Push Rod Length?

[CamaroZGuy]

just went out and did some measuring, first tested with a stock push rod and the mark was a bit high on the valve then tested at a 7.250 and got this.

http://i907.photobucket.com/albums/ac278/A_Roubal/Car%20Build/2013-02-08_22-17-24_336.jpg

dose the 7.250 look like the proper length?

[Bersaglieri]

Looks almost like it has two patterns on it, is the old one towards the top?

Did you do a full sweep? Is this rocker in the middle or on either end of the head? Did the plunger in the lifter depress at all as you turned over the motor or did you mock it up as a solid lifter?

Which aftermarket heads are those, AFR?

Ok enough questions, if you checked all those things I'd say that middle line looks pretty much spot on.

[CamaroZGuy]

re colored the lifter after each test, and did 2 full turns of the crank (1 turn of the cam), set the rockers at 0 last then 1/2 turn preload, they are AFR 210's with a spring recommended by LE (not sure the make, bu i think a Lunati).

but i set my calipers at a 7.250 (cause i saw that Call911 was selling a set) and tested, as far as the stock size i could have probable gotten away wiht but the 7.250 looks better.

[chile]

it looks good. According to comp cam you want the pattern close to the center but leaning on the inside of the valve.

http://www.youtube.com/watch?v=Cqx8Cs6O6Vo

[CamaroZGuy]

it looks good. According to comp cam you want the pattern close to the center but leaning on the inside of the valve.

http://www.youtube.com/watch?v=Cqx8Cs6O6Vo

that is the method i used.

[Fastbird]

I think that looks good.

[96LT1355Z28]

Good video, here's what was sent to me by Lloyd Elliott years ago with pictures of how the pattern should look:

The following is a method of verifying proper valve train geometry. After you have estimated the required pushrod length using a Pushrod Length Checker, use this method to verify that the valve train geometry is correct (using the rockers you are using in your engine):

15514

1
The first step is to install a solid lifter and an adjustable pushrod. Mark the tip of the valve with a marker


15515
2
Install your rocker arm and set it up with zero lash.

15516

3
Rotate the crankshaft clockwise several times. Remove the rocker arm. The contact pattern of the rocker tip will be where the marker has been wiped away from the valve tip. The pattern should be centered on the valve tip, and as narrow as possible. If it is not, experiment with varying the pushrod length to yield the best pattern.

15517

4
Pushrod Too Long: Notice how the pattern is wide, and shifted to the exhaust side of the valve tip.

15518

5
Pushrod Too Short: Notice how the pattern is wide, and shifted to the intake side of the valve tip.

15519

6
Pushrod Length Correct: Notice how the pattern is narrow and is centered on the valve tip.

[CamaroZGuy]

Good video, here's what was sent to me by Lloyd Elliott a years ago with pictures of how the pattern should look:

The following is a method of verifying proper valve train geometry. After you have estimated the required pushrod length using a Pushrod Length Checker, use this method to verify that the valve train geometry is correct (using the rockers you are using in your engine):

http://us-mg6.mail.yahoo.com/ya/download?mid=2_0_0_45_5083_AEp5%2fNgAAJNwT0LTSAdAO WU0ym0&pid=2.2&fid=Saved&inline=1&appid=YahooMailNeo

1
The first step is to install a solid lifter and an adjustable pushrod. Mark the tip of the valve with a marker

http://us-mg6.mail.yahoo.com/ya/download?mid=2_0_0_45_5083_AEp5%2fNgAAJNwT0LTSAdAO WU0ym0&pid=2.3&fid=Saved&inline=1&appid=YahooMailNeo

2
Install your rocker arm and set it up with zero lash.

http://us-mg6.mail.yahoo.com/ya/download?mid=2_0_0_45_5083_AEp5%2fNgAAJNwT0LTSAdAO WU0ym0&pid=2.4&fid=Saved&inline=1&appid=YahooMailNeo

3
Rotate the crankshaft clockwise several times. Remove the rocker arm. The contact pattern of the rocker tip will be where the marker has been wiped away from the valve tip. The pattern should be centered on the valve tip, and as narrow as possible. If it is not, experiment with varying the pushrod length to yield the best pattern.

