got the 455 together.nothing but an occasional backfire??
July 21st, 2013, 03:03 PM
#1
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Posts: 314
got the 455 together.nothing but an occasional backfire??
I got the 455 together...................nothing but an occasional backfire??
I replaced the camshaft, lifters, harmonic balancer, water pump, timing chain. I carefully had#1 cylinder at TDC when replacing the gears and chain.
the distributer had the vacuum canister facing passenger side rear and number 1 cylinder ( Distributer) had the rotor pointing to #1 cylinder.
Any Ideas??
thanks in advance
joepenoso
I replaced the camshaft, lifters, harmonic balancer, water pump, timing chain. I carefully had#1 cylinder at TDC when replacing the gears and chain.
the distributer had the vacuum canister facing passenger side rear and number 1 cylinder ( Distributer) had the rotor pointing to #1 cylinder.
Any Ideas??
thanks in advance
joepenoso
July 21st, 2013, 03:17 PM
#2
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Join Date: Jun 2008
Location: Cabot, Pa.
Posts: 207
backfire
I had the same problem on my 455. I found that I was brain dead on my timing gear.
Got that fixed and made sure that the timing mark was at 4 degrees( about). Made sure I was on compression when I check the position of the rotor. It fired right away.
Ran a little rough until I timed it. With yours back firing. I would say it is a timing problem. Double check everything. Hope this helps.
Alb
Got that fixed and made sure that the timing mark was at 4 degrees( about). Made sure I was on compression when I check the position of the rotor. It fired right away. Ran a little rough until I timed it. With yours back firing. I would say it is a timing problem. Double check everything. Hope this helps.Alb
July 21st, 2013, 04:24 PM
#4
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Posts: 314
Make sure balancer and pointer are at 0 or maybe +4 degrees TDC.
Check it's the compression stroke by having no spark plug and feeling air pressure against the finger as it reaches that position.
Make sure distributor rotor is pointing at #1 cylinder plug wire.
Fire her up and break in the lifters
is that it??
Thanks
joepenoso
Check it's the compression stroke by having no spark plug and feeling air pressure against the finger as it reaches that position.
Make sure distributor rotor is pointing at #1 cylinder plug wire.
Fire her up and break in the lifters
is that it??
Thanks
joepenoso
July 29th, 2013, 07:12 PM
#12
72 Olds CS
Join Date: Jun 2011
Posts: 6,657
so wait, when the marks are as shown in the below pic thats when #1 is on the comp stroke and I can put in the dist w the rotor pointing at #1 ?
Ive had my 350 apart and I would like to avoid any thru the carb backfires if I can
July 29th, 2013, 07:32 PM
#13
Connoisseur d'Junque
Join Date: Sep 2010
Location: The Hudson Valley
Posts: 21,183
Hint: It's the opposite of Chebby.
- Eric
July 29th, 2013, 08:14 PM
#14
72 Olds CS
Join Date: Jun 2011
Posts: 6,657
duh stupid digital clocks yes I blame the digital clocks for me not knowing where/what 6 and 12 is...
Oldsmaniac wrote that and I copied it but nothing was clicking
ok so I will rotate to the 12 12 position and put in the dist...thanks eric
Oldsmaniac wrote that and I copied it but nothing was clicking
ok so I will rotate to the 12 12 position and put in the dist...thanks eric
July 29th, 2013, 08:18 PM
#15
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Location: The Hudson Valley
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Remember, it's easy enough to confirm, because both valves are closed at TDC on the power stroke, which means you should have a tiny bit of rocker play or be able to spin the pushrods between your fingers.
- Eric
- Eric
July 30th, 2013, 07:33 PM
#16
ZATBAD 72
Join Date: Nov 2008
Location: Kansas
Posts: 65
My manual shows the marks at 6 and 12. Is this not right?
http://www.flickr.com/photos/99610205@N07/9406340382/
http://www.flickr.com/photos/99610205@N07/9406340382/
July 30th, 2013, 07:41 PM
#17
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Join Date: Sep 2010
Location: The Hudson Valley
Posts: 21,183
Yes, it is right.
They're both right.
The manual does not tell you to set it at 6:00 / 12:00 and then just stab the distributor - it tells you to confirm compression stroke by looking at the valve positions on #1.
The point of that picture in the manual is to make sure that you have the cam lined up right, which is easier with the dots right next to each other, not to have the engine set that way to put everything else together.
Remember, the point of the Engine section is not to tell you how to rebuild the entire engine, but rather to tell you how to repair individual parts that are broken - it says to put the distributor in the way it came out, and that if the engine has been turned, to check the valve positions and use that as a guide.
- Eric
They're both right.
The manual does not tell you to set it at 6:00 / 12:00 and then just stab the distributor - it tells you to confirm compression stroke by looking at the valve positions on #1.
The point of that picture in the manual is to make sure that you have the cam lined up right, which is easier with the dots right next to each other, not to have the engine set that way to put everything else together.
Remember, the point of the Engine section is not to tell you how to rebuild the entire engine, but rather to tell you how to repair individual parts that are broken - it says to put the distributor in the way it came out, and that if the engine has been turned, to check the valve positions and use that as a guide.
- Eric
July 31st, 2013, 07:11 AM
#19
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Join Date: Jun 2010
Location: Rogues Island, USA
Posts: 3,613
Eric you are correct. I timed my cam last week and when the timing set was dot to dot the cam is not on the base circle but 180* out. It's just a matter of turning it over so the dots are both at 12 o'clock. This puts the cam on it's base circle and the #1 piston at TDC on the compression stroke. The crank gear will rotate twice for every turn of the cam gear.
This is why timing the cam is stressed so much on this website and others. I was 3* retarded by installing mine 'straight up' and had to advance the cam by 4* to get it to 1* advanced.
This is why timing the cam is stressed so much on this website and others. I was 3* retarded by installing mine 'straight up' and had to advance the cam by 4* to get it to 1* advanced.
July 31st, 2013, 07:48 AM
#21
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Location: Northern VA
Posts: 47,357
July 31st, 2013, 07:50 AM
#22
Yes, it is right.
They're both right.
The manual does not tell you to set it at 6:00 / 12:00 and then just stab the distributor - it tells you to confirm compression stroke by looking at the valve positions on #1.
The point of that picture in the manual is to make sure that you have the cam lined up right, which is easier with the dots right next to each other, not to have the engine set that way to put everything else together.
Remember, the point of the Engine section is not to tell you how to rebuild the entire engine, but rather to tell you how to repair individual parts that are broken - it says to put the distributor in the way it came out, and that if the engine has been turned, to check the valve positions and use that as a guide.
- Eric
They're both right.
The manual does not tell you to set it at 6:00 / 12:00 and then just stab the distributor - it tells you to confirm compression stroke by looking at the valve positions on #1.
The point of that picture in the manual is to make sure that you have the cam lined up right, which is easier with the dots right next to each other, not to have the engine set that way to put everything else together.
Remember, the point of the Engine section is not to tell you how to rebuild the entire engine, but rather to tell you how to repair individual parts that are broken - it says to put the distributor in the way it came out, and that if the engine has been turned, to check the valve positions and use that as a guide.
- Eric
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