RobbMc Fuel Pump results & install tips

:TU: RobbMc fuel pump upgrade = very pleased

Sorry for the long post


I will not only explain my set up which you might or could have, I will also explain how I solved my issues and install tips needed if you work on your car yourself like me (most of the time)..

If you are a long time Buick veteran you know I like to tell a good story. Only been about 14 years since I joined this forum.


For those of you that plan to have your numbers matching car until you die, but you are in my camp and also want to make BIG Buick HP/TQ, which typically means new non original parts, but.you will store all original parts so when your wife or kids sell the car (after you die.. will I or you really care at that point.were dead) the new owner gets all the stock parts, #s matching stage 1 heads, # matching Q-jet, distributor, intake, manifolds, etc.... well thats what some lucky bastard will get when he/she (I have 2 daughters) buys or inherits my 1970 QQ Stage1 GSX, that will be when Im 6 feet under!


Scroll down to my auto sig so you can see my set-up, I made two boo-boos with my current 550HP+ set-up, I kept my stage1 fuel pump and also my one level above stock TQ converter. (est 2200-2400).. learn from my mistakes, thats the POINT of this thread.. I solved both and could not be more satisfied....:TU:


Once this engine was in, running, tuned and mostly broken in (a few hundred miles), I started getting on it and it was just not performing as I expected. Dont get me wrong, it went well, but just not like I know it should have. So after actually doing PROPERV8 Buick forum research, it was obvious my cam, head set up was way too BIG for my converter. So I contacted COAN, sent them the engine dyno from Michaels Racing Engines and they custom made a converter for my set up. THIS IS THE ONLY WAY TO GO, not cheap, but you only live once (Im a father of two, wife is stay at home mom. Single income family, we live in the San Francisco/San Jose bay area where everything is waaaaay more expensive than it should be (guarantee no one pays more for GAS than us..)but I worked this $900 converter..yes..$900 converter.. into our budgetbarelythank GOD I pay the bills and not her.... . She had no idea
:3gears:

Once installed..WOW.!!!!!.... It was as if the car had another 100HP, seriously, hard to explain what a proper converter can do once you are making power in the right RPM range with big Cam, Alum Heads, Headers and Holley. you have to upgrade converter in my type of set-up or you will not be satisfied, bottom line.

Once the converter was in. it had another symptom which was falling on its face once I was above 5000 RPMs. From 3500-5000 holy cow batman.. :Brow: ..... but after that, it was starving for fuel and also had a small vacuum leak at the base of the carb. I fixed the vacuum leak and ran a fuel pressure gauge from my Earls dual feed -8an braided set up and duck taped a FP gauge to my window and went for a ride.. yikes. I already had my return line on the stage1 FP plugged, even with that I was only getting 4-5 lbs at idle and sub 4lbs when I was getting into it.:eek2: ..

So I researched here and the RobbMc Buick 550HP FP got great reviews, especially converting from the 3/8 stock/factory fuel line to line for 450HP+ set ups. Convert to and this pump is good to 550HP+ and upgradable to 1100HP.



Heres where my advice and real world experience kicks in.

I call RobbMc, great guys to talk too (there were 2 main guys when I called, I called 4-5 times over a week or so as I try to be thorough ), they dont try and over-sell you, they are very interested in your set-up, what you plan to do and they will help you get the right parts from them and also the right parts from the hardware store if you use rubber hoses.

I tell him my engine dyno numbers (see auto sig), he says the 550HP pump will be fine, but I should convert to fuel line. After telling him I wanted to keep my stock lines in place as this is a real GSX and someday it could be converted back to factory stock specs.. not on my watch, but looking out for one of you who might buy this if I got hit by a truck. Im Sicilian, it happens


He said I should run -8AN line (1/2) from the tank (needs a new tank fuel pick up that they sell), then -8an line plumed to the pump. I order the 550HP fuel pump and new gas tank pick up from them that has -8an fittings. I put the GSX up on jack stands, drop the tank, clean it, remove the stock pick up, remove stage1 pump, etc. I replace ALL the rubber in the back, paint the fuel tank, install new -8an pick up and start pluming the braided line right along the factory line from the tank.. what a PAIN let me tell you, pluming the braided line over the rear drivers side rear spring, back down thought the frame and following the stock fuel line up to the front driver door. is no fun, but I got the -8an line to that point. Not sure how to actually run the braided line though the stock front-drivers side frame near the engine following the stock fuel lines (line IN from tank is 3/8 and return line is 5/16), there is just very little room and funky bends through the front frame that would be fine if the body was off, but with body on. Will be tough.o No:


The day after Thanksgiving my wife asks me to get all the Christmas boxes down (we must have 15 of those plastic bins filled with Christmas stuff. I realize they are ALL above the GSX in the garage storage. Now I started this fuel system upgrade beginning of October and of course I tell herno way I can get those boxes until I move the car and I need to finish what Im working on, so I bought myself an entire car/garage day (if you have small kids like us, Stella is 3 & Sofia is almost 5, you dont get entire garage days but. I got one since I told her the only way she as getting all her Christmas boxes was with me moving the car. I know if I tried to get boxes, I would have dropped something on the car. Guaranteed



Heres where the story ends and the install tips and results begin:

I had the braided line plumed 2/3 of the way, instead of finishing the conversion, I re-dropped the tank, put the stock pick up back in, (I had already replaced all the rubber hoses at the tank) and installed the new RobbMC pump with stock lines (when installing a FP, make sure you are at TDC or you will fight the FP arm). If you dont know how to find TDC, then this thread is beyond your skills anyway.

