Skookum 300 4bbl conversion write up - Page 3 - Ford Truck Enthusiasts Forums

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Skookum 300 4bbl conversion write up

 
  #31  
Old 09-23-2018, 12:38 PM
SixerFixer
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Ok, so the #4 spark plug is working just fine. With 120psi of compression, and good spark...... tt's definitely getting fuel as its runner is directly under the carb.... All of the manifold bolts were torqued down to 30 ft-lbs from center out...... i guess i'll get the brake parts cleaner and start spraying to it runs different. Lol For anyone wanting to do this swap there's two special little parts that you need to have if you are keeping the factory hard lines/efi fuel system from the springlock connectors back. For the supply side #54180 and for the return #54184 these two little beauties adapt the spring lock connectors for the fuel rail to 3/8-16 mpt for a fuel pressure regulator. Sticking with the efi intank pumps and lines simplifies the work you have to do physically, but then you have to find a regulator to take that 45-50psi down to 4-7psi. So you'll definitely need a return style regulator which the existing return line comes in very handy for. If i had the funds to do so i would drop both tanks and just pull the in tank pumps and run a metal pick up tube with a screen in both tanks and run rubber hose all the way up with a Standard FV1 fuel selector at the tanks to switch em. Run the positive wire from one of the pumps from the selector switch in the cab to the solenoid and bingo you're golden. Normally open on one tank, and flip the switch it engages your solenoid and switches to the other tank. Run a jigger pump after the fuel selector valve and you've got an unstoppable setup. unfortunatly my funds don't permit that. I just really hope the pressure regulator i have will work. I'm skeptical but for the sake of money and time spent i really need it to work.
 
  #32  
Old 09-23-2018, 01:12 PM
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Just a thought; is the carb mounted fore/aft or sideways? It may be a fuel distribution problem if the carb is fore/aft. Are you using the Offy 360, the Offy regular (non-360) manifold or a Clifford?
 
  #33  
Old 09-23-2018, 05:08 PM
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The carb is mounted standard with the bowls facing the radiator and firewall. I'm using an offy C-series "open plenum" manifold. It's not a true open plenum as there is divisions between runners, but it is mostly an open plenum. 360? Is that another name for the dual port?
 
  #34  
Old 09-23-2018, 10:36 PM
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Originally Posted by SixerFixer View Post
The carb is mounted standard with the bowls facing the radiator and firewall. I'm using an offy C-series "open plenum" manifold. It's not a true open plenum as there is divisions between runners, but it is mostly an open plenum. 360? Is that another name for the dual port?
The 360 designation was for the 3X1 manifold I used on the small Ford six. Looking at the pictures of the 300 cid C manifold online, it appears the secondary butterflies are right over the #4 intake passage with the carb installed fore/aft. There doesn't appear to be a choice in turning the carb sideways to improve fuel distribution either unless it will fit that way without redrilling. My love/hate relationship with Ford inline sixes runs back almost 50 years so some things have changed. Personal opinion, the Dual Port would have been a better bet with a stock cam and compression.

I would be of the opinion the fuel distribution is bad for the #4 hole and the fix would be to turn the carb sideways to improve fuel distribution. Primaries should be toward the engine. I know it might not be easy with the throttle linkage but that's where I would go first after checking for vacuum leaks and before trying other things.

This is the problem with every single carb inline six, fuel distribution. Things get better with multiple carbs because the fuel can be dialed in by tweaking an individual carb in the set. I've done this with a number of small Ford sixes, using the Offy tri-power adaptor plate after some heavy machining. Three of the small (190 cfm?) carbs with no progressive linkage works very well by using a manemometer to sync the air flow at idle.

 
  #35  
Old 09-24-2018, 12:03 AM
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Well unfortunatly i can't turn it 90 degrees not because the manifold wont allow it(it will allow it to run either way) but the fuel rail will be in the A/C receiver/drier with the throttle linkage parallel the firewall, with the throttle linkage parallel to the radiator it would be in the valve cover.
That's the fuel line. So as i have it now the fuel line is about an inch away from the A/C box and thats the barb fitting threaded onto the end of the fuel line. I physically can't turn the carb any less than 180 degrees. The problem with the logic of #4 not running right cause it's under the secondaries is that cylinders 5&6 are still firing very cheerfully and they're even further away from the primaries than #4.
This is what I meant when i said it wasn't a true open plenum.
 
  #36  
Old 09-24-2018, 12:17 AM
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I honestly would love to have a triple carb setup instead of the single 4bbl but my funding is self sufficient and it's not very sufficient to say the least. I totally agree with you on the fuel distribution problem with a single carb, but i don't think that's the case with my missing(non firing, not missing as in gone for all you wise guys)cylinder. I think a triple duece setup with Carter YF 1bbls would do pretty well on a stock setup. The Webber 2bbls would be better for those looking for more smiles per gallon, but for right now the 1x4bbl is what I was able to afford and so far it seems like a great improvement when you start flicking the throttle linkage. Sounds very healthy, and the throttle response is incredibly crisp. Just that miss around what passes for an idle(1500rpm) but then again i really can't hear if the miss goes away after "idle" as it's a little hard to hear anything standing next to it running like that.)..... tomorrow will be checking for vacuum leaks around the manifold/port area of #4 cylinder just to cross that off the list. We'll see what tomorrow brings.
 
  #37  
Old 09-24-2018, 01:20 AM
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Well, heck. Now I understand why the Edelbrock carb is so popular; it can be turned as evidenced by numerous images of said Eddy sixer manifolds bearing a sideways Edelbrock. The 390 Holley is a single feed so it was never an issue but those rides that ran the big six/390 Holley didn't have A/C installed either.

