Idiot with Ford 360 - fuel overloading issues

[cowboy6622]

Okay guys...

First off, please don't give me crap like everyone else does about building a Ford 360 without putting a Ford 390 crank and rod set in it.... that's all anyone around here likes to talk about...... I've heard it.

Second, I built a 1975 Ford F-100 supercab longbed and built the original 360.  The heads needed work and I wanted a 4 bbl intake and I found a set on craigslist, C8 heads without the emissions, and a c5 intake.  However, I figured out when I put the thermostat on that this was not a regular old 4 bbl intake.  it had a huge thermostat opening and was a relatively tall intake.  I'm thinking it came off something like a 361 or a 391. 

I also put an Edelbrcok 600 cfm carburetor on it (my 390 in my '68 Torino had a 650 I believe, so I figured it should be fine), but the whole time I've owned it, when you would punch the throttle, it would overload with fuel, surge, and just not accelerat.e  Plus, when cranking it, it was easy to flood it out and took a lot to play with the choke and the such.

Then, the other day, it got to where it would hardly take fuel at all, and I barely nursed it home.  I fouled the plugs out flooding it so much I believe, haven't had a chance to pull the plugs out yet, but that's what it acts like.


So the question... could putting a 361-391 4bbl intake on a set of stock built c8 cylinder heads off a 390 be a problem, or should I buy something like a Edelbrock with a 500 carburetor?  Or both?

[My427stang]

Sounds like the carb just needs work, have you gone inside it yet?  The 600 certainly isnt too big.

Also, FWIW, big thermostat doesn't mean truck, there are plenty of big thermostat intakes out there, even hot rod ones. 

[cowboy6622]

Never went into the carb but it was brand new and I never did anything to any other Edelbrock I ever bought... tuned the piss out of it, the vacuum was perfect on it though.

[My427stang]

Well if its flooding here is what to look at

- Is the choke closing or adjusted too tight?
- Is the choke assmebled wrong and flopping around?
- Is the fuel pressure too high?
- Is the float misadjusted or bad needle/seat?
- Is the spark from the coil wire good and blue?
- Is the air cleaner lid too close or hitting the choke?
- Is the firing order correct? (wouldnt flood the plugs, but I'd double check just to rule out multiple issues for running crappy
- (Only saw this on a Chebby) is the carb sitting flat on the intake?  I had a ZZ-4 crate motor that needed a spacer because it hit the carb flange and held the carb up slightly

It sounds like too much fuel or bad spark, I can't see the manifold, but I am guessing you do not have a 361/391 FT intake, I don't think they'd readily bolt up with a different exhaust port crossover

[chris401]

Unrelated to your problem there is a slight mismatch between the small intake ports on C8 heads with C5 lowriser intake. If you like the cast there are a few 4v options like a T or C6AE-G. I am cleaning up a 360 for a stand also, they aren't that bad with the right cam and intake. Did you use the 390 pistons or find some early 361 pistons?

[GJCAT427]

If the manifold were an FT you would have a very serious exhaust leak between the heads and the manifold. In fact I don`t think the hold down bolts would line up in the center.

[cowboy6622]

I know there were a couple of different firing orders for FE's so I could check that.  What should mine be again, exactly?  I went by whatever is on my intake.

The choke was hte first thing I checked.  It is closing and opneing properly without any "flop."

The carburetor does have a 1" spacer.

The air cleaner has a spacer to be above the carburetor as well (Edelbrock air filter won't sit on an Edelbrock carb without a spacer - go figure.)

I haven't got a gauge or anything to check the fuel pressure. However, i've had three different fuel pumps on the truck.  The fuel bowl in the filter near the carburetor is staying full.

I haven't checked the spark yet but all components of the ignition system were new.... doesn't necessarily mean a lot!

I used stock pistons.... some were marked 390 4v, some aren't marked at all and I presume they're 360 pistons.  I can see no visible differences in the pistons anyway, I researched and found out several late model 360 engines came with 390 4v pistons.  Apparently, they were trying to knock the inventory down at the end of the run.

[Bad Byrd]

Mech fuel pump or electric?

If your pig rich is more then likely carb or Ignition. However I would do a compression check as well, Had a crate SBC many years ago that would foul plugs within 200 to 300 miles......................turned out that compression in that brand new motor was 90 average in all 8 holes.

[machoneman]

I'd beg, borrow or steal another carb to swap on first. Why 3 fuel pumps btw? Did they actually fail or what?

[Drew Pojedinec]

-Check Fuel pump pressure.  (Autozone sells a cheap plastic "T" with a gauge for $5 that is good for diagnosis)
-Make sure coil is good
-Like Machoneman said, borrow a known good carb or figure out how to set yours.
-You never mentioned what your current timing is.  Initial should be 10-16 and total should be 34-40 depending on the engine.

[cowboy6622]

The timing is set at about 6*, but I have advanced it as high as about 14 and it made it worse.  I thought the Ford timing on engines back in that day was 6* TDC without the vacuum... the vacuum advances it about 24* I believe.

The first pump I put on was trying to make it look stock with the filter... if you order a pump with the "in cab" fuel tank, it has the fuel filter on the bottom, but it also dies quickly. Two fo those later I learned my lesson.  I then went with the pump without filter and that one hasn't failed yet, anyway.  I've heard of people having trouble with modern fuel pumps.  I thought that maybe the pump being so far from the tank was hurting it. 

USually, when a fuel pump is going bad for me, the fuel bowl wouldn't be full... it would always have half a bowl or something.  The little glass bowl with the filter in it has been as full as it can be the whole time.

I've adjusted the carburetor... I can get it to pull anywhere from 20-24 lbs vacuum.  When it messsed up last time on the road, I adjusted it the Edelbrock way mentioned in their videos... turn the adjustment knobs in until the engine changes pitch, then loosen 1/2 turn.  Didn't make a difference.

[chris401]

I missed that the first read, you said your intake was relitivley tall. I have a C5AE-C and it is from a stock 66 352 Galaxie. I think they just under 5" tall trey to carb mount. If its a high performance round port or FT it may be a bad vaccum leak. And you may be having to over fuel it to keep it going. Any blue smoke from sucking oil? Someone who knows the intakes could verify yours with picture or casting number.

[Joe-jdc]

Firing order on FE is 1-5-4-2-6-3-7-8.  You need to set your timing to 12*btdc with the vacuum line disconnected and plugged.  Your symptoms all point to the carburetor needing a complete cleaning and adjusting back to stock specifications.  Also, a new set of plugs, and a spare coil should clear up any other problems.  Joe-JDC

[cowboy6622]

It was a brand new Edelbrock, right out of the box and onto my intake!  Has anyone ever known them to have problems out of the box?

[Joe-jdc]

No, they usually work decent as shipped.  It sounds like you have a timing/spark issue since the carb is new.  If the coil is weak, plugs old, and wires old, vacuum canister not working, you need to troubleshoot further.  I would start with simple tune-up first.  Fresh plugs, plug wires, points, condenser, timing set to at least 12*btdc, check fuel pressure, check vacuum canister for proper advancing of timing, coil, fuel filter, ground wires, battery cables, engine grounded, etc.  Then let us know more.  Joe-JDC