8BA doesnt have power

trentclark

trentclark

Member
Hey guys. just starting to get my 47 pickup on the road with the newly rebuilt 8BA. It has the ford 94 carb rebuilt, edelbrock elect fuel pump, stock dizzy w vac advance, stock 8BA heads, headers to cherry bombs, standard 3 speed. its 12 volt neg ground.

I spent a lot of time on the road getting it to run smoothly. kept adjusting the timing and fuel mixture. timing at 475rpm is 4 deg btdc. had to restab the dizzy one tooth counter clockwise to get to 4 btdc but the vacuum advance is against the water neck and cannot back counter clockwise any more. if I have it one tooth clockwise, it almost is on a belt. carb mixture is about 1.5 turns open. sounds great at idle but when I need power to get up a hill it really struggles. it doesn't backfire or die but just doesn't have the pop to get up the hill. If i'm on a flat to downhill road i can hit 45 in 3rd. If im going the other way on a slight incline i cannot get past 30 in 3rd.



any ideas of what I am doing wrong. any help is appreciated. God Bless
 
Look at a mechanical advance dizzy. Bubba/charlie/etc ...all here. less worries. It will be a lot of little things that add up to overall power.
 
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If you watch the timing marks (using a timing light) at idle, then speed the engine up to 2000 rpm does it advance?

The stock distributors are not a very good setup but should do better than what you describe.



Terry
 
Tinker, I will look at the mech dizzy. dont know anything about them.

Cadillac 512, it does advance so its working. I have a bosch timing light and it shows the rpms and advance.
the distributor vacuum is attached to a port in the back of the carb. hmmm?
 
I'm not a fan of the original vacuum distributors, but some are. I would go with the converted Chevy. You can get them as full mechanical or with both. Full mechanical is much easier to set up.
 
JSeery, thanks. I will look into that. Bubba/Charlie know that I understand.


as to your first question, do I have the vacuum advance connected in the right port? I have another port in the carb base plate, not sure of the difference.
 
It sounds like you have the distributor hooked up to the proper vacuum port, and it does seen to be working from your description. I personally would take another try at re-installing the stock distributor. I have a lot of experience with them and you should not be having the trouble you are with the distributor fouling on other engine parts. Are you sure you didn't move it two teeth? Also, are you sure the rest of your ignition system (points, condenser, coil) are up to snuff? There are a lot of bad components out there lately. I would try to get the stock setup running before I would spend good money on an aftermarket electronic distributor. Contrary to a lot of misinformation out there, the stock ignition system on these engines works just fine if properly set up with the proper carburetor.

Oh yeah, the "bump" on the stock front pulley is at 4 degrees BTDC and is where the ignition should be set, not 4 degrees before it.

Also, remember the old saying : "90% of all ignition problems are carburetion related and vice-versa".
 
Did you in fact insure that when the distributor was located with the number one position located at 6 o'clock the number one piston is located at top dead center?? (top of compression stroke)
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Tubman has got a good idea. I run the stock load a matic & it works fine with the stock carb. Isky cam & Offy heads. 51 Merc's sugestion is on the mark too.
Love your truck !!!!
 
51 MERC-CT said:
Did you in fact insure that when the distributor was located with the number one position located at 6 o'clock the number one piston is located at top dead center?? (top of compression stroke)
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That is my thought too. I also experienced it where some bone head (me) when he replaced the timing gear managed to get it a couple of teeth out of time... Strangely it actually ran, no power and sputtered and backfired a lot. Seeing as how this is "confession" time... Remember these flatheads are cyl. are numbered front to back, 1-4 on passenger side, 5-8 on the drivers side. Hooking up the wires to the distributor in a "Chevy" pattern will also impact the power...
Thanks, I feel better now having gotten these transgressions off of chest. I understand that there is no statute of limitations for these... Chap
 
Something not mentioned was point dwell which should be 27 degrees, and has to be verified before setting any initial timing. The timing bump on the pulley is 2 degrees BTDC and will provide good performance, but some additional advance is usually better, depending on fuel quality, altitude, driving habits etc.
 
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Remove your distributor and install it so it doesn't touch anything and can be fully adjusted. Then check: firing order, condition of spark plug wires, cracks or carbon tracks in dist. cap, rotor and make sure vacuum diafraghm (spelling) is working. Do you have any vacuum leaks?
 
Thanks, all good advice (and confessions). ill go thru every comment this weekend and hope to find the issue. I do want to keep it as stock as possible. ill let you know what i find. God Bless
 
Just so we have the full picture, Trent, is the vehicle the one in your avatar?

It looks quite low, what size are the rear tires??

Mart.
 
A defective condenser will seriously affect engine power. This is because a weak or open condenser will not allow the coil to be fully charged, resulting in a weak spark at the plugs. We reuse condensers rather that rely on the poor quality of those now sold.
 
When an otherwise fine running flathead all of a sudden has not much power it can also be that the spring ******** one of the sets of points has broken. The engine will run on one set of points but not real well due to lack of dwell. Not the case here but something to keep in mind on dual point setups.
I suspect the Loadmatic which needs everything perfect to perform adequately or not on right tooth of drive..
 
Mart, the avatar is the truck, I did lower it a few inches. the tires are 255/60R15. a little shorter than the stock tires i assume. Nice head stud removal video btw.

Supereal, I will swap out the condensor. does anyone like Napa sell good ones anymore?
Deuce Roadster, its a single point Loadmatic, set to .015 clearance. I think that is correct.

Ill load some photos once I remember how to do it, been a while.
 
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