Modifing a 2.5 non-SVT UIM

I think what demon ment is that if I gasket match the UIM it will fudge up because the LIM with be much smaller thus creating a major retard in the air flow.

I was thinking about what demon said and I was wondering what if I port the primary larger on both the UIM and the LIM. Or would this still not have any effect???

Every case may be different. I have port matched many engines by matching the gaskets, but others I have done differently because it was obvious that the results would not be beneficial. You really need to critically inspect the pieces involved to make a determination. I have not tried to do so with the Duratec.

I believe that porting the intake by cutting it open for access then welding it shut when finished is doable, but the skill needed to port such long ports as well as the hassle and expense of properly welding everything back when finished is beyond the level of most nearly any entry level hot rodder. I have helped do it on a Ford 302 but it was so much work that I would not likely do it again. It really did wake up the 92 Thunderbird we did it to though. The Mustang manifold would not fit under the hood and the Thunderbird manifold was very restrictive before we started.

hmm I need to do some thinking on this and I come up with something tomorrow because I worked 12 hours today and i'm beat. oh and i'm off to work for 6 in the morning. So we can fight this out tomorrow guys lol

Originally posted by BigC:
WRONG!
Every serious engine builder IN HISTORY has stood by gasket matching in relation to engine porting.

Perhaps the UIM on a Contour should not be ported, but to say that "gasket-matching on an engine is a joke" is completely IGNORANT.

It is plainly obvious you have no idea about any of the measurements of the parts you are talking about.

Split Port UIM (2000 SVT)
Primary: 30.5mm
Secondary: 31.8mm

Split Port UIM Gasket
Primary: 35mm
Secondary: 36.4mm

So you want to significantly widen the port and slow down the intake charge to match it to the gasket that is 5mm larger.

LIM (Returnless)
>Inlet
Primary: 33.5mm
Secondary: 34.7mm
>Outlet
Primary: 32.5mm (Mine â�?��?? 33mm)
Secondary: 34mm (Mine â�?��?? 34mm)

LIM Gasket
Primary: 34.7mm
Secondary: 35mm

Now you want to do the same things again!

Cylinder Head Inlet Ports (with flashing cleaned - untouched are smaller)
2000 SVT 2.5L Primary: 33mm
2000 SVT 2.5L Secondary: 34mm

So that's small, huge, medium, large, medium. 5 changes up & down in port size. Not a very good idea at all for obvious reasons.
This is all on SVT parts. Stock parts would have a much greater size differential at each step.

Larger is not always better. Actually most of the time it is not because maximum port flow ability is just one small part of the whole picture. Velocity, taper, and cylinder filling are far bigger parts of the design of the manifold system.

Saying "CUT AND DRY" that gasket matching the port is the best thing you can do and you "SHOULD ALWAYS" do it to every engine is completely wrong. PERIOD.
Matter of fact there have been countless dynos over the years (flip through any of those same decent books or magazine series) that shows gasket matching makes little to no difference in the overall power curve. In some cases it hurts power because the intake charge is slowed down and energy is lost. We have one of the extremes of the later.

So yes the term "gasket matching" is a joke when it's thrown around like most people use it. Like you used it in this example.
The port as a whole is what is important. Enlarging it to match the gasket when it alters the design & flow of the port is bad and will always be bad.

I already mentioned that I didn't know much about the Contour/Duratec. My argument was not about the Contour. Great information regardless.

More often than not, gasket-matching is glorified by its gains. It would not be listed in and explained by such large publications if it was such a "joke." Your speculations are just that- speculations. Your opinion is noted, and I'll stand by a method I have always been satisfied with. The struggle for extra power in a motor by car enthusiasts has led to lots of modifications that many view as frivolous. This modification has proven time and again to add horsepower and improve airflow on vehicles.

I never said that you "should always do it to every engine" either. You said, "Enlarging it to match the gasket when it alters the design & flow of the port is bad and will always be bad." That is one of the least intelligent statements I have ever read. It is common sense! Rough castings often restrict flow, and cause excessive amounts of pressure and resistance. By smoothing out said castings, better flow and increased velocity OFTEN result in HP gains. This is true often in intake manifolds, exhaust manifolds/ports, cylinder head ports, and even rough oil passages. Ever notice why aftermarket components such as these (aftermarket cylinder heads come to mind) often come with machined/polished/bigger surfaces/ports?

