porting a diesel head / manifold ?

There are many sled pullers that have ported their heads and matched all the connections, but this is in highly modified engines. The gains are there in my mind. I just don't think there would be enough to justify doing it in a typical OTR engine unless the motor is also gonna be used for after hours play (dyno contest or sled pulling).

 

Don't know if matching head and manifold makes much difference but porting intake and exhaust ports will help a lot, especially seat and bowl area is very bad in production heads, there is a lot of flow to be gained. Basic porting in that area costs maybe a couple of hundred bucks.

 

That's about it but back cut valves don't always work, depends on many things so better not do it because the gains would be small any way. Diesel heads are the same as gasoline except intake ports are swirl type shaped and you should not change that swirl part even if you usually gain flow at flow bench. Diesels need that swirl to mix fuel and air and that is one part that factory engineers spend a lot of time and money.

 

I personally have an OCD type disorder with exhaust port matching. Every time I buy something with a new motor attached to it I rip off the exhaust and match the head. From chain saws and lawn mowers to generators, motorcycles and pickup truck motors. You'd be surprised at how much steel or gasket material there is to be removed. Its all a power robbing restriction. I have never not experienced at least a little gain. I have one little Husqvarna chain saw that I guarantee you I doubled its power in doing so.

Invest in a can of dykem steel blue (or red) layout fluid as itll be your best friend for doing this kind of work.

I started learning by doing simple "gasket match" port jobs. I went real slow and practiced on something that isn't too awful important, like an old chain saws and weed eater.

Jumping to the next level is a little different. You can ruin a head real easy or spend hundreds of hours doing a port job just to have the flow bench show no improvement or a loss! Black magic is what I would call it lol, and I leave it to the pros.

 

Where can you get this type off head work done or where do the tractor pullers get work like this done. What about a c18 head would it flow anymore or have stiffer springs?

 

Depending on the situation matching the ports isn't always what you want for performance gains. If the exhaust port in the head is slightly smaller than the port in the manifold, that can actually be a good thing. It creates a step that when air flows in one direction (small hole to large) it's pretty much unrestricted, but when it tries to backflow, it slightly holds it back. Anti-reversion of the airflow. In the case of an OTR size diesel engine, this could be of benefit to the turbo, as it would attenuate the pulsation that would reach the turbocharger under some running conditions.