Skookum 300 4bbl conversion write up - Page 2 - Ford Truck Enthusiasts Forums

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Skookum 300 4bbl conversion write up

 
  #16  
Old 09-18-2018, 09:25 AM
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Originally Posted by timbersteel View Post
Evan has 1st shot on the EFI stuff.
Much appreciated, but I don't need those parts. Mine work just fine, they're all yours.
 
  #17  
Old 09-18-2018, 11:20 AM
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Now that you're mostly done lol I'll share my experience.

85 300, bored .040 over, factory cam, Clifford intake and a 390 Holley and long tube headers. Never a stumble, even at 5000 rpm. That was running on a POINTS distributor with a pertronix electronic conversion and tuned for 5000 ft above sea level, where as I live at 1000ft.

it's getting a quickfuel 450 carb and Davis HEI with the rebuild at .060 over and a compression of 9.7:1 with a Schneider 140 bumpstick.

also, running on the primaries alone on a 600 4bbl is NOT the same as a 300 2bbl. They are measured at different pressures, not to mention that primaries are smaller than secondaries usually.
 
  #18  
Old 09-18-2018, 12:46 PM
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anyone ever tuned a quadrajet to run on a 300? i bet that would be a pleasure to drive
 
  #19  
Old 09-18-2018, 04:03 PM
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Originally Posted by KubotaOrange76 View Post
anyone ever tuned a quadrajet to run on a 300? i bet that would be a pleasure to drive
It would have good throttle response, but even the "small" 750 quadrajet is 225 cfm or so on the primary side and the 850s are 275cfm.
properly tuned they are a fantastic carb, but most people don't have the patience to get them dialed in.
 
  #20  
Old 09-18-2018, 04:45 PM
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i couldn't believe the difference it made when i stuck a 795 cfm on a warmed 460. Going from a Holley 750 the increased throttle response and low end was incredible
Took some time to get it dialed in, but it ran awesome, ran damned near with truck on its side too

ok high jack off
 
  #21  
Old 09-18-2018, 07:50 PM
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Hijack.... the other way looks weird.
 
  #22  
Old 09-19-2018, 10:45 AM
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Originally Posted by BigBlue 94 View Post
with the rebuild at .060 over and...
Ummmmm....... just a word for the wise, i would highly reccomend not boring out a 300 that much. Even boring one .0050" over for the FE pistons is risky. It has been done, i dont really see the need for it or gains from it. But to each their own i guess. Either way let us know how it works out.
Mudsport96, again with the quadrajets? Alright Alright a guy can take a hint. I promised in the last thread id do a comparison between a couple of carbs down the road. I just gotta get the one im using running and driving long enough to justify taking back off the road again lol. Ya know i've got this funny little feeling that you're quite smitten with those Quadrajets........ hmmmmmmm I'll get to it that's a promise, just want to get this truck back on the road. It's killing me walking past it everyday. Been off the road for almost three months now in preparation of the swap. Not solely for the swap though...... read my last response in my previous thread...... *sigh*
 
  #23  
Old 09-19-2018, 03:46 PM
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  #24  
Old 09-19-2018, 04:05 PM
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SixerFixer, PM sent
 
  #25  
Old 09-19-2018, 09:08 PM
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Got your PM timber. So i just got the fuel fittings for the fuel reg today only to find out that what was supposed to be a 9/16" lip with 3/8" inside is actually a 11/16" lip with 1/2" inside. So basically i got two supply fittings and no return fitting. Very dissapointing as they were already closed by the time they were delivered. Oh well, getting the cooling system back together so i can actually run the engine for longer than 10 seconds. I know you're not supposed to run an engine without coolant(unless it's a VW lol) but if figured for the amount of time it ran it wasn't anywhere near long enough to get to any temperature id be concerned about. With the manifolds all torqued down from inside to outside, and everything good to go i tried again last night to see if it would run right. Close but no cigar...... It's running slower than before, but still way too high(1500rpm). It's running much smoother, just gotta chase around hopefully only one vacuum leak. It really sucks parts wise for this project as most everything i've ordered that says it'll fit, won't fit or needs major modification to fit. And quite a lot of sellers listing parts don't like to give very good info on them like sizes, or anything specific other than the year and engine. Yeah a fuel rail adapter fitting for a 1996 f150 4.9l will fit but there's two lines in different sizes, but it doesn't even give a size. Just seems like quality nowadays is really hard to come by...... rant over.
 
  #26  
Old 09-20-2018, 12:02 AM
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Got your PM Sixer.
 
  #27  
Old 09-20-2018, 07:39 AM
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Bust out the propane torch and vacuum pump?
 
  #28  
Old 09-21-2018, 12:47 AM
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timbersteel, you're inbox is full.

The vacuum leak has been narrowed down to the #4 cylinder as when it's "running" you can take the plug wire off and it stays the exact same. Yes the plug wire is good, as when you put it near grounded metal you can hear it sparking. 65,000 volts makes an impressive arc length. The cylinder reads about 120psi compression, and the plug ground strip is solid white. It's weirdthat #4 would be not firing as it's runner is located directly under the carburetor as is #3. It would need to be a very sizeable vacuum leak to not have combustion in that cylinder as fuel goes there anyway. Both bolts intake and exhaust side are torqued down to 30 ft-lbs so i don't know how there would be a leak around the runner or how it could be fixed. Any help/ideas would be very much appreciated.
 
  #29  
Old 09-21-2018, 01:07 AM
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Hey SixerFixer, I deleted some stuff. Let me know if you PM me again.
 
  #30  
Old 09-21-2018, 01:11 AM
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Concerning #4 cylinder, try swapping that plug to another cylinder, or if you have another spare spark plug, swap it with a known good one to rule out a defective or failed plug. Just something simple to rule out. Ive had brand new plugs bad/defective out of the box.
 

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