351W built for torque

efloth

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Hello to the best group of gearheads on the planet!

I'm building a 351w for a 1993 4x4 f150 with an E4OD. We have a three-horse trailer that we tow regularly. Our 1995 f150 4x4 with the same engine/trans is just slightly underpowered so I am building a higher performance 351 for the 1993. I am in California, so heads and headers are CARB compliant.

I have almost all of the parts to get started:

Cleaned, checked and honed 1994 roller block at standard 4" bore.
.010 under crank kit with aluminum bearings
Speed pro H336P hypereutectic pistons with matching Hastings Moly rings
AFR-1472 Aluminum heads - 58cc chamber, 165cc Intake runner (recommend by AFR for better low end torque vs the 185s)
1/2" ARP head bolts
Fel-Pro Performance Head Gaskets 1011-1
Scorpion 1022 Pedestal mount 1.72 roller rockers (I'll be ordering correct length pushrods and pedestal shims when I get to that point)
Standard volume Melling oil pump
Ford factory oil cooler from a 1994 van
AEM 340LPH fuel pump
Summit shorty headers

I'll be tuning the stock ECU and running 80lb Siemens Deka injectors. Compression ratio will be 9.7 (thanks Paul!)

I am a bit unsure about the stock truck roller cam and lifters. I have read that the early to mid 90s cobra cam with 1.7 RR'S is the best for truck torque but I'm not sure if the expense is worth it. I can't see needing to rev past 5500RPM in a truck, but I don't want to leave performance on the table since I already invested in some nice heads. Looking for recommendations on cam selection or if I should buy new lifters if keeping the stock cam (has 200k miles on it).

Would you guys recommend port matching the stock lower intake to these heads? I would need to add roughly .300 to the height and .200 to the width to be in the ballpark. I have access to a CNC machine so that may be a fun project. AFR Recommended the Edelbrock 3881 intake - $1000 I'd rather not spend but open to doing so if the gains are substantial.

Do you guys see any issues with my plans so far? Am I just going to blow out the rear end? I'd appreciate any input. Thanks guys :)
 

pmuller9

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Great set of heads.

The AFR heads flow well up to .600" lift and your valve lift should be just over .500" to take advantage of the head flow.
The problem with the stock cams including the mid 90s Cobra cam is the lack of valve lift.
Secondly, the stock heads have poor flowing exhaust ports compared to the intake ports, so the stock cams are split duration with both exhaust duration and valve lift favoring the exhaust cam lobe.

The cam profile for the AFR heads should have closer to a single pattern with valve lifts just over .500".
Since you have a torque converter the off idle torque is not critical.
A good .050" duration would be around 210 degrees on a 114 degree separation angle for computer compatibility.
That should give plenty of power from 1000 to 5000 rpm.

I don't see any "off the shelf" 351W hydraulic roller cams for computer use with a 114 degree LSA.
It would have to be custom which is the normal cam order these days.

Would you guys recommend port matching the stock lower intake to these heads? I would need to add roughly .300 to the height and .200 to the width to be in the ballpark.

If the intake manifold ports are smaller than the head port entry, then leave it alone.
The step from manifold to head helps block reversion in the head port at low rpm.
However, it sounds like the stock intake is very restricted and will lose some upper rpm horsepower where you will need it for pulling a load up long grades.
 
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pmuller9

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It is highly recommended to size the injectors so most of the dynamic range is used.
A 351W only needs 30 lb injectors to make 400 hp using an 80% duty cycle.

When the ECM is operating in closed loop mode, it "Seeks" to maintain the target A/F ratio.
If the injector is way too large, the deviation from target A/F ratio as it seeks gets very large because the incremental change in fuel quantity is larger than it needs to be.

The ECM has the best fuel control when the incremental changes are as small as possible and still has enough injector capacity to meet maximum power requirements.
An EFI system is digital (not analog) and changes are made in steps.
 
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efloth

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It is highly recommended to size the injectors so most of the dynamic range is used.
A 351W only needs 30 lb injectors to make 400 hp using an 80% duty cycle.

When the ECM is operating in closed loop mode, it "Seeks" to maintain the target A/F ratio.
If the injector is way too large, the deviation from target A/F ratio as it seeks gets very large because the incremental change in fuel quantity is larger than it needs to be.

The ECM has the best fuel control when the incremental changes are as small as possible and still has enough injector capacity to meet maximum power requirements.
An EFI system is digital (not analog) and changes are made in steps.
I am running 80s on my ~200HP 300 @ 52psi with the stock ECM. When tuning for larger injectors you change the scalar appropriately. When my HEGO switches between rich and lean the pulse width changes a small fraction of a millisecond (at idle on e85 is like 1.4 to 1.5ms).

The issue with running larger injectors with higher fuel pressures is at decel (loads less than idle), you can run into such short pulse widths that are actually below the minimum consistent pulse width of the injector. This causes some carb like popping sounds in the exhaust but does not affect drivability. I do not have this symptom on e85; only when I flip the switch on the dash for my gasoline tune and put gasoline in the tank. I should have used the 60's knowing that the inline 6 needs higher fuel pressure to prevent vaporlock. No issues of the sort on the v8 since the stock regulator is 30-40 psi.

In my experience, tuning a system set up for 14lb/hr injectors and moving to 80lb/hr is mainly about reducing transient fuel and accel enrichment parameters appropriately. Accel enrichment multiplier went from 1 to .1 (.07 on e85) and transient fuel multipliers are even more extreme at basically just above zero (.016 accel and .023 decel).

The better atomization of these injectors provides some nice performance/drivability improvements once dialed in. On longer trips, I have attained 14-15mpg on E85 which would be near 20mpg if running gasoline, so efficiency is good as well.

The point of installing larger than necessary injectors is that once you are finished you can install power adders or move to other fuels without having to retune the entire thing again. You already have fuel delivery headroom, and the cost difference is basically zero.

More here:
 

pmuller9

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Thanks.
Being able to change the Scaler for fuel and being able to run E85 is what I needed to know.
I'm assuming you will set this engine up as a dual fuel also.
 
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efloth

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The problem with the stock cams including the mid 90s Cobra cam is the lack of valve lift.
Secondly, the stock heads have poor flowing exhaust ports compared to the intake ports, so the stock cams are split duration with both exhaust duration and valve lift favoring the exhaust cam lobe.
Thanks Paul. I looked up those 90s cams and they are definitely lacking in the lift department.

@decipha recommended this cam advanced 4 degrees. It has 112 LSA but he said that's not a problem when using the higher resolution VE table patch. (same one I integrated into my 4.9 tune) Lift with the 1.72RRs would be .536/.548


However, it sounds like the stock intake is very restricted and will lose some upper rpm horsepower where you will need it for pulling a load up long grades.
There are a lot of different opinions on this one. I'm still on the fence. I have a buyer on the stock upper for $200. If I can sell the two stock intake sets for $800 I could see going for the Edelbrock 3881.
 

efloth

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Thanks.
Being able to change the Scaler for fuel and being able to run E85 is what I needed to know.
I'm assuming you will set this engine up as a dual fuel also.
Yes dual fuel for every Ford I own from now on. Only reason to run gasoline is for road trips when e85 is not available. e85 is between my house and work for $3.79 where gas is just under $5 at the cheapest place in town.
 

pmuller9

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Thanks Paul. I looked up those 90s cams and they are definitely lacking in the lift department.

@decipha recommended this cam advanced 4 degrees. It has 112 LSA but he said that's not a problem when using the higher resolution VE table patch. (same one I integrated into my 4.9 tune) Lift with the 1.72RRs would be .536/.548



There are a lot of different opinions on this one. I'm still on the fence. I have a buyer on the stock upper for $200. If I can sell the two stock intake sets for $800 I could see going for the Edelbrock 3881.
The trick flow cam with the AFR head will provide a very strong power band from converter stall to 5000 rpm and will pull to 5500 rpm.
The torque peak will around 3000 rpm and be very flat.

The stock oval runner intake will cost you torque especially at 3000 rpm and over.
The Edelbrock rectangular runner intake will allow the AFR head and Trickflow cam combination to breath at the midrange and upper rpm regions.
 
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efloth

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That sounds like what I am looking for. Any thoughts on the Melling 24214? It looks similar to the TFS1. Only reason I am asking is there is a lightly used one on eBay for under $200. Single pattern and .535 lift with 1.72 rockers

Product Attributes
Advertised Exhaust Duration: 285 deg
Advertised Intake Duration: 285 deg
Basic Operating RPM Range: 3000 RPM
Cam Type: Retro Roller Cam
Computer Controlled Compatible: No
Exhaust Duration at .050 inch Lift: 219 deg
Exhaust Valve Lift: 0.498 in
Exhaust Valve Lift with Factory Rocker Arm Ratio: 1.600 in
Intake Duration at .050 Inch Lift: 219 deg
Intake Valve Lift: 0.498 in
Intake Valve Lift with Factory Rocker Arm Ratio: 1.600 in
Lifter Type: Roller
Lobe Separation: 110 deg
 

pmuller9

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That sounds like what I am looking for. Any thoughts on the Melling 24214? It looks similar to the TFS1. Only reason I am asking is there is a lightly used one on eBay for under $200. Single pattern and .535 lift with 1.72 rockers

Product Attributes
Advertised Exhaust Duration: 285 deg
Advertised Intake Duration: 285 deg
Basic Operating RPM Range: 3000 RPM
Cam Type: Retro Roller Cam
Computer Controlled Compatible: No
Exhaust Duration at .050 inch Lift: 219 deg
Exhaust Valve Lift: 0.498 in
Exhaust Valve Lift with Factory Rocker Arm Ratio: 1.600 in
Intake Duration at .050 Inch Lift: 219 deg
Intake Valve Lift: 0.498 in
Intake Valve Lift with Factory Rocker Arm Ratio: 1.600 in
Lifter Type: Roller
Lobe Separation: 110 deg
I would prefer a wider LSA with at least 112 degrees or more.
Secondly, I would not buy a used camshaft.
Besides, the used Melling camshaft has a shipping charge, and the new Trick Flow camshaft doesn't making the price difference even less.
 

pmuller9

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Stock main caps and bolts are fine.
If the rods are out of the engine, I always have the rods tested for cracks then replace the stock rod bolts with ARP bolts and have the rods resized.
Cheap insurance.
 

efloth

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Having a hard time sourcing those rods!

I ended up getting a broken piston in the first set of 4" Standard bore H336CP, so they sent me a whole new set. I have 7 left over if anyone wants them, just pay the shipping. They will need to be weight matched and a couple have some minor dings that will need to be cleaned up.
 

efloth

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Got the cam today. I'm planning on installing this cam on the +4 keyway on my timing set. It looks like it already has four degrees ground into it. I hope I don't run into PtV clearance issues with the 1.73 rockers.

Hopefully rods and intake will be here this month so I can start putting this guy back together.

Have a great Labor Day weekend!
 

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pmuller9

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Got the cam today. I'm planning on installing this cam on the +4 keyway on my timing set. It looks like it already has four degrees ground into it. I hope I don't run into PtV clearance issues with the 1.73 rockers.
Be sure to check the cam timing using a degree wheel and dial indicator.

After the cam is installed and the cam timing has been checked, you can temporarily install a head with light checker valve springs on cylinder #1 and use a dial indicator to check valve to piston clearance.
Intake VtP clearance is tightest around 10 to 15 degrees ATDC.
 

efloth

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So if I install this cam advanced 4°, The valve events I'm checking for would be 4° or 2° earlier than listed on the card?
 

pmuller9

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So if I install this cam advanced 4°, The valve events I'm checking for would be 4° or 2° earlier than listed on the card?
The cam has a 112-degree lobe separation angle so the cam would be in a neutral position with the intake and exhaust lobe centers at 112 degrees before and after TDC.
If you advance the cam 4 degrees, the intake lobe center would be at 108 degrees ATDC and the exhaust lobe center would be at 116 degrees BTDC as shown by the cam card under LOBE CL

You use the .050" lobe lift points to degree the cam.
The intake lifter would open .050" at 108 - 1/2 the .050" intake duration which is 221 degrees or 108 - 221/2 or 2.5 before TDC
The cam card rounded it off to 3 degrees BTDC.
The .050" closing point will be 221 degrees from the opening point which is 221 - 3 -180 or 38 degrees after BDC.

The .050" opening and closing points shown on the cam card are the specs you use to degree the cam 4 degrees advanced.

Use a 9 keyway crankshaft sprocket roller timing gear set.
 
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