EVO Ajustable Push Rod Question

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Oct 11, 2008 | 10:55 PM

deleontow

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From: San Jacinto CA

EVO Ajustable Push Rod Question

OK, I replaced the lifters, and found that the bike already had adjustable pushrods, I had a lifter start to go bad, roller was really loose. My question is how tight are the push rods supposed to be? The lifters I purchased are extremely noisey, I thought that I might have a bad lifter, but there brand new, and they were primed and sat in oil over night before they were installed. I am ready to remove them and inspect them, or replace them, but they are brand new. So before I go further, how tight or loose is the push rod supposed to be?

Oh yeh its a 98 Electra Gluide EFI]

Thanks
David

Oct 12, 2008 | 04:18 AM

pajoe

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From: Highspire Pa

It depends on the threads per inch of the particular push rod you are using,
I think you can multiply " .6 x the threads per inch " to get the number of flats you need to turn them, or if you know the brand name do a search for the installation manual they include with the product. I have Custom Chrome 59227 Revtec II Chromemoly pushrods they recommend to set at 4 full turns (24 flats), they have 36 threads per inch.

Big Boyz head porting has a good guide:

http://www.bigboyzheadporting.com/showthread.php?t=131
The easy way is to take the number of threads per inch and multiply by .6
For example ....
24tpi TIMES .6 EQUALS 14.4 flats
30tpi x .6 = 18 flats
32 x .6 = 19.2

Oct 12, 2008 | 09:42 AM

hotrod351

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From: Arizona

thats right. you need to find out what pushrods you have, i found out i have vthunder and they take 3&1/2 turns.

Oct 12, 2008 | 10:19 AM

t150vej

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From: NC USA

here's another one......

Last edited by t150vej; Jan 1, 2009 at 06:46 AM.

Oct 12, 2008 | 10:23 AM

t150vej

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From: NC USA

To answer your question, the lifters need to be compressed approx. half-way of their travel. Travel of big twin hydraulic lifters is typically .200

This is the reason for the formulas you've been given, to adjust the rods to .100

Oct 12, 2008 | 10:45 AM

deleontow

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From: San Jacinto CA

OK So if I understand you corrctly, I have to compress the lifter .100 so after the pushrod touches the lifter, compress it another .100 ?

Thanks all for the reponse.

David

Oct 12, 2008 | 11:06 AM

t150vej

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From: NC USA

Correct.
But keep in mind, the lifter has to be at the bottom of it's travel (in relation to the cam) It's the internal piston in the lifter that is to be compressed to half it's travel in adjusting.

Follow this link that PAJoe provided, and scroll down to the "how to adjust" section..
http://www.bigboyzheadporting.com/showthread.php?t=131

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Oct 12, 2008 | 06:44 PM

deleontow

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From: San Jacinto CA

Thanks to all who replied, I adjusted the pushrods and took the bike for a normal ride, the lifters stayed very quiet. I also learned something else that will be very helpful to others with this bike. I have always had a low oil presure issue, so after I installed the lifters, I removed the bypass spring and valve from the oil pump, cleanded and made a 1/8 shim for the spring. I installed the shim on the top part of the spring, at the time it made my cold presure go up, but once it was hot the same issue was present. Now after adjusting the pushrods the oil presure stayed much higher than ever. Running at 3000 rpms the oil presure stayed at 35 psi. Now it is colder than it was before, so I did shut off the oil cooler, but the presure was still there. I dont understand the relation between the improperly adjusted pushrods, to low oil preusre but there is something there. I am going to post this possible fix on another post.

Again thanks to all.

David DeLeon