RAD Merc SVT
CEG'er
Ok another question. Anybody know what the most I can mill off the heads would be? I want to take off thirty thousandths and that should bring my port match 3L to about 11:1 compression
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RAD's 3L build
- Thread starter RAD Merc SVT
- Start date
RAD Merc SVT
CEG'er
Could use some help on the above questions. DMD Ford part number? How much can I mill off the heads?
RAD Merc SVT
CEG'er
Alright so I'm trying to figure out how much I can mill off the heads. But my Chilton doesn't tell me the Valve lift or rocker arm ratio. So if anybody knows the valve lifts for the SVT cams that would be great, or give me the rocker arm ratio and I'll just find the lobe lift on the SVT cams I have
I don't think that anything can be milled off. I would think that if one did there would be a risk of the tensioners not being able to function correctly, let alone it might allow the piston to contact a valve.
RAD Merc SVT
CEG'er
Well I figure that the tensioner will be capable of making up for the increased slack in the chain. (Not sure though) And if I can get the numbers I need I'll do the math to figure out how much can be taken off or I'll just assemble it with some modeling clay, rotate the engine, and measure how close the piston is to the valve.
Just a heads up;
do you have forged rods ?
From what i've read; the slightly raised compression of the SVT engine, accelerates the demize of the powdered metal con rods and leads to early spun bearings. I can only think that this compression ratio with stock con rods will do the the same ....only quicker ....G.
CSVT#49
Addicted CEG'er
Yea if you check out the 3L part number thread, I updated it showing they are all the same and listed the new part number.
As for machining the heads, I'm having BPE Racing do a resurface on my heads for the mating surface and they will remove up to 0.02" with out problem. However they may just be a general number they toss around and may not be something to hold true too.
I'll have to do some digging for the valve lift and get back to you.
CSVT#49
Addicted CEG'er
Found it. I actually picked it up off of the Taurus Club forum, but it was pulled from DemonSVT's website before it went down. Here's everything he had listed. Also the post from the Taurus Club is this, http://www.taurusclub.com/forum/87-engine-drivetrain/114740-duratec-cam-info-svt-cams-3l-taurus.html.
DemonSVT's Old Website said:
RAD Merc SVT
CEG'er
Holy crap that is a sweet find. That answers all my number needs. It says that .006 is the max limit for surfacing. Is that with Piston and Valve clearance already accounted for? So .003 should be safe?
Also in regards to gorman, those numbers state that milling .003 off won't drastically affect the engines compression in terms of worrying about bearing failure. While I was concerned with the Rod issue as well, after talking to my machinist who has worked on engines for most of his life, (although he is not very familiar with the Duratec) He claims that it is almost definitally an oiling issue or the fact that people are just abusing the engines. Finally my auto teacher who has been around the world of automotive claims that the powdered design is a better design seeing as they are cast as a whole then broken so the caps match up perfectly with the rest of the rod and therefore is creating a better "grasp" on the bearing to the crank. Now note this is what the auto people I turn to say about this issue and they do not have extensive research with the Duratec motors.
Also in regards to gorman, those numbers state that milling .003 off won't drastically affect the engines compression in terms of worrying about bearing failure. While I was concerned with the Rod issue as well, after talking to my machinist who has worked on engines for most of his life, (although he is not very familiar with the Duratec) He claims that it is almost definitally an oiling issue or the fact that people are just abusing the engines. Finally my auto teacher who has been around the world of automotive claims that the powdered design is a better design seeing as they are cast as a whole then broken so the caps match up perfectly with the rest of the rod and therefore is creating a better "grasp" on the bearing to the crank. Now note this is what the auto people I turn to say about this issue and they do not have extensive research with the Duratec motors.
crewchiefpro
Hard-core CEG'er
It is not an oiling issue. If it was then the MAIN Bearings would be junk, and that is simply not the case. The mains get priority oiling, they would be the first to go. Oil tends to fall out of larger gaps when the rod big end stretches. This causes additional wear on the bearing because the pump cannot keep oil pressure high enough. Eventually the rod bearing heats up to the point it welds itself to the crank, spins and eventually grabs the rod until it breaks in a million powdered metal pieces.
The cool stuff happens after that when the broken rod, now free to explore the block, starts banging into every object it can find until it encounters a weak spot, such as the side of your nice aluminum block. It punches a big azz hole then continues to poke anything in its path until it no longer can hit anything.
You see it is simple physics. If it was an oiling problem the mains would do the same as the rods, and the motor would sieze up. This is simply not the case, the motor will continue to run until there is no more oil to the other rods, or fuel. It can unhappily run on 2 or 3 cylinders that will be left. Sure it will sound like a bad reggae band missing a few instruments but it will run.
