Anyone port the Fiero V6? I know the 3800 is a fine motor and theres good reason to go there. Still I bet a ported 60* would be way satisfying. Maybe not though. Currently porting out an Iron Duke to get some practice and see what the results will be but plan a swap. I mean unless porting really helps the Duke tremendously. By porting I mean hogging the pocket to 90% of the valve size as well as the gasket matching and over all smoothing/casting flaws etc.
------------------ 84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White
I built the crap out of my V6. Ported the heads, the intake, and the exhaust manifolds. Had a crazy cam in it and a Holley 390 4bbl. It ran great, but it just left me wanting for a 350
There is a member on the site that knows of a kit they sell to port heads. Apparently it takes about 10 seconds to do each head, and from what I've seen it looks pretty much perfect. Hope he chimes in, cause I'd love to buy it.
There is a member on the site that knows of a kit they sell to port heads. Apparently it takes about 10 seconds to do each head, and from what I've seen it looks pretty much perfect. Hope he chimes in, cause I'd love to buy it.
It's a $100K CNC machine pre-programmed to port the V6 heads?
That will still take quite a bit longer than 10 seconds though. There is no way you're going to port a head in 10 seconds. It's just physically impossible to do it, with currently available technology.
It's a $100K CNC machine pre-programmed to port the V6 heads?
That will still take quite a bit longer than 10 seconds though. There is no way you're going to port a head in 10 seconds. It's just physically impossible to do it, with currently available technology.
No, let me try to find the thread with that post and I'll get back to you.
I recently got back my Manifolds. Heres where the long process of porting begins!
My buddy has a Hole Saw kit (similar to what's pictured below) which includes a cutter which is the exact same size as the inside of the manifold ports.
You may not wish to hear this, but it takes about ten seconds per port to do a perfect job! I'm not kidding. I'm surprised more people don't use this method.
For some reason I thought this was for the heads, but it's for the manifolds. My bad, guess I just kind of scrolled past it one day and didn't fully read it.
My buddy has a Hole Saw kit (similar to what's pictured below) which includes a cutter which is the exact same size as the inside of the manifold ports.
You may not wish to hear this, but it takes about ten seconds per port to do a perfect job! I'm not kidding. I'm surprised more people don't use this method.
[This message has been edited by Patrick (edited 08-01-2014).]
Interesting how things get changed... I seem to recall it was me who originally posted that.
The hole saw exhaust manifold porting trick has been around for quite some time. I did my first hole saw porting in 2005 and posted about it in 2008 in this thread and even had pictures: //www.fiero.nl/forum/A...090907-2-089203.html
According to the Herb Adams dyno tests of old, porting the exhaust manifolds resulted in a 5 horsepower gain. Not bad for a no dollar addition.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
I built the crap out of my V6. Ported the heads, the intake, and the exhaust manifolds. Had a crazy cam in it and a Holley 390 4bbl. It ran great, but it just left me wanting for a 350
According to the Herb Adams dyno tests of old, porting the exhaust manifolds resulted in a 5 horsepower gain. Not bad for a no dollar addition.
Cool, is there some reason not to port the intake area? That is supposed to be where the main gains are almost unanimously....according to David Vizard anyway.
The hole saw exhaust manifold porting trick has been around for quite some time. I did my first hole saw porting in 2005 and posted about it in 2008 in this thread and even had pictures: //www.fiero.nl/forum/A...090907-2-089203.html
No no no... I'm not taking credit for the idea!
Look at the post I quoted. It was a post of MINE from six months ago. Now look at what was quoted in zzzhuh's post just before my last one. That was MY same post from six months ago attributed to ragging_fiero (with another sentence added). Not a big deal, but you don't usually see that type of a quoting mix-up done here.
[This message has been edited by Patrick (edited 08-02-2014).]
I'm going through this process right now. I started by porting the exhaust manifold and adding 1.6 rockers. The exhaust and rockers made a difference, but then one of the brand new pushrods failed, so i used that as an excuse to pull the heads of too and am going to port the intake and heads. The three areas of concern are port matching the intake and plenum, gouging out the valve bowls, and removing the restriction in the exhaust tunnel wall behind the spark plugs. They say that the exhaust manifold is only part of the problem and all these head restrictions must be cleared too. Then you'll need to mod the plenum to finish the job. Only then will those huge valves be able to breath.