I can understand your arguments, but to say that this is a waste of time is a stupid comment. This porting and polishing by itself may not add huge HP gains, but the increased flow supplements other parts of the motor, and combined with bigger modifications, can make major differences in power. That's why people do it.

But improperly done porting can hurt power. I know because I've done it. It was a wonderful waste of about 20 hours of labor as well as a destroyed set of heads. I got carried away with the valve pockets.

Since the beginning you have taken my comment out of context.

You were talking about gasket matching "BY ITSELF" and nothing else. My statement was about it "by itself" and I most definitely stick by it because my statement is true. Common sense true to put it in your wording.

Now you come to the defense of it again by stating examples of full porting jobs of the heads and manifolds and stating the using of the gasket as a template can show gains. That is most definitely NOT gasket matching BY ITSELF now is it. It's also not a given on every engine. (but everyone does it and recommends it you claim???)
However it is not a "definite" proposition for the reasons I gave in my last post. You remember, the ones you just stated were "common sense" yet you argued against in your first response to me.

(which is it by the way???)

Then you chime in with "Rough castings often restrict flow, and cause excessive amounts of pressure and resistance." That's like the "well duh" of statements. I even referred to it using the stock vs SVT statement. The SVT UIM uses the Extrude Hone process which does exactly what you just explained to me.

(SVT heads as well for that matter)

However. You seem to state it like in order to "remove the rough castings" you have to hog out the ports. That is not true at all. You can smooth out the ports and only take a small amount of material out. You do not have to open them up to match larger gaskets. You do not have to oversize them and lose velocity.
Which brings up velocity & cylinder filling. Those are far more important then changing to port size to just match a gasket. Like I stated before there are more important factors then maximum flow ability. Runner length, port volume, port velocity, swirl effect, cylinder filling ability, et cetera. I'm not saying maximum cfm ability is not important but exceeding the needs of the engine is gaining you nothing and almost always hurts other areas.

I will end with the following.

Why tell someone to do something you have no idea how to work on. Your advice was completely incorrect on this subject. Your using general knowledge and stating it will work because "Every serious engine builder IN HISTORY does " still does NOT make it correct.

My first response was against using gasket matching on our platform and just blindly using gasket matching by itself on any engine. Both statements are very correct and I stand behind them.

For what I have seen in your posts. You may have some good books and obviously have some good experience but by arguing for just one small part you don't seem to fully understand the whole picture of why things work the way they do. Take that however you want as it's just my opinion. I have plenty of them. When it comes to automotive related knowledge I believe my way of thinking shows well for itself in the cars I have built. Other opinions may not. They're not my opinions.

Originally posted by DemonSVT:

Originally posted by BigC:
WRONG!
Every serious engine builder IN HISTORY has stood by gasket matching in relation to engine porting.

Perhaps the UIM on a Contour should not be ported, but to say that "gasket-matching on an engine is a joke" is completely IGNORANT.

It is plainly obvious you have no idea about any of the measurements of the parts you are talking about.

Right there I explained that the Contour's UIM should not necessarily be ported. You're right about that. It is very apparent that you know more about the Duratec platform than I do. I have yet to do any serious engine modifications to the Duratec, and that is why my argument in relation to it ended.

However, I will continue to argue for the idea of gasket-matching in relation to porting. When two mating ports are opened to the size of the gasket, the flow is increased, and if the the gasket is from a good company (i.e. Felpro...) then you can be assured that the port can never be the wrong size, because the gaskets will always be the same. Besides- this increases the duration of use of said gaskets.

I have never encountered a situation where this method has led to a loss of power; at times, it has happened that there was no change, but never have I encountered a loss of power.

Originally posted by DemonSVT:
Enlarging it to match the gasket when it alters the design & flow of the port is bad and will always be bad.

This statement would be true only if stock ports were perfect. Often, the design and flow MUST be altered to increase flow to a level that ONLY allows the engine to breathe as it was intended. How can it be bad if it increases power?

The few instances which you've pointed out as being bad subjects of this method are EASILY negated by the thousands of helpful and successful instances that can be observed in just about any "Engine Building" publication, car magazine, or even on automotive programs on TV.

Perhaps we should agree to disagree.

just out of curiosity, what is extrude honed porting? I know the svts have it and I don't.

very sad.

Originally posted by BigC:
and if the the gasket is from a good company (i.e. Felpro...) then you can be assured that the port can never be the wrong size, because the gaskets will always be the same. Besides- this increases the duration of use of said gaskets.

