Push rod length question.
#298605
04/24/09 10:12 PM
04/24/09 10:12 PM
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Joined: Aug 2004
Posts: 229 Carmel, IN
jhkintx
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enthusiast
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OP
enthusiast
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Carmel, IN
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If my pushrods are too long what behavior can I expect from the engine? Currently I have a vacuum leak that I can't locate and when I turn off the engine you can hear the valvetrain clicking. Also, with a 2400 stall converter and 3:91 gears the car is a little weak out of the hole and idles rough (rougher than one would expect). Below is a list of mods.
1) Stock 70 318 short block 2) Magnum heads milled .040 3) Mopar thin head gaskets 4) Mopar 7.625 pushrods 5) Mopar cam 280/474 (lift is 505 with 1.6 rockers) 6) Edelbrock Perf intake 7) Holley 600 vac sec
Last edited by jhkintx; 04/25/09 09:59 PM.
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Re: Push rod lenght question.
[Re: jhkintx]
#298606
04/24/09 10:37 PM
04/24/09 10:37 PM
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Joined: Jan 2003
Posts: 5,791 Hamilton, Ontario Canada
Magnum
master
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master
Joined: Jan 2003
Posts: 5,791
Hamilton, Ontario Canada
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Too long and the hydraulic lifters will be at the bottom portion of their range. The worst case scenario is they will be bottomed out and you will have no compression.
69 Super Bee, 93 Mustang LX, 04 Allure Super
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Re: Push rod lenght question.
[Re: jhkintx]
#298607
04/24/09 10:46 PM
04/24/09 10:46 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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If the lifter pumps up it can hold the valves open (maybe just a touch) that would give you the rough idle and the lack of performance. Also the intake leak can give you both the idle issue and lack of power Did you use a push rod length checker to determine the length needed
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Re: Push rod lenght question.
[Re: jhkintx]
#298608
04/25/09 01:46 AM
04/25/09 01:46 AM
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Joined: Dec 2007
Posts: 7,759 So Cal
HealthServices
Why would you even post that?
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Why would you even post that?
Joined: Dec 2007
Posts: 7,759
So Cal
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You can burn a valve if the it is incorrect for too long of time.
Allen
Here's a novel idea, let's not throw a bunch of parts at the car hoping it will fix the problem and instead spend a little time diagnosing it first.
Life was a little easier when I was just a wrench.
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Re: Push rod length question.
[Re: jhkintx]
#298610
04/25/09 10:15 PM
04/25/09 10:15 PM
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Joined: Jan 2003
Posts: 25,200 Upper Midwest
MoparforLife
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 25,200
Upper Midwest
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Quote:
I was told to add rocker shims and see if the lifters quit clicking. Does this make sense as a starting point for trouble shooting?
I don't understand the clicking when you turn the engine off. Are you real sure of what you are hearing???? If you have lifters clicking the push rods are to short not too long.
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Re: Push rod length question.
[Re: MoparforLife]
#298611
04/27/09 01:37 PM
04/27/09 01:37 PM
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Joined: Aug 2004
Posts: 229 Carmel, IN
jhkintx
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OP
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Carmel, IN
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Quote:
Quote:
I was told to add rocker shims and see if the lifters quit clicking. Does this make sense as a starting point for trouble shooting?
I don't understand the clicking when you turn the engine off. Are you real sure of what you are hearing???? If you have lifters clicking the push rods are to short not too long.
I'm 100% sure the clicking comes from under the valve covers; it is very distinctive "click, Click, Click" for about thirty seconds to a minute on both sides of the valvetrain.
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Re: Push rod length question.
[Re: jhkintx]
#298612
04/27/09 01:53 PM
04/27/09 01:53 PM
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Joined: Jan 2003
Posts: 25,200 Upper Midwest
MoparforLife
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 25,200
Upper Midwest
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Quote:
Quote:
Quote:
I was told to add rocker shims and see if the lifters quit clicking. Does this make sense as a starting point for trouble shooting?
I don't understand the clicking when you turn the engine off. Are you real sure of what you are hearing???? If you have lifters clicking the push rods are to short not too long.
I'm 100% sure the clicking comes from under the valve covers; it is very distinctive "click, Click, Click" for about thirty seconds to a minute on both sides of the valvetrain.
New one to me. Any one else heard of this????
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Re: Push rod length question.
[Re: jhkintx]
#298615
04/28/09 03:03 PM
04/28/09 03:03 PM
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Joined: Jan 2003
Posts: 16,123 Grand Haven, MI
patrick
I Live Here
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I Live Here
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Posts: 16,123
Grand Haven, MI
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with the engine off, as you state in the first post???!!!
1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!*** 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
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Re: Push rod length question.
[Re: jhkintx]
#298617
04/29/09 09:38 AM
04/29/09 09:38 AM
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Joined: Jan 2003
Posts: 75,274 A gulag near you.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,274
A gulag near you.
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Quote:
As soon as you shut down the engine, the clicking will last 30 - 60 seconds.
Kind of makes no sense , once you turn the engine OFF nothing is moving , so what's clicking ???
You could throw shims under it I guess , but if your rocker to valve tip geometry isn't off it may be so don't use them as the cure. But you have MAGNUM heads , they don't have a shaft mount system do they, shims go where? I'm lost on new smallblock stuff .
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Re: Push rod length question.
[Re: JohnRR]
#298618
04/29/09 10:29 AM
04/29/09 10:29 AM
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Joined: Jan 2003
Posts: 16,123 Grand Haven, MI
patrick
I Live Here
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I Live Here
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Posts: 16,123
Grand Haven, MI
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yeah, when the engine is turned off, nothing is moving, so I don't get where the noise would come from unless it's just the ticking of hot parts contracting when cooling? or maybe lifter bleed down closing open valves?
magnums are pedestal mount. shims could go between the pedestal and the head....
1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!*** 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
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Re: Push rod length question.
[Re: Topher]
#298621
04/30/09 07:51 AM
04/30/09 07:51 AM
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Joined: Aug 2004
Posts: 229 Carmel, IN
jhkintx
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Carmel, IN
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Quote:
It's cooldown from the exhaust.
Now start chasing why the car isn't performing as it should. First thing to do is run a cylinder leakdown test, that will tell you many things about your engine.
As stated earlier; the clicking is NOT cooldown from the exhaust. Wish I could fiqure out a way to post a video clip to validate my issue. After reading the responses so far; I could describe the clicking as possibly the sound of metal hitting metal under pressure. It is not easy to discribe unique sounds with text.
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Re: Push rod length question.
[Re: scratchnfotraction]
#298623
04/30/09 09:24 AM
04/30/09 09:24 AM
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Joined: Jan 2003
Posts: 75,274 A gulag near you.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,274
A gulag near you.
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Quote:
lifter bleed down and the valves clicking shut,IMO
runs like poop cause they are hanging open
This would be the only plausible answer other than the sound the exh makes cooling down .
As far as the frustration of the thread starter , WE collectively are not in front of your car so there are only 1 or 2 possible answers since the engine is NOT RUNNING when this happens. no matter what we say you are going to have to get your hands dirty and start ripping into it because it appears you do not like the answers you are getting .
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