Porting & Polishing Intake...

[Petrograde]

Since I'll be adding some bling to my intake. (http://www.mercurymarauder.net/forums/showthread.php?s=&threadid=6716) I was thinking about porting and polishing it.

A guy at work said "porting and polishing is for 60's technology, I doubt if you'll see any performance gains, you might actually lose some"

hmmm,... does this make sense to anyone,..

I know Dennis Reinhart offers a ported and polished intake, anyone use it yet? What are the gains?

Any clarification on this would be appreciated!

Thanks!

Tom

[Petrograde]

While I have the intake off,.. is there anything else I can do?

I was thinking about a bigger throttle body, like LML did. Also,.

any sense in putting in a new MAF sensor? I seems to me someone had done this. But, the search doesn't like the word "MAF" :rolleyes: Any benefits?

Any ideas?

Thanks again!

Tom

[TAF]

Tom,

I believe Dennis posted that the P&P upper and lower intake only made nominal HP gains on a N/A Marauder.

As to changing the MAF...it opens up possibilities for tuning concerns. I don't know if/how LML ever got all of those worked out.

I think you can get (maybe) 5-8 HP out of the polishing, but would consider it mostly an aesthetic upgrade.

[stumpy]

From what little I know about porting, the intake may not yeild as much gain as porting the heads. In fact if you don't do it right you may hurt flow by disturbing the surface friction that causes swirl, which increases air velocity. To test this theory, try and find an aftermarket intake for a 4.6l DOC or even SOC engine. If there were gains to be had then Edelbrock would be selling them like hotcakes. Case in point, some have tried but noone sells an aftermarked intake for the LT1 because they can't improve on what GM got perfect the first time. However, you could try port matching both the instake and heads to the gasket for a nice increase in flow.

As for the MAF, you'll definitely want to look into a PCM upgrade to compensate for the extra air flow. If the comupter doens't properly read the increased air flow it will not compensate with extra fuel and you'll run too lean and possibly burn valves and pistons.

HTH

[FordNut]

I would probably install a second knock sensor, even if I didn't hook it up yet. I believe TTA did this.

[Petrograde]

Originally posted by FordNut
I would probably install a second knock sensor, even if I didn't hook it up yet. I believe TTA did this.

hmmm,... good idea. Hey TTA,.. how difficult was it?

Tom

[Marauderer]

Once you have the lower intake out you will see the top of the engine block (valley). There will be a knock sensor bolted in on the right side of the motor with a cable going out the back and into a harness on top of the motor. There is an identical threaded hole on the left side of the motor a little closer to the front just waiting for number two. You can buy the knock sensor at the dealer for 68.00 last time I checked. Just bolt it into hole number two and follow the same cable path as the first (will take you all of 2 minutes).

The only problem is that you can't take advantage of it until you change PCM's, but at least you will already have the motor broken down and the hard part done!

For those that don't know - the advantage of a second knock sensor is greatly improved knock detection that will allow the properly equipped tuners to safely give you more advance and thus more power. In fact the PCM itself will be able to give you more advance automatically!

This is a tangent but I haven’t seen anyone fully explain this so I will take a stab at it. When you tune your car, you have several ways of giving it spark; based on a base table that accounts for “load” and “RPM”. Then you have multiple modifiers such as “air charge temp”, “engine coolant temp”, and most notably among the others “knock sensor input”.

Many people don’t know this, but the knock sensor can automatically add timing up to a limit that you can preset, and at a rate that you preset until it detects knock as well as pull timing if it hears anything scary. Having a second sensor lets a tuner (and the PCM) get a little more aggressive in a very safe way with the amount of timing that the sensor is allowed to add. In other words, having two sensors lets the PCM detect the beginning of “knock” long before it becomes harmful due to the increased sensitivity and add or pull timing accordingly. The net effect is that your car is running closer to the edge of knock under all conditions and thus producing way more power!

We are slightly ripped off now, as they went with only one sensor that is located closer to one bank. Even though it is the one more prone to knock, we have to be a little more careful during tuning as we are still only listening to one bank and have to essentially guess that the others aren’t knocking.

BTW and a re-hash of old info - if you wonder why we don't have two already. I have it on authority that our engine was always designed for two, but the Marauder development team had to go with an older PCM for the first year of production which only supports one. They actually planned all along that they would go to 2 sensors when the new PCM became available, thus the dual knock sensors in the 2004 model.

Also, the reason they put the sensor on the right side as they did instead of the left, has to do with the fact that the piston that usually fails first is on that side due to a coolant flow problem.

The latter, I am currently researching an answer for and planning a write up. Many serious racers have already done the little talked about "cooling mod", but I am hoping to find a solution that does not involve pulling the motor; maybe the transmission only, which would give me a good excuse for a full tranny rebuild or replacement!

The MAF replacement is another deal all together. Our factory MAF’s are problematic at best for tuning purposes. What happens is that they falsely plateau prior to reaching their peak output voltage and stick or stay that way for several hundred rpm before climbing again. This is tricky for tuning as normally you set a commanded A/F ratio and adjust airflow through another table in the PCM. Well since your airflow table gets screwed by the plateau, you have to falsely ask for a richer mixture than you really want to get the real world A/F that you are asking for. Replacing your MAF with a 90mm lightning MAF will eliminate this problem and let a tuner work their magic with your car more accurately!

[Effster]

marauderer,on the blower kit,,,where did they have you relocate the knock sensor?i noticed that it hit the bottom of the new intake

[Petrograde]

Thanks Marauderer! I think I'm starting to get a vague notion of how this stuff works! lol

Tom

[SergntMac]

Originally posted by Marauderer
Many serious racers have already done the little talked about "cooling mod", but I am hoping to find a solution that does not involve pulling the motor.

Heard this myself, Bill, probably from the same source. Somehow I got something backwards, but that doesn't matter. Do you think the valve problems in #7 and 8, as well as the steam in one tailpipe, may all be linked back to this. This coolant flow needs to be addressed, uneven engine temps can lead to serious complications.

[TripleTransAm]

What Marauderer said...

I've always wondered myself why the cheap bastards went with a PCM that didn't handle two knock sensor inputs.

Also didn't realize there was some method to their madness as to which side they chose to snoop for knock.

As Sarge said, looks like that driver's side of the engine is taking a beating. Hasn't anyone in Ford Engineering heard of computer flow analysis????

Based on all this I'm reading, looks like the ultimate "tuning" path is to get the '04 PCM with second knock sensor + the bigger MAF and then you can go ape***** with the tuning.

[Marauderer]

I'm not sure on the steam from one tail pipe issue, but it could kind of make sense if one side of the motor is getting hotter than the other. I haven't noticed the steam problem myself, but I tell you what. I have a laser based temperature gun (part of my rolling test bed aresenal) that I can use to check the temps of both exhaust and probably more accurately, the cats on both sides of the motor and let you know if there is any significant difference after a decent drive around town!

Yeah, Jerry told me about the cooling problem and I wish I had listened to it before I pulled my motor apart for the second time as I could have taken care of it then! I think he might also have a handle on a way to do it with the transmission out, but since our conversation I have found a couple of additional avenues to consider as well. That guy is chock-full-o information!

Effster, I drilled and tapped a hole myself to mount the knock sensor in the back of the engine valley. Since then I have also seen a spot on the drivers side of the block under the exhaust manifold next to a freeze plug. It looks like it might be a more sensitive location. I'm going to order a new sensor after Christmas, put it there and program my chip to knock at part throttle (say 1,250 RPM in 4th gear) and test to see if it is any better than where I have it now.

Where did you mount yours?

[Effster]

marauderer,,,hahahaha..i did the same thing!in between the 2 ribs back by the bellhousing mounting flange.just wanted to know what they did on theirs,,if they cheated and mounted it to the back of the head