Engine/Transmission (1994 - 1998) Port and Polish Head

[AWard]

Who has had their head ported and polished? What kind of differnces will it make? and Does anybody know of any web sites besides Piers that show and explains doin it?

 

[Vaughn MacKenzie]

I think Piers is the only one. There was discussion here or NW Bombers about porting and it's something that needs to be done right. It's all about swirl and consistent air flow. If not you get different flow characteristics dependant on valve lift (ie what part of the intake cycle you are in), so if it's not nice and consistent across all valves then you can easily end up with uneven flow across the cylinders at different RPM & power levels.

I ported the head on my '96 myself but the engine isn't real smooth, so I think it's because of the port job I did. Next time I'll let Piers Diesel do my porting for me.

 

[Bodie]

A flow bench is almost necessary for porting and polishing.

 

[DBraunig]

I had mine done when the gasket failed. A local man with a great reputation and 20+yrs experience. He did an outstanding job in my opinion, and I was pleased with the results. I probably dropped 100-150 degrees egt wot, and egt seems to climb slower. The numbers are similar to a stage III head. If it helped spool up, it was minimal, but the egt drop was nice. I have pic's in my gallery of his work.







Dave

 

[hdm48]

Just plan on porting the exhaust manifold and turbo or else it's like stuffing a cork in the exhaust system.







Dave

 

[JWestley]

I know Forrest Nearing had his head ported by raymac heads. Kinda pricey, but he's making some good power with low drive pressure

 

[Forrest Nearing]

Just plan on porting the exhaust manifold and turbo or else it's like stuffing a cork in the exhaust system.







Dave

well, the exhaust manifold and turbo flow a lot more than the exhaust valve and bowl, so while porting them will certainly help, porting the head without porting the exhaust manifold and turbo will help a great deal

 

[DValentine]

I found the water jacket on my first port job-the number six exhaust chamber. The wife told me to get a Piers head and quit messing around. So I did.



I did a little more work on it though... . didn't tell her that. I was happy with the results. I also did some work on the exhaust and turbo.



Now the truck puts out 161 horses at the crank. :-laf



Have fun. hdm 48 knows quite a bit about porting.



Dave

 

[Timebomb]

My egts do not sweep quite as fast as they did befor I ported mine. I guess an EGT reduction would be the biggest change people see.

 

[Bobcat698]

I found the water jacket on my first port job-the number six exhaust chamber.

We did too a few weeks ago. Its a great feeling. . :{

 

[JTEdieselram]

Be careful how you spend $$$ on porting. I had haisley do mine, and what I got was crap. I asked for stage 3, paid $700. 00 which I thought was a great deal, got the WORST port job I have ever seen. Nothing on the intake, only the 1st inch or so of the exhaust port was smoothed out. Looked like someone spent maybe 30min on the whole head. Haisley's explination: there shop does not actually do the work..... must have been a new guy... ... Refunded the "$50. 00 they made off the deal" HUUUUUUUGGGGGGEEEEE rip off, I am angry just thinking about it. I waited almost 4 months to get the head, so I did not send it back, but I am definatally not satisfied with the work.

 

[arthr31]

Wow, interesting data point, thanks for sharing. What would you have done differently knowing what you know now? And, what did you originally set out to do by porting the head???
Thanks man. -arthr

 

[Vaughn MacKenzie]

I've always wondered if there's a way porting could be done with a CNC machine. Something like that could get super consistent results between all ports then final polish by hand. I suppose the tight angles you have to take getting in there would rule that out.

 

[Forrest Nearing]

tons of porting is done via CNC... once you have a good map, it's the best way to go IMO

 

[Vaughn MacKenzie]

So I wonder if any of our vendors in the diesel arena are doing this? I suppose it would take a lot of work building a 3-d profile for the exact port shape you would want, but with a scrap head that can be cut up it through the ports it should be fairly do-able.

 

[Highfinance97]

I have a head that has some small cracks in the valve seats.

Im curious of how close the water jackets are to there and if maybe the cracks could go that deep

because i dont want to do the porting and put bigger valves in if im going to be risking them getting bigger and ruining my head or worse the engine





Michael