FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: cjshaker on September 28, 2017, 08:32:02 AM
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What is the general consensus on how much horsepower a certain size AN fitting can feed?
Example: Can an -8AN fitting feed 600 horsepower? 700 horsepower? How about a -10AN?
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From personal experience I know that a #8 line with a big mechanical pump (Clay Smith) will feed a 700 HP engine with no problem, because that's what I ran on my Mach 1 in 2005, before during and after Drag Week that year. I think I would move to a #10 line at the 800 HP level. May or may not be required, just guessing on this...
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Way too many variables to answer that question. How much pressure are you dealing with? Just the fitting alone or are we talking about lines attached? Some manufacturers have small holes, some have larger for the same AN size fitting.If you take into consideration the lines it's attached to (or that is attached to it) how long is the line? Are we talking from the regulator to the carb? From the fuel pump to the carb? It's an easy answer if you have fuel flow numbers. I've seen -6 lines off a regulator feed more than 1K hp easy. A -6 line @ the carb can flow a LOT of fuel compared to a pair of 90 jets... but most of the time the fitting will be the restriction in the system. There are also "high flow" fittings vs. standard fittings, and then there are drilled out fittings like I do with most of them.
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I'm talking about from the tank to the pump, then to the regulator. It'll be feeding 2 carbs, so I know I can go smaller from the regulator to the carbs. I'm also aware that the fitting is always the restriction, so no need to overthink it. I'll be looking into the fitting hole size before I make a final call.
Jay, I was looking at the Clay Smith mechanical pumps. Have you ever had a problem with yours? The 1/2" fitting size will match my tank pick-up, so it should work fine for my needs given their flow capability.
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My philosophy on main feed lines is you can't get too big, especially with a mechanical pump. I would run a -10 line from the tank to the pump but most guys run 1/2" line or a -8. In that case, just make sure the fitting isn't a restriction. Remember...the pump is sucking through that line and any resistance will work against the pump. Volume in the line, in that case, is your friend. If you have an electric @ the tank, then you're pushing and you can crank up the pressure so a smaller line won't necessarily hurt.
We deal direct with Clay smith and I've been to their shop in CA. If you're hard set on a mechanical, there isn't a better one on the market. I've seen their pumps feed 1200hp BB Chev blown off-shore marine engines.
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Not a "problem" exactly, but a heads up - Due to the physical size of the pump body there will be a small point of interference between the pump and the corner of the block near where the oil filter adapter bolts on. It will need a small bit of clearance grinding done on the block. This is for the factory cast iron block, I don't know if it also applies to any of the aftermarket blocks. Also, if I remember, the inlet and outlet ports are 180 degrees opposite each other, that part of the pump can be clocked, but the relationship between the two doesn't change. It's a small possibility, but that could be an issue with interference with the fittings and lines depending on if there is anything else on your car in that same area. Jay has given the heads up about the block interference issue before, I just recently bought a Clay Smith pump for my project, so I've been looking at some of the mock-up issues, but I haven't actually installed and run it yet.
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Thanks for the heads up on the fitting orientation, Kevin. I'll look at that a bit closer. I'm not sure if that will cause an issue with the CVR pump and Jays' adapters or not. I saw the clearance issue warning on Clay Smiths' website, but that shouldn't be difficult to deal with.
Scott, this is the intake. And it will be going on a stock stroke/bore 360 in my daily driver truck, so fuel flow numbers shouldn't be that high. ;)
(https://s19.postimg.org/710dd6tub/PSE.jpg) (https://postimages.org/)
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Also, if I remember, the inlet and outlet ports are 180 degrees opposite each other, that part of the pump can be clocked, but the relationship between the two doesn't change. It's a small possibility, but that could be an issue with interference with the fittings and lines depending on if there is anything else on your car in that same area.
After thinking about this, I don't see how they could be 180* from each other. If that was the case, it seems that no matter how you clocked it, one fitting would be aimed pretty much directly at the block or water pump. Could you verify this with your pump, Kevin or Jay?
