Pushrod length ques.
Originally Posted by stang90gt50
Agreed...when you have guys recommending different ratio rockers and 7.6" pushrods to fix the problem, your recieving advise from the wrong people (no offense to you guys trying to help, but you should leave it to people with knowledgeable background and not what youve read on the internet)
Get a pushrod length checker, do it right. Most likely a 7.400" pushrod is going to work perfect, if the heads are milled alot sometimes a 7.35" will be right. Only way to know is check with pushrod length checker.
Get a pushrod length checker, do it right. Most likely a 7.400" pushrod is going to work perfect, if the heads are milled alot sometimes a 7.35" will be right. Only way to know is check with pushrod length checker.
Thanks
Ron H.
Originally Posted by NoMoreFWD
I have just set up a couple motors in the last couple weeks that use stud mounted rockers. Raising or lowering the rocker arm pivot point is the only way to change the valve tip contact.
According to an article in the Aug. issue of Circle Track by Keith Dorton, rockers without roller tips can cover some error. This would be in your favor.
A couple questions.
Did you turn the motor over a couple times and are you getting a clean line on top of the valve? Maybe post a pic?
Are there any shims under the rocker pedestals? I assume there isn't, but moving the rockers down will solve your problems.
How much lift does the cam have?
As far as the lifter preload, I agree with MSURacing's post. I would lean toward .070" of preload. The dyno comparisons that I have seen make more power with less preload.
According to an article in the Aug. issue of Circle Track by Keith Dorton, rockers without roller tips can cover some error. This would be in your favor.
A couple questions.
Did you turn the motor over a couple times and are you getting a clean line on top of the valve? Maybe post a pic?
Are there any shims under the rocker pedestals? I assume there isn't, but moving the rockers down will solve your problems.
How much lift does the cam have?
As far as the lifter preload, I agree with MSURacing's post. I would lean toward .070" of preload. The dyno comparisons that I have seen make more power with less preload.
I think i may measure how much preload is on the lifter with the stock pushrods, maybe if its too much and I try shorter pushrods to correct it it will also move the contact patch farther in. I'll check that within a day or so when I get time.Thanks
Ron H.
Originally Posted by Mrbowtie26
There are no shims under the rocker arm pedestals, I tried using the stock pushrods with the stock rocker arms as I heard aftermarket rockers can sometimes be too heavy etc and poss. cause problems. I wish I had shims under my rocker pedestals that I could remove to lower the rocker and shorten the pushrods to move the contact point closer to intake side but I dont I think i may measure how much preload is on the lifter with the stock pushrods, maybe if its too much and I try shorter pushrods to correct it it will also move the contact patch farther in. I'll check that within a day or so when I get time.
Thanks
Ron H.
I think i may measure how much preload is on the lifter with the stock pushrods, maybe if its too much and I try shorter pushrods to correct it it will also move the contact patch farther in. I'll check that within a day or so when I get time.Thanks
Ron H.
I am not following what you are taling about here? Are you refering to stock rockers or aftermarket? There is no adjustment on the stock ones umless you were to cut all the stancions apart from each other and adjust them individually by millilng them down and then fine tuning with shims.
Originally Posted by MSURacing
I am not following what you are taling about here? Are you refering to stock rockers or aftermarket? There is no adjustment on the stock ones umless you were to cut all the stancions apart from each other and adjust them individually by millilng them down and then fine tuning with shims.
11 Second Club
Joined: May 2007
Posts: 226
Likes: 1
From: Sydney
Originally Posted by NoMoreFWD
I was reading an engine build by W2W. They stated that stock preload was about 1.5 turns on the 8mm pedestal bolts and reccomend a little over 1/2 turn preload hot. Most of the time they use 7.325" pushrods and said this eliminates the low rpm thrashing noises. I'm sure you'll get it worked out. Keep us posted.
cheers.
c