I'm going through this process right now. I started by porting the exhaust manifold and adding 1.6 rockers. The exhaust and rockers made a difference, but then one of the brand new pushrods failed, so i used that as an excuse to pull the heads of too and am going to port the intake and heads. The three areas of concern are port matching the intake and plenum, gouging out the valve bowls, and removing the restriction in the exhaust tunnel wall behind the spark plugs. They say that the exhaust manifold is only part of the problem and all these head restrictions must be cleared too. Then you'll need to mod the plenum to finish the job. Only then will those huge valves be able to breath.
Hey there F85, tell us if there might be room for larger valves. It seems so often people wanting a performance boost think swap rather than bettering what they have. Show pics if you can please.
It's only a $0 mod until you start breaking the manifold bolts to get them off. Then it quickly becomes very expensive.
Yes, that's a real possibility. If that happens you will need the drilling fixture to get the broken studs out ( Rodney sells them) or you could use the method developed by Ed Parks. Ed used to weld a bolt to the stud crosswise and used a slotted socket to get the studs out. The heat of the welding process greatly helped. He told me that they only encountered one bolt in the years that he worked on Fieros that had to be drilled out. I just spray the bolts will PB blaster a few days in a row and let the car sit. Never had a problem but if the engine is high mileage, the rust bad the drilling fixture and an easy out must be put into use. As for porting the intake; the ports really narrow down in the LIM around the fuel injector boss. I've ported this area and its helps, but overall the Fiero plenum does not flow all that well and on the 3.4L swaps it chokes the engine over 4500 RPM.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Regarding the over all design of an engine... Seems easier to use a large piston to push trapped air OUT a small valve opening than to take a large piston to try and pull atmospheric air thorough a small valve opening. The piston is GOING to push that air out regardless and it has metal to back the force. When the air is drawn IN the air is kinda stretched and it's density thinned until it reaches equalibrium. This is why it seems the gains would be won on the intake side for porting for the most part.
------------------ 84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White
Oh I see what your saying now. See that's just it, air stretches and squashes of course. Here's another way of saying it. Take a syringe and extract 1cc of water from a cup. Pull hard and we will have to wait until the syringe fills at it's own pace. Now using the same force plunge the syringe and the water is shot across the room at a much greater velocity.
Originally posted by White 84 SE: Regarding the over all design of an engine... Seems easier to use a large piston to push trapped air OUT a small valve opening than to take a large piston to try and pull atmospheric air thorough a small valve opening. The piston is GOING to push that air out regardless and it has metal to back the force. When the air is drawn IN the air is kinda stretched and it's density thinned until it reaches equalibrium. This is why it seems the gains would be won on the intake side for porting for the most part.
Huh? Do you not understand how 4 stroke internal combustion engines work?
Cool, is there some reason not to port the intake area? That is supposed to be where the main gains are almost unanimously....according to David Vizard anyway.
Vizard sells lots and lots of books . . . you will find others who do not sell lots and lots of books that will counter most of what he writes about and make more power than he is
You have to apply different thoughts to each engine design, just because it works with one design doesn't mean it's going to work with another engine. If you do not have the tools to measure your gains you will never know what those gains are by just hogging out material.
Even CNC heads start out as a hand worked design that was then digitized for mass production. One does not just sit down at a CNC machining center and make a wonderful flowing head design, someone spent quite a few hours on a flowbench and porting bench with grinder in hand perfecting that port first . . .
------------------ "There is no more formidable adversary than one who perceives he has nothing to lose." - Gen. George S. Patton http://www.flowbenchtech.com
Uh.... well yeah, I checked wikipedia 4 stroke engine ..no new knowledge there, pretty simple. In any case I recommend reading Vizards' "How to port and flow test cylinder heads to any one interested in engines. Having done so I find a new awareness of the spongy, fluid nature even gooey nature of air and fuel as it is processed by an engine.
So back to the topic. Any one do real porting work on the stock V6 and can talk of where the gains are to be had or maybe what to watch out for, that kind of stuff? I know some mentioned the exhaust. Interesting that the exhaust may offer a significant restriction. Care to elaborate regarding performance after porting etc?
Vizard sells lots and lots of books . . . you will find others who do not sell lots and lots of books that will counter most of what he writes about and make more power than he is
You have to apply different thoughts to each engine design, just because it works with one design doesn't mean it's going to work with another engine. If you do not have the tools to measure your gains you will never know what those gains are by just hogging out material.
Even CNC heads start out as a hand worked design that was then digitized for mass production. One does not just sit down at a CNC machining center and make a wonderful flowing head design, someone spent quite a few hours on a flowbench and porting bench with grinder in hand perfecting that port first . . .
