View Poll Results: What lenght pushrod are you running??
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Poll: What legnth pushrods are you running
01-25-2010, 08:04 PM
#22
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01-25-2010, 08:23 PM
#23
Based on the quick research I did last night, I thought .060 - .100 was the norm, and I would have said leave it alone. I did some more digging though and found a few points of interest:
I did also find a couple that said .040 to .060, but the overwhelming majority seems to be closer to .100" preload. If you are up for ordering another set of pushrods, it seems you should still safely fall within the acceptable range.
For the record, I assumed you wouldn't know the preload either, but I guess it was just the way you worded some of your posts.
Best of luck!
I run around .120 of pre load with very low valvetrain noise. I have hit the limiter at 7400 at least 6 time's with zero problems.
also have tried less but then the noise come's back. Not saying to run that much pre load but i do.
just put in a 243/251 .624/.624 lsl lobe'd cam in with the same preload and the valvetrain noise is still not as bad as a xer with a .090 preload
I think gm spec is from .080-.120 on the ls7 lifter's
also have tried less but then the noise come's back. Not saying to run that much pre load but i do.
just put in a 243/251 .624/.624 lsl lobe'd cam in with the same preload and the valvetrain noise is still not as bad as a xer with a .090 preload
I think gm spec is from .080-.120 on the ls7 lifter's
may be this will help
Gotcha This is from the link above from Katech on lifter preload:
1) The only way to properly check (and know where you are in the travel) is
to use a special checking lifter or completely compress a stock lifter.
a) Checking lifter consists of a lifter that has been disassembled
to install shims that lock the plunger at the top of travel in the lifter body.
If using this method you would add length to the checking pushrod to put the
final pushrods into the middle of travel of the plunger.
b) Using a stock lifter, you must make certain that you have pumped
all the oil out of the lifter. To do this leave it at valve full open (highest
spring load) for a while with an indicator on the pushrod side of the
rocker. Watch to see when the indicator stops moving (when the plunger is
fully compressed in the lifter body). Once you have compressed the lifter
rotate the engine to close the valve, extend your checking pushrod to full
length. Using this method you will subtract length from your checking
pushrod to put the final pushrods into the middle of travel of the plunger.
2) Typical plunger travel on Gen 3/4 lifters is 0.150 - 0.200 depending on
the manufacturer, year, etc. We recommend 0.075-0.100" from the bottom of travel (using method 'b' described above) or 0.075 from the top of travel (using method 'a' described above). That will generally put you close to the middle of travel. While there are many different strategies for where to put the plunger, for street use we strongly suggest that near the middle of travel is the safest for durability.
3) The more precise method of checking is 'a' because you are not guessing
that you got all the oil out.
Vinci recommends two full turns when using Crane adjustable rockers, which equates to approximately .084". This is what I am using
Gotcha This is from the link above from Katech on lifter preload:
1) The only way to properly check (and know where you are in the travel) is
to use a special checking lifter or completely compress a stock lifter.
a) Checking lifter consists of a lifter that has been disassembled
to install shims that lock the plunger at the top of travel in the lifter body.
If using this method you would add length to the checking pushrod to put the
final pushrods into the middle of travel of the plunger.
b) Using a stock lifter, you must make certain that you have pumped
all the oil out of the lifter. To do this leave it at valve full open (highest
spring load) for a while with an indicator on the pushrod side of the
rocker. Watch to see when the indicator stops moving (when the plunger is
fully compressed in the lifter body). Once you have compressed the lifter
rotate the engine to close the valve, extend your checking pushrod to full
length. Using this method you will subtract length from your checking
pushrod to put the final pushrods into the middle of travel of the plunger.
2) Typical plunger travel on Gen 3/4 lifters is 0.150 - 0.200 depending on
the manufacturer, year, etc. We recommend 0.075-0.100" from the bottom of travel (using method 'b' described above) or 0.075 from the top of travel (using method 'a' described above). That will generally put you close to the middle of travel. While there are many different strategies for where to put the plunger, for street use we strongly suggest that near the middle of travel is the safest for durability.
3) The more precise method of checking is 'a' because you are not guessing
that you got all the oil out.
Vinci recommends two full turns when using Crane adjustable rockers, which equates to approximately .084". This is what I am using
For the record, I assumed you wouldn't know the preload either, but I guess it was just the way you worded some of your posts.
Best of luck!
01-25-2010, 08:40 PM
#24
01-26-2010, 04:42 AM
#28
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my motor isnt finished yet, will be running 7.325 with .050 preload, so 7.375 with patriot 5.3 stage II's 59cc, howard cam .578/.587 226/232, ls7 lifters, harland sharp 1.7 na rockers, dual gold springs. btw if anybody has a similar setup or any opinions on any of the equipment im runnin give me some feedback! this is my first ls1 build. thanks
02-01-2010, 01:36 AM
#31
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Just came in from the garage measuring my pushrod lengths for my build.....came up with 7.325 with a factory MLS headgasket (believe they are close to .050 if I am wrong)+.075 preload (LS7 lifters) so that puts me at 7.4. I am going to run unmilled Lingefelter 243's with a TSP V3 cam (231/234 .648/.598). This is my first build, looks and sounds about what everyone else is close too in regards to length but figured some advice wouldnt hurt!
