Contour Enthusiasts Group Archives Forums Modifications 3.0L Duratec Parts needed for rebuilding a 3.0L Cylinder Head

Terry,



I havent done anything yet, i am just planning.


Trevor,


Hmmm...So what LIM is everyone using then on their 3.0L? Or is that not the concern because they are using the 2.5 heads and the valve covers for the 2.5 heads will allow use of the 2.5 LIM and UIM?

Warmonger is using the 2.5L heads, and I guess I could always try to reduce compression by having the machine shop that does the P&P job reshape the combustion chamber to lower compression. I just dont want to run around with really high compression.

Warmonger did say to get the 35mm intake valves out of the 3.0 head and put them in the intake of the 2.5 head, as well as use the 32mm 2.5L intake valves and move them over to the exhaust side. this should allow the 2.5 head to flow just as much as the 3.0 head....

I want to keep the SVT manifolds that i have, so it looks like i will have to go with the 2.5 heads and port match the two manifolds together as well as to the heads for optimum flow....


Im also not to keen about making a scoop in a stock hood to accomodate the larger UIM. At some point in time i wish to get a full carbon fibre hood, and theres no way Im gonna cut up a $700+ hood to make a scoop. I am hoping that a local shop that a fellow SoCal NECO guy has contacted will be making a replica of the Cougar S concept car hood, which had a small scoop in the back. If they make that hood then I will buy it.....

Nikolas

Just wondering, what's wrong with the regular Duratec main bearings. They're used in all the Duratecs, even the 240 HP Jaguar S-Type. How much power are you planning on making?

Copper/lead(tri-metal-Clevite-Vanderville)bearings are more 'forgiving' with crank whip.......

Procyon,

My goal is to get 300HP to the crank...about 260ish to the wheels or so....

If I only get 275 (which i think is EASILY attainable, just costs $$) then I will still be happy....

Like Trevor Cole says....better to play it safe and spend the extra money up front for that ease of mind.....

TERRY,

are the intake valves on the 2.5L made of the same material as the exhaust valves? I need to know if it is suitable to use the 2.5L intake valves as exhaust valves on a 3L engine to increase flow. We all know that exhaust valves are often sodium filled......


Nikolas

I was under the impression that you would be trying to use the 3.0 heads but wanted to know if you could/should use the 3.0 UIM. Perhaps I missed something. So you plan on doing a 2.5L/3.0L hybrid correct? If that is the case, then the 2.5L heads will clear the UIM and you have nothing to worry about. However, if you use the 3.0L Heads and Block, it would be best to use the 3.0 UIM with a modified hood as opposed to spending the extra money to modify the UIM or have a custom spacer built. The money saved could go towards the tri-metal bearings.

At this point, you would be doing a 3.0 Longblock with the 2.5L oil pan and pickup tube ... a lot less complicated to install with less downtime. I recommend this not only for these reasons, but also because I would never use JB-Weld inside the engine, which is what everyone is doing to plug the gallies that don't match between the head and the block. The proper way to block these gallies is to weld them shut and then redeck the block ... a lot more expensive, but done right with 0% chance of anything dislodging and killing your motor. JB-Weld "could" come loose if not done correctly and even then, I still wouldn't trust it. Besides, nobody to date has tried the direct swap of the 3.0 (almost direct, the 2.5L oil pan & pickup tube needs to be used), or so I gather from my research on the subject.

Chezterr,

Just putting the stock 3L valves in the svt head and widening the secondary intake port will most likely allow it to flow more than the stock 3.0 heads (though I have no flow data to back it up). If you bump up to 32mm exhausts, your limitation would now be focused towards the intake side. Since widening the passages on the intake secondary passages will help that, then you don't necessarily have go with 32mm exhausts. I am mainly suggesting that as an option since you already have them, and because you are shooting for 300hp. For 300hp you want to breath well at high rpm, and those bigger exhausts will help. You will be the first to attempt it if you go through with it, but I predict some good results with the right other mods.

As far as the tri-metal bearings: I defer to what Terry says about crank-whip as I have no knowledge about that. However, there are a good many more engines that have NOT failed to crank whip and oil starvation than there are that have. This is just to put the whole thing into perspective. If I were you, I'd go and buy the Cougar or Mondeo dual mode damper (aka harmonic balancer) that Terry recommends to prevent crank whip for a lot less money, and just use the standard bearings that you get for the long block. Then run a 1/2 court of oil over capacity to provide a bit more in the pan at high rpm.

Just my opinions.

warmonger

Trust me , the crank does whip and tri-metal bearings are far better than the stoc version.Have used Clevite/Vanderville type berings(copper/lead) for many years .As any good engine builder,race or stoc,will tell you, in any motor they are the best way to go...30 years + around many types of engines,incl F1, tells me that....

TERRY,

are the intake valves on the 2.5L made of the same material as the exhaust valves? I need to know if it is suitable to use the 2.5L intake valves as exhaust valves on a 3L head to increase flow. We all know that exhaust valves are often sodium filled......


Nikolas

Well there you have it, sounds like the best advice to me. If I do any work down there, I may get some of these bearings and throw them in soon.

warmonger

Terry,


have an answer to my above question?

Nikolas