So, the fact you can't idle down below 1500 tells me there is a massive air leak somewhere around the #4 intlet port or the carb has possibly been monkeyed with prior to installation. With a Holley, they are kinda "Install, set idle speed, set idle mix, tweak idle speed, done." Get a propane torch, add a 2' or so hose from the torch tip, hold it near the base of the runners, let a bit of propane go for several seconds. When you find the vacuum leak, the rpms will flare from the added fuel.

You said you were having trouble juggling the intake & exhaust while you bolted it all together on the head. Did you by chance us some High-Tack to hold the gasket on the head and did you take a few long bolts, cut the heads off and cut a slot in the end for removal as guide studs? Just asking, since I've been there, done that a few times. Try installing an Eddy manifold and headers on a late '80's E-150 van. Without guide studs, you're just spitting in the wind. Also, make sure the gaskets match the ports. I've had name brand gaskets that couldn't seal a port, the hole in the gasket being bigger than the exhaust manifold on a 240 six in an f-100.
 
  #38  
Old 09-24-2018, 12:11 PM
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Well there hasn't been any monkeying around with the carb other than making sure the idle screw was letting the throttle linkage return to idle. Which it is. Will be running "diagnostics" on #4 to see if and where there is a vacuum leak. No i didnt macgyver any studs to hold the manifolds in place to line em up. I held the intake in place, while a friend moved the exhaust manifolds around with a prybar(exhaust system was still attatched to manifolds) till everything was where it was supposed to be and then we ran the bolts in and torqued to 30ft-lbs. The ports matched up to the gasket as well as can be expected on these engines.
 
  #39  
Old 09-25-2018, 08:18 PM
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Removed the A.I.R today as the gasket was being held back a tiny bit by every injector. Also while running the rail would start to melt my throttle cable..... no bueno. Going to the ag store to get plugs to replace the injectors. They seem to be just a hair too small to be 1/4" pipe thread....... anybody know what thread they are? And yes i will be removing the air pump as well as it's locked up almost entirely but what does move sounds nasty and crunchy. It won't be used anyways as the rail is already removed.
 
  #40  
Old 09-25-2018, 10:29 PM
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So nevermind on the thread size, they're not actually a pipe thread(weird but ok...?) they're a 9/16-18 fine bolt thread. The only thing that kinda sucks is the bolts i got are green and Grade 5 which means big hex heads. Green would be ok if there was literally anything else that was green in the entire engine bay, but there isn't. Oh well.... guess i'll have to make due. I've got half of the injectors removed and "plugged"(as far as the socket will let me and a wrench isn't any greater help) so i covered up the rest and i'm calling it a night.
 
  #41  
Old 09-25-2018, 10:46 PM
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You might try a little brake fluid on the green heads to see if the paint comes off. I got bunch of brake fittings recently that were all sorts of fruity colors until I got brake fluid on them.
 
  #42  
Old 09-25-2018, 10:49 PM
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Well i figure the coating the bolts have on them should disappear after a couple heat cycles. Hopefully. Otherwise im just going to get a little exhaust paint and paint the tops of em black. Or whatever color i feel suits better. Anything but shiny green.....lol
 

Last edited by SixerFixer; 09-25-2018 at 10:50 PM. Reason: exhasut>exhaust
  #43  
Old 09-26-2018, 10:55 PM
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Good news is the final piece i needed for the fuel system came today, and now the fuel system is hooked up. Reg is now dialed in for 6psi and holding rock steady. I think im just going to take the threaded plug ends off the air tube, and just seal em up with some high temperature schmoo or just weld the tops closed. The bolts don't want to go more than halfway in as they hit the gasket and the valve cover mounting surface and it just doesn't look right. The bad(very very bad news) is that I couldn't find any vacuum leaks, it had good compression and was getting plenty of fuel and air. Much how many things seem to happen to me, just wanting to cross it off the list to be sure it wasn't it. I did a leak down test on the #4 cylinder. As the test was ocurring it was showing a 30% leak (100psi in, 70psi holding) and after testing the valves, i heard a dripping. The overflow tank for the radiator was overflowing.. Apparently there's a head sealing issue with the #4 cylinder letting air into the coolant, and letting coolant into the oil much to my dismay at my finding froth city under the valve cover....... So the head has to come off again to see what the hell is going on. Looking back i should've seen the signs, the PCV valve and breather aren't hooked up to any hoses and as such were letting out a bit of "dirty air" which i've now come to realize was the escaping compression/fuel from #4 going into the crankcase and coolant.Well looks like tomorrow's gunna be a fun one..... Gotta order a new head gasket and bolts again..... *sighs* was really hoping it was just a vacuum leak.
 
  #44  
Old 09-27-2018, 04:34 AM
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That sucks! At least you know where to look, though. Hopefully it's just the gasket.
 
  #45  
Old 09-27-2018, 03:28 PM
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So the head is completely off, and i'm a little more concerned. There doesn't seem to be any noticeable difference to the gasket, no scratches, dings, divits, tears, nothing. All the impressions for the passages are indented where they're supposed to be.....All the holes line up spot on..... There was about a tablespoon of coolant in the piston dish for #4 cylinder. I'm a little at a loss cause if it isn't the gasket then it's the head..... I really don't want to have to have it machined as there's no machine shops in the entire county. I'd have to go about an hour and a half drive and pay costs of machining it flat(which i don't have). This project kinda has the "one step forward two steps back" feel to it......
 

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