351 EFI build discussion

[Rox Crusher]

There are at least four of us building 351 EFI motors over the winter.

I really love what I see in Viper's motor and he has said I could copy his if I want. Probably makes sense to do just that but I also want to open the discussion and learn through this process. I'm no motor guy so I can take all the schooling offered.

Me, I'm going for increased performance / power for trail without sacrificing street-ability or reliability. Not looking for any stroker type horsepower.

I'm sure I will use GT40 (GT40P? Not totally out of the question), lightening lower, explorer upper, and have a Explorer harness with 17lbs injectors so plan to go OBDII.

Phil, this is your cam and I recall you saying you might have went with slightly more compression if doing it differently ? Can't remember what all you did or didn't say.

Sounds great. Which cam are you running?

This one.
]

image.jpeg

I also saw similar cam being used by a guy on CB.com.


[QUOTE=rguest3;2413805]351W F4TE Block with 9.4 Compression
Lightning GT-40 Aluminum Intake
Aluminum Heads - 170-190 cc intake runners
Comp Cam - XE266HR with 114 Lobe Separation
ProM #24 Injectors and Matching Air Meter
BC Headers with 2 into One

Have built this combo before and am currently doing the same. NO tuning needed with A9L/A9P and RJM Harness.

Great Low end torque and very good RPM range. Slight lope at idle.[/QUOTE]

I don't plan to change anything in drive train but will switch to bronco hut headers and exhaust.

So, looking for input on cam, rocker arms, maf, and injector combinations.

[ZOSO]

Im going to go with more cam and heads to match my ported intake. My cam specs are 218/224*@ 0.050" and 495/500lift 112lsa. 75mm tb 39lb injectors and an 85mm maf. Doing more research and really thinking about AFR 165's now over edelbrock heads. IMO the GT40/p heads don't flow enough for a cammed 351.

[JGZ]

Here's a spreadsheet I found that may be useful as far as different heads are concerned.

[Viperwolf1]

There are at least four of us building 351 EFI motors over the winter.

I really love what I see in Viper's motor and he has said I could copy his if I want. Probably makes sense to do just that but I also want to open the discussion and learn through this process. I'm no motor guy so I can take all the schooling offered.

Me, I'm going for increased performance / power for trail without sacrificing street-ability or reliability. Not looking for any stroker type horsepower.

I'm sure I will use GT40 (GT40P? Not totally out of the question), lightening lower, explorer upper, and have a Explorer harness with 14lbs injectors so plan to go OBDII.

Phil, this is your cam and I recall you saying you might have went with slightly more compression if doing it differently ? Can't remember what all you did or didn't say.

Sounds great. Which cam are you running?

This one.
]

image.jpeg

I also saw similar cam being used by a guy on CB.com.


[QUOTE=rguest3;2413805]351W F4TE Block with 9.4 Compression
Lightning GT-40 Aluminum Intake
Aluminum Heads - 170-190 cc intake runners
Comp Cam - XE266HR with 114 Lobe Separation
ProM #24 Injectors and Matching Air Meter
BC Headers with 2 into One

Have built this combo before and am currently doing the same. NO tuning needed with A9L/A9P and RJM Harness.

Great Low end torque and very good RPM range. Slight lope at idle.

I don't plan to change anything in drive train but will switch to bronco hut headers and exhaust.

So, looking for input on cam, rocker arms, maf, and injector combinations.[/quote]

Here are my engine specs. Compression ratio at 8.7:1 with stock metric hypereutectic pistons and 64cc GT40s. 64cc is after .005" of milling. I would have liked to been around 9:1 but that would involve milling block or heads more or going with a different piston.

And here is the desktop dyno chart with both GT40 and AFR165 heads.

351w specs.pdf

351w dyno.jpg

[Rox Crusher]

Ok, thanks guys.

Phil, were you unable to find a different piston to increase the compression ratio or were planning to take care of it with additional machining (but didn't) ?

[ZOSO]

Phil, What is the primary size on the headers? Not at these power levels but with a healthy stroker someone needs to build some 1 7/8" primary headers.


and another note is the explorer 65mm tb flows about 650cfm.

[ZOSO]

Ok, thanks guys.

Phil, were you unable to find a different piston to increase the compression ratio or were planning to take care of it with additional matching (but didn't) ?

Or just run a gt40p head with a 58cc chamber.

[Viperwolf1]

Ok, thanks guys.

Phil, were you unable to find a different piston to increase the compression ratio or were planning to take care of it with additional matching (but didn't) ?

Neither. Budget was more important.

[Rox Crusher]

Ok, thanks guys.

Phil, were you unable to find a different piston to increase the compression ratio or were planning to take care of it with additional matching (but didn't) ?

Neither. Budget was more important.

same here

[ZOSO]

Ok, thanks guys.

Phil, were you unable to find a different piston to increase the compression ratio or were planning to take care of it with additional matching (but didn't) ?

