Aftermarket EFI installation - Questions

Rembrant wrote

Oh...I was looking at the Earl's fittings and vapor guard hose...I didn't know you could buy fittings to do it with the nylon hose...hmmmm...very interesting, thanks Gary.

I'm off to go search for Dorman fittings I guess...haha.

Yep you can get them in Dorman and use the nylon hose.  I personally am looking at rubber and stainless steel hardline for my build using rubber between the fuel tank and the fuel filter/regulator and a short run between the hardline on the frame and the hardline on the engine.  The Vapor Guard hose is quite good as well but you will need some fuel injection hose clamps to clamp them on and you need the earls vapor guard hose ends to not tear the inner sheath that creates the vapor barrier.

If you decide to do hardline for most of the run on the frame, Inline Tube sells a long wheel base 3/8" stainless steel prebent hardline or a OE steel prebent hardline for under $100.  This is what I will be doing and just simply cut the end off infront of the tank rent a quick disconnect flare tool to flare it for the 3/8" quick disconnect outlet on the filter/regulator assembly then cut the other end under the hood and flare it in -6AN to make my -6AN male threaded hose end connection between hardlines at block and frame.

The cost comes out about the same either way between all rubber line or hardline but with the hardline I dont have to worry about the rubber hose blowing out some where with age.  Fewer amount of rubber hose means I can actually carry a short piece of hose and a screw driver and make a replacement on the side of the road if need be.

The nylon hose would probably be the cheapest but I used it at work and I dont like it but I am sure it would last just as long as a metal hardline.

Rusty_S85 wrote

The OE system you can run and Holley makes a Terminator wiring harness/ECM to hook up to the OE EFI system making it more like the sniper/terminator when it comes to tuning and data logging.

If I had a OE EFI system I would go the Terminator ECM/harness route.  You can now data log and make changes via a hand hell or through a laptop.

I've been thinking about this EFI more and more, and now I'm curious about the Multiport kits. Seems like the only real choices are Edelbrock, or a Holley ECU kit with OE stuff...

https://www.summitracing.com/parts/edl-359300/make/ford

How much better is multiport going to be over a throttle body EFI kit? Hard question to answer, I know...but it seems like it would be far superior. Maybe not in my application, but obviously there's no better method of fuel distribution...

If I did go with OE stuff, I'd have to source a bunch of parts...but what all would I need? Upper and lower intake, obviously. Injectors, fuel rails, throttle body, etc. Would there be any benefit in the end over the Edelbrock multiport EFI kit? I guess the main benefit would be that it would have MAF (assuming I used the EFI parts from a Mustang?)

I can't definitively answer the question about how much better a multi-port is over throttle body, but it interesting to note that none of the automobile manufacturers still use throttle body - as far as I know.  So there's obviously some advantage since it has to cost more.

As you said, the multi-port approach gives the best distribution possible since each cylinder should ingest the same amount of air with each revolution and giving each injector the same pulse should give the same amount of fuel.  That's not true of a throttle body system where fuel can drop out of the mix due to twists and turns of the intake runners, which vary by cylinder.

But another thing not normally though of is that the engineers can design the intake manifold/plenum differently for multi-port vs throttle body/carb use.  I've run into that on Big Blue where I'm currently using an multi-port EFI plenum with a carb and have a lean off-idle issue.  Apparently that is because the plenum is "big", meaning that the engineers didn't have to keep the runners small in order to keep the fuel in suspension.  So the runners are big and at low velocity I'm having dropout issues, which I've covered up by fattening up the mix.

So if you think about it the multi-port plenum can deliver more power because it doesn't have to keep the fuel in suspension.  That doesn't mean that all plenums will deliver more power, but they can be designed to do so.

Multi port is very efficient as you are spraying fuel at the intake valves directly into the cylinders vs a throttle body which is acting like a carburetor and spraying the fuel into the air stream at the start of the intake manifold.

There is also two forms of multi port fuel injection as well, sequential fire and group fire.  Sequential fire will give you the best fuel economy as each injector sprays in order for intake valves that are open and group fire just fires a group of injectors at a steady pulse even if the valve isnt open.

The ProFlow 4 edelbrock multi port efi would probably be more cost effective.  But you will have to make more changes when it comes to throttle cables.  Its why I decided on the Sniper Stealth as in theory I should be able to reuse the OE throttle cable as its basically a 4150 carb pattern.

Yes, Ford used "bank-fire" port injection up until the mid-90's on many of the trucks.  For instance the 460 was bank-fire throughout its life save for 1996 on the CA-spec trucks, which is what Bill/85lebaront2 is running, and what I'm going to install on Big Blue this winter.

