When I received my TF heads the guide plates were already installed. It is now several years and about 2,000 miles later. I find that one pushrod has a large gouge in it, so I assume that guide plate is out of adjustment. The other 15 pushrods are ok. I am using CC roller tip rockers and I can see the marks from the rollers across the valve tips. What baffles me is, some valves have a pattern going from top to bottom (intake to exhaust) while others have a pattern going sideways (front to back).

Which way should the pattern be? How do you adjust the guide plates for any problems you find? I have looked everywhere I can, and can find no detailed step by step description on how to adjust them.

Thanks,

 

Your rocker arm should only travel about 1/3 of the way across the valve stem or your pushrod lengths are WRONG! The were pattern sould be parallel to the roller tip if, you are seeing wear patterns inother directions, it is a sure sign of valve float from weak valve springs (catastrophy is just around the corner.) The TFS "twisted wedge" cylinder heads have major issues with their valve traing alignment and guide plates and we once spent the better part of 2 days "adjusting" guide plates on these heads. Adjusting the guideplates entailed cutting some apart and Heli-Arc welding them into proper position for proper alignment. The "twisted wdege" heads are great flowing but, the other problems with them caust them to not be on our list of "prefered" cylinder heads.

 

Since Chevy started using self aligning rockers u need to b careful of what p-rods are used with what guide plates. But lets start with most aftermarket guide plates need at least hardend if not chromoly p-rods to prevent excessive wear. Of course there are exceptions like the cast in head stock guide slots or the later self-aligning rocker heads that don't have hard guide-plates but normal/soft plates and can use an unhardend p-rod.
Guide plates do just that in guiding the p-rod correctly onto vlv tip. Not rocket sience but u want a tight fit and travel across middle of vlv tip without dragging on plates. I just use an old p-rod and work it side to side in new g-plate until i get what i want - or a rod 1/32" larger than vlv stem will do it. And there is some slop/tolerance in g-plate mounting holes u can use to help line things up.
Now for vlv tip travel it needs to be in the range between the top 1/3 of vlv tip to the bottom 1/3 of vlv tip to prevent side loading on vlv stem and rapid vlv guide wear and close is good enough - u just don't want the rocker tip at the edge of vlv stem. I used both the Moroso and the ProForm p-rod length checker (<$10 each from Summit) to select proper p-rod length for correct rocker tip travel. Easy to use the checker tool - just follow directions. Bought my corrected length p-rods from Summit too for < $100 (Trick Flow).
Yea, better check ur p-rods for smooth movement and upgrade to hardend/chromoly the correct length.
Hope this helps - sorry but hard to explain those side to side marks on vlv tip without being there. cardo0

 

I bought a pushrod length checker and it came with no instructions. Anyway you could explain it to me?


Thanks

 

The pushrods are heat treated Comp Cam. Only had the gouge all the way around, on one of them. The others were fine.

BTW, the heads are TF 23* not Twisted Wedge.

Solid LT1 - The heads and springs have about 2,000 miles on them.

Thanks,

 

For starters, the 23° TF heads require a custom-length pushrod. Is that what you have? (And in fact, TF doesn't provide a recommended length for the CC roller tips. Weird.)

Anyhow...you need to get the pushrod length confirmed. And perhaps change over to self-aligning rockers.

I hate to say it, but this is one of the reasons I passed on the TF heads and went for the cheapie Dart IE's instead...

 

Running stock length 7.800. Yes I have to check length since the block was decked 0.025 at least. I assume I'll need shorter pushrods by at least 0.025 because of the block decking or isn't it a straight relationship?

 

When I contacted TF about pushrod length for use with CC rollers -- without any decking -- they told me I'd have to do the pushrod length check. They didn't even know!

Bottom line: Ya gotta do the check using a pushrod length checker