya on the 12-valve thing... . I love the simplicity and le$$ money to modify part of it... . plus 1001 other reasons.

When I say port/polish... that's a bit of a generic term... I leave the porting up to people who know. For those who have done it I'd LOVE to hear what worked and didn't work and why.....



Matt

 

[CAJUNCUMMIN]

I recently rebuilt my 95 12 valve, used 370 parts check my signature also did my own port and polish on head, kdp retainer,pump mods,timing. I thought a lot about which route to take with the overhaul so far I am very happy with the results. call me for the details I can tell you what works for me.

225 473 3596

Les Ewen

 

[Don M]

I'll holler here real soon... ... Lower compression pistons sound like a real good idea for EGT reduction. I am asuming the 370 slugs are lower compression. Is this done with a bowl top design or what?

I saved your number.



Don~

 

[John_P]

Don:



If you give Dan Scheid a call at "Scheid Diesel" in Terre Haute,

Indiana I think he can help you. They just finished building a

truck for pulling competition. They used "370 Diamond B"

engine parts along with the ported head etc. His phone

number is: 1-800-669-1593. Also, Joe Donnelly ported his

head on his 96'. You may want to e-mail him.



Hope this helps you some.



---------

John_P

 

[Smoker]

Scheid's Pull Truck

While we are on the subject of their truck, I must add that I pulled against this truck last night. They have got one helluva truck. If he had not of let off of the fuel, he would have probably took Dave Mitchell last night. There's not a doubt in my mind.

On the subject of porting and polishing, Mitchell told me last night that for our trucks, the best thing to do is polish it real smooth. He said that there wasn't much use for porting our heads since we're turbocharged.

 

[John_P]

Smoker:



I am glad to hear Scheid's truck is doing better! I spoke

with Kent Crowder at Scheid a couple of weeks ago and

he said they were having some "growing pains" with it

after the initial engine rebuild.



-----------

John_P

 

[HoleshotHolset]

I'm really looking forward to bombing the heck out of my truck, that's for sure. Eventually, I would like to see 600rwhp. Of course this is many years down the road and MANY thousands of dollars later... .

I'm going to try water injection once I start bombing mildly..... it works wonders for lowering EGTs on the gassers I race.

Matt

 

[DHRA]

Port and polish

Had mine done about a year ago, saw a 35 degree difference on cruising, up to 150 degrees cooler on heavy acceleration. The best thing was having the castings removed from the valve seats, copper seating them, and having the head milled. They took out a BUNCH of casting. It was worth the $500 I put into it. Of course I had the heavier valve springs installed.

 

[HoleshotHolset]

If I'm not mistaken... . removing the castings around the valve seats is known as "bowl work". I did this to a turbo gasser head and it woke it up like you wouldn't believe. I don't want to have my head milled any more than what is required to make it perfectly flat for good gasket sealing action..... I definitely do not want to increase compression ratio by decreasing combustion chamber size.....

I'm glad to hear that it's running great... does it feel better ("seat of the pants") ?

The decrease in EGTs is from the increased airflow with same fueling..... so in essence, you can run more fuel and have the same EGTs as before. I like this... .



Matt

 

[moparguy]

Try searching for Joe Donnelly's post. Over a year ago Joe was discussing the porting job he did on the little sickly white Ram he has. As I recall he really didn't do anything drastic, and most of it was in the bowl area.



Added in edit; I just searched, had to use just Joe's last name, but brought up a lot of post. I didn't find the one I mentioned, but did find a ton of 12 valve stuff I may review just for my benefit when I get the time.



Good luck, Ronnie

 

[DHRA]

Nothing for the seat of the pants, she seemed to have deepened her growl though... .

Bowl Work is done in the morning with the latest copy of the TDR... .

 

[Joseph Donnelly]

I ported Sickly's head over 2 years ago. EGT dropped about 200-300 degrees but hp didn't change when checked at the 390 hp level. Might do some good on the hp at higher levels.



Bowl work was the major improvement, I believe. Just smooth and round it off like a carburetor venturi. Get a good 3 angle job on the valves matching them to the seats and trying to get the depths the same--around 0. 052" to 0. 055" from the valve surface to the deck surface. I also narrowed the guides a little, especially where the intake guides protrude into the ports and pinch them in (the ports come in to the side not directed to the guides--hence the swirl effect). I polished the grinding marks to help minimize hot spots.



I also cut off the knot in the way of #1 and smoothed out the casting letters inside the plenum. Also cut back the lump for the fuel filter boss that we don't need; retapped the holes that now go into the plenum for pipe plugs. I also deburred the outside of the casting and ground some at the fuel filter boss outside where it is close to the injection pump, for more clearance.



Hope this helps. Work carefully, wear goggles, enjoy your quality time with the Ram

 

[Piers]

I took an old head and cut it into pieces so I could better see where some of the water jackets & other important things were. If someone wants to either guide me thru the picture posting part or want me to send you the pic's so you can post them, send me an e-mail & I'd be happy to do so.

 

[HoleshotHolset]

Piers,

I'd love to see those pictures of the cut-apart B5. 9 head... .

I'm pretty sure my HoTMaiL account can handle up to 1MB worth of attachments.



Matt

 

[HEMI®Dart]

Don,



Its much cheaper & easier to lower the compression by using a B series marine head gasket. They come in thicker sizes than OEM gasket. Joe D has one on his truck. The part #'s were in a thread at one time.