From my reading the bank-fire approach worked quite well, but true sequential is slightly better.  And since one of my goals was OBD2, which only the EEC-V SEFI system had for the 460, my choice was made for me.

So, I took a rather drastic detour from my earlier plans and I ended up ordering a Summit 500CFM carb.

https://www.summitracing.com/parts/sum-m08500vs

I know the defacto standards these days are Edelbrock and Holley, but from what I could find the Summit carbs seem to get pretty good reviews. You guys will know more about it than me, but I guess it is an old Autolite? design, that Holley later took over as a #4100 model, and now Summit has it.

Anyway, I have tossed this idea around for a couple years and decided to bite the bullet and try it out. An EFI swap was going to cost me over $2000, and I just couldn't come to terms with that right now...lol. The two big benefits of the Summit carb are the fact it is 500CFM (instead of my current 600CFM Holley) and I guess the annular boosters? I'm told that it will run better/crisper, etc...

Internet reviews are a bit sketchy of course, but I found a lot where guys swapped out a Holley for one of these and they claim the difference was night and day. Subject to interpretation I guess...

When I built this truck, I had it in my head that I wanted a Holley carb on it. There was no reason in particular, it was just a brand recognition thing and it was stuck in my head. It's funny though, I didn't realize that so many people dislike them lol. I've had people come up to me at the local car meets and comment "oh I see you have one of the junk Holleys on there" lol. A lot of people tell me that they could never get them to run right.

Anyway, I wanted to try something different and EFI was a bit too rich for my blood right now. I've got some other things that I want to spend my money on, like getting my AC swap done, the serpentine swap with 3G alternator, and some serious sound proofing in the cab.

Stay tuned. I'll start a new thread later to review the Summit carb.

That's a nice looking carb.  And I've heard and read good things about the annular boosters.  I'll bet you have a great experience.  I'll stay tuned!

A lot of people like that carburetor.  👍

I think (and hope) you'll find it a perfect compliment to your 302!

Looks nice!

Interesting, I never messed with Holleys until I got this truck. I like it.

I’ve made several adjustments, changed jets and all and so far I like it. It’s a new 4160 I bought several years ago.

Rembrant wrote

So, I took a rather drastic detour from my earlier plans and I ended up ordering a Summit 500CFM carb.

https://www.summitracing.com/parts/sum-m08500vs

I know the defacto standards these days are Edelbrock and Holley, but from what I could find the Summit carbs seem to get pretty good reviews. You guys will know more about it than me, but I guess it is an old Autolite? design, that Holley later took over as a #4100 model, and now Summit has it.

Anyway, I have tossed this idea around for a couple years and decided to bite the bullet and try it out. An EFI swap was going to cost me over $2000, and I just couldn't come to terms with that right now...lol. The two big benefits of the Summit carb are the fact it is 500CFM (instead of my current 600CFM Holley) and I guess the annular boosters? I'm told that it will run better/crisper, etc...

Internet reviews are a bit sketchy of course, but I found a lot where guys swapped out a Holley for one of these and they claim the difference was night and day. Subject to interpretation I guess...

When I built this truck, I had it in my head that I wanted a Holley carb on it. There was no reason in particular, it was just a brand recognition thing and it was stuck in my head. It's funny though, I didn't realize that so many people dislike them lol. I've had people come up to me at the local car meets and comment "oh I see you have one of the junk Holleys on there" lol. A lot of people tell me that they could never get them to run right.

Anyway, I wanted to try something different and EFI was a bit too rich for my blood right now. I've got some other things that I want to spend my money on, like getting my AC swap done, the serpentine swap with 3G alternator, and some serious sound proofing in the cab.

Stay tuned. I'll start a new thread later to review the Summit carb.

Thats the carb I bought for my 302 when I started my build, the 600cfm Summit Vac Secondary.  It is a upgraded Holley version of the old Ford 4100 4V carb.  From what I have gathered Holley actually builds these units for Summit so what you are getting is essentially a Holley built carb just without the Holley name plastered all over it.  It also has annular boosters as you mentioned which atomizes the fuel better than a straight dog leg booster.  The OE carbs went annular for better atomization but in aftermarket carbs you dont get annular boosters unless you are willing to spend $800 - $900 on an edelbrock carb.  I havent seen one holley with annular boosters which makes this carb a great affordable unit for someone wanting OE style performance for the street.

You can also use the Holley quick change secondary spring kit on the Summit carb as well as the Holley secondary cam kit as well.

I actually bought all of that, the quick change secondary kit, the cam lobe kit to change out the accelerator pump squirt profile as well as a jet kit for fine tuning the jets.

