Need tips on T&D RR install.

[Sybil TF]

Ok, I have a brand new set of T&D RR's just begging to be installed soooooo, any one care to tell me how to do this so I can be sure to supervise my man slave in the right direction? Going on my 96GTS.

[slitherv10]

Are you putting them on stock heads or did you port and polish those?

Did you have any idea as to what it will add in terms of performance...HP, TQ,,response,,,etc..would be interested as I have been thinking of building the motor in my 96 slowly as well

[Sybil TF]

Stock heads.Have M&M headers, hi-flow cats and Borla cat back. Just doing bolt on stuff right now. I see a SC in my future though.

[Sybil TF]

Well, hell I am the only one on here that will do self install. Sweet.

[Fatboy 18]

Sorry I can't offer any advice, but I would also like to see an install guide, I have often thought about this mod for my car :)

[ViperTony]

I've done it. Gathering some pics and details to post here soon. Hopefully tomorrow.

[99RT10]

I've done it. Gathering some pics and details to post here soon. Hopefully tomorrow.


That would be great to put in the "How to" section. Thanks Tony!

[Sybil TF]

I've done it. Gathering some pics and details to post here soon. Hopefully tomorrow.

Thank you!!

[ViperTony]

You're going to need an adjustable push rod length checker to measure for new push rods. I have an adjustable TD push rod length checker you can use. PM your address and I'll drop it in the mail. Or you can just get one for about $20. It's a good idea to measure for new push rods. Cheap insurance. I'll post some information this afternoon.

[Sybil TF]

You're going to need an adjustable push rod length checker to measure for new push rods. I have an adjustable TD push rod length checker you can use. PM your address and I'll drop it in the mail. Or you can just get one for about $20. It's a good idea to measure for new push rods. Cheap insurance. I'll post some information this afternoon.
Got one, thanks tho.

[345s-bspinnin]

I did a T&D lifter install after I got my heads ported (Gen III). Good advise on the pushrod length checker, but you need to make sure that you have the right preload on the lifter. It is important for proper lashing and torquing down the rockers.

This thread has good info: http://ls1tech.com/forums/generation-iii-internal-engine/1207770-lifter-preload.html

[slitherv10]

What will adding the TT rockers do as far as performance etc.

[Sybil TF]

What will adding the TT rockers do as far as performance etc. About 10-15 hp so I am told.

Some claim 20hp. That's about it. Only $1,500 for 20hp, sweet lol.

[slitherv10]

About 10-15 hp so I am told.

Some claim 20hp. That's about it. Only $1,500 for 20hp, sweet lol.

Will it make the exhaust note any different?

[Sybil TF]

Will it make the exhaust note any different? I'll let you know when mine are on but mine is kinda loud so probably won't be able to tell a difference. I can't see how a little more lift and and a little less friction could cause more exhaust noise.

[Fatboy 18]

This is a good read :)

http://www.viperacr.com/tuners/reference.html?submit=submit

[345s-bspinnin]

What will adding the TT rockers do as far as performance etc.

Basically zero if the ratio is the same no stock engine. However, a jump in ratio means a multiplicative effect in cam lift, and thus the mentioned gains ranging in 15-20 hp on fully OEM setup. However, the real benefits come to those with built engine who chose to spin their engines higher. The shaft mounted rockers allow for better valve train stability. Furthermore, these are adjustable, and thus allow better lashing. Although the lashing is not as critical on a hydraulic lifter, it becomes a necessity when moving over to solid roller cams. In that latter, these are a necessity for spinning the engine sky high.

[ViperTony]

What will adding the TT rockers do as far as performance etc.

Actually, on a stock engine they help add a little bit of horsepower and a more stable valve train. They increase lift. I've been told 10-15rwhp. I never dyno'd a before/after with the rockers as this was more of a long-term series of related modifications for me. But the rockers compliment other modifications such as the heads/cam mods you're considering. I add my rockers after I did headers and exhaust to help the engine breath better. When I added my GG heads and cam the rockers were a must as the stockers couldn't handle the new spring pressures. The increase lift provided by the 1.7 ratio complimented the package as well.

