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  #31 (permalink)  
Old 02-03-2008, 04:28 PM
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checked 3 cyl for compretion .got dark.all 140psi.tommarow im gonna go back to the 66jets and try timm=ing again because i DID NOT PLUG THE VACCUM ADVANCE WHEN TIMMING IT BEFOr.also got the motor to tdc nd the pointer from all the angles i looked at it. was just past the # 1 plug point right where it should be with room for swisting the dist both ways.

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  #32 (permalink)  
Old 02-03-2008, 04:41 PM
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Quote:
Originally Posted by talleyho
checked 3 cyl for compretion .got dark.all 140psi.tommarow im gonna go back to the 66jets and try timm=ing again because i DID NOT PLUG THE VACCUM ADVANCE WHEN TIMMING IT BEFOr.also got the motor to tdc nd the pointer from all the angles i looked at it. was just past the # 1 plug point right where it should be with room for swisting the dist both ways.
If I understand this right! Your plug from #3 cylinder "got dark". Check your valve adjustment, it most likely has a tight intake valve.
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Old 02-03-2008, 10:00 PM
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i have had a 307 run at 180 out before it had no power but it did run when and engine is 180 out but it does sound to me like he has added to the problem i still feel its a vacuum leak as i said in the first post i made but in my last post i just tried to help .he was talking about the timing if i thought it was the timing i would start over from the beginning.
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Old 02-04-2008, 02:33 PM
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NEW bREAkthrough fellas.retimed the thing by the BOOK this time PLUGING the vac adv, thats what i FORGOT.NO BACKFIRES!!YIPPEE.set at 9 befor at 550idle.the got dark thing was refering to the sky but it dosnt have much power at all.not really bogging just plain WEAK.no burnouts.ill change the plugs whitch even after cleaning didnt do much that carbon is tenaciuse.think thatll help?ill also redo the idle adj screws.should i advance a little more?
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Old 02-04-2008, 02:38 PM
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Yes, try more timing.
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Old 02-04-2008, 02:38 PM
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turned the motor to top dead center ,i watched the valves.and the rotor button was pointin to the #1.ive said this before i think.so cant be 180 out.

someone tell me how 1 tooth off make a big difference.EXCEPT for a MECHANICLE obstacle.meaning twisting the cap and the wires binding or the cvac adv running into the intake.
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Old 02-04-2008, 02:52 PM
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it runs right? so no, it's not 180 degrees off.

When you time it, if you see the timing mark on the balancer and timing chain cover without the distributor twisted all out of wack then it is ok. And even if it was twisted around too far, it still will work.

The one thing you should test for is true TDC. Need to use a piston stop tool to find TDC with the head on. You could have a year mismatch between the cover and the balancer.

does the engine have a "high performance" cam in it? The vacuum and cranking pressure is kind of low which indicates a long duration cam.
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Old 02-04-2008, 04:19 PM
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i dont know what cam is in it.the guys i bought from didnt mention anything about a cam.my dad and his friend while we were toolin with it said it sounded like it had alittle stepup in the cam.but mydads been wrong about many things. i set it to 10btdc and runs faster.set to 12 btdc and runs even faster.tommorow gonna bring up more and see. ps cranking pressor low?psi low?how much of these things should there be?
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Old 02-04-2008, 05:22 PM
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there really isn't any set number. Compression ratio and cam timing will effect the cranking pressure. and gages can be wrong also. It's just that low vacuum is a sign of a big cam. However, it can also be cause by low ignition timing and a incorrect idle mixture.

A bigger cam also bleed off cylinder pressure due to a late closing intake valve. Retarded cam timing can also cause that. 140 is kind of low for a stock cam. For example my 8.75:1 cr BBC with a mild cam has the same cranking pressure as my 11:1 cr sbc with a big cam (around 175). But I have two gages and one reads 150 and the other 175, so you never know.

turn the timing up to 16 degrees and adjust the idle mixture screws for highest idle. Then measure the vacuum.
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Old 02-04-2008, 06:04 PM
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Quote:
Originally Posted by 454C10
there really isn't any set number. Compression ratio and cam timing will effect the cranking pressure. and gages can be wrong also. It's just that low vacuum is a sign of a big cam. However, it can also be cause by low ignition timing and a incorrect idle mixture.

A bigger cam also bleed off cylinder pressure due to a late closing intake valve. Retarded cam timing can also cause that. 140 is kind of low for a stock cam. For example my 8.75:1 cr BBC with a mild cam has the same cranking pressure as my 11:1 cr sbc with a big cam (around 175). But I have two gages and one reads 150 and the other 175, so you never know.

turn the timing up to 16 degrees and adjust the idle mixture screws for highest idle. Then measure the vacuum.
I also have a gauge that reads a maximum 125PSI, so I called my Snap-on dealer and I bought a new gauge. Desperate to get the compression test done, on the 3rd cylinder as I was getting ready to crank it over, the wind blew the hood closed right across the gauge, now even more desperate, I installed a 500 psi transducer to the assembly and used my Snap-on Vantage to finish it up. One costly compression test for me.
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Old 02-04-2008, 06:07 PM
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Quote:
Originally Posted by duntovman
i have had a 307 run at 180 out before it had no power but it did run when and engine is 180 out but it does sound to me like he has added to the problem i still feel its a vacuum leak as i said in the first post i made but in my last post i just tried to help .he was talking about the timing if i thought it was the timing i would start over from the beginning.
no it didnt, it is impossible.
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Old 02-05-2008, 09:48 AM
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Originally Posted by T-bucket23
no it didnt, it is impossible.
oooh yes i did when and engine is 180 only means that number one and number 6 are crosswired by the dist. or mabye your not wise enough to know that .they will still fire and run if the timing is advanced far enough .

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  #43 (permalink)  
Old 02-05-2008, 01:22 PM
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carb. backfiring

OOho, yea, they're both on the up stroke, but if you'll check the valves are different. One is on the compressor stroke and the other is on the exhaust stroke. Maybe i've just got the wrong cam in there to.
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Old 02-05-2008, 03:08 PM
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Originally Posted by lanierledford
OOho, yea, they're both on the up stroke, but if you'll check the valves are different. One is on the compressor stroke and the other is on the exhaust stroke. Maybe i've just got the wrong cam in there to.
you are correct on your strokes and other i think i just got lucky [actually i thought it was in time ]that one time about 20 years ago but
i have had one run when 180 out it didnt run good but with the timing advanced extremely it did run but only for a few seconds it might never do it again thats kinda dangerous on the other valve train ,,then again i have heard a 5.0 ford engine will actually run at 180 out i dont know if its true or not.
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Old 02-08-2008, 01:33 PM
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well 16btdc didnt seem to make a big difference if any.still no burnout.dang.could it be too small excel pump?dosnt SEEMlike bogging just poor exceleration and power.should i try more advancing ?
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