What turns a carb into a flamethrower?

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Anonymous

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:shock:

we got the motor back in and fired up...other than a pesky tranny leak and valve cover leak (Aussie intake runners interfance thingy) and a very old exhaust patched in temporarily, things are good.

What would cause my carb to POP on cranking then shoot flames? :oops: It's a Holley 2300 500CFM on the AUssie 2502V intake.

It seemed to only happen now that I tied the exhaust in. I used some flex-pipe exhaust peices to tie the headers into the old 2 mufflers. Can't afford to rebuild the whole exhaust system yet. Would increased back pressure from an old, tiny exhaust cause this? It didn't seem to happen with the 2" headers wide open (not that I could hear it if it did!).

I've got a DSII/MSD combo. GOt the DIzzie dialed in around 10 deg BTDC (at least it was...gotta recheck that).

more questions coming...
 
I would check for:

timing set improperly

Distributor 180 degrees out of phase

Firing order incorrect

Firing order reversed

Big honkin' vacuum leak
 
firing order is right 1-5-3-6-2-4 around clockwise

we built the motor with #1 on TDC so I don't think it'll be 180 out

my guess is timing, but vac leak huh? i'll have to do some searching if that be the case...nothing obviously uncorked.

timing questions:

which direction (CCW or CW) will give more advance? More advance mean more before TDC, right? I THINK it's CCW to increase the advance right?

which side of TDC is BEFORE TDC? Sounds silly I know. Are the timing marks to the DRIVER's side of TDC more advance? That seems to be the case and makes sense..just want to be sure.

We had it dialed in at around 10deg BTDC before hooking up the exhaust. Would hte back pressure be cause for readjusting the timing?
 
The engine crank turns in a clockwise motion. The marks on the drivers side the the TDC mark are RETARDED marks, and the passenger side at ADVANCED marks.

My first instinct is timing 180* out, but if you got the car running...hmm.

Check your timing though and make sure you aren't running too retarded.

Slade
 
i had too much then.....started clacking....

i retarded it and am running much better. I really gotta do this correctly....
 
"The marks on the drivers side the the TDC mark are RETARDED marks, and the passenger side at ADVANCED marks."

Do you mean the marks on the POINTER or on the DAMPNER?

I'm mentally twisted on this...

I have marks on my dampner:

(pass. side) 20....10....TDC...10...20....30...40 (driver's side)

I also have marks on the pointer on my block (can't remember exactly what it looks like):

(pass. side) | | | | TDC | | | | (driver's side)

If align the two TDC marks (on the right stroke of #1), that's TDC right?

right now, my timing looks like this:

| | | TDC | | | | (pointer)
20....10....TDC...10...20....30...40 (dampner)

I set the 10 degree mark on the dampner at TDC on the pointer. What am I doing wrong here guys?! :?
 
I'm new to the ford six but looking at what you have I'd say you are running 10 degrees retarted.
I'd try turning it till the tdc marks line up on the pointer and the balancer.
and try to start it from there.
I had a vee eight a 302 that I installed a 351W cam in.
I'd fire that thing up and it would run like crap. open the throttle and I had a flame thrower.
the firing order was different on two cylinders. just enough to shoot flames.
Could that be a problem here? the new cam has a different firing order?
Nathan
 
I think Nathan is right, looking at your sketch. I think you have a mix-n-match set of pointer/damper. On older engines the TDC mark is a single notch and all the timing marks are on the cover. On later engines you sometimes find a single peg on the cover with marks on the damper.....

The first thing you need to do is check TDC to see where it is. The best way is with a piston stop, but you can get a fairly good idea by just inserting a wire into the #1 plug hole and rotating the crank slowly until it tops out. Then compare marks. If the two TDC marks both correspond at TDC, then it's easy. To get to 10 BTDC advance your marks should look like:

..................| | | TDC | | | | (pointer)
20....10....TDC...10...20....30...40 (dampner)
 
from the marks you guys made here

..................| | | TDC | | | | (pointer)
20....10....TDC...10...20....30...40 (dampner)

and his mark...I thought he was 20 degrees off....initial advance was in retarding mode (not a cut)
 
defintely retarded! :oops:

OK, i just set it so that the 10deg mark on the dampner is at the TDC pointer on the block. As I turned it to that from where it was the idle went down and if I turned it any further, it felt like it was going to stall.

I'll double check TDC after dinner..obviously true TDC will make all the difference.

Firing order is perfect.
 
OK, my TDC's were all muffed up. I found TDC (true TDC), marked the dampner accordingly, and proceded to set the timing so that the new TDC mark was right around 10deg before TDC (toward the passenger side of TDC on the pointer)...right? :? WOW. What a difference. THAT's a bit more like she should be running.

I'm still confused a bit though...i always thought that as you turn the dizzie, if the idle goes UP that's more advance and as it goes down, that's less advance...no? BEcause as I turn the dizzie to get it to what I thought now to be BTDC according to the above info,the idle is dropping, as I pass 10deg BTDC the idle stops dropping as rapidly. As I turn it the otherway, moving now to what based on the above would be more retarded, the idle goes up. :?: WTF?? Can that be related or coincidence?


Now, i have two (or 10) more questions:

1. which vacum port on the carb should i have the dizzie attached to? I've got the Holley 2300 500CFM. There is a port sticking out from the base of the carb that pulls about 20 HG's of vac at idle (idle is a bit high) and there is one just above that level that pulls less than 5HG at itle but shoots up with throttle. There also is the really large one at the back of the carb which I think is for brake booster or PCV right? I set the timing with no vac line attached and currently have the dizzie hooked on the one pulling 5HG's

2. now I hear what I would attribute to lifter tapping. Do I need to readjust my roller rockers now that my timing is different (and right) or am I hearing pinging? How do I correct it? I tried backing the dizzie off more toward retarded (moving the dampner marks more toward the driver's side)

3. I've got some white spoke coming from my valve cover caps...was dat?

Thanks agian tons all!

OH YEAH! Here is the kicker. Since the rebuild, I have NOT been able to use my ignition switch. Turn the key and NADA. I've been using a remote starter. Well, after adjusting my timing, now all of a sudden my ignition switch works again. :?: :?:
 
I hear water goes down the drain in the opposite direction down under- maybe the OZ head fires in reverse direction as well? :lol: :roll: :lol:
 
It's true. In Oz the distributors are all 180 degrees out and #1 is the rear cylinder and #6 is in the front. Really. Check it out.8)

The reason your idle starts to decrease past a certain advance is because the spark fires too early and the piston is trying to push the piston the wrong way.
 
don't screw with me here...you aren't serious right? (about #1 cyl switheroo) :evil:
 
Absolutely! Check it out. If you reverse the numbering, you will find that #1 is now 180 degrees from where it was (because it is now #6). All the rest of the cylinders follow suit, swapping position 180 degrees until you get to #6 (which used to be #1). Course, since your timing mark is in the American position and not the Aussie location, it's 360 out as well......

Ok, I'm just messing with you....:twisted:

You can call any cylinder #1. You just have to move the timing mark to correspond. Convention for most manufacturers is to use the front cylinder as #1.

Early Jaguar XK engines do have #1 at the rear and #6 at the front. Can't count the number of Jags I have "fixed" because the timing was "off". :D
 
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