But I am not using mine I kept all of it in the box and I am going Sniper Stealth.

I am leaning towards using it on my 351W in my Mercury since there is no fuel tank options out there with in tank pumps unlike our trucks where the 85/86 had the large opening fuel tank for the in tank fuel pump.

In the end I bought that carb cause it came highly recommended and everyone loved it.  Same way everyone loves the AFR 165cc Renegade heads on the 302`s.

Rusty_S85 wrote

In the end I bought that carb cause it came highly recommended and everyone loved it.  

Ya, it seems to get pretty good reviews when installed on the small V8's. I specifically wanted a 500CFM, and the smaller Holley carbs (465, 390, etc) are really expensive...like almost double the cost of this one. A couple people have told me that the 500CFM will work better on a 302 than a 600CFM. After all, a 302's max requirements are barely 400CFM, so a 500CFM carb might actually be a better fit.



I had my 302 (actually, 304 I think) broken in and tuned on a dyno, but the down side of that is that they basically only tune the engine between 2800-5500RPM. That is all well and good, and it is also where most people's brains are when discussing HP and TQ, etc.

My interest is in street and highway drivability, mainly between 1500-2500 RPM, and this is where the 500CFM and annular boosters is supposed to shine the very best.

Something I've noticed about the Holley 4160 I have installed now is that it doesn't like the cold, and it takes a long time to warm up. I have to clarify that, because when I say "cold", I just mean a fresh start, even on a warm day, and when I say takes a long time to warm up, I'm not referring to coolant/engine temps, I just mean that it seems to take a long time to really smooth out. The climate I live in is quite a bit different than what some of you experience down south. This summer in particular has been cold and damp, and a "hot" day this year has only been about 70F.

It seems like the hotter the ambient temps, and the hotter the truck gets, the better it works, and the smoother it runs. Last year when we had some hotter days (maybe 80-85F), and I was driving for a while, and even stuck in traffic, the engine would run the smoothest.

Maybe one of you guys can tell me what all that means, but I've had it in my head that it is the carb that is working better when it is hot.

Anyway, after reading up on the Summit carb, I found a few people reporting that they run great in the cold (even in winter temps), so that drove my decision...at least partly.

We will see. I'll start a new thread on the Summit carb when I get it, and try to come up with a comparison between the two. It was on back order for a couple weeks, so it will likely be September before I can get to it. I also have to deal with relocating my IGN coil, so that will throw a small wrench into this swap as well.

I have an AFR gauge installed, so that will help with any jetting changes, if required. I might grab a jet kit myself, just so I have it on hand and can get this carb tuned quickly if required.

I know you have the AFR gauge on, but I'd guess that the reason it runs better in warm ambient temps is that the mix is a bit lean.  As the inlet air temp goes up the AFR gets richer.

When I got my new Holley 4160 I jetted down for the altitude I live at, 4100 feet.

I have since jetted up, it came with number 66’s, went with 64’s, back to 66’s and now 68’s. I also richened the idle mixture.

Could be the 460’s drinking problem or the carb, but this truck likes it richer. Runs better when “cold” as you described, I will find out this winter but so far no or very little hesitation or stumble (pumping the pedal to keep it running) when accelerating when freshly stated for the day.

I was going to add choke, but it’s better so I didn’t.

Rembrant wrote

Rusty_S85 wrote

In the end I bought that carb cause it came highly recommended and everyone loved it.  

Ya, it seems to get pretty good reviews when installed on the small V8's. I specifically wanted a 500CFM, and the smaller Holley carbs (465, 390, etc) are really expensive...like almost double the cost of this one. A couple people have told me that the 500CFM will work better on a 302 than a 600CFM. After all, a 302's max requirements are barely 400CFM, so a 500CFM carb might actually be a better fit.



I had my 302 (actually, 304 I think) broken in and tuned on a dyno, but the down side of that is that they basically only tune the engine between 2800-5500RPM. That is all well and good, and it is also where most people's brains are when discussing HP and TQ, etc.

My interest is in street and highway drivability, mainly between 1500-2500 RPM, and this is where the 500CFM and annular boosters is supposed to shine the very best.

Something I've noticed about the Holley 4160 I have installed now is that it doesn't like the cold, and it takes a long time to warm up. I have to clarify that, because when I say "cold", I just mean a fresh start, even on a warm day, and when I say takes a long time to warm up, I'm not referring to coolant/engine temps, I just mean that it seems to take a long time to really smooth out. The climate I live in is quite a bit different than what some of you experience down south. This summer in particular has been cold and damp, and a "hot" day this year has only been about 70F.