The new RobbMc FP body is bigger than your stock stage1 pump, if you are like me, have a Holley and had -8an braided line already coming from the pump up to the carb, you will need to go to your local speed shop and get new fittings to the pump since its mass is wider, you will need to extend the braided line (I will take pictures later, but it will make perfect sense once you are in this stage. The stock stage1 pump body is say 4 wide and the RobbMc is at least 5 wide, so your existing -8an line will most likely not fit, the 180 degree fitting will need an extension.



Just be patient if you make this FPump swap, end result is great, but you most likely will need some fine tuning hardware wise to get there.



Also, when you remove a stock or stage1 pump its pretty easy, once the fuel lines are un-hooked, there are only 2 bolts to remove the FP.

Installing the new RobbMc pump is not as easy since the pump base is lager as I mentioned above. Not sure if other people needed to do what I did to install the LARGER RobbMc fuel pump, but the power steering belt was in my way when trying to get the front bolt (farthest forward, closest to radiator) threaded from below. So I loosened the PS belt to give my hand more room to get that front RobbMc FP bolt started, with the PS belt out of the way, it was much easier to get my hand in there .

The other bolt (only two bolts for a fuel pump), no way I could get it started using my hands/fingers, just no room from any position. I used a 3/8 size 3 in length (key is 3.) ratchet extension with a deep (deep also key) socket (standard socket you just cant get it started, at least I couldnt). When installing this fun 2nd bolt, (working from the bottom of the car, you cant do it from the top, if you can I need lessons from you), make sure the FPump gasket is lined up or you wont get the 2nd bolt in. :rant:

Put the FP bolt it the 3 extension with deep socket and work it up over the FP working from the bottom, you dont have much room between the RobbMC pump and the block, but you will get it in there.. just be patient. Do this by hand turning the 3 extension & deep socket, one you get the bolt started, turn it until you cant turn it anymore by hand, then grab your 3/8 ratchet, connect it to the 3 extension (dont take it off the bolt, use your headbrain and turn the ratchet a click at a time until it mates with the 3 extension, then TQ down that bolt).

The good news is RobbMC recommends once you install in it, you run it for only a few minutes, then you take the FPump off and make sure there is no issue with wear on the cam/arm, this was strongly recommended by them. :eek2: ... this was my first thought, but once you install it once, the 2nd time is easy.

I would say it took me 45 minutes first time to get this FP in (after TDC), but with my advice above, you should nail it in 10-15 minutes, thats all it took 2nd time, actually less..


Now on to the good stuff.


With the stage1 pump and even the return line plugged, I said above I was only getting 4~lbs fuel pressure under load at upper RPMs. No where near enough fuel pressure for this set-up, thank goodness (I am thanking the Big Man upstairs) that I didnt lean this thing and fry a piston..ray: ray: ray:

With the RobbMc 550HP fuel pump using stock 3/8 lines, I ran a fuel pressure gauge and duck taped it to my windshield. The car was fully warm and I went for a ride. Fuel pressure at idle and revving it in my garage/driveway, was 7+. I take it out and no way I can nail it in 1st gear and get traction, useless., so in 2nd gear at 5500-5600RPMs (ran out of road each time at 90-100MPH), it was. 6.4 to 6.6 lbs pressure. Plenty. :TU:

So this fuel pump with stock lines is enough. I will still finish the conversion to line, Im 2/3 done, but just wanted the rest of you to know even with stock line and the return line hooked up (not plugged), I have sufficient fuel pressure.


VinMan

 

Good article but remember volume is just as important if not more so than pressure.:TU:

 

VinMan, Whats the cost or the total conversion to 1/2"?

 

Thanks for responding to MY post regarding Carter vs. T/A pumps. Thanks to your post, I now will spend the extra $100.00 and go w/ the Robb Mc pump. No point in saving $100.00 and then melting a piston. I, too, am shooting for about 550 h.p. w/ my Gessler-ported Bulldog heads, Wiesco flat-tops, etc.

Some of your pump installation problems could have been alleviated by installing studs in the timing cover, instead of using fuel-pump bolts.

Not only do the studs facilitate the install, but they are much better if you have to elongate the fuel-pump holes to clear the double-roller timing chain.

Thanks, as well, for confirming my suspicions that the install of a 1/2" in is one P.I.T.A.