This is a dangerous assumption. Often intake gaskets have way too much void space. Perhaps in cases where the additional material removed would be too much to work well, new gaskets should be made before attempting to match the ports to the gaskets.

Fine putty-like material forced through the intake (with a rough nature, like putty sandpaper..) and effectively sands the inside of the manifold in a manner that would be impossible to do with normal tools, due to shape, and distance of passages. Also ensures a uniform pass, as the material is pressurized through there.

Increases size (slightly), smoothness and uniformity.

Ray

Originally posted by elraido:
just out of curiosity, what is extrude honed porting? I know the svts have it and I don't. very sad.

There is a company strangely enough known as "Extrude Hone" that does this process. As far as I know the Contour SVT is the first and only production car to use the process. It is usually done by hot rodders.

Basically an abrasive putty like material is forced through the ports. The putty both polishes the port and removes some metal, making the port larger in diameter as well as smoother. The material used as well as the pressure used and the number of times the process is done determine the finished product.

This is an expensive process, and thus the reason that it was only done for the SVT.

IIRC, the SVT engineers said that the process was worth about 10 hp for the 98 and an additional 5 (15 total) for the 99 and 00.

Maybe you two should just whip it out and measure it so you can get your crap of back and forth, need to have the last laugh, non sense out of the way...

So anyway..

So from what I understand the UIM should not be enlarged what so ever? Then why is the SVT manifold larger then a non-svt manifold? or am I wrong on this? Also have you ever looked at a non-svt manifold? The holes are not very uniform at the exit. I wanted to smooth these exits out and at the same time enlarge them slightly (better air flow IMO).

I think someone got carried away...I have a non-SVT duratec and can't find/afford the SVT UIM/LIM. So for 10 bucks + a gasket I wanted to optimize a manifold. Or is this still wrong and can someone actually post a reply to me and not bark back and forth??? (and your both right in your own ways, you're just not on the same field so back off and go sit in some time out seats, jesus chirstmas)

Thanks

I certainly hope you were replying to someone else, and not me. (you replied to my post, so I can only assume, though I think its Demon and BigC you are referring to.

FWIW: I'd just let them talk about it. You want someone to answer you and only you, and NOT debate reasons why you shouldn't or should do it? I can give you a concise, straightforward answer directed only to you if that is what you feel you have to have..

don't not go out and don't do it unless you don't want to not ruin it.

That is as fickle as I can be in a concise manner. (Psst.. I think you would rather APPRECIATE having two rather established, and obviously educated members debating YOUR question on YOUR behalf, FOR you. Better information to be had all around.

Ray

Yes Ray I was refering to BigC and Demon. It seems to turned more into whether gasket matching is good or not post. I wanted to try to redirect it to my question before it wonders off and becomes a flame war. Sometimes I'm just to straight forward with what I think.

oh nice use of double negatives, you made me have to read that three times...

Originally posted by ZeroHour:

So from what I understand the UIM should not be enlarged what so ever? Then why is the SVT manifold larger then a non-svt manifold? or am I wrong on this? Also have you ever looked at a non-svt manifold? The holes are not very uniform at the exit. I wanted to smooth these exits out and at the same time enlarge them slightly (better air flow IMO).
Thanks

I have not ported one of these engines. Demon has. I respect his perspective

The issue is not that you cannot enlarge the ports in these engines. The issue is that if you don't do it right, you can do more harm than good. It is Demons opinion that trying to match the ports using the gaskets on this engine will give you a poor port shape and cause more harm than good.

I have ported many heads. I have made mistakes when porting heads. I have had large gains when it was done properly (nearly 20% in porting alone). I have also lost nearly as much when it was done wrong. It is nice to know what others who have gone before have learned. If I were porting heads on a Duratec, I would investigate matching the ports to the gaskets because it has worked for me on other engines. I would look at it very critically because someone who has gone before found it disadvantagous and would have to have a compelling reason to go ahead. If I were to go ahead and then find that I had lost power in the process, I would have no one to blame but myself.

So perhaps this is a place in which the two of you should agree to disagree. Unless you both are willing to have a "port off". Each of you supply an example of what shape you think will work best and have them tested on a flow bench.