http://us-mg6.mail.yahoo.com/ya/download?mid=2_0_0_45_5083_AEp5%2fNgAAJNwT0LTSAdAO WU0ym0&pid=2.5&fid=Saved&inline=1&appid=YahooMailNeo

4
Pushrod Too Long: Notice how the pattern is wide, and shifted to the exhaust side of the valve tip.

http://us-mg6.mail.yahoo.com/ya/download?mid=2_0_0_45_5083_AEp5%2fNgAAJNwT0LTSAdAO WU0ym0&pid=2.6&fid=Saved&inline=1&appid=YahooMailNeo

5
Pushrod Too Short: Notice how the pattern is wide, and shifted to the intake side of the valve tip.

http://us-mg6.mail.yahoo.com/ya/download?mid=2_0_0_45_5083_AEp5%2fNgAAJNwT0LTSAdAO WU0ym0&pid=2.7&fid=Saved&inline=1&appid=YahooMailNeo

6
Pushrod Length Correct: Notice how the pattern is narrow and is centered on the valve tip.

pics are broken...but good info!

[96LT1355Z28]

Pics work for me can anyone else see them?

[CamaroZGuy]

Pics work for me can anyone else see them?

i just checked with IE, Fire Fox and Chrome and pics dont work. :(
15512

[96LT1355Z28]

Hummm, I'm using IE at work and they're showing up even when you quoted me! I see the screen shot where they're broken though. I'll see what I can figure out cause the post isn't that helpfull without the pics!

**EDIT** added as attachments, workin now??

[CALL911]

...but i set my calipers at a 7.250 (cause i saw that Call911 was selling a set) and tested, the stock size i could probable gotten away wiht but the 7.250 looks better.

I had a "very close" but not right size in my car shortly after the motor was rebuilt and the blower installed. Drove it a few hundred miles and the pushrods broke off one of my rocker studs which punctured a valve cover. To make matters worse, this all happened 250 miles into a 600 mile road trip. Thanks to a novel idea by Fastbird, I was able to limp the car the rest of the way home safely, where I had to buy new pushrods, rockers, rocker studs, and a new valve cover.

I don't think the difference was much between the pushrods. But I tell you this so you know that even if they are off by that little bit, things can go wrong.

From the looks of things it seems you have the appropriate length. But I disagree that you would have gotten away with using the stock length pushrods.

[CamaroZGuy]

I had a "very close" but not right size in my car shortly after the motor was rebuilt and the blower installed. Drove it a few hundred miles and the pushrods broke off one of my rocker studs which punctured a valve cover. To make matters worse, this all happened 250 miles into a 600 mile road trip. Thanks to a novel idea by Fastbird, I was able to limp the car the rest of the way home safely, where I had to buy new pushrods, rockers, rocker studs, and a new valve cover.

I don't think the difference was much between the pushrods. But I tell you this so you know that even if they are off by that little bit, things can go wrong.

From the looks of things it seems you have the appropriate length. But I disagree that you would have gotten away with using the stock length pushrods.

im just happy that luck hit at the right time and you where selling the size i needed.

and i am not leaving any thing with this engine to chance, i have WAY too much time and money invested to skimp out on something and have it fail. some mite say that my engine is "over built"

[CamaroZGuy]

Hummm, I'm using IE at work and they're showing up even when you quoted me! I see the screen shot where they're broken though. I'll see what I can figure out cause the post isn't that helpfull without the pics!

**EDIT** added as attachments, workin now??

yes, they are working now! thank you.

[CALL911]

im just happy that luck hit at the right time and you where selling the size i needed.

and i am not leaving any thing with this engine to chance, i have WAY too much time and money invested to skimp out on something and have it fail. some mite say that my engine is "over built"

From my experience there is no such thing as being "over built" for an FI application. There is sim

[CALL911]

im just happy that luck hit at the right time and you where selling the size i needed.

and i am not leaving any thing with this engine to chance, i have WAY too much time and money invested to skimp out on something and have it fail. some mite say that my engine is "over built"

From my experience there is no such thing as being "over built" for an FI application. There is simply those who setups are built to handle boost properly, and those who aren't.

I probably don't need quite the low CR I have or the very high dollar internals, but I built things to last and to handle more than what I would throw at it.