In and of themselves I don't believe Rockers are worth the money for pure power increase. Combined with other modifications then yes they're worth it and needed especially in case where higher spring pressures would obliterate the stock rockers. Not good.

I purchased my T&D new old stock for $700. They were never used, still mounted in their original packaging. So in my case, it was a bargain.

[Troublemaker]

I always thought there real benefit was reduced friction in a motor, which in turn adds to faster revving and slightly freed up horsepower. Going to a 1.7 adds another benefit mentioned above.

[ViperTony]

So, installing the T&D rockers requires paying attention to a few things namely: proper geometry, valve lash, proper pushrod length, pre-load. It's not as complicated as it may sound.

I assume you know how to remove the valve covers so I won't go there. :D Once you have the valve covers removed you can disassemble the stock rockers:

3091

You may find some graffiti in your heads. After trying to figure out what the inscriptions meant I came to the conclusion that they read: "Yellow vipers are faster".

3092

Next you'll want to remove the pushrods by simply pulling them up and out. Be careful not to drop them into the engine, it's possible, don't ask me how I know this.

One you've removed the stock valve train you're ready to install the T&D rocker stand. The rocker stand has "V10" stamped on one side. You want the "V10" facing towards you when you bolt down the rocker stand to the head. Don't install all of the stand bolts yet as you need to check for rocker geometry first. So I installed the stand with a couple of bolts first:

3093

The above image show the stand installed. It also shows a T&D rocker assembly disassembled. T&D instructions discuss how to check for rocker geometry using the stand height gauge that comes with the kit. It's the small L-shaped aluminum piece in the bag with the washers (shims). There are two ways to check for rocker geometry, The T&D is the more cumbersome of the two approaches. Essentially, you disassemble one of the rockers and mount the pedestal portion over one of the valves as show above. You then need to remove the spring from the valve you're working on with a spring compressor tool, hold up the valve so it doesn't drop into the cylinder, etc. I didn't do that. Instead, I modified the stand height gauge so that it would fit over the pedestal and valve tip without interfering with the spring:

3095

Using the modified stand height gauge, holding it perpendicular to the pedestal and valve stem will indicate if the geometry is off or not. The T&D kit comes with various-sized washers use to raise the rocker stand, if needed, to achieve proper geometry such as when the rocker stand is too low. In some case, the rocker stand is too high and may require milling the stand bosses on the cylinder. In most cases, milling the stand bosses on the head is not required on stock heads.

[ViperTony]

FYI, this is a good read on what checking the rocker geometry is all about: http://www.pontiacpower.com/faqs4.htm

The easier way to check for rocker geometry involves using tape and a sharpie. I learned this from Greg Good and it's reliable and easier to perform. I'm comfortable doing this procedure now because I've done it so many times. But the procedure requires that you have either the correct length push rod or an adjustable push rod checker set to the correct length and the rocker torqued down with appropriate lash. Essentially, you take a sharpie and mark up the rocker roller tip. Place a piece of tape (optional) on top of the valve stem. Rotate the engine until the rocker goes threw two iterations of movement. This will leave behind a line on the tape/top of valve stem indicating the sweep of the rocker:

3098

In the pic above I didn't use tape on the tip of the stem but the line is clear. If you look at the picture above, the second valve has a mark left behind from this procedure. If the sweep is too wide, or the mark is too high up or too low on the valve stem the geometry is off. It should leave behind a very narrow line a hair before the center of the valve stem. I also used an adjustable pushrod length check set to the proper length with zero lash (more on this later). However, there's yet another simpler way to do this and I borrowed Ellow Vipers pics from 6 years ago here:

Without a push rod, take the tape across the valve stem. Lift up the rocker with your hands and slap it down on the valve/tape. You mark up the rocker roller with a sharpie when doing this too:
3099

Let the rocker fall a few times on the valve to make mark in the tape:
3100

Remove the rocker and look for the indentation on the tape. If you marked the roller with a sharpie you should see a line on the tape. If not then take a pencil or marker and trace the indentation in the tape:

31013102

If the geometry is off then you can use the shims provided in the kit to raise the rocker stand to correct it. Check the geometry again to verify it's correct. At this point, you can check for pushrod length using an adjustable push rod length checker. More to follow....

