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Discussion Starter · #1 ·
My brothers car has a set of TFS T/W heads on it. They are the pedestal mount type. When we first put them on(1995) we used the stock length pushrods.(6.272) We used ford motorsport 1.73 rocker arms with a B303 cam. The car ran fine and we had NO valve train problems.(40,000+ miles including weekly racing). We then changed cams to a stage one TFS cam, and that's where the problems start
The rocker arms started moving left or right and coming off the valve tip. We then found out that you have to use longer than stock pushrods.(at least 6.500 according to TFS) Ok, next problem... With any thing longer than 6.300 the valve begins to open as we tighten down the rocker arm bolt
Yes we have the lifter on the base of the cam lobe, we tried this several times on every cylinder
So what gives? any ideas? Do I need a special lifter to use with the adj. pushrod? Neither the heads or the block have been machined. I tried calling TFS, but their phone monkey gave me the run around(he had no idea!!!) Thanks guys!
 

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It sounds like they sold you a small base circle cam like the ones used for retrofit.

Your best bet is to get a kit for checking pushrod length and measure exactly what you need and then buy that.

Either that or return the cam and buy one that doesn't have a small base circle.
 

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Discussion Starter · #3 ·
The TFS cam is a standard base circle(part#51402000). I've tried several pushrod tools, every valve, different shims, bolts, pedestals, rocker arms etc... The strange thing is that the stock length(6.272) seems right.
The valve tip wear pattern is perfect. Everything looks good just the damn rocker arm keeps falling off the valve tip.
Oh yeah, I don't know if every rocker would fall off of every valve, because once the first one falls off, you know you have a problem right away. I suspect the additional lift of the new cam may be causing the problem.(540/552)for the new versus (519/519)for the old. That's with the 1.73 rockers. Thanks.
 

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You have found the defect in the early TW heads. The geometry is off if you go to a larger cam. You could try shimming up the pedestals but I doubt it will help. They will modify your heads for free to stud mount if you send them the heads. Try the shims first since it will be quick and easy. A 1.6 rocker may stay on the tip but then you lose lift. I had my heads converted to studs about two months ago.

JL

EDIT: After rereading your post I think proper shims may fix your problem. Go to the archives and read our article on Rocker Arm Ratios for the procedure.
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Jim Langley

Technical Editor

Fordmuscle.com

'65 Mustang GT, 289 (Warp 65)

'92 Mustang, 5.0 T5Z (Green Machine II)



<font size=-1>[ This Message was edited by: FasterDamnit! on 5/13/02 2:03am ]</font>
 
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