i need push rod help

Topic: i need push rod help (Read 1058 times) previous topic - next topic

i need push rod help

February 26, 2006, 01:47:08 PM

whats up every one recently i turned my 68 casting engine to efi and roller setup but the 6.272 pushrods are to short i think it is because i am using 1.7 roller rockers, guides, and screw in studs. i took a measure ment and it says i need a push rods about 6.43 but i didnt have the head gasket on but i believe that my gasket is .045 thickness its a standard fel pro so correct me if i am wrong so if i add that to my length i would need 6.475 so would a 6.500 pushrod be safe thanks for all the help you guys

i need push rod help

Reply #1 – February 26, 2006, 03:49:08 PM

best bet would to get a adjustable one from summit and the mesure it once you get the proper geometry.

i need push rod help

Reply #2 – February 26, 2006, 05:09:55 PM

thats what i measured it with a trickflow adjustable and what geometry are you talking about think you can fill me in thanks

i need push rod help

Reply #3 – February 26, 2006, 05:14:06 PM

Quote from: Sprayingsmooth

thats what i measured it with a trickflow adjustable and what geometry are you talking about think you can fill me in thanks

relation of the rocker arm tip to the valve. Ill see if i can find you a write up.

i need push rod help

Reply #4 – February 26, 2006, 05:58:53 PM

Here you go maybe we can make this a sticky:D

How To Verify Proper Valve Train Geometry

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):

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

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

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.

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

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

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

i need push rod help

Reply #5 – February 26, 2006, 06:49:16 PM

May i ask what camshaft you are running?Not the specs,just whether or not it's a reduced base circle shaft or not.What lifters are you using?Stock 5.0 ho or after market.I don't know you or what your knowledge may be,but just checking to make sure you are running the correct setup.You do realize that to run a roller cam setup in the older engines,when using stock roller lifters that is,that you have to run the reduced base circle camshaft.Just checking,meant no offense.If so,thats probably one reason the ford racing pushrods are too short.

i need push rod help

Reply #6 – February 26, 2006, 10:51:05 PM

it is the e303 cam and i am using the ho lifters i taped the block for the spider hold down i have been educated on the reduced base circle and we agreed that the e303 cam didnt have enough lift to cause any real problems like raising out of the lifter bore to much popping the guides off but by all means educate me some more i am always looking to learn more about any thing and thanks for the geometry lesson i will check that tomarrow thanks every one

oh yeah not sure if this helps any but i did install the e303cam and roller lifters and stock stud mount rocker arms with the short push rods and it fit now that i put screw in studs guide plates and roller rockers the push rods are to short thanks again every one

i need push rod help

Reply #7 – February 27, 2006, 04:30:08 PM

The reduced base circle cam was used due to the oil hole for the lifter in the block.If you were to set a stock hydralic flat tappet lifter side by side with a stock roller lifter you will see why.Line the bottom of the wheel up with the bottom of the flat tappet and you will see that the oil groove(so to speak)doesn't line up.You will end up starying the lifters for oil.There are a few brand name companies that sell reduced base circle cams,problem is,they aren't exactly cheap.I'll do a little checking at summit and will edit this if i find something out for you.
Well,i found out that http://www.summitracing.com has some crane lifters pn crn-36532-16 that allow you to use the factory or after market type roller cams and you won't have to use the spider or doglegs to run them.Also do a search using "roller cam conversion".Found a few interesting links with advice and part numbers