Neither. Budget was more important.

same here

Easy enough for you to bump the compression up if you are going to be boring the block out. Talk to the machine shop about what it will take with your heads to get the compression to 9.5:1. You'll be happy you did and it will still run easily on pump (85-87)

[akaFrankCastle]

Here are my engine specs. Compression ratio at 8.7:1 with stock metric hypereutectic pistons and 64cc GT40s. 64cc is after .005" of milling.

So you recall the part number and casting dates from the heads?

I think I recall reading that some early version of GT40s could have had chambers as small as 60cc.

[Aztec77Bronco]

I'm also planning a 351W efi. Currently I have a 302 HO w/ the 351W firing order. Are there any particular block codes I should look for in a builder 351W block?
Rox I want a setup similar to yours with the 4R70W but I'm hoping with a 351W I don't need 4.88 gears for a daily with 35" tires. I'll pull a little power with vintage air, but I'm only gonna do mild wheeling and pass exploration around Ouray, Silverton, Durango, & Rico so I need it to be dailyable (is that a word?) more than offroad extreme.
Phil is there a specific cast series I should look for in the 4R70W? Better half is in parts and service so I can get stuff at a slightly better cost.....I hope. Building my stash so I can finally get Ole' Red over and meet y'all face to face finally!

[Rox Crusher]

Easy enough for you to bump the compression up if you are going to be boring the block out. Talk to the machine shop about what it will take with your heads to get the compression to 9.5:1. You'll be happy you did and it will still run easily on pump (85-87)

Block looks to be virgin but will probably have it bored .20 over.

Don't have heads yet. Have been planning to use GT40 but the GT40P look like they flow better. Biggest concern would be header fitment.........planning to go with the BH / Sandersons which reportedly work with either GT40 / GT40P.

[ZOSO]

Easy enough for you to bump the compression up if you are going to be boring the block out. Talk to the machine shop about what it will take with your heads to get the compression to 9.5:1. You'll be happy you did and it will still run easily on pump (85-87)

Block looks to be virgin but will probably have it bored .20 over.

Don't have heads yet. Have been planning to use GT40 but the GT40P look like they flow better. Biggest concern would be header figment........planning to go with the BH / Sandersons which reportedly work with either GT40 / GT40P.

What I have found is yes the p heads flow a little better. they also have smaller chambers to bump compression. If you pick up the headers soon you can try them on my p heads i have.

[Viperwolf1]

Here are my engine specs. Compression ratio at 8.7:1 with stock metric hypereutectic pistons and 64cc GT40s. 64cc is after .005" of milling.

So you recall the part number and casting dates from the heads?

I think I recall reading that some early version of GT40s could have had chambers as small as 60cc.

F1ZE-AA, which is the marine/explorer version. 3A14 (14JAN93) and 3D7 (7APR93) are casting dates. These should be big chamber version. I think the cobras got the smaller ones but they have a different casting number.

[akaFrankCastle]

I think the cobras got the smaller ones but they have a different casting number.

And I think that was the F3ZE part number. But only those that were cast between 93-95 or so. From what I recall, they can be found in very limited numbers on very early 96 model year Exploders. Leftovers from the Cobra lines after the mod motors made their debut.

I still need to cc my heads but I THINK they are F3's.

[Viperwolf1]

I'm also planning a 351W efi. Currently I have a 302 HO w/ the 351W firing order. Are there any particular block codes I should look for in a builder 351W block?
Rox I want a setup similar to yours with the 4R70W but I'm hoping with a 351W I don't need 4.88 gears for a daily with 35" tires. I'll pull a little power with vintage air, but I'm only gonna do mild wheeling and pass exploration around Ouray, Silverton, Durango, & Rico so I need it to be dailyable (is that a word?) more than offroad extreme.
Phil is there a specific cast series I should look for in the 4R70W? Better half is in parts and service so I can get stuff at a slightly better cost.....I hope. Building my stash so I can finally get Ole' Red over and meet y'all face to face finally!

Any 351W block will work but the late ones were made to accept roller cams. Look for F4TE block casting to find one of those in anything '94-'97.

I went with 4.88 gears in the new Bronco with 351W/4R70W. Tires will be no taller than 33" until I decide to cut it and buy a set of flares. That overdrive gear takes a big bite out of the rpm. 4.88 is same as 3.40 gears with a direct drive transmission. Would you ever run 35s with 3.40 gears?

Look for a '98 or newer 4R70W. they have some stronger internal parts.

[Viperwolf1]

Easy enough for you to bump the compression up if you are going to be boring the block out. Talk to the machine shop about what it will take with your heads to get the compression to 9.5:1. You'll be happy you did and it will still run easily on pump (85-87)

Block looks to be virgin but will probably have it bored .20 over.

Don't have heads yet. Have been planning to use GT40 but the GT40P look like they flow better. Biggest concern would be header fitment.........planning to go with the BH / Sandersons which reportedly work with either GT40 / GT40P.

