454 Timing ? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

JCaldwell · 09-22-2009, 09:05 AM

Hey guys I just got my 454 fired up this weekend for my 72 K20 it is bored .40 over, a .510 lift comp cam aluminum intake and 770 holley and its running and 18 degrees retarded just fine and smooth when I turn the distributor to 0 when running it gets real choppy like it should but when I go to give it gas it falls on its face..anybody got any ideas? Thanks

71tahoe · 09-22-2009, 10:26 AM

1. The balancer spun and the timing mark is off.

2. Are the vacuum lines plugged while setting timing?

3. Timing tab is misaligned.

JCaldwell · 09-22-2009, 04:43 PM

well the vacuum lines are plugged but dont know about the other

ProStreet68SB · 09-22-2009, 05:12 PM

were you reusing the old balancer?
If you did, there is a good chance that as mentioned by 71Tahoe that the outer ring of the balancer is spun from where it should be.

JCaldwell · 09-23-2009, 12:30 PM

Quote:

Originally Posted by ProStreet68SB

were you reusing the old balancer?
If you did, there is a good chance that as mentioned by 71Tahoe that the outer ring of the balancer is spun from where it should be.

Yea its the old balancer..could that actually happen? What do you think the timing she be at?

JimKshortstep4x4 · 09-23-2009, 07:51 PM

Usually big blocks will run better with a lot of timing. I would try 12 degrees btdc and bump it up if needed.

Jim

mixermike · 09-23-2009, 08:37 PM

i'm running 24 degrees btdc on my 396 bored 40 over with comp cam

JCaldwell · 09-25-2009, 05:08 PM

Quote:

Originally Posted by mixermike

i'm running 24 degrees btdc on my 396 bored 40 over with comp cam

Oh wow 24 degrees maybe Im rite then..I was figuring about 8 to 10

LONGHAIR · 09-25-2009, 06:24 PM

Quote:

Originally Posted by JCaldwell

its running and 18 degrees retarded just fine and smooth when I turn the distributor to 0 when running it gets real choppy like

Are you sure that you are not confusing advanced and retarded? It has happened more than once.

JCaldwell · 09-30-2009, 04:45 PM

Quote:

Originally Posted by LONGHAIR

Are you sure that you are not confusing advanced and retarded? It has happened more than once.

Retarded is BTDC right?

**john** · 09-30-2009, 05:08 PM

BTDC is advanced. (before top dead center)

Rreemo · 09-30-2009, 05:29 PM

Another piece of advice on this....on an engine like that I wouldn't screw around with setting it at base. You need to be timing that thing at full advance. It's hard for me to say how much without knowning a little more details about the engine, most importantly compression ratio.....but assuming it's in the 9.5 - 10:1 range I'd suggest that you start around 32 degrees, and work your way up 2 increments at a time until you find your sweet spot.

Most of my big blocks have always liked about 34-36, but I used to have a 468 that only ran like it should've at 40....so you never know until you mess with it.

*2tons of fun* · 10-01-2009, 11:33 PM

wft are you turning the dist to 0?

when the motor is running the the line should run uphill to nearly straight up and down at heavy throttle.

i ran my old 454 at 24ish btcd too.

as far as the balancer goes, take the retaining bolt off and look at the keyway, it should line up with the timing mark on the outer ring.

lyrikz · 02-10-2010, 02:55 PM

Quote:

Originally Posted by Rreemo

Another piece of advice on this....on an engine like that I wouldn't screw around with setting it at base. You need to be timing that thing at full advance. It's hard for me to say how much without knowning a little more details about the engine, most importantly compression ratio.....but assuming it's in the 9.5 - 10:1 range I'd suggest that you start around 32 degrees, and work your way up 2 increments at a time until you find your sweet spot.

Most of my big blocks have always liked about 34-36, but I used to have a 468 that only ran like it should've at 40....so you never know until you mess with it.

When you are setting the advance timing, what rpms do you want the engine at???

71 super · 02-10-2010, 05:43 PM

My 402 likes to be around 16* btdc to run its best.

09-22-2009, 09:05 AM	#1
JCaldwell Registered User Join Date: Mar 2009 Location: Newport Va Posts: 27	454 Timing ? Hey guys I just got my 454 fired up this weekend for my 72 K20 it is bored .40 over, a .510 lift comp cam aluminum intake and 770 holley and its running and 18 degrees retarded just fine and smooth when I turn the distributor to 0 when running it gets real choppy like it should but when I go to give it gas it falls on its face..anybody got any ideas? Thanks __________________ 72 K20 Project now! 70 GMC K20 (Farm truck) on 35's 71 Gmc K20 (Parts truck) 72 Blazer (Parts) 74 3/4 ton (Farm truck) on 35's 84 3/4 ton K5 (Mud toy) on 38.5's 86 3/4 ton (puller) on 36's 98 Cummins (Puller) on 305's Last edited by JCaldwell; 09-22-2009 at 09:06 AM.