I think I should have never said gasket mathcing. haha The gaskets for the manifold are much larger then the actual diameter of the hole. I was only going for some airflow modification. The whole reason I asked is like what Big Jim just said, I don't want to do more harm then good! I'd really rather not destory a UIM and waste the time doing it, especially if someone knows from past experiences.

figure I'd give an update, I"m going to start cleaning that manifold from the yard today. maybe then I can get some pictures and explain in better detail what I want to do.

couldn't edit my post, but cleaning the manifold is a hold as of now. I only had a can and a squrt because someone used the 3 cans I had to clean a !@##$@!@%&&@#&@#@ lawn mower. Don't ask.... I'm picking some up after work tonight.

I've ported 3 sets of duratec heads. I've dyno tested two of them.
I'll tell you that you can gasket match but be prepared to go all the way down into the head and up into the upper intake a little bit. I had a hybrid and I gasket matched my upper and lower while leaving a small amount of taper in the lower manifold and then of course I tapered on into the cylinder. My results turned out quite well but I'll tell you that for a mild 3L it would have been overdone. For a modded 3L and later a turbo it turned out awesome!

So you're both right, somewhat.

screw everyone, I am going to take an exacto knife and start carving into the manifold anyway I want.

Originally posted by elraido:
screw everyone, I am going to take an exacto knife and start carving into the manifold anyway I want.

Good luck.

lol me too but i'm gonna go at it a butter knife!

okay not really, I'm gonna run for more TB cleaner tomorrow so I can clean the manifold I have and then post pictures to what I want to do to it. Maybe then It will clear up some of this!

Gang,

Demon's information is based on the 2.5/3.0 V6 Duratec platform. So what he has said is indeed correct about gasket matching the UIM/LIM. Think of what he is saying(specific to our platforms) in terms of an exhaust pipe. Smooth mandrel bend or cheap flex pipe. For lack of a better way to draw it, the example below is a straight , mandrel pipe:

AIR
|
V
| |-UIM
| |-LIM
| |-Heads

Gasket matching effect or cheap flex pipe:

AIR
|
V
/ \-UIM
\ /-LIM
/ \-Heads

I know this is a stretch, but the point is there. Now, which exhaust would you rather have on your car, the smooth consistent one, or the one with several expansions and contractions.

Think about it. His notes are specific to OUR engines, not hot rods in general.

DEAR LORD it took 5 and a half cans of the Valveline Syn TB cleaner to get crap to stop coming out of the UIM. I knew it was dirty, but wow! And does that stuff stink! I'm glad I did it about 60 ft away from the house. After about 10 minutes the bugs stopped flowing around me...

Well either way I've finished cleaning it and I came in for lunch. So afterwards I'm going for pictures!

LOOK ITS A SOLAR ECLISPE!
not really, but how round is this circle?

That "circle" is one of the air ducts on the manifold.
It is hard to tell from the digital pictures but on the manifold there are casing lines that run right to the port. They are indented and have a small rough edge:

This is an example of how i want to clean up the manifold:

(I outlined the gasket on that side because as you can see the hole is not centered with the gasket)

I wanted to go through and widen/smooth out the cast and remove the lines from the manifold. I know that I can't remove the rough from the cast all the way through but from the way I look at it, if its last couple of inches is smoothe and widened would it not provide a slightly improved air flow?

That was my thoughts, maybe I'm just a lone sheep out in a field on this one...

What you are doing is not really "smoothing" the port, but gasket matching.

Bike explained it very well as to why gasket matching may not be beneficial (air flow/velocity):

Originally posted by Bike2112:

AIR
|
V
| |-UIM
| |-LIM
| |-Heads

Gasket matching effect or cheap flex pipe:

AIR
|
V
/ \-UIM
\ /-LIM
/ \-Heads

By not having a smooth flow of air (like in his top diagram), but turbulent air flow (pictured in 2nd diagram), you may actually be hurting performance rather than helping it.

I see both sides of this modification, but IMO in most cases of mildly modded Contours (basic bolt-ons), it's better to leave it be or smooth rough edges - NOT gasket match.

okay yes I said i believe mutliple times now that I AM NOT GASKET MATCHING the manifold. It wasn't till after the first message and I realized what a mistake it was to use the term(considering the gasket is not near the same size as the port). Of course it would be stupid to gasket match the thing consider you'd be cutting the two ports into one if you did...

Quote:

it's better to leave it be or smooth rough edges

I was wondering if it would still be bad to smooth the edges where the casting line was. AND yes that would involve slightly enlarging the port because the lines are indented.

Is anyone behind "smoothing the edges" or should I just scrap this entire thing and use the alumium to make cans?

I didn't gasket match, but went close. I just cleaned up as much of the casting flash as I could and tried to make the ports as smooth as possible as far in as I could get.

No need for the "rolleyes" for the subject.

Someone tries to help and you want to throw them a rolleyes.

This is exactly the piss-poor attitude that causes a rift between old-new CEGers.

Gasket match it, leave it, recycle it, use it as a paperweight, whatever.

pete...do you ever sleep...?

Originally posted by Stazi:
I didn't gasket match, but went close. I just cleaned up as much of the casting flash as I could and tried to make the ports as smooth as possible as far in as I could get.

This is what I think I going to do.
Was there any noticable gain or difference?
What method did you use to go afterthis project?
I've seen/heard dremel/rotorary tool at low rpm, sand
paper, and files(???).

Pete don't worry I was only joking about making cans out of it! But a paper weight! behold the possibilities! You are wise!

Originally posted by ZeroHour:
LOOK ITS A SOLAR ECLISPE!
not really, but how round is this circle?

That "circle" is one of the air ducts on the manifold.
It is hard to tell from the digital pictures but on the manifold there are casing lines that run right to the port. They are indented and have a small rough edge:

This is an example of how i want to clean up the manifold:
(I outlined the gasket on that side because as you can see the hole is not centered with the gasket)

I wanted to go through and widen/smooth out the cast and remove the lines from the manifold. I know that I can't remove the rough from the cast all the way through but from the way I look at it, if its last couple of inches is smoothe and widened would it not provide a slightly improved air flow?

That was my thoughts, maybe I'm just a lone sheep out in a field on this one...

I think you have the right idea. You are still way within the gasket and that very light clean up should be beneficial. Be careful though, it would be easy to go too far.

ive done this to 2 sets of intake manifolds (uim and lim), not gasket matching, but smoothing out the edges (somewhat widening the port). in my opinion the only noticeable difference was the black paint that we ended up putting on both of the UIMs

lol I was going to possible paint mine gloss or flat black when I was done too. If their isn't much of a gain I would still believe that in the long run that the crap won't build up as fast or as much because of the smoother walls. When cleaning the manifold I bought The EGR passage was clogged similar to mine and that inside was DIRTY!(when cleaning my EGR I didn't clean down inside, so the inside of mine probably looks sad) I did notice when cleaning it a majority of the gum was clinging to the rough. So maybe not a real big proformance, but preventive maintance deal.

Since a few people have done this, what tools did you use? I plan on borrowing/buying a vernier calipar(speeling?

) to keep the ports the same size. But for actual removal?

I started smoothing out the UIM today. I took the time to cut away alot of casting lines that help all that goo block up the EGR passage ways. I also slightly enlarged the entrance from the TB by ~1.5mm. I got a start on but didn't finish the primaries. I'm taking them from a rough 27mm to a 29mm. Originally I was going to try to only go 1 mm bigger, but it just wasn't enough to get out the casting lines. So far its going good though!

Figured I'd bump this up. With everything going on around here been to busy to keep up with this project!(ESU orientation, work, gf, grandparents are visiting this week)BUT I did take the time today and I finished the primary ports. They are all now at 29MM. They need to be smoothed but all the heavy cutting is done. I'm going through about 1 sand "drum" on my dremel per hole and its taking ~25-30 minutes per hole. I'm taking my time and trying to do it nice. I am also trying to keep all sanding down the tubes even so I don't create ovals above the now improved circle ports.

oh and since I'm done with 6 that means I'm 1/2 way there!

not really because they still need porting, smoothing, and I have decented to repaint the manifold! not sure what colors yet though! I need to get some pics of my engine bay and I'll post some of my thoughts and let you guys chime in. (yes I know this is aesthetics but it goes with the post)

Linky

Link to a geocities page where the pictures will load up. Hoping to get some feedback. oh and the darn text WILL NOT line up for whatever piss reason. Just bare with it! I got them as close as I can and I need to leave for work! haha Later guys. Thanks for the opinions in advanced!

Dear Lord...Well its been almost another month, but I've gotten further on the project. I'm just to freakin busy lately (working 45 hours + sleep + GF + graduation parties). But today I made a leap in progress. All holes are not sized with the dremel and 6 of them I have sanding process near completion! Just figured I drop an update.