High School Kid looking for a bit of help!

[Schober Motorsports]

Hey FBBO,

I got a 67 Coronet, 440cid, 727 torqueflite. Been working on it for about the past year or so... Been having alot of problems, but I sure think I'm behind them. Learned a bit too...

Now (Second time around) I got the engine back in the car after some catastrophic failure. Started up great, warmed up great, had no major issues.

Now the problem I'm coming across is that when you floor it, the engine bogs down instead of having instant response. What can I do to get that response?

440 cid
452 Heads
Hughes Whiplash Cam
Roller Rockers
750 Holley
MSD Ignition Box
Edelbrock TM7 Intake
Port Matched heads and very mild porting
Headers

Thanks, Craig

 

[gremlinsteve]

what kinda timing are you running?
new carb? old used carb? how longs it been sitting?

steve

 

[70rr-brian]

As Steve said...very likely carb (accelerator pump, float etc...Could also be secondaries opening too early.) or timing. But are you certain there is no vacuum leak?

 

[moperformance]

First things first. When you move the accelerator with the engine off, does the accel pump squirt fuel into the throat of the carburetor. If not then you have a problem with your accelerator pump circuit or clogged passage in your carburetor. If yes then start vehicle and let idle. Are there any vacume leaks? If so repair them. If not check ignition timing. It should be before top dead center. Look at your service manual for specs. I would imagine it would be between 5 and 10 degrees before top dead center. Here is the one thing to watch out for. If you harmonic balancer has started to come apart, the timing marks will no longer be correct. Adjust the timing by twisting the timing counter clockwise. This will advance the timing. Adjust it a few degrees at a time. If the throttle response gets better then it may have been timing
This advice was from condor74.I just cut and pasted.a lot easier then typing

 

[70rr-brian]

I also just looked at your engine picture... What are you doing for crankcase ventilation? I couldn't really see much from the picture. Also, is the vacuum advance now hooked up?

 

[Mo70Road Runner]

Great looking car!

 

[bigmanjbmopar]

Is it me or does that carb not look like a 750 Holley? more like an old eddy or carter? wonder if he changed the points and has the vacuum connected? I like those headers TTI? nice and snug. Craig you say you have the msd box but you have the old distrib?

 

[Schober Motorsports]

Hahah I apologize bigmanjbmopar, its an old picture JUST when I put the engine in the first time, forgot that I had that edelbrock on there!!!

Its a freshly rebuild engine, I'll be sure to check if they're are any leaks.

All the pumps are working I know that for sure, Timing is at 32 overall, I believe thats what Hughes recommended for overall timing.

Headers are a swapmeet special, I don't have the slightest clue!

Its also a used carb that has a rebuild kit in it. And I forgot to add, its a 700 Holley if it really makes a huge difference!

 

[HEMI-ITIS]

Might need to go to a lighter spring in the vacume secondarys:edgy:

 

[Racer99]

Could need a stiffer spring on secondaries.....too much air will cause a bog just as not enough....really should do a plug check to determine if its a lean or rich bog first....32° total timing is good as long as everything is in order before all the mechanical and vac advance max's out....do a plug check first, sounds like carb tho

 

[oldbee]

Need to know vacuum rating on carb power valves. Also rear float may be set to low and not allowing fuel to flow quick enuf. Yeah,stiffer spring on secondary,not lighter(that lets them open up quicker)The Holley carb books that are out there have a wealth of information.

 

[Meep-Meep]

In addition to the above suggestions I'd like to ask what kind of compression are you running? Did you do a cranking compression test?

 

[goose69]

If you're looking for vacuum leaks, did you try the old spray carb cleaner or starting fluid around the base of carb?