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Another consideration is the affect of inertia on the fuel, on a drag-based 'launch' with a much larger than necessary tank-in-the-back to an engine-mounted fuel pump. You may find it advantageous to use a 'pusher' pump in the back to overcome such problems.
KS
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Also, if I remember, the inlet and outlet ports are 180 degrees opposite each other, that part of the pump can be clocked, but the relationship between the two doesn't change. It's a small possibility, but that could be an issue with interference with the fittings and lines depending on if there is anything else on your car in that same area.
After thinking about this, I don't see how they could be 180* from each other. If that was the case, it seems that no matter how you clocked it, one fitting would be aimed pretty much directly at the block or water pump. Could you verify this with your pump, Kevin or Jay?
That's why I bring the subject up, it can be an issue. I dropped my pump off recently to my machinist so he has it for his mock-up purposes, so I don't have it handy. Maybe Jay can dig out his. In the meantime here's a screen shot from the Clay Smith website, this is the small block pump just because of how the picture is oriented, but I think the mid section of the body is the same on all. You'll notice on this picture how one port is on the right and you can't really see the other port. It may not be exactly 180 degrees, but they are generally opposite of each other.
(https://s5.postimg.org/tmsg6996f/IMG_8660.jpg) (https://postimages.org/)
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Thanks for the heads up on the fitting orientation, Kevin. I'll look at that a bit closer. I'm not sure if that will cause an issue with the CVR pump and Jays' adapters or not. I saw the clearance issue warning on Clay Smiths' website, but that shouldn't be difficult to deal with.
Scott, this is the intake. And it will be going on a stock stroke/bore 360 in my daily driver truck, so fuel flow numbers shouldn't be that high. ;)
(https://s19.postimg.org/710dd6tub/PSE.jpg) (https://postimages.org/)
Nice!
I still say get as much fuel to the regulator as you can, take care of the needs after that. ;)
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Kevin is right, the inlets and outlet are 180 degrees apart and you can't change them with respect to each other. Mine was installed on a Shelby block and there was a significant amount of grinding involved on the block, plus a little on the pump, to get it to fit. I had it clocked as shown in the photo below; the line pointing down is the inlet:
(http://fepower.net/Photos/Posts/ClaySmithFP.jpg)
Have I ever had any problems with it? Well, yeah I have. When I first got it, it didn't work! I was in a hurry so I took it apart to try to figure out what was wrong. The one way check valves in the pump are pressed into the main body, and a couple of them had just fallen out! I pushed them back in and staked them in place, and have had no problems since. But, I only ran the pump for about 4000 miles in 2005. I switched to electric pumps after that. Part of the reason for that was the headaches in dealing with this pump, but the electrics haven't exactly been trouble-free either...
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Try this link. http://aeromotiveinc.com/wp-content/uploads/2014/06/power_planner_carburetedsystems.pdf
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Thanks for that information. I can see where space would be an issue, especially with my factory oil cooler lines adding to the mix. I still think I'll give it a go, for reliability reasons.
Ken, I don't think I'll be pushing enough G's to have that issue, but I'll deal with it if it becomes one. I know it'd be wise to keep a half tank full to help keep that from happening, and I can modify the pick-up to extend further rearward, if need be. I'd like to stay away from a fuel cell or welded on sump for several reasons.
Russ, thanks for that link, but I'd prefer to stay mechanical. Electrics just add more complexity and chances of failure. During Drag Week, Freiburger said something that rings true every year: Closely paraphrasing..."The three main issues causing breakdowns during Drag Week are roller lifters, electric fuel pumps and automatic transmissions". I can't even count how many guys had issues with their automatics. I know of at least two guys who had to rebuild their transmissions 3-4 times during the week! I may not be able to avoid the roller lifters, but I can the other two.
Edit to add that it does give some interesting info on the AN sizes required though. Thanks again for that link.
