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newbie - '64 F100 has a poor idle

Posted By chris70 9 Years Ago
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chris70
Question Posted 9 Years Ago
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Hello everybody,my name is Christian and i live in Italy.I drive a 1964 f100 and build a new 292 engine for it.
It's 0.30 bored over,has a b intake and G heads with little work done,and an Isky e4 cam.
Has anybody experience with this cam? How much advance timing does it need to run properly?
I started the engine yesterday and had a poor idle with the timing set at 15° and between 13 and 15 HG reading on the vacuum gauge at 600rpm idle.
Is that normal for this cam?
Any help would be apreciated as nobody here has any experience with Y blocks.
62bigwindow
Posted 9 Years Ago
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Can't help you with the tuning but welcome. There is a lot of knowledgeable people here. I'm sure you will have that y running good in no time.

Durham Missouri
Rowen
Posted 9 Years Ago
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Welcome, chris70 to Y Blocks Forever, I to am a newbie to the y block. You will find a wealth of information and more than a willingness to help from the great folks here! Good luck with your new ride, enjoy and keep the rubber side down. Rowen

Rowen
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Ted
Posted 9 Years Ago
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Welcome to the site.  My own E4 camshaft in a 272 idles with 15-16 in/Hg vacuum.  10°-12° BTDC would be a normal starting place for the initial ignition timing and that would be checked with the vacuum to the distributor unhooked.  The Isky E4 ground on 108° lobe centers will have a small amount of 'rump' which is normal.  At this point, check that the damper ring hasn’t slipped as that will give an erroneous value when setting the timing with a light.  In lieu of double checking the TDC mark on the damper to insure it’s correct, try setting the timing to the maximum manifold vacuum reading with the distributor vacuum unhooked and see if that helps.

As far as to the poor idle, a bit more information will help.  All the valves need to be set correctly and the pistons/valves all need to be sealing.  The carburetor also needs to also be in good condition as any vacuum leaks, internal stoppages or restrictions at the air bleeds will create problems.  A cranking compression check will verify that all the cylinders are tight on both ring seal and the valves closing properly.  All cranking compression readings do need to be within 10% of each other from the lowest to the highest.  If there are any cylinder checks that are abnormally low for the compression readings, then readdress the valve lash on those particular cylinders.  If the valve lash checks out okay, then a leak down test on the cylinders will verify if you have a valve seating issue that will require the cylinders heads to be pulled off of the engine in which to correct.


Lorena, Texas (South of Waco)


chris70
Posted 9 Years Ago
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Changed the carburetor base plate gasket and now idles quite smooth.
I will check the timing in the next days and set it with the vacuum gauge.
chris70
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Thanks Ted for the info on how the cam should "feel".
Changed the pcv valve and put a smaller one,adjusted the idle screws on the carb and know i've 15-16 hg at idle by 650 rpm.
Set the advance with the vacuum gauge and it rides very good now but according to my timing light i'm at 20°.
Assuming the balancer is at his right place wuold this be a problem for the engine?
Ted
Posted 9 Years Ago
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chris70 (8/12/2015)

Thanks Ted for the info on how the cam should "feel".
Changed the pcv valve and put a smaller one, adjusted the idle screws on the carb and now i've 15-16 hg at idle by 650 rpm.
Set the advance with the vacuum gauge and it rides very good now but according to my timing light i'm at 20°.
Assuming the balancer is at his right place wuold this be a problem for the engine?

Assuming that the 20° timing reading is with the vacuum advance unplugged, then move the timing back to 16° and give it a try.  The only problem with the 20° initial value is that it makes the total timing much further out there and especially under light cruise situations where you are using the vacuum advance portion of the distributor.  If the distributor is re-curved with a shorter lead built into the timing curve, then the 20° value would be okay.
 
Be cautious in using ‘dial back’ timing lights as some of those give erroneous values.  There’s always the possibility that the damper marks are not in sync with the timing pointer; that can only be confirmed by doing a TDC check at the #1 or #6 piston and insuring the timing pointer is indeed at the zero mark on the damper.


Lorena, Texas (South of Waco)


chris70
Posted 9 Years Ago
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I finnaly won the war against vacuum leaks and returned the advance to 15° and now is idling pretty smooth and i'm reading 13-14 hg by 600rpm and 8-9 hg in gear by 450-500 rpm.
I noticed that in traffic temperature goes about 170°-180°,my previous 272 was a bit cooler,around 160°.Is that normal?
charliemccraney
Posted 9 Years Ago
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170-180 is fine.  160 is really too cold.



Lawrenceville, GA
chris70
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Had a little spare time after holiday to work on the truck so i changed the spark wires with 8,5mm MSD super conductor and put 57 main jets on the Holley.
Went for a spin yesterday and it's like FLYING!!!!!
Absolute amazing,it's a complete different car compared to the worn out 272.
Now the temperature went back to constant 160° even in heavy traffic,guess i need a warmer thermostat.


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