4.6L DOHC Research Resources

[buickconvert]

I've been doing a ton of research on the Ford modular engines and engine management lately, but there seems to be a lack of info on the DOHC engines and even more so on engine management. Anyone recommend a good book/website?

I'm interested in finding out all kinds of information:

*How much boost can a 4.6 DOHC engine handle (Marauder engine
specifically) on pump gas w/out methonal or any kind of extra injection

*Are the intake valves opened at different times to promote swirl
(my understanding is that the cylinder head has a swirl dam, so I suspect this might be the case) . . . if not, sounds like a good tweak to try.

*How flexible is the stock computer? Could you get it to control a gear splitter with a reflash? Control boost? Adapt it to use a wideband for lean of stioch cruise and accurate WOT A:F control?

I'm pretty new as far as FoMoCo goes (but been into cars for most of my life), so it's a pretty steep learning curve. I've already learned a ton by using the search function on this forum. . .but not everything I was looking to learn;)

[JMan]

I'm no expert on this stuff but I have an opinion on everything. So here goes-

I have no clue how much boost those engines will handle, but with proper airmass calculations, the injectors and EEC-V computer will pour it on to a great degree. I'm certain above a critical point, fuel delivery systems require modification as well.

The SOHC engines from ~'03 up have a swirl dam in the combustion chamber. The DOHC head does not AFAIK. The two ports are of differing shape and angle to promote swirl and give better breathing at high RPM's. I believe both valves have the same timing. Some one will verify I'm sure. The Cobra head is not a weak spot and probably won't need any tweaking until you get to huge HP numbers!

The EEC-V is capable of tremendous calculations on its own with no modifications. They are extremely fast compared to other O.E. computers as well. Unfortunately, Ford has not adopted the use of wide-band A/F sensors as yet. I'm not sure the tables could be changed to acurately utilize them either, however I don't know that. Presumably you want to run a cruise A/F ratio above stoichiometry (14.67:1) to achive a leaner cruise and maintain a lower ratio (~12:1 or lesser) for acceleration. That would be difficult with an O2 sensor. They only know presence/ no presence of oxygen. Therefore maintaining a specific ratio is a shot in the dark.

I have no idea what a gear splitter is? Excuse my ignorance. Next question, why control boost? You can modulate boost with your right foot, correct?

I hope I answered more questions than I raised!

Welcome aboard and Happy Maraudering!

J

[SergntMac]

Sean Hyland has published two books, one specifically on the modular engine, and another on building the Mustang 1994-2004. Look here?

http://www.amazon.com/s/ref=wbnavss/104-9001758-2467164?url=index%3Dblended&field-keywords=sean+hyland&Go.x=5&Go.y=10

I haven't seen much more in print, other than the Helms guides, which don't cover modding.

If you want to play with your EEC, you can start with one of these...

http://www.amazon.com/OTC-Ford-EEC-V-104-Pin-Breakout/dp/B000HAKG2K/sr=8-2/qid=1157800547/ref=sr_1_2/104-9001758-2467164?ie=UTF8&s=automotive

If you're intending to supercharge a stock Marauder engine, the "rule of thumb" for us has been to keep the boost limited to 10 PSI or under. With the right tune and intercooling, the Marauder can get very quick, and remain rather reliable.

[LVMarauder]

+1 to Mac. I have SH modular power book. Its pretty good, covers everything and gives real world engine combinations that work.

[Loco1234]

http://www.foxlakeracing.com/

These guys port Mod Motors. ...and they port them the best....

If you wanna know specifics that you can't find in writing....
Go to the next best thing. A direct source. These guys work with these motors and Heads day in and day out. They know their stuff.

They are very nice and willing to speak with people.

I'd try them for specific's on how different mod motor heads are setup and how them can be modified for superior performance.

[fairlane347]

Sean Hyland has published two books, one specifically on the modular engine, and another on building the Mustang 1994-2004. Look here?

http://www.amazon.com/s/ref=wbnavss/104-9001758-2467164?url=index%3Dblended&field-keywords=sean+hyland&Go.x=5&Go.y=10

I haven't seen much more in print, other than the Helms guides, which don't cover modding.

If you want to play with your EEC, you can start with one of these...

http://www.amazon.com/OTC-Ford-EEC-V-104-Pin-Breakout/dp/B000HAKG2K/sr=8-2/qid=1157800547/ref=sr_1_2/104-9001758-2467164?ie=UTF8&s=automotive

If you're intending to supercharge a stock Marauder engine, the "rule of thumb" for us has been to keep the boost limited to 10 PSI or under. With the right tune and intercooling, the Marauder can get very quick, and remain rather reliable.


My opinion but don't by the book by Sean Hyland! I waisted my $$$ on that peice of crap, it leaves alot to be desired.:down:

[buickconvert]

The SOHC engines from ~'03 up have a swirl dam in the combustion chamber. The DOHC head does not AFAIK. The two ports are of differing shape and angle to promote swirl and give better breathing at high RPM's. I believe both valves have the same timing. Some one will verify I'm sure. The Cobra head is not a weak spot and probably won't need any tweaking until you get to huge HP numbers!

The EEC-V is capable of tremendous calculations on its own with no modifications. They are extremely fast compared to other O.E. computers as well. Unfortunately, Ford has not adopted the use of wide-band A/F sensors as yet. I'm not sure the tables could be changed to acurately utilize them either, however I don't know that. Presumably you want to run a cruise A/F ratio above stoichiometry (14.67:1) to achive a leaner cruise and maintain a lower ratio (~12:1 or lesser) for acceleration. That would be difficult with an O2 sensor. They only know presence/ no presence of oxygen. Therefore maintaining a specific ratio is a shot in the dark.