Ahh... well now were getting somewhere. Thank you. Hmmm, so you imply Vizard may not be a significant authority than? O.k. cool, food for thought but not much food, more like a rice crispy ghost snack. Got any dirt on him?
Originally posted by White 84 SE: Got any dirt on him?
Nope, a Google search might lead you to some counter discussions though.
If you can get his flowbench design to work let me know cause I don't know anyone who has one working and getting accurate results ie Floating Depression Flowbench.
On the V6 first bottle neck you need to address is the neck on the intake right behind the throttle body. Then you can start working on the ports. That's where I'm getting ready to start at now . . . not a lot of love around here for the cast iron V6 engine though.
------------------ "There is no more formidable adversary than one who perceives he has nothing to lose." - Gen. George S. Patton http://www.flowbenchtech.com
Hey there F85, tell us if there might be room for larger valves. It seems so often people wanting a performance boost think swap rather than bettering what they have. Show pics if you can please.
I can't get pip or hosting to work, so no pics. The valves that are in the 2.8 heads are right next to each other. I dare say that they are so big that you couldn't put larger valves in there. The 2.8 already enjoys an H.O. setup.....with exception for the built-in restrictions.... i.e. sloppy exhaust log welding and punching, exhaust valve ridge, exhaust tunnel restriction, intake valve bowl size, intake port match restrictions, and plenum neck restriction.
Just doing the exhaust log restriction mod and 1.6 rocker install changed top end performance and would pull dangerously close to redline. The 1.6 rockers simply increase the travel of the valves to open them up a hair more. I was surprised at the difference. I did not confirm with a dyno or a g-meter...... my ass told me.
You can fit larger valves, 1.78 and 1.5. Also change to flat top valves for a 3cc reduction in combustion chamber. In my case it helped towards a 10:1 compression ratio. These valves are also lighter.
While doing all the work to port it, why not buy new valves and get even more flow.
I built the crap out of my V6. Ported the heads, the intake, and the exhaust manifolds. Had a crazy cam in it and a Holley 390 4bbl. It ran great, but it just left me wanting for a 350
I can't get pip or hosting to work, so no pics. The valves that are in the 2.8 heads are right next to each other. I dare say that they are so big that you couldn't put larger valves in there. The 2.8 already enjoys an H.O. setup.....with exception for the built-in restrictions.... i.e. sloppy exhaust log welding and punching, exhaust valve ridge, exhaust tunnel restriction, intake valve bowl size, intake port match restrictions, and plenum neck restriction.
Just doing the exhaust log restriction mod and 1.6 rocker install changed top end performance and would pull dangerously close to redline. The 1.6 rockers simply increase the travel of the valves to open them up a hair more. I was surprised at the difference. I did not confirm with a dyno or a g-meter...... my ass told me.
I see, thanks, this is stuff we would not know but by experience. There is a book available that focuses particularly on the 60* V6 and it's build up. It's rare and costs like $100 (which does not necessarily represent it's worth). For those interested. It may very well be a superb book I don't know.
Don't forget to switch to the 2.8 valves from the 87-89 aluminum head motor...and get appropriate guides. They are within .020" of stock V6 iron head valves' height but have a smaller diameter valve stem which increases net flow a little since there is less valve stem area in the stream and wide end of the valve allowing more air into the combustion chamber.
The marginal height difference is adjusted out when setting the lash. My next set of heads will use these.
Originally posted by White 84 SE: By porting I mean hogging the pocket to 90% of the valve size
This only improves power/torque if you have a cam with enough valve lift to get out of the low lift flow regime. Otherwise it just kills velocity and hurts performance.
This only improves power/torque if you have a cam with enough valve lift to get out of the low lift flow regime. Otherwise it just kills velocity and hurts performance.
30* valves improve low lift flow dramatically without a cam change If you wanted. I just bet that casting limitations and conservatism in the design room leads to choking throats in pre-CNC heads as a rule. It is just a theory though.
Anyone port the Fiero V6? I know the 3800 is a fine motor and theres good reason to go there. Still I bet a ported 60* would be way satisfying. Maybe not though. Currently porting out an Iron Duke to get some practice and see what the results will be but plan a swap. I mean unless porting really helps the Duke tremendously. By porting I mean hogging the pocket to 90% of the valve size as well as the gasket matching and over all smoothing/casting flaws etc.
Not a big deal, but you don't usually see that type of a quoting mix-up done here.