Joy to the world to be are blessed with chitty powdered metal rods.
I'm glad you read that post and have considered it ... i have no desire to see anyone's engine fail.
The advice about the con rods came from Terry Haines .. a guy who was involved from the begining of this engine.
If you search his name, you may find the huge thread where this issue was thrashed out. Many senior members can advise you too ...since they all know what Terry Haines said.
could check NECO too ... G.
The advice about the con rods came from Terry Haines .. a guy who was involved from the begining of this engine.
If you search his name, you may find the huge thread where this issue was thrashed out. Many senior members can advise you too ...since they all know what Terry Haines said.
could check NECO too ... G.
RAD Merc SVT
CEG'er
Yea I know who Terry Haines is and I read his thoughts on the Rods thats what got me concerned. I must have missed the part about the main bearings because that makes alot of sense.
As I was sitting eating a bowl of brain food (cereal) I realized something. Forget .003" thats nothing I want to take off .030"! So when it reads .006" is the Max safe limit does that mean you basically can't mill these heads at all?
Edit: Still looking for Fords DMD part number too if anyone knows that. Or should I just ask for the most updated pulley for the 2.5?
As I was sitting eating a bowl of brain food (cereal) I realized something. Forget .003" thats nothing I want to take off .030"! So when it reads .006" is the Max safe limit does that mean you basically can't mill these heads at all?
Edit: Still looking for Fords DMD part number too if anyone knows that. Or should I just ask for the most updated pulley for the 2.5?
CSVT#49
Addicted CEG'er
Well I think you need to search harder... I did a google search for Cougar DMD damper and found this link to a NECO thread...
http://www.newcougar.org/forums/general-info/46734-dual-mode-damper-dmd-65-a.html
CougarGT@NECO said:
Price per Tousley Ford website seems to have gotten a bit pricey... might be worth searching the web (eBay, CEG classifieds, NECO classifieds) for a better deal...
CSVT#49
Addicted CEG'er
Also since the OEM DMD is becoming more and more expensive... this option is looking more and more appealing....
Fluidampr for Duratec 3.0L. I contacted Fluidampr and they told me this will in fact work on these 3L engines. Even though it says that it is for the Mazda 3L. Just a bit spendy at $318.77, cheapest I have found it yet.
Fluidampr for Duratec 3.0L. I contacted Fluidampr and they told me this will in fact work on these 3L engines. Even though it says that it is for the Mazda 3L. Just a bit spendy at $318.77, cheapest I have found it yet.
RAD; here's something else you might like to know. I have been looking around for a 3.0L engine. While i was in the dealership buying parts, i asked about 3.0L part numbers. I was told that the ST220 engine has the same part number as all the other 3.0L engines in the mondeo range. This lead us to believe that the extra power of the ST220 comes from tuning. I'm not sure how much extra power you will gain by skimming the head ... but for the sake of reliability couldn't you gain it by tuning instead ? ...G.
CSVT#49
Addicted CEG'er
Clearly no one reads what I post around here....
I said this a long time ago. The extra gain in horsepower comes from the exhaust system on the ST220. The engine is no different then the other 3L equipped Mondeo's. This is also why there is nothing special about the so called "ST220" UIM as it is the same as the std 3L UIM on any Mondeo and is not worth anymore because it came off of a ST220.
i do try to read up ... but a 3.0l wasn't on my list
until i bought a Vortec kit.
I think the engine part number doesn't include the intakes and exhaust as you pointed out .... so there may well be a gain from the aluminium manifold. It also has the capability of being honed of course ...G.
CSVT#49
Addicted CEG'er
The UIM is the same between the ST220 and the 3L Mondeo. This has been confirmed by MEG.
That said I believe it offers an improvement over what we have available here in the states, but it does not provide an increase in power for the ST220 over the std 3L Mondeo. This is however why I picked up a UK Mondeo 3L UIM and had it extrude honed.
RAD Merc SVT
CEG'er
Well if compression ratio is a concern for these rods let me ask you this, if the compression ratio on a 98-99 SVT is 10.02 and the ratio for a 00 is 10.31 do the 00 SVT's have a higher rate of bearing failure?
From what i read about the 'test to destruction' tests that Terry Haines was involved with, SVT engines had a higher failure rate than the lower compression SE engines. Cranking the compression rate up by this much may do the same. Forged rods seem to be a first step if you are going to up the power by any meaningful amount. ...hope this helps ...G.