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Thanks Doug
I used that link when I was building my fuel system and I had to use the electric pump for EFI
See you next year at Drag Week
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That Aeromotive diagram just confuses people. Their stuff is all over the place - one pump uses -10 AN for 1500 HP, the next uses -12 AN in -10 AN out for 2000 HP, then they recommend a return reg that either won't go below 18 PSI or uses a #8 return which may or may not be enough when you're feeding 550 HP with 420 GPH @ 7 PSI. I'm researching methanol for up to 650 HP and it's surprisingly hard to find a consensus on pumps and regulators in the 100~250 GPH ranges. That includes BLP, Aeromotive, MagnaFuel, Holley/QuickFuel, APD, Product Engineering, Weldon, etc.
More or less as above - on gas, #8 should be good to 750HP or better. Note that #10 flows more and if your fuel comes from the rear, increases in line size increase the head pressure, requiring larger pumps to move the fuel forward. That where my pipe rack has an advantage - when I leave, all the fuel up front WANTS to go back to the motor LOL. The return line has the inertia problem.
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Thanks for that information. I can see where space would be an issue, especially with my factory oil cooler lines adding to the mix. I still think I'll give it a go, for reliability reasons.
Ken, I don't think I'll be pushing enough G's to have that issue, but I'll deal with it if it becomes one. I know it'd be wise to keep a half tank full to help keep that from happening, and I can modify the pick-up to extend further rearward, if need be. I'd like to stay away from a fuel cell or welded on sump for several reasons.
Russ, thanks for that link, but I'd prefer to stay mechanical. Electrics just add more complexity and chances of failure. During Drag Week, Freiburger said something that rings true every year: Closely paraphrasing..."The three main issues causing breakdowns during Drag Week are roller lifters, electric fuel pumps and automatic transmissions". I can't even count how many guys had issues with their automatics. I know of at least two guys who had to rebuild their transmissions 3-4 times during the week! I may not be able to avoid the roller lifters, but I can the other two.
Edit to add that it does give some interesting info on the AN sizes required though. Thanks again for that link.
Most electric fuel pump issues come from inadequate wiring. Seen it a thousand times in the marine world.
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Chris, you and Ken bring up good points about a larger line and the effect it has on pulling that extra volume forward. So after thinking about it, here's my plan:
Use a RobbMc 1/2" pickup/return unit with optional #10 fittings. Drop the line to #8 to get volume weight down and run to the Clay pump. That way I can step up to #10 if I find it's needed. Although I think the Clay pump will work fine on either, I can go with a pusher electric if it doesn't work as expected.
Scott, you're right about electrical problems being a big culprit. Electrics draw a lot of current, and a lot of guys don't do the electrical work necessary to see it's fed right. And like offshore racing, drag use is a violent activity that will expose weak or unsupported connections in a hurry. But I've also seen plenty of failures of pumps. Much more than mechanical anyway. I'm also not a big fan of the noise they generate. Not a big deal for a strictly drag car, but for something that gets road use, it's just irritating.
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Chris, you and Ken bring up good points about a larger line and the effect it has on pulling that extra volume forward. So after thinking about it, here's my plan:
Use a RobbMc 1/2" pickup/return unit with optional #10 fittings. Drop the line to #8 to get volume weight down and run to the Clay pump. That way I can step up to #10 if I find it's needed. Although I think the Clay pump will work fine on either, I can go with a pusher electric if it doesn't work as expected.
Scott, you're right about electrical problems being a big culprit. Electrics draw a lot of current, and a lot of guys don't do the electrical work necessary to see it's fed right. And like offshore racing, drag use is a violent activity that will expose weak or unsupported connections in a hurry. But I've also seen plenty of failures of pumps. Much more than mechanical anyway. I'm also not a big fan of the noise they generate. Not a big deal for a strictly drag car, but for something that gets road use, it's just irritating.
Couldn't agree more on electric vs mechanical.
If you're thinking that the fuel in a larger line between tank and pump will be more effected by G forces and acceleration than a smaller line, that's a myth.
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Don't resize the line based on potential G forces. Size your lines to carry the fuel needed. Note that 700 HP on gas works to 51.5 gallons/hr. Figuring losses in the system, people usually add 50~100% to that more or less. So a 110 GPH pump would be more than sufficient. - 8 lines are plenty good for 140 GPH pumps. Usually the 250+ GPH pumps go to -10 AN outlets. Note, this is all for gas - For methanol, you can about double everything. When you start looking at the pumps, you'll note that the bigger pumps are all putting out flow numbers at levels like 18 PSI, requiring either a fuel return from the pump or a return regulator at the carbs to knock it down to the 6~8 PSI for carb feed. IMHO all power applications benefit from a return style fuel system. I avoid dead head regulators like the dentist.
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I like the Mallory 140 gph electric pump, it is nice and quiet and I haven't had one quit on me. The Holley vane pumps are horribly loud, and I have seen a couple fail. I also really like the Aeromotive A1000 and Eliminator pumps; they are not too loud and I use them for all my EFI stuff, but I have had a couple of those quit on me. Both times on Drag Week, in fact,once in 2009 and once in 2015. Fortunately for me I had spares on hand during those events. Aeromotive is really good for repairing or replacing a failed electric pump at a very modest charge.
I think the only mechanical pump I'd run on a really strong engine is that Clay Smith, and after the hassle it was to install it, I'm sticking with electrics.
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Don't resize the line based on potential G forces. Size your lines to carry the fuel needed. Note that 700 HP on gas works to 51.5 gallons/hr. Figuring losses in the system, people usually add 50~100% to that more or less. So a 110 GPH pump would be more than sufficient. - 8 lines are plenty good for 140 GPH pumps. Usually the 250+ GPH pumps go to -10 AN outlets. Note, this is all for gas - For methanol, you can about double everything. When you start looking at the pumps, you'll note that the bigger pumps are all putting out flow numbers at levels like 18 PSI, requiring either a fuel return from the pump or a return regulator at the carbs to knock it down to the 6~8 PSI for carb feed. IMHO all power applications benefit from a return style fuel system. I avoid dead head regulators like the dentist.
Spot on. I do the 100% for gas and that's using .5 lb/hp/hr which is really more than most engines will use. I don't believe you can have "too much" fuel pump or fuel delivery. I've also seen power gains with 4.5 - 5 psi @ the carb vs 6.
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Use a RobbMc 1/2" pickup/return unit with optional #10 fittings.
What's that?
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Use a RobbMc 1/2" pickup/return unit with optional #10 fittings.
What's that?
Link: http://robbmcperformance.com/products/1085_fordsend.html
Others available too.
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Thanks for all the great input. I think the 140 gph Clay pump with a #8 line will feed enough, but may have to discuss that more with Blair. Having 2 carburetors should ease the demand slightly on the pump, at least initially in the run, having more bowl volume on hand. Maybe I'm wrong about that. Any other mechanical won't be enough, so it's the Clay pump, or electric.
I have had that Mallory pump on my list for a while after seeing past threads about electric pumps, and that's the way I had originally intended to go. If I can stick with mechanical though, I'd prefer that. I just like mechanical stuff, it seems to be more reliable. However, I do have some concerns about grinding on the block in that area, and how much it would require. I'm sure the SOG block won't require as much as the Shelby block, but the iron will also be much thinner than the aluminum. It may not be worth it. I may wait and see how it works out for Kevin.
Kevin, is your machinist near the point of checking the fit out? Could you give me a heads up on how it works out on your block? I'm not sure if you're using a BBM or stock block, but they both should have roughly the same fitment clearance as the SOG block.
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Mine's a original Ford 427 block. I didn't take a picture at the time I looked at it, but the area of interference I have pointed out with the pencil on the stray 390 block in the picture below. It's right on the corner and about a 1/4" trimmed with a grinder will do it in my case. Like Jay said you could take a little off the pump body as well.
(https://s5.postimg.org/ykk9fyw8n/IMG_8701.jpg) (https://postimg.org/image/fs8ecdzub/)
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I am also running a Clay Smith mech pump in my Galaxie as I'm sure you already know. I am using a bottom feed kit on my pump. It replaces the bottom plate on the pump and allows you to run either or both line from the bottom. I don't know if Clay Smith sells them but mine is Edelbrock. I am also using a RobbMc dead head regulator with his small orifice fitting to the return line to help prevent vapor lock. It only requires a 1/4" line running back to the tank. Right now I am running a 1/2" line from the tank and have had no issues with the pump/line. The fuel system issues I thought I had earlier this year turned out to be related to my street carb and nothing else. I am the same as you, for DragWeek I prefer to run a mechanical pump too.
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Use a RobbMc 1/2" pickup/return unit with optional #10 fittings.
What's that?
Link: http://robbmcperformance.com/products/1085_fordsend.html
Others available too.
Nice! And he has one for a Fairlane! Thanks! Looks like a nice part...something else I don't have to make. :)
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The dual quads are much easier on the fuel system needs, you have enough bowl volume to make it to half track so unless you plan ten mile flat out runs you can get away with less pump than a single carb.
I wouldn't run and larger line than 1/2". Mechanical pump may have trouble sucking.
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Kevin, thanks for taking the time to post that picture. I thought it would be in the recessed area, which is thinner and near the water jacket. The area you show should provide enough meat to clearance it.
I am also running a Clay Smith mech pump in my Galaxie as I'm sure you already know. I am using a bottom feed kit on my pump. It replaces the bottom plate on the pump and allows you to run either or both line from the bottom. I don't know if Clay Smith sells them but mine is Edelbrock.
Alan, I didn't notice that you were running a Clay pump, and I wasn't aware of that bottom feed kit. It looks like a nice piece but I think that may cause interference with my oil cooler lines. One of the lines runs right below the pump, so space is a little tight around there, and I'd like to keep the cooler for those longer runs on hot days. I had also planned on plumbing an oil accumulator into the top of my adapter.
(https://s19.postimg.org/ghm1pg58z/IMAG0689.jpg) (https://postimages.org/)
Now that I look at this closer, the inlet/outlet may cause an issue with my filter adapter for the cooler, or possibly even the plumbing for the accumulator. Crap, I hate to spend the money and not have it work, but I guess there's only one way to find out.
The dual quads are much easier on the fuel system needs, you have enough bowl volume to make it to half track so unless you plan ten mile flat out runs you can get away with less pump than a single carb.
Tom, that's what I was thinking, but it wouldn't be the first time I've been wrong. I'll be running 2 660 center squirters, so it may not be quite as much reserve as 2 VS carbs, but should still help a bit.
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McRobb in tank pick up see attached
Doug why -10 if your running a -8 line ??
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Doug why -10 if your running a -8 line ??
Because that gives me the option to go larger if it's needed. It's the same cost either way for the AN fitting upgrade, so a reducer is cheaper than having to refit them for -10. I'm pretty sure a -8 will work, but you never know what the future holds :)
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The basic Carter performance pumps (at least the ones that were made back in the day) were perfectly capable of supplying more fuel than needed for the vast majority of street cars. They had the advantage of being clockable on line position. Back in the time when I had access to the information, all of the large bodied six valve pumps were being made by one company (Blackstone???) and were relabeled by a wide array of marketers. No idea whether the guys selling them now are modifying pumps or whether one of them bought the tooling or ?
Holley pumps used to be made by Pierce Governor - I think Carter got that contract for a little while - then who knows. Carter used to make their own stuff, then that division got sold. Probably made in azzspakistan now...
As mentioned earlier, the inlet size line is most critical since its under vacuum and working through a tank end restriction at that if you are using some sort of strainer at the pickup end. A return line system is a huge positive even if its restricted with an orifice, just to keep cool fuel flowing and reduce vapor lock tendencies.
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As mentioned earlier, the inlet size line is most critical since its under vacuum and working through a tank end restriction at that if you are using some sort of strainer at the pickup end. A return line system is a huge positive even if its restricted with an orifice, just to keep cool fuel flowing and reduce vapor lock tendencies.
Barry, I will be running a return style regulator just for that reason, but with the carburetors placed so high on the tunnel ram, vapor lock should not be an issue. They're pretty isolated from engine heat :)
The RobbMc pick-up does not use a strainer at the pick-up end, according to his website. Because of that, a filter will be needed as soon as it leaves the tank.