[ViperTony]

For reference, here are the T&D Rocker Installation Instructions:

3103310431053106

[ViperTony]

Placeholder post for pushrod length check, lash and pre-load.....

You'll need to rotate the engine or camshaft when doing this installation. There are a few ways to do this. One is to rotate the engine manually using the bolt on the harmonic balancer. Another method is to use a bump-start switch connected to the starter just under the driver's side exhaust manifold. I think I picked up a bump start from Autozone for a few dollars. Inexpensive and easy to use.

It helps to have all of the spark plugs removed when doing this. Gear is in neutral. Key in the off position.

You'll need to find top dead center or TDC. I found a useful tool for this. It screws into the spark plug hole of the cylinder you're working on. It's not a piston stop. I can't remember where I purchased this from...

3107

Basically, you screw this into the spark plug hole of the cylinder you're working on, rotate the crank until the plunger tops out on the tool to find TDC. A straw or screwdriver also works for this purpose. Finding TDC is one way to check for pushrod length but there's another method as well. We'll discuss this later.

When I did my rockers I never took pictures of these steps so I apologize for the lack of visuals here. If someone has pictures of these procedures please post them. Hopefully this thread will be useful for folks who decided to install T&Ds.

I started with Cylinder #1 in checking for pushrod length. I rotated the crank until Cylinder #1 was at TDC. You don't have to check every cylinder. I checked three for good measure. Starting with Cylinder #1 I installed my push rod length checker for the intake valve and a rocker arm assembly then I installed a rocker assembly on it. Make certain the checker is seated into the cup of the lifter. T&D instructions state to check for pushrod length with the Rocker Adjustment Screw turned down 1 full turn from the full screw out position. So (from full out) turn the rocker adjuster screw down/in one full turn. This is the initial adjuster position.

For reference:
3108

Next you want to adjust your push rod length check to get to zero lash. Using your fingers screw the push rod length checker until it begins to touch/seat against the cup of the rocker arm. Work it slowly using your fingers to twist the push rod and feel for when the push rod is touching the cup. You don't want to put pressure on the rocker or on the lifter. You simply want to take up the slack between the push rod and the rocker. If you've put load on the lifter you've gone too far. If you're turning the adjuster and its causing the rocker to move down on the valve you've gone way too far. Back it out and do it again. I used my fingers to turn the push rod adjuster until there was no slack between the top of the push rod and rocker cup. I also wasn't able to spin the push rod with my fingers at zero lash. I also felt zero lash by rattling the rocker, adjusting the push rod until the rattle was gone.

Once you've achieved zero lash remove the push rod length checker (without turning the push rod adjuster and losing all that work you just did) to get your push rod length. The tip here is that with T&D you need to measure the push rod with the rocker adjuster screw turned in 1 full turn from the full out position and with the push rod adjuster turned to zero lash. Check a few cylinders to be certain though many tell me this is not necessary I did anyway.

I don't remember what my push rods measured out to be. I'm going to say 7.5". The T&D instructions further states to add another .050" to the final measurement to preload the lifter. So I think mine were 7.55". You have choices for push rods. I went with beefier push roads recommended by Dan Lesser. He ordered my Trend Double-Tapered 3/8" push rods. When I saw these new push rods I realized how wimpy the stockers were.

I used the "Finding TDC" process for finding the base circle of the cam. There's another method recommended by many engine builders and Greg Good educated me on this one. I've used it when I did my heads and cam:

- Adjust the Intake Rocker when the Exhaust Valve For That Cylinder Begins To Open.
- Adjust the Exhaust Rocker when the Intake Valve For That Cylinder Starts to Close.

Do this by watching the valves move on the cylinder you're working on. I'll leave it up to the experts to determine which method works best. :D

More to come...

[ViperTony]

So you've measured for your push rods and are ready to install them. Using either the TDC procedure or Exhaust/Intake opening procedure to get to the base circle of the cylinder you're working on begin installing the push rods. I started with Cylinder #1. Install the push rods into the cup of the lifter (make certain it's resting in the lifter cup and not the top of the lifter). Install the rocker assembly and torque the shaft hold down nuts to 25 ft lbs. Run the rocker adjuster screw all the way UP till it bottoms out. Now start turning it back down until it just touches the push rod. You want to take up all play (same as you did when you measured for push rod length) but you don't want it putting pressure on the push rod. It is better to have a few thousands play than to have it pressing on the push rod.

If your push rods are the correct length your new push rod will touch the rocker cup with the rocker adjustment screw turned in 1 full turn from the full "Out" position. Due to variations in the valve train geometry the amount of turn may vary from one full turn. If all of them vary dramatically, then the push rods are the wrong lengths. I would worry if the adjuster hits the push rods at less than 1/2 turn or greater than 1-1/2 turn. Done properly, you'll need no more than two full turns of the rocker adjustment screw from the full out position.

Once you find the position where the adjuster just touches the push rod you adjust it down one full turn and that is it. Tighten the adjuster screw jam nut 20 ft lbs. Wash, rinse and repeat for each of the cylinders.

[ViperTony]

Thanks to JackB several years ago he found a way to speed up the adjustment of the rockers. I hope he doesn't mind me sharing this here but here it is:

"I just had some head work done and before I adjusted the rockers I looked at making the process a bit easier. I have adjusted rockers multiple times and it has never been easy. Everyone has had to come back more than one time to get it right. The key is to manually rotate the engine by hand, via the harmonic balancer bolt head. Using the following sequence you only have to rotate the crank two revolutions. This method also assures that the lifters are on the base circle. Taking my time it took me 30 minutes to adjust the rockers, plus, I did not have to come back and adjust them a second time. There is also no need to warm the engine.

One of the keys to proper geometry is the correct pushrod length. With the T&D's you must measure/size the pushrod with the rocker adjusting nut one turn down. You then turn/preload the adjuster down one further turn, that is ideal. Each full turn of the adjuster equals .050"."

3110

[ViperTony]

It's possible that the T&D Rockers may hit the oil baffle inside the valve covers. This is not always the case but it happened on my installation. I put the valve covers back on, started up the Viper and I could hear/feel the rockers hitting the oil baffle. When I removed the valve covers I saw the little marks left behind in the baffle from the rockers. So you may need to adjust the baffles is this is the case. There are a number of ways to do this. Some have take a ball peen hammer to the baffle and hammered in the clearance. I call this the brute force method. Others have simply removed the oil baffles but this cause more oil to make it's way to the PCV system. I made the mistake of purchasing "Oil Baffles" from a vendor (not on here) which turned out to be nothing more than two flimsy pieces of aluminum large enough to shield the front of the valve cover PCV openings. A waste of money. Others used tin snips to cut slits into the baffles directly over the rockers.

I wanted to do something more OEM-like and simply modified my baffle by raising the 1/4" gaining enough clearance over the rockers. So I took my valve covers and removed the baffle:

3111

I removed the screws securing the baffle to the valve cover. My gasket material is copper in color because I did this mod before I took this picture. I believe the OEM gasket material is black in nature. Once you remove the baffle you'll need to clean off the gasket residue.

With the baffle removed, I was able to get to the vc stands holding up the baffle. I simply took my RotoZip and shave off about 1/4" from each one. Washed and cleaned them.

3112

This pic shows the screw stands shaved down about 1/4". I then re-installed the oil baffle (I used LocTite on the baffle screws) and applied a new bead of gasket. I used RTV Copper as that's what I had available. Re-installed the