Regards,

Ranger
Aiken, SC

 

I forgot to mention that 7 p.s.i at idle will probably not suit my Osborn-prepped Q-jet, so I will have to use a regulator. I used to use one years ago. Had a vacuum line to it. I think the name was "Cageler," or something like that.

Anybody know if they're still around, or if another regulator would thusly adjust for idle vs. full-throttle operation?

Best,

Ranger
Aiken, SC

 

I am surprised it would make a difference in 1st gear. The carb bowls should be full of fuel for the initial blast. Before I changed to 1/2" on my bracket car I didn't have a problem until about 1/2 way through 2nd. Good story and directions. I would like to add another hazard possible with a cheapo pump.
I had the little roll pin that holds the pump arm come off one time and drop into the pan where it met mister crank shaft and was slapped right through the pan leaving a BB sized hole. This created a nice little stream of oil that shot right on the header. This created one of those dooms day smoke trails that says you just had a major melt down. I had an electric pump backing up the stock pump so it didn't quit running and sounded great and had good oil pressure.
I idled down the return road and to the pits. The spray of oil was so fine it was burning off the header and not hitting the ground. We saw the problem as soon as we raised the car but didn't know what caused the hole. Luckily
one of the first things I did when getting ready to pull the engine was pull the pump and the pump arm was flopping around. All we did was fix the pan
and eliminate the mechanical pump. Ran for two more years before tearing it down.

Bob H.

 

In stead of braided we use the NHRA approved rubber line made by some of the big manufactures and sold by Jeg's & Summit. Much easier to work with and lighter as well.

 

running the -8 line is do able just takes some time, did this in March. I removed the old fuel line and kept the stock return line and vent lines. new tank, 1/2" sending unit,-8 braided line to RobbMc pump. some pics.

http://i349.photobucket.com/albums/q361/kick71/FErebuild002.jpg
http://i349.photobucket.com/albums/q361/kick71/newFS005.jpg
http://i349.photobucket.com/albums/q361/kick71/newFS004.jpg
http://i349.photobucket.com/albums/q361/kick71/newFS002.jpg

 

John, have you noticed the Jegs stuff shrinking in length? wondering because I swear my an-8 has shrunk in length.

 

I also have the robmc 550 pump and 1/2 in pickup. Had a small problem with the pump which was taken care of by them for the cost of shipping. I am very pleased with their products and customer service. :beers2:

 

What sort of problem did you have? For that price, I would think that the quality control, while not "perfect," would be pretty tight/good.

I don't want any problems, nor do I want to ship the pump back and forth.

--Ranger
Aiken, SC

 

Sorry guys, was gone all day yesterday and busy at work all day today.

John.... you are correct, Volume is important, good catch and point :TU: that's why I still will convert to 1/2 line.

Just still not sure how the heck I will snake the braided line through the drivers side frame with the stock lines in place...o No: I might just have to re-route it which would mean I would be taking the line up near the headers, then back down again. I wonder what effect that would have on pressure and volume..o No:



Freakazoid, I can guess at total price for the -8an line and fittings, it's the fittings that cost the most... without pump, I'd say the braided lines and fittings all the way to the carb will cost you a solid $200+ to $225-ish.....ou:

 

Vinman, that's why I said to you that rubber line. Check it out.

 

John, I looked on Jeg's and Summit's website and couldn't find the "rubber" line you are talking about. Peace, Mike D.

 

this maybe it?
http://www.summitracing.com/search/...-350-Hose/?keyword=ear-352008erl&autoview=SKU

 

John.... about the rubber..... what the heck do I do with $200+ of braided lines and fittings.... o No: .... that's one issue I have.

I wish I would have talked to you first.

Not that I might not swap back to rubber, I could sell my braided kit including in tank -8an pick up and all the fiitings that would get someone right to the pump..... maybe I'll go that route. Then I need to get the non -8an pick up from RobbMC, maybe they will just swap it with me since I didnt use it.


I'll figure it out.



Thx

 

check this out too.. http://www.jegs.com/p/JEGS/JEGS-Push-Loc-Hose/764426/10002/-1

it's still a lot cheaper. its called Push-Loc. Jegs I found had the cheapest prices in this material and the AN fittings for the ends.

 

What the heck is with this disclaimer for that hose:

"Not for use on brake, gasoline, nitrous or power steering systems."

Got to be wrong. :error:

Devon

 

WTF! that wasn't there when I bought it a year ago!!

EDIT.. sounds like I'll be chaning it all out to Aeroquip "Socketless" GRR!!!! you can only get blue

EDIT: blasted an e-mail to JEGS. I could have sworn they said it was NHRA cert.

 

CRAP!! there are some other guys pissed about the JEGS push-loc thing

check this out. http://www.modularfords.com/<wbr>forums/showthread.php?t=142975

Jegs changed the page.
nate.

I like having to change all my fuel line... They better credit me for it.

-nate