Please help me verify my valvetrain geometry
Thread Starter
Launching!
Joined: Dec 2001
Posts: 231
Likes: 0
From: Wilmington, NC
Please help me verify my valvetrain geometry Once and for all, I'm trying to ascertain whether or not the #'s are off or where they need to be.
there are extra #'s, that make it harder, but I know some of you guys are smart enough to do this in your heads, which is why I'm looking to you--
I am as incompetant at math as I am to the art of applying lipstick...
Here's the scenario:
-----
(BC on cam unknown, but the cam is a Speed Demon Motorsports 226/.591/112, if that helps)
LS1 5.7 heads milled .040
Cometic .078 gaskets (vs .055 stock)
valves recessed .030
rockers shimmed .030
using 7.400 PR's
----
Is the PR length correct for these #'s?
How about estimated preload on the lifters?
Should I change anything to optimize geometry?
I have a friend who's saying that I'm losing a lot of power due to improper geometry, but I want to hear what you think!
I'm desperate to figure these #'s out the right way <img border="0" alt="[judgement]" title="" src="graemlins/gr_judge.gif" />
there are extra #'s, that make it harder, but I know some of you guys are smart enough to do this in your heads, which is why I'm looking to you--
I am as incompetant at math as I am to the art of applying lipstick...
Here's the scenario:
-----
(BC on cam unknown, but the cam is a Speed Demon Motorsports 226/.591/112, if that helps)
LS1 5.7 heads milled .040
Cometic .078 gaskets (vs .055 stock)
valves recessed .030
rockers shimmed .030
using 7.400 PR's
----
Is the PR length correct for these #'s?
How about estimated preload on the lifters?
Should I change anything to optimize geometry?
I have a friend who's saying that I'm losing a lot of power due to improper geometry, but I want to hear what you think!
I'm desperate to figure these #'s out the right way <img border="0" alt="[judgement]" title="" src="graemlins/gr_judge.gif" />
Re: Please help me verify my valvetrain geometry Well if your valve is closed roker arm should be centered (the tip of the roker) with the valve. what type of lifters are you using. and check your pre-load. comp r lifter i use go about 1/4-1/2 turn on 22lbs.
harry
harry
Thread Starter
Launching!
Joined: Dec 2001
Posts: 231
Likes: 0
From: Wilmington, NC
Re: Please help me verify my valvetrain geometry If I had the tools and ability to check preload myself, I wouldn't have to ask these questions <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" />
The lifters are stock, by the way, and the car does run fine--at least to the point that I'm sure all the valves are closing...(I've got 800 miles on this setup), but the valvetrain is very loud---sewing-machine-like. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
<small>[ August 27, 2002, 03:35 PM: Message edited by: MDL-01C5 ]</small>
The lifters are stock, by the way, and the car does run fine--at least to the point that I'm sure all the valves are closing...(I've got 800 miles on this setup), but the valvetrain is very loud---sewing-machine-like. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
<small>[ August 27, 2002, 03:35 PM: Message edited by: MDL-01C5 ]</small>
Re: Please help me verify my valvetrain geometry The only sure fire way to check this is to mark the tip of a valve with a black marker, bolt the rocker back down and rotate the engine over by hand a few times. The wear pattern should be centered on the valve tip.
Shane
Shane
Thread Starter
Launching!
Joined: Dec 2001
Posts: 231
Likes: 0
From: Wilmington, NC
Re: Please help me verify my valvetrain geometry OK thanks...--I'll give that a shot tomorrow...
What do you all think about the power-robbing aspect that my friend is claiming?
(BTW--it's not 2-3 HP he says I'm losing, but like 20+...from pushrods)
Is there any validity to that claim?
What do you all think about the power-robbing aspect that my friend is claiming?
(BTW--it's not 2-3 HP he says I'm losing, but like 20+...from pushrods)
Is there any validity to that claim?
