Champion ported Irons with 1:55 T&D Roller Rockers push rod clearance

[Toby_Goodmk]

I spoke to some knowledgeable people today about the champion irons having issues with push rod clearance. I have seen on the board with searches that most of the issues have been with the GN1 heads and the instructions included with T&D comment that 1:65 will need machining to make clearance in the push rod bore. My irons are relatively new within the past 6 months and the T&D are brand new. I am in the block machining stages so I would like to inform the machinist if this issue is going to come about.

SO.......what is the consensus? I have seen some have issues, many others have not had issues. Anyone out there with 1:55 T&D and Champion irons had any issues with push rod clearance?

 

[hensleyt]

TA 1.55 rockers on new champion .500 lift no problem

 

[Nick Micale]

To answer your question, your T&D 1.55 rockers are the same ratio as stock, and we have never seen a pushrod issue with these, or even the 1.65's.

The stock iron head, which Champion re-works, need the rocker pedestals on the heads to be clearanced to fit the T&D rockers properly.

There is no pushrod clearance issue on iron heads, but you will encounter this problem with GN1 alum heads when using stock rockers, as the larger valves have wider spacing which increases the distance between valves.

The TA heads have accounted for the wider valve spacing with the pushrod holes being placed to accommodate stock or roller rockers.

 

[Toby_Goodmk]

Perfect. Thanks for the clarification

 

[turbofabricator]

OK I have installed a lot of T&D rockers on 8445 iron stock heads. You MUST have a .100" shorter pushrod to achieve the correct rocker geometry. If you are using a flat tappet cam, just use stock small block Chevy lifter and you can use stock pushrods because the SBC lifter has a .100" shallower push rod cup. (All else being equal). If you are running a hydraulic roller cam ......just order everything from the vendor and it'll usually work.

 

[turbo96max]

Can I ask for some related feedback maybe you guys can help.. How did you decide or what is the determining factor of which rocker ratio to use? I too am going to use champion worked ported irons w pedestals already worked with a comp 210/215 and comp roller lifters. Im trying to figure out what ratio I need and pushrod length. Fullthrottle recommends 8.225" pushrods . The heads have the behive roller springs.

 

[bison]

I've never seen pushrod clearance issues in an iron head especially with a 5/16 pushrod. No cylinder head is exempt from pushrod clearance issues though. I've clearanced many myself and also had several sets of aluminum heads sleeves to be sure I could get a 3/8 pushrod in. Rocker to retainer/spring clearance is another problem that often occurs on springs with 1.550" and large o.d. It is absolutely critical for these to be checked and addressed before running the engine. Rocket arm alignment and geometry needs to be adjusted per head. This stuff is all up to the assembler. It is not the supplier or machinists fault if these items are found to be a problem. I've worked on countless engines with a shit house of valvetrain issues. Broken springs, inadequate sping pressures, running on the brink of bind or in bind, horrible geometry, poor roller centering, pushrods clobbering the pushrod holes, lash on hyd lifters, excessive preload, non shielded lifter in a non bushed block, blown out threads all over the rocker retention points, bolts to short, bolts too long, pushrods too short, pushrods too long, bad valve jobs, bent valves, drain holes blocked, rockers hitting valve covers, 2 different heads on the engine (yes different combustion chambers!) different thickness head gaskets on each side, different springs on each head, too much spring pressure, etc. theses are not "drop in" items. A little extra documentation and smarts will save days and days of aggravation.


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[fastblackracing]

I've never seen pushrod clearance issues in an iron head especially with a 5/16 pushrod. No cylinder head is exempt from pushrod clearance issues though. I've clearanced many myself and also had several sets of aluminum heads sleeves to be sure I could get a 3/8 pushrod in. Rocker to retainer/spring clearance is another problem that often occurs on springs with 1.550" and large o.d. It is absolutely critical for these to be checked and addressed before running the engine. Rocket arm alignment and geometry needs to be adjusted per head. This stuff is all up to the assembler. It is not the supplier or machinists fault if these items are found to be a problem. I've worked on countless engines with a shit house of valvetrain issues. Broken springs, inadequate sping pressures, running on the brink of bind or in bind, horrible geometry, poor roller centering, pushrods clobbering the pushrod holes, lash on hyd lifters, excessive preload, non shielded lifter in a non bushed block, blown out threads all over the rocker retention points, bolts to short, bolts too long, pushrods too short, pushrods too long, bad valve jobs, bent valves, drain holes blocked, rockers hitting valve covers, 2 different heads on the engine (yes different combustion chambers!) different thickness head gaskets on each side, different springs on each head, too much spring pressure, etc. theses are not "drop in" items. A little extra documentation and smarts will save days and days of aggravation.


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X 100 on this ^^^^^^^^^^^^^^^^^^^^^^^ Valve train set up is one area that a lot of novice builder/assemblers struggle with. I once saw a smallblock chevy that the fellow had used hardware store variety All-thread for head studs, I was dumbfounded, did not know what to say.

 

[earlbrown]

Odd. When I built my 4.1 (with 8445s , 5/16 pushrods and stock rockers) I had to put my heads on a mill and open up the push rod holes. They were NOWHERE near concentric with my pushrods. Two of them were damn near touching.

I marked the location left to right with layout die, pulled the heads, and put the holes where they belong.