Not enough difference in GT40 and P heads to notice at these power levels. Well, unless you notice a burnt plug wire every couple months that is. Use what's easier and cheaper.

[casadejohnson]

I started my 5.8 build a year ago and then got side tracked by life and the house remodel. Soon, but not as soon as you guys, I will be back at it. My current 351w and C4 are going to go into the 68 Bronco for the boy which gives me the opportunity to go 5.8 roller and maybe 4R70 in mine. Anyway, I went back and forth on GT40 vs GT40P heads ( I have Both in the parts pile ). Honestly, they are so close, I don't think it matters what you use. P's have a tiny bit more compression and regular 40's have more header options. I talked with EFI guy about this at length and we even came up with a few cam options. The problem is ,when you try to research 5.8 / 351w motor builds, what you find has more to do with making your fox body mustang go fast than it has to do with building low end torque for your Bronco. I'll be very interested in watching this thread. Even in the time since I started ( And Stopped ) working on mine my wants have changed a bit. I'm also planning on upgrading the current 80's truck heads on the 351w for GT40's or P's before we move it over to the kids Bronco.

[Viperwolf1]

A couple things to watch out for on the heads is head bolt hole size and pushrod hole machining. 351W uses 1/2" head bolts so the holes will probably need to be drilled. A high lift cam will require the pushrod holes to key-holed. You guys with stock GT/P heads may want take a look at these.

20141221_112635.jpg

[JGZ]

I redrilled my head bolt holes over the weekend.What do you consider hiigh lift?I've also talked to a few people that say there's a coil bind issue with anything over .500 lift meaning the springs need to be changed on the GT40 p heads.There are drop in springs so no machining for those.

[Viperwolf1]

I redrilled my head bolt holes over the weekend.What do you consider hiigh lift?I've also talked to a few people that say there's a coil bind issue with anything over .500 lift meaning the springs need to be changed on the GT40 p heads.There are drop in springs so no machining for those.

.500" and above. Since you brought up the spring issue, neither GT40 or P factory springs and parts are good for that much lift either. Spring upgrades are needed. Problem is the lock grooves are at different heights between intake and exhaust valves on these heads so most spring kits won't work. Here are the springs I used and the P equivalent.

http://www.alexsparts.com/sb-ford-gt40- ... -580-lift/
http://www.alexsparts.com/sb-ford-gt40p ... t-vsk7l49/

[ZOSO]

I redrilled my head bolt holes over the weekend.What do you consider hiigh lift?I've also talked to a few people that say there's a coil bind issue with anything over .500 lift meaning the springs need to be changed on the GT40 p heads.There are drop in springs so no machining for those.

.500" and above. Since you brought up the spring issue, neither GT40 or P factory springs and parts are good for that much lift either. Spring upgrades are needed. Problem is the lock grooves are at different heights between intake and exhaust valves on these heads so most spring kits won't work. Here are the springs I used and the P equivalent.

http://www.alexsparts.com/sb-ford-gt40- ... -580-lift/
http://www.alexsparts.com/sb-ford-gt40p ... t-vsk7l49/

And with all this extra work to get them to fit a 351 with a higher lift cam you are almost to aftermarket head territory. Along with a new set of BH headers I found it's just as much to just run some edelbrocks or afr's. just something to think about.

[JGZ]

Bronco Hut has new stainless headers on their face book page you might wanna look at.

[landshark]

I can't wait for you guys to figure this all out for me.

[Kinder]

I'm gathering the last few pieces needed to finish TFB's 351 build. I'm going to follow Vipers build specs except the compression ratio, looking to get 9+. It's a '95 roller block, GT40 heads, same cam as Viper. Difference will be induction, I don't have a GT40 lower, so it'll be the truck lower w/ adapter to mustang upper. It should make it to the machine shop this coming week. It'll get the Explorer front dress and EFI via EFI Guy.

[airbur]

Guys....while mine is a 427, all the exterior parts are 351 compatible so I'll provide any info/help I can. I have the stainless Bronco Hut headers (I was the prototype for the 351w block).

[Moab Mike]

I can't wait for you guys to figure this all out for me.

Ditto

[Justin]

What Mike said. What are the costs involved in a stock rebuild? I've got a good set of GT40 heads and am willing to do the building myself, so it'd just be the machine work on the bottom end and rebuild kit. After talking with Zac a little bit I'm starting to thing this is less expensive than I'd thought. Might do a complete drivetrain swap with my ZF to minimize down time once my rig is back on the road.

[Viperwolf1]

What Mike said. What are the costs involved in a stock rebuild? I've got a good set of GT40 heads and am willing to do the building myself, so it'd just be the machine work on the bottom end and rebuild kit. After talking with Zac a little bit I'm starting to thing this is less expensive than I'd thought. Might do a complete drivetrain swap with my ZF to minimize down time once my rig is back on the road.

Depends on how far you want to go. You can do rings and bearings for just a couple hundred. If you're boring, replacing pistons and balancing you better plan at least $1,000.