4.0 SOHC Performance Motor Build

I've been helping the mustang crowd come up with a decent set of rods to use in place of the stock forged I-beam rods and I've found a couple different options out there. I want to use this thread for documentation purposes for all the options found and eventually, there will be info about all things needed to build this motor along with the estimated cost. Finally, after the research is done I'm going to put a motor together.


The Objective

A 4.0 SOHC that will consistently hold 500HP and 600HP at the drag strip. (for a decent cost) - in other words, if this can't be done for a certain price, then a different motor is a better option.


Stock 4.0 SOHC INFO

Deck Height 8.858
Bore 3.953
Stroke 3.31
Rod Length 5.748
Piston Pin Height 1.44


Cylinder Bore
Diameter 3.9530
Out-of-round limit 0.0010
Taper 0.0010


Piston / Rings
Standard DIA 3.9520 3.9528
.5 MM OS 3.9716 3.9724
1 MM OS 3.9900 3.9910
Piston to bore limit 0.0012 0.0020
Compression Ring end gap (top) 0.0080 0.0180
Compression Ring end gap (Bottom) 0.0180 0.0280
Oil Ring Snug Fit


Crankshaft and connecting rods
Crankshaft endplay 0.0020 0.0126
Connection rod journal DIA 2.1250 2.1260
Out-of-round and Taper limit 0.0003
Bearing oil clearance (desired) 0.0003 0.0024
Bearing oil clearance (allowable) 0.0005 0.0020
Connection rod endplay 0.0036 0.0106
Main bearing journal DIA 2.2430 2.2440
Out-of-round and Taper limit 0.0003
Main bearing oil clearance (desired) 0.0008 0.0015
Main bearing oil clearance (allowable) 0.0005 0.0020


Valves and related
Intake
valve seat angle 45 Degrees
valve seat width 0.0600 0.0940
valve seat runout limit 0.0020
Stem diameter standard 0.2740 0.2750
stem to guide clearance 0.0010 0.0020
valve face angle 45 Degrees
valve face runout limit 0.0010

Heads
68CC cambered

Camshafts
lobe lift (intake and exhaust) 0.2590
Allowable Lobe lift loss 0.0050
endplay 0.0003 0.0070
Journal DIA (ALL) 1.1000 1.1040
Bearing Inside DIA (ALL) 1.1020 1.1040
Journal-to-bearing (oil) clearance Standard 0.0020 0.0040
Journal-to-bearing (oil) clearance Service Limit 0.0060

Rods

Rod Option 1

The first rod option is a Forged H-beam Manley rod that states it holds 700-800HP on a 4.6 V8. We v6 dudes have to overkill here because 500 HP on a v8 is different for 500HP on a v6.

4.6 L Stroker w/ 22 mm pin and a 2.000" crank journal
Part No. 14044-8
Center-to Center 5.850"
Big End Bore 2.125"
Big End Width .940"
Pin End Width .940"
Pin Bore .8671"
Gram Weight 612


Here is the rod.



With this rod option, the rod journal (big end with the lip) will have to be narrowed by .064" per side. It should only be the little lip you see sticking out. The chamfer will then have to be re-cut and this should be it.

This rod is longer than the stock 4.0 SOHC (Stock is 5.748" and this one is 5.840") this means the custom piston being made needs to have a shorter pin height.

Custom pistons with floating pins will then need to be made to whatever compression you want. These rods go for around $579.50 for a set of 8. This means if you buy 3 set's for a v6, the fourth set is free. Furthermore this means the rod cost per rod will be $72.44 (Not counting the machining cost) If we estimate the machining cost, say 150.00 per set of 8, we come up with $91.19 / rod.

The H-beam rod option already available for the 4.0 SOHC is $125.00 per rod so you can see we've already beat that.

So, to recap this option.

Estimate $91.19 / Rod
Estimate HP the rod can handle is 700-800HP

This should be good for 500HP on the 4.0 SOHC


Rod Option 2

SBC rods.

UPDATE (9-5-2009) - I've decided to go this route for rods. The first option is still available; however, the cost was the deciding factor.