09-22-2009, 10:26 AM	#2
71tahoe Registered User Join Date: May 2006 Location: Jonesboro, AR Posts: 916	Re: 454 Timing ? 1. The balancer spun and the timing mark is off. 2. Are the vacuum lines plugged while setting timing? 3. Timing tab is misaligned.

09-22-2009, 04:43 PM	#3
JCaldwell Registered User Join Date: Mar 2009 Location: Newport Va Posts: 27	Re: 454 Timing ? well the vacuum lines are plugged but dont know about the other __________________ 72 K20 Project now! 70 GMC K20 (Farm truck) on 35's 71 Gmc K20 (Parts truck) 72 Blazer (Parts) 74 3/4 ton (Farm truck) on 35's 84 3/4 ton K5 (Mud toy) on 38.5's 86 3/4 ton (puller) on 36's 98 Cummins (Puller) on 305's

09-22-2009, 05:12 PM	#4
ProStreet68SB The Engine Whisperer Join Date: Sep 2006 Location: Ohio Posts: 770	Re: 454 Timing ? were you reusing the old balancer? If you did, there is a good chance that as mentioned by 71Tahoe that the outer ring of the balancer is spun from where it should be. Last edited by ProStreet68SB; 09-22-2009 at 05:13 PM.

09-23-2009, 07:51 PM	#6
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Re: 454 Timing ? Usually big blocks will run better with a lot of timing. I would try 12 degrees btdc and bump it up if needed. Jim __________________ 1971 Shortbox step side 4x4, 350 sbc, 3:07 rear end 1965 Impala SS 400 sbc, Muncie rock crusher 1966 Impala SS 396 bbc, TH 400 1969 El Camino, 350 sbc, TH 350 1971 Snowplow built on a Blazer frame 1972 GMC Short bed, stepside, TH 400, 427 BBC

09-23-2009, 08:37 PM	#7
mixermike Registered User Join Date: Jan 2008 Location: Post Falls, Idaho Posts: 606	Re: 454 Timing ? i'm running 24 degrees btdc on my 396 bored 40 over with comp cam

09-30-2009, 05:08 PM	#11
john member #16 Join Date: Dec 1999 Location: Yuba City Ca. Posts: 3,618	Re: 454 Timing ? BTDC is advanced. (before top dead center) __________________ john http://67-72chevytrucks.com/vboard/showgroups.php board vendors http://www.flickr.com/photos/1745471...7602865984234/ Last edited by john; 09-30-2009 at 05:08 PM.

09-30-2009, 05:29 PM	#12
Rreemo Registered User Join Date: Oct 2005 Location: North Texas Posts: 179	Re: 454 Timing ? Another piece of advice on this....on an engine like that I wouldn't screw around with setting it at base. You need to be timing that thing at full advance. It's hard for me to say how much without knowning a little more details about the engine, most importantly compression ratio.....but assuming it's in the 9.5 - 10:1 range I'd suggest that you start around 32 degrees, and work your way up 2 increments at a time until you find your sweet spot. Most of my big blocks have always liked about 34-36, but I used to have a 468 that only ran like it should've at 40....so you never know until you mess with it. __________________ 72' LWB Cheyenne 73' Camaro Z28/RS 70' Chevelle RagTop 00=ss=00

10-01-2009, 11:33 PM	#13
2tons of fun Account Suspended Join Date: Jan 2009 Location: galt ca, Posts: 749	Re: 454 Timing ? wft are you turning the dist to 0? when the motor is running the the line should run uphill to nearly straight up and down at heavy throttle. i ran my old 454 at 24ish btcd too. as far as the balancer goes, take the retaining bolt off and look at the keyway, it should line up with the timing mark on the outer ring.

02-10-2010, 05:43 PM	#15
71 super Registered User Join Date: Sep 2005 Location: Canton North carolina Posts: 3,079	Re: 454 Timing ? My 402 likes to be around 16* btdc to run its best. __________________ 67 blue step side- bb 68 gold and white swb cst anniversary 68 custom swb hot rod Ls swap 69 swb cst 6 cylinder/ overdrive 69 black/black cst bb swb 70 orange and white cst Canada built truck swb bb 71 black and white super swb bb 71 red and white super swb 72 green and white super swb 4x4 62 nova wagon 400 series Ls swapped 68 Camaro 327/4 speed- 1 owner, original paint 66 Volkswagen bettle 69 auto stick Volkswagen Beetle



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