Exhaust manifold porting

[Crazy_Matt]

Anyone ever port one? Do they even need it? Or does it flow well enough to not even bother?

 

[Djfreema]

I wouldnt even waste my time,you probably wouldnt even notice any difference in these motors. Just my opinion.

 

[Westech]

lol come on its like dressing up your dog whats the point

 

[Dieselsmoke]

lol come on its like dressing up your dog whats the point

 

[devilman96]

Sorry guys but I disagree... Porting is one of the most over looked engine mods out there. Turbos aside there is little more you could do to an engine to gain so much from a single modification. With the limited number of HP modifications we can perform on these pigs it would be worth looking into!

I have never run the numbers on a deuce but judging by the size, shape, and crap quality of the factory ports walls I would bet there is vast room for improvement. Engines are built for efficiency but they are also designed around mass production so there is give and take. Casting is the cheapest and most inconsistent way to produce a part, the more its cleaned up and made consistent the better it will perform. Unlike today's high efficiency high output engines these pigs were cast when the consideration of "port quality" on a production diesel was unheard of.

The only way to really tell would be to flow test the head and crunch the numbers to see where the CFM and displacement meet up, If I ever have to pull mine I will have it on the flow bench!!!

They may be dogs but port jobs put on a 10-15% increase in HP... That would be slightly more than just dressing er up!!

 

[Dieselsmoke]

what's the point of doing all these engine mods to these trucks? Turn up the fuel a bit and call it good. They've got plenty of power. Want quicker 0-60 times, buy a sportscar. Want to go faster, change your gearing. JMO

 

[Westech]

 

[cranetruck]

Unlike today's high efficiency high output engines these pigs were cast when the consideration of "port quality" on a production diesel was unheard of.

Can you give us an example of one of these diesel engines in particular for comparison, please, with a continous power rating of about 150HP.
I'm sure we have come a long way, but there are also a lot of compromises out there and few, if any, will run without electric battery power.

I still like my multi, no matter what you call it.

PS. Castings are perhaps the best method to achieve consistant quality, just look at turbines and the double walled intake manifold of the multifuel engine, hard to make any other way, even today.

 

[Djfreema]

Regargdless of how much porting is done on the exhaust, you still have the choke point of the turbo. If is was a gasser engine that turned very high rpm's and didnt have a turbo, I'm sure it might be worth the trouble to smooth out the flow. Your not going to notice anything on the butt dyno in these trucks. I agree with diesel smoke, turn up the fuel a bit and call it a day

 

[Crazy_Matt]

Ive seen decent amounts of extra power thats was had from porting my turbo omni manifold.

egts went down ~100 degrees

turbo spooled quicker

porting the exhaust housing and turbine inlet also helped



going from 2.25" to 3" mandrel bent exhaust really made a difference 7mpg and egts went down even more


I'd like to ditch the stock duece turbo and get a D series or get a holset of some sort. Then maybe take a stab at cleaning up the exhaust manifold.

I know this thing aint gonna be a hotrod or what not- so why not make it kinda efficent and run decent till it blows up someday ?



Anyone have pics of a exhaust manifold? Im curious....

 

[cranetruck]

Anyone have pics of a exhaust manifold? Im curious....

Here you go:

 

[devilman96]

CT I cant give you numbers on another 150HP (I know yer lookin for one). If I get the chance I will do my own and I promise will make a full blown picture and dyno display for ya. I agree with your PS also but they can (and do in most cases) much more automated machining afterwards to clean up to them today as where it was not possible years ago. This is why you are starting to see so many cars with plastic intake manifolds. Plastic casts with a smoother surface and doesn't need the clean up. Plastic... it makes things go really fast... and makes them fail even faster!

DS... Because Im a very bored little boy!!! I hear what your sayin but this IS my sports car.

 

[Crazy_Matt]

It doesnt look like much can be had by porting it. Unless port matching it ,cleaning up the turns and turbo flange area would help.

 

[cranetruck]

Don't underestimate 60's technology. In the image below, guess which sub assembly was made in the 1960's?
The circuit board on the right is from a new (about 2000) flasher unit. This one blew like a fuse when overloaded. The flasher built in the 1960's could handle an overload until the circuit breaker tripped.

I like to think that the multifuel engine was designed for similar duty.
It may only put out 140 or so HP, but it can do that forever and a day.

BTW, the assembly on the left is the power amplifier in the VIC-1 intercom AM-1780 box. No compromises here.

 

[DrFoster]

porting... nah. maybe doing a bit of flow honing on the heads and them maybe it would make a difference, but honestly, for the 2%ish expected increase from the reduced turbulence imo isn't worth the time and cost. That's just me. I'm a bit odd.