It seems like the hotter the ambient temps, and the hotter the truck gets, the better it works, and the smoother it runs. Last year when we had some hotter days (maybe 80-85F), and I was driving for a while, and even stuck in traffic, the engine would run the smoothest.

Maybe one of you guys can tell me what all that means, but I've had it in my head that it is the carb that is working better when it is hot.

Anyway, after reading up on the Summit carb, I found a few people reporting that they run great in the cold (even in winter temps), so that drove my decision...at least partly.

We will see. I'll start a new thread on the Summit carb when I get it, and try to come up with a comparison between the two. It was on back order for a couple weeks, so it will likely be September before I can get to it. I also have to deal with relocating my IGN coil, so that will throw a small wrench into this swap as well.

I have an AFR gauge installed, so that will help with any jetting changes, if required. I might grab a jet kit myself, just so I have it on hand and can get this carb tuned quickly if required.

I think it really depends on the build of your 302.  If you are running OE heads with a fairly stock cam then the 500 cfm would probably be better.  In my case running AFR heads pushing 255 CFM flow on the intake side with a aftermarket roller cam the 600 cfm would have been more correct for me due to the ability for higher flow.

I dont remember where I read it but I read that a intake valve opening sooner creates a supercharger effect where the scavaging of the exhaust pulls the air intake charge in as if you had a supercharger forcing more air and fuel in.  This also helped me decide on 600 cfm for my 302 build as well.  The sniper how ever is 800 cfm but it doesnt matter on the air velocity as you are not dependent on air velocity to meter the fuel as you are in a carburetor.  So over sizing the air flow is not a hinderance as the fuel injectors will inject the proper amount of fuel for how ever much air your engine is able to injest.

On my setup using the cfm calculator on summits site putting in 6000 rpm max rpm (cam redlines at 6,000) and 307 displacement (engine is bored 0.040" over calculates to 306.8 cid) it gives me 453 cfm for a street carb and 586 cfm for a racing carb.  The street carb cfm is based on 85% VE as that is where your stock street engine will operate at around 85% VE.  the racing size is for 110% VE which is where performance engines are based.

Summit also has a article on VE (found below) that states a modern stock engine is 85% VE, a slightly modified engine* is 100% VE, and a Highly Modified Engine** is 115% VE.

It states for * to be performance cam, performance intake manifold, headers, ignition upgrade.  It states for ** to be aggressive cam, performance intake manifold, headers, ignition upgrade, aluminum or ported iron cylinder heads, 11:1+ compression.

https://help.summitracing.com/app/answers/detail/a_id/4741/~/volumetric-efficiency-%28ve%29

I fall some wheres between the two which is where I consider my engine to be around 100% to 110% VE with the roller aftermarket cam, the performer intake, the shorty headers, the 255 cfm intake flow AFR Renegade heads, and the 9.5:1 compression ratio I am almost at.  I how ever am still running the stock ignition system cause I dont agree with summit, the ignition system only needs to be upgraded for two reasons, higher than stock RPM which I will not be turning over 5,500 rpm and I believe the DSII is good to 6,000 rpm with no performance issues, or super high compression which 9.5:1 is not super high, the Explorer 302`s came with GT40 heads and 9.5:1 compression and I doubt their OE ignition system was hotter than the DSII system.

I agree with you on the tuning for where you spend most of your time.  Its why I selected the parts I did even though I had many people on performance forums tell me I am hindering my performance with the Performer intake over the Performer RPM intake.  The Performer RPM intake doesnt come into its power range till 1,500 rpm and goes to 6,500 rpm.  The Performer intake comes into its power range at idle and goes to 5,500 rpm.  For me the Performer covers more of my rpm range than the RPM does.  For me my engine will spend majority of its time between 1,500 and 3,000 rpm.  I doubt I would turn more than 3,000 rpm cause I am setting up my C6 and 9" rear axle to give me a 75 mph speed of around 2,750 rpm like I currently have.  That would put 65 mph to 75 mph with in the 2,400 - 3,000 rpm cruise range that crane lists for my cam.  In your case with you running down around 1,500 - 2,500 rpm you need the power tailored to that rpm range more than you need it at 4,500 rpm.  Its why I am willing to give up some top end power to move it more to the bottom and mid end range.

I dont think you could go wrong with going with the 500cfm on a 302.  Like you noticed with the sniper and any EFI system that is offered to fit a wide range of engines they shoot for high CFM which confuses people cause they are thinking in the terms of carbs that too much CFM will make your engine sluggish and a pig at low rpm.  I find myself even at work having to remind customers that the reason the sluggish nature shows up is with a carb you are relying on air speed to create a low pressure point to pull fuel in and too big slows the velocity down and makes it harder to pull the required fuel in and you dont have that issue with EFI.  In fact every one Ive installed has a super crisp throttle response crisper than the carbs that were installed on the car that came in.  I even seen major improvements on OE stock spec restoration jobs switching from the OE carb to aftermarket EFI.