The second rod option is a SBC eagle H-Beam rod that is 5.7" long from center to center. The stock 4.0 sohc rod is 5.748" so this rod is .048" shorter. This means the custom piston being made needs to have a longer pin height depending on the compression desired. The rod journal bore on this rod is 2.1" where as the stock 4.0 SOHC has a 2.125" rod journal. This means the bore has to be opened up. The cost per a set of 8 is lower for this rod ($359.00) so this puts us at $44.87 / rod. The machining cost will offset this and I'll update the thread when I get the info.

The good about this option is the ARP rod bolts are 7/16" where as the first option has 3/8" rod bolts.



Pistons

Compression Ratio for boost

UPDATE (9-5-2009) - I've decided to go with a 9.5:1 compression ratio (custom forged piston) and then get the piston tops coated.

Here is a formula for helping pick a compression ratio for a boosted engine. Anything between 16:1 to 18:1 is what to shoot for on a street set-up. Anything above 20:1 is race car country.

((boost psi / 14.7) + 1) x motor compression = effective compression.

Here is the 4.0 SOHC with 9.7:1 compression running 14 LBS of boost...

Effective Compression
18.93809524

Here is the 4.0 SOHC with 9.5:1 compression running 14 LBS of boost...

Effective Compression
18.54761905

Here is the 4.0 SOHC with 9.5:1 compression running 16 LBS of boost...

Effective Compression
20.25782313

Here is the 4.0 SOHC with 9.5:1 compression running 50 LBS of boost...

Effective Compression
42.69319728
(Okay, this is a little much)


A motor with 8:1 compression running 18 lbs boost VS a 9.5:1 compression motor running 12 lbs boost will have almost the same effective compression and about the same peak power. The big difference will be where you see the power, and how much of a demand will be placed on the supercharger/turbo. Obviously, the 9.5:1 motor is going to have far greater torque and low end power as the boost is only starting to come in. It is also going to be much easier to find a blower/turbo to survive at only 12 lbs of boost -vs- one that would have to put out 18 lbs of boost. It is now very easy to see why a higher compression motor with lower boost is becoming so popular.

Assembly Instructions

Download SOHC_Engine.pdf from FileFactory.com

There's still a BUNCH of work that needs to be done here so this should be considered "A work in progress" until I remove this line from the thread.

 

[Jakee]

No, sorry. It's been apart for a long time and sitting in the back yard. I miss it. Just when I think I can start back something comes up.

 

[Limited02]

Sorry to hear, hopefully things will look up for the better for both of us and we'll go on to claim the number one spots I doubt it would be able to happen for me, but I have considered working a time with James Henson about getting a bunch of the Ex/Mounty's over to his shop for a dyno day. Would be fun and give everyone a chance to meet in person.

 

[Jakee]

Hello Everyone,

I'm looking for opinions here. I haven't been able to work this project because of other commitments but I'm getting ready to dedicate some time to it. But I'm stuck here. Part of me wants to scrap the v6 and swap in a 5.4. This does make more sense but then I'll have to redo everything (the turbo will be to small….etc)

There’s good and bad to every option and it really depends on a person’s goals on which way to go. I really have no goals anymore; I just like the challenge of making it fast. So what do you guys think here? What would you rather see; A built V6 that runs 12’s or a 5.4 V8 that runs……(don’t know)

 

[Limited02]

You are now thinking of switching to a 5.4 Modular? If I was going that far, I'd switch to a stroked/H/C 5.8 Windsor with fuel injection(http://www.efisupply.com/dfi.htm) and a T56 6-speed or a built AODE.

But from my experience, I wish I would have stayed with a V6 in my Ranger. It would have been finished and not sitting for a LONG time. The main reason I switched to a V8 is because I wanted the sound(and extra power).

If you stay with your current setup and maximize it(better internals/more boost) you'll be driving it sooner and going plenty fast. The problem with modding anything is that it's a never ending process, so it doesn't matter what route you go because you'll never be finished

I vote V6!!!

 

[CDW6212R]

Honestly Jake, if reliability is a concern, you have to change transmissions. A strip only car can put up with trans failures every so often. The 4R70W seems to be the only good choice right now for these smaller trucks. If you had an F series sized truck, there are two better choices for that.

If you do want any great street use, everyday use etc, then A/C is needed. I wouldn't cut out the AC ever unless I lived in Canada or farther north. That is required with any modular Ford engine. Just the huge number of swap issues makes those too much trouble.

If speed is the goal, the smallblock Ford is really the best. It has the most parts available inside and out, it's cheaper to build, and very reliable. Everything except the 4.0's will have big issues for the headers, and the cat pipes if you have 4WD.

Commit to your goals, identify the big problems, and then get on it. You should pick the brains of Troll's brother. I think you would trust his experience with the 302 trucks, and he can steer you to what the big issues are for racing. I'd concentrate on building an engine with the best heads, intake manifold, and the camshaft custom made for them. I think 2.0HP/CI is the limit, Jay Allen proved that with his 347. Find the parts for you that will survive your goals. Have fun and keep us posted.

 

[2000StreetRod]

Members will be interested no matter what

I believe you should focus on your own objective(s) and not consider what the Forum members want to see. They will be interested no matter what route you choose. The more extensive the modifications required the less likely other forum members will be able to duplicate them.

I agree with Don that you should consider what transmission will survive a high performance engine and place a lot of emphasis on budget constraints. Going from the SOHC V6 to the 5.0 block will require a lot less work and money and allow using a strong transmission (4R70W) with kits available to make it stronger. There are also numerous and less expensive performance upgrades for the 5.0 than there are for the 4.6 or 5.4.

If you perform your modifications in stages like me then you will be able to have the fun of driving the vehicle in between modification stages and keep up your interest and enjoyment. If you plan and start a massive and expensive undertaking the chances are good you'll either lose interest or run out of money before the effort is completed.

Don't lose sight of what your vehicle is: a shortened fairly heavy mid-size SUV. It will never be a Cobra.

 

[Limited02]

I believe you should focus on your own objective(s) and not consider what the Forum members want to see. They will be interested no matter what route you choose. The more extensive the modifications required the less likely other forum members will be able to duplicate them.

I agree with Don that you should consider what transmission will survive a high performance engine and place a lot of emphasis on budget constraints. Going from the SOHC V6 to the 5.0 block will require a lot less work and money and allow using a strong transmission (4R70W) with kits available to make it stronger. There are also numerous and less expensive performance upgrades for the 5.0 than there are for the 4.6 or 5.4.

If you perform your modifications in stages like me then you will be able to have the fun of driving the vehicle in between modification stages and keep up your interest and enjoyment. If you plan and start a massive and expensive undertaking the chances are good you'll either lose interest or run out of money before the effort is completed.

Don't lose sight of what your vehicle is: a shortened fairly heavy mid-size SUV. It will never be a Cobra.

That was my problem with the Ranger. V8 swap took to long and I ran out of money, then sold it and never got to truely enjoy it But the new owner is picking up where I left of and then some!!!

Didn't James Henson put a 4R70W behind his 4.0?

 

[CDW6212R]

That was my problem with the Ranger. V8 swap took to long and I ran out of money, then sold it and never got to truely enjoy it But the new owner is picking up where I left of and then some!!!

Didn't James Henson put a 4R70W behind his 4.0?

James swapped in a 5R55S, one of the somewhat stronger versions of the 5R. All of the small 5R transmissions have slightly smaller internals than the 4R70W. The 4R70W is a descendant of the AOD, and it was just barely big enough for V8's. Over time it has been developed into a nice strong trans. The 5R's are just a little smaller and there isn't anyone trying to upgrade them for performance use. I don't mean mild performance, I mean serious power usage. The AOD was always in Mustangs and all V8 cars, so it had aftermarket interest early on. That is where the 4R70W came from. The 5R is just about the same size as the A4LD that began in 4cylinder Thunderbirds. It has improved greatly since then to become a good V6 trans for these heavy trucks. But 500hp or more is a lot different to handle. I think it's just not the best way to go right now. If a company does come along and find a way to make it handle more power, then great, I really love the gearing.

 

[Jakee]

http://www.mustangcollective.com/cpg/albums/userpics/Adapter_Installation_Instructions.pdf

 

[pazzo1969]

jake, i would sill go the v6 route... i believe it would be able to dip very low 12's into the 11's. as we have talked about before, i think getting a tranny that will hold up will be your biggest task. not really sure what it would take to shoe a 5.4 in there, already looks tight as hell.lol i'm sure between us we could get that little monster rolling. i've told you before i would help you out. mike

 

[Jakee]

Thanks Mike. The 5.4 was just a thought. This is what happens when you leave a project half done - you start to lose focus.

Anyways, I believe the 5.4 would take a hell of alot of work to make fit. That engine looks very wide to me.

I'll stick to the old plans and carry on. Build the motor, break the transmission and adapt to a new stronger tranny..LOL I forgot I haven't ran with meth inj. or had a decent set of tires at the track so I know theres more to tap into. Then, if I build the motor right, there's even more.

 

[Jakee]

Was cleaning up the intake manifold and noticed there was a crack in it, right behind the TB. Wonder how long that was their?

Anyways, looks like a new intake is now in demand.

 

[Jakee]

Been putting the truck back together as is - no motor build yet because money is allocated toward a teenage son with a wild side. Many of you probably know what I'm talking about. So I’m tired of looking at the truck in the backyard and decided it was time for it to run again.

I did make a few upgrades, or at least I think upgrades, so maybe we'll see better times out of this truck.

1) As posted above, the intake had a small crack. This is not a result of the pressure causing failure but a result of me porting the intake mouth to far. It’s now fixed so I’ll need to turn the boost down first to make sure I’m not at 15LBS without a crack.
2) New wider wheels all the way around and still looking for a track set-up.
3) The PCV system is now different and I’ll elaborate on this later.
4) Tranny temp gauge is finally being installed – been sitting on the shelf in my garage for over a year now.
5) Turbo was rebuilt and all piping from the Y back was cleaned up and coated.
6) Been working on a new tune and will have to re-tune once back together. The crack is fixed so it’ll be different.
7) Once back together I’ll drive around for awhile on 10 lbs of boost. I’ll then up it to around 12 to see if it holds together, especially the tranny. I may push further to see how far I can go till it breaks.

Anyways, I'm ready to drive it again and have some fun!

 

[2000StreetRod]

Good news!

I'm glad that you are back to work on your SOHC V6!

 

[Jakee]

Thanks 2000SR. Should be fun.

 

[Limited02]

Glad to hear you finally got it back together! Looing forward to how it wall works out and please post some updated pictures!!! I still haven't seen the wheels on it!

 

[mr.p]

AWESOME. I cant tell you what a difference the 285's did on my sport. It GRIPS the road. No more understeer!

I have recently been looking at following the same path as you but i need help choosing a turbo size. I would only want around 11psi but i would like to start spooling as low as rpm possible. Do you have any boost at 2000rpm? The sts kit is very expensive, if i could find a cheaper way to go for parts, i could easily get it done.

 

[Jakee]

If you plan on mounting underneath like I did then shoot for a T04E 60/1 "P" trim with a .58 A/R turbine housing and .60 A/R on the compressor housing. The boost comes in close to 2000 RPMs under load and I havn't seen the intake air temp rise much at all at 9Lbs.

 

[mr.p]

where would i locate one of these? or the best place to purchase one?

 

[Jakee]

It depends on what sort of quality you’re looking for. You could look into the sts universal stage 1 or 2 kit. I believe I picked mine up for a little under 2 grand.

Or you could find the closest match (the exhaust turbine housing side of .58) and go with it. I don't think you'll find the same compressor spec as above unless you go with the STS version or you know how to change out the compressor housing.

You can kill yourself with the details but if you go with the 60-1 TO4E P-trim with a .58 Turbine housing you should get in the ball park.

http://www.turbobygarrett.com/turbobygarrett/tech_center/turbo_tech101.html

http://www.turbobygarrett.com/turbobygarrett/tech_center/turbo_tech102.html

http://www.turbobygarrett.com/turbobygarrett/tech_center/turbo_tech103.html