Pushrod Length
Thread Starter
Drifting
Joined: Dec 2005
Posts: 1,309
Likes: 20
From: Woodstock Georgia
Pushrod Length
I know there's a thread here somewhere about L-98 factory pushrod lengths, but I just can't find it. I'm upgrading to a new set of Brodix IK200 cylinder heads, cam, and roller rockers, and wanted to make sure that I order the correct length hardened pushrods.
Thanks!
Thanks!
Safety Car
Joined: May 2006
Posts: 4,290
Likes: 140
From: Salem NH
Whenever you change the heads you HAVE TO MEASURE PUSHROD LENGTH AND CHECK GEOMETRY WITH A CHECKING PUSHROD.
There is no way the new heads will be machined EXACTLY to the same height as your stock heads, and stock pushrods won't work.
-- Joe
There is no way the new heads will be machined EXACTLY to the same height as your stock heads, and stock pushrods won't work.
-- Joe
Safety Car
Joined: Sep 2003
Posts: 3,599
Likes: 24
From: Orange County NY
St. Jude Donor '10-'11-'12-'13
Melting Slicks
Joined: Jan 2004
Posts: 2,659
Likes: 3
From: Oxford CT
I had to do that on my old mustang. I think its a push rod, and all you do is screw it to make it larger or smaller, then turn the engine over by hand to make sure you have exact top and bottom .
Drifting
Joined: Oct 2005
Posts: 1,259
Likes: 0
From: bakersfield cali
go to the compcams or crane ( i can't remember which) website, they have a detailed steb by step procedure to check the lenght of your pushrods. you will also need a push rod length checker, which is basically two pushrods that can be adjusted for length.
when i swaped over to my miniram and fast burn heads, the stock l98 pushrods were a little too long.
when i swaped over to my miniram and fast burn heads, the stock l98 pushrods were a little too long.
Thread Starter
Drifting
Joined: Dec 2005
Posts: 1,309
Likes: 20
From: Woodstock Georgia
Nothing's ever easy is it? 
AFR lists two part numbers for pushrods (I went instead with the 195 68cc angle L-98 street heads), the 6600's and the 6601's (+.100).
AFR lists two part numbers for pushrods (I went instead with the 195 68cc angle L-98 street heads), the 6600's and the 6601's (+.100).
Last edited by silver86; Mar 8, 2007 at 02:27 PM.
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Thread Starter
Drifting
Joined: Dec 2005
Posts: 1,309
Likes: 20
From: Woodstock Georgia
Actually...my stockers were 7.890. I'm guessing the difference between flat tappet and roller tappets are to blame in my 86E. The one's that I need to get are just over 7.520, I don't have calipers, so I'm running down to the speed shop today to make absolutely sure (I used a metric ruler and converted to inches...best I can see, I need 191 mm). But, it is a huge difference. I actually pulled a lifter from the old block and used it to take the measurement so the lifter wouldn't collapse when I rotated the engine.
Race Director
Joined: Feb 2004
Posts: 12,517
Likes: 19
Actually...my stockers were 7.890. I'm guessing the difference between flat tappet and roller tappets are to blame in my 86E. The one's that I need to get are just over 7.520, I don't have calipers, so I'm running down to the speed shop today to make absolutely sure (I used a metric ruler and converted to inches...best I can see, I need 191 mm). But, it is a huge difference. I actually pulled a lifter from the old block and used it to take the measurement so the lifter wouldn't collapse when I rotated the engine.
I am so used to the factory roller stuff that I spouted off that number.
Sorry about that.
Remember that when checking the length, you need to install a checker spring in place of the factory valve spring. This provides just enough pressure to work without collapsing the lifter.
Thread Starter
Drifting
Joined: Dec 2005
Posts: 1,309
Likes: 20
From: Woodstock Georgia
No problem Pete ...I wasn't posting to point out inaccuracies. Rather just to point out the importance of actually using a pushrod length checker. If it wasn't for you guys on here, I probably would've thrown the stockers back in and had some HUGE issues (I don't put engines together very often, as you can tell!).
I came up with using the lifter off the old engine since I had just run it, and thought the lifter wouldn't collapse if I rotated the engine. I had to pull the intake anyway, and it seemed like saving a step not having to remove the springs from the heads, install the lighter springs, the re-install the valve springs again. I had already taken the base measurement at zero lash, but wanted to make sure the geometry was good when it turned over.
Thanks again guys!
...I wasn't posting to point out inaccuracies. Rather just to point out the importance of actually using a pushrod length checker. If it wasn't for you guys on here, I probably would've thrown the stockers back in and had some HUGE issues (I don't put engines together very often, as you can tell!).I came up with using the lifter off the old engine since I had just run it, and thought the lifter wouldn't collapse if I rotated the engine. I had to pull the intake anyway, and it seemed like saving a step not having to remove the springs from the heads, install the lighter springs, the re-install the valve springs again. I had already taken the base measurement at zero lash, but wanted to make sure the geometry was good when it turned over.
Thanks again guys!
Last edited by silver86; Apr 3, 2007 at 09:36 AM.