But I know EFI is not for everyone.  Part of me hates the idea of going EFI cause you are relying more on computers and electronics than with a carb.  But at the same time I know it can do so much more and give me more than a carb would.  I can now with this setup install a remote start system on my truck to actually warm the engine up and get the cab nice and warm before I go outside to go to work.  Something like that you really cant do with a carb cause there is no way to prime the system and set the choke for a cold start since its all mechanical.  Another positive is you can link so much between the sniper to the Dakota Digital cluster if you run one.

Rusty_S85 wrote

I think it really depends on the build of your 302.  If you are running OE heads with a fairly stock cam then the 500 cfm would probably be better.  In my case running AFR heads pushing 255 CFM flow on the intake side with a aftermarket roller cam the 600 cfm would have been more correct for me due to the ability for higher flow.

Right, understood. I will never be anywhere near 4500+ RPM, so I wouldn't need the extra capacity of a 600CFM. The 500CFM is supposed to be a little more responsive in the lower RPM range where I'll be, so it should do me just fine. My 302 is bored 0.020" over, with factory style flat top pistons, GT40 Explorer heads, and a full Comp Cams kit (XE-256H). My compression is right around 9:1. My truck is just a cruiser, and once in a while highway traveler. In hindsight, I probably should have built it a little milder than I did.

Fingers are crossed that the Summit carb works nicely. I'll report back when I get it all installed and set up.

Smaller primaries and annular boosters should help quite a bit with response at low flow rates.  

ArdWrknTrk wrote

Smaller primaries and annular boosters should help quite a bit with response at low flow rates.  

Thanks Jim, that's what I'm aiming for.

Any thoughts on carb spacers? I am running a dual plane Edelbrock intake, and currently have a 1" four hole spacer under the carb. Should I try an open spacer, or leave the four hole that's in there now?

Rembrant wrote

ArdWrknTrk wrote

Smaller primaries and annular boosters should help quite a bit with response at low flow rates.  

Thanks Jim, that's what I'm aiming for.

Any thoughts on carb spacers? I am running a dual plane Edelbrock intake, and currently have a 1" four hole spacer under the carb. Should I try an open spacer, or leave the four hole that's in there now?

Keep the 4-hole spacer.  These work better at lower RPM street use.

I think you made the right decision going with a smaller 500 cfm Summit carburetor.  It is a better size for your 302 engine, and the annular boosters will atomize fuel almost as well as fuel injection. The Summit carburetor is very similar to a Ford Autolite 4100, which is what I have on Lucille.  And honestly, I can't tell the difference between driving it and my other two vehicles that have fuel injection.  Other than pushing the gas pedal down [once] to set the choke on a cold engine, of course.  But that is what makes driving it unique!

The Bullnose trucks are the very last generation of trucks to use a carburetor, and I personally think having a carburetor is actually part of the personality and charm of these old trucks.

I agree that the four hole spacer is probably best for this application.

But I have to point out, Rick,  that my '87 came with a carb even though the fuel injected heads that arrived on the '88 model year are designated E7TE because they technically started production then.

Some of the medium duty 429's and the 460's in F53's were carbureted up to 1990 or '91!

Rembrant wrote

Rusty_S85 wrote

I think it really depends on the build of your 302.  If you are running OE heads with a fairly stock cam then the 500 cfm would probably be better.  In my case running AFR heads pushing 255 CFM flow on the intake side with a aftermarket roller cam the 600 cfm would have been more correct for me due to the ability for higher flow.

Right, understood. I will never be anywhere near 4500+ RPM, so I wouldn't need the extra capacity of a 600CFM. The 500CFM is supposed to be a little more responsive in the lower RPM range where I'll be, so it should do me just fine. My 302 is bored 0.020" over, with factory style flat top pistons, GT40 Explorer heads, and a full Comp Cams kit (XE-256H). My compression is right around 9:1. My truck is just a cruiser, and once in a while highway traveler. In hindsight, I probably should have built it a little milder than I did.

Fingers are crossed that the Summit carb works nicely. I'll report back when I get it all installed and set up.

You should be fine either way.  It sounds like yours is pretty mild build I dont know how much milder you could go without it be a stock engine.  I think my build is a bit higher up on the mild scale, yours sounds like its basically a stock 302 just with a Comp Cam thrown in.