My understanding of a wideband was that it allowed you to "lock on" to a specific AF ratio at WOT, and in the case of the Honda Insight IRRC, run lean of stoich. I know for Buicks for sure, the Accel DFI system runs closed-loop using the O2 sensor at WOT.


Next question, why control boost? You can modulate boost with your right foot, correct?



Yes, if I was planning on going with the supercharger route, but not for a turbo.;)

[buickconvert]

http://www.foxlakeracing.com/

These guys port Mod Motors. ...and they port them the best....

If you wanna know specifics that you can't find in writing....
Go to the next best thing. A direct source. These guys work with these motors and Heads day in and day out. They know their stuff.

They are very nice and willing to speak with people.

I'd try them for specific's on how different mod motor heads are setup and how them can be modified for superior performance.

Sweet :thanks:

I'll shoot them an email sometime. . .

[SergntMac]

My opinion but don't by the book by Sean Hyland! I waisted my $$$ on that peice of crap, it leaves alot to be desired.:down:Don't mask your feelings, tell us how you really feel?

I can't say I agree with every theory Sean Hyland speaks of, he does a few things the hard way. However, as an introduction to the topic for an owner who possibly doesn't know a SOHC from the DOHC, it's not a bad start on the basics. His data collection and documentation has shown to be on the money, and it's a decent reference guide on the internals. For a beginner, it's a must read, just stay out of the deep end...

[Breadfan]

Don't mask your feelings, tell us how you really feel?

I can't say I agree with every theory Sean Hyland speaks of, he does a few things the hard way. However, as an introduction to the topic for an owner who possibly doesn't know a SOHC from the DOHC, it's not a bad start on the basics. His data collection and documentation has shown to be on the money, and it's a decent reference guide on the internals. For a beginner, it's a must read, just stay out of the deep end...

And build your own engines, don't buy his.

[MM_BKK]

Yes, if I was planning on going with the supercharger route, but not for a turbo.;)

But you didn't mention supercharger or turbo. Anyhow, you're better off with an aftermarket boost controller such as Turbosmart, Innovative, Greddy, Apexi, Blitz or HKS just to name a few for your turbo boost controller (much easier to manage and you have a lot more options with them). As far as the idea of splitting your gears with an extra overdrive unit, I think you are completely wasting your time. First of, I don't think you'll have enough room in the floor tunnel to fit the unit then you'll have to get a custom length driveshaft made then you'll have to figure out how you want to control it and I think it just add unnecessary weight and parasitic loss. I'm not sure what you want as a cruising RPM, but if you keep the factory 3.55 rear end gears and 4R70W transmission which has a .70 overdrive ratio, your final drive ratio is then 2.49:1. At 65 MPH, your cruising RPM is about 1950 (most of us here are turning about 2300 with the 4.10 gears). If you're going to be turbocharging the engine, you don't need a lot of gears. It will only give you serious traction problems and you'll probably have to tub out the rearend if you don't want to spin the rear tires. If you get a built forged shortblock and an under the hood intercooled turbo setup (not the one at the back of the car) running at about 25psi max with methanol injection, you could easily be making over 700 RWHP. If you run this motor with a 3500 stall converter, you probably won't even noticed much turbo lag (just a tremendous amount of torque!). This should put you in the 11 seconds range in the 1/4 mi. if not sub 10 sec. At 180 MPH (if you dare to go this fast) the engine will only be turning at about 5400 RPM.
I hope this helped shed some light.

[buickconvert]

Hmm, hadn't even considered keeping the 3.55's. I'm not interested in methanol though, have an alky kit on my GN, and I hate having to make sure I got alky before I hit it. . .no better than NO2 IMO. That limits me to about 10 psi, so the question becomes, can I still run into the 12's (low preferable, high acceptable) at 10 psi (turbo) on pump-gas with the 3.55 gears. . .

STS claims 400/450 WHP/WTQ with the 05 Mustang GT engine at 6.5 psi. The dyno chart shows 350 WTQ at 2750 RPM. . .you may be right about not needing 4.10 gears. Certainly food for thought. . .and obviously the $$ for the overdrive would fill many a gas tank. . .

What I don't want btw, is a high-strung race-car, I want something I could drive everyday if I wanted.

[JMan]

My understanding of a wideband was that it allowed you to "lock on" to a specific AF ratio at WOT, and in the case of the Honda Insight IRRC, run lean of stoich. I know for Buicks for sure, the Accel DFI system runs closed-loop using the O2 sensor at WOT.


A wideband allows you (Or your PCM) to view or read actual A/F ratio feedback. As far as WOT fueling goes with an O2 sensor, you can only adjust to keep very little oxygen present in the exhaust stream (~850+ miilivolts) and not a specific amount. Yes, if the exhaust stream starts to show oxygen (<850mV) you can enrich, but thats after the combustion event and slightly downstream to boot. In other words, the PCM doesn't have a clue the intake side is too lean until after the fact. Whereas with a wideband it constantly knows where the A/F ratio is and can adjust at the onset of an enleanment phase. I hope this techno-dope make sense in layman's terms. If you wish a greater explanation, PM me. I'm exuding GEEK!

J

[ScottB]

Anyone recommend a good book/website?


As you are searching, you might expand your searches to the Mach 1 and the Navigator for anything related to these heads, they are the same (intakes are different). That would give you more to look at regarding things like cam profiles and tunes.

here are different heads you can play with, but I'm assuming you are chasing the bolt-on oute right now?