• Welcome to the Contour Enthusiasts Group, the best resource for the Ford Contour and Mercury Mystique.

    You can register to join the community.

split port 3l uim or svt uim?

9

95pgt-t

Hard-core CEG'er
Joined
Nov 20, 2006
Messages
3,163
Location
oneonta,ny
Okay, I know ported isnt nesc. the "best" way to go w/a 3l swap,but i'm buying a car that already has this setup: ported 3l heads,svt cams,st220 valve springs,98 SVT lim & uim,little bit of chamber work,opt. tb,headers/ypipe. My question is,before I have it tuned,should I swap to the 3l split port uim? should i gut the lim,or switch to the larger Taurus/returnless SVT lim and leave the imrc setup? I also plan on adding a opt. 65mm tb. Any help or opinions would be appriciated greatly,thanks:cool:
 
Leave it alone. If you really want a full 3.0, pull out the engine you have and start over. Once you have cut into the heads to align the injector nozzles they will never again function as designed with the 3.0 intake manifold.

Many will argue that what you have is not ideal, but it does work pretty well and provides a lot more power than the old 2.5.

Tune it and enjoy it.

I'm sure you will get other opinions.
 
Tried both and have known others that have tried both. Everyone goes back to the SVT UIM so stick with that. There really isn't a significant difference either way to make the switch to the 3L split port worth the connection hassle.
 
i ran a 3l uim on 2.5 before,didnt think it was hard to install,good to know that its not worth it though,what about the lim,leave it,gut it or get the slightly larger one?
 
95pgt-t said:
i ran a 3l uim on 2.5 before,didnt think it was hard to install,good to know that its not worth it though,what about the lim,leave it,gut it or get the slightly larger one?
Click to expand...

Acid port that thing and remove the secondaries :shrug:
 
It doesn't really matter that much. You are dumping both ports into a single chamber, and then splitting it again out to the valves. Stick w/ the SVT UIM, all the parts already fit.
 
In theory, a worthy modification to consider is the SHO SHOP LIM modification where they enlarge the ports and install new secondaries to match the larger posts.

I say in theory, as I have not heard that anyone has dyno'd it yet.

There was or is a group buy for it.
 
I gotta say, since the head inlets are already going to be hogged-out, I see little reason to keep the original design. If I were doing a port-matched 3L, I would go 3L split-port UIM, but get rid of the center divider to merge the runners, then flatten the floors of the UIM exits for each cylinder. Then I would drop the IMRC, port-match or step the UIM exit & LIM entrance & at least partially merge the runners for each cylinder... but that's just me. :cool:

I don't think any of this is the "optimal" way to do things, but with the head hogged out, & SVT cams, the strongest point of the build should be increased potential flow volume at upper RPM's. I would try to make use of it & open up everything else. Granted, this is easy for me to say since I have the resources to do all the work, test my theories, & start over if the end result isn't what I'm looking for. So this might not be a great way to go for everyone, especially since no one that I'm aware of has done it. But I share the belief of many that using the oval-port heads negates any bonuses that the dual-runner IM's provide. Plus, I go a step further & generally dislike the design of the Contour UIM... ESPECIALLY once a 3L block is involved. And the IMRC? COMPLETE waste on a 3L swap, IMO.
 
Big Jim said:
In theory, a worthy modification to consider is the SHO SHOP LIM modification where they enlarge the ports and install new secondaries to match the larger posts.

I say in theory, as I have not heard that anyone has dyno'd it yet.
Click to expand...

April. The car is in storage.
 
Rara said:
Just FYI, the ST220 valve springs are exactly the same as the SVT or any of the other Duratecs. Same rates, same size, everything.
Click to expand...

are you sure about that? my research has shown that some time after 2002 (hence the 2S7Z prefix, which replaced the YF1Z) but i havent confirmed it was made across the board on all duratecs. Granted, that part number is now what you get when you buy valve springs for any duratec, it didnt come with the earlier ones. does that mean that the 04 taurus engine that is in the car already had the st220 springs? maybe, but either way, it now has fresh valvesprings to go along with the new seals and lapped valves- and valve springs that are without a doubt the same as the st220
 
turbo_fox said:
are you sure about that? my research has shown that some time after 2002 (hence the 2S7Z prefix, which replaced the YF1Z) but i havent confirmed it was made across the board on all duratecs. Granted, that part number is now what you get when you buy valve springs for any duratec, it didnt come with the earlier ones. does that mean that the 04 taurus engine that is in the car already had the st220 springs? maybe, but either way, it now has fresh valvesprings to go along with the new seals and lapped valves- and valve springs that are without a doubt the same as the st220
Click to expand...

There was a part number change, yes, but as you also discovered, they are all directly interchangeable. I spoke with the engineer from the company that supplies the springs to Ford, and his comment was that there was a change that affected either where the spring was made, or who was supplying the raw steel. To be fair, I am going by memory on a conversation that occurred several years ago, but my clear takeaway was that all of the springs were directly interchangeable.
 
Rara,

If you don't mind me asking, where does the behive shaped spring fit into all this. Somehow I thought that is what the ST220 spring was.

In any event, there is no need for stiffer springs. Valve float does not seem to be a problem with any of the normally available cam sets.
 
You must log in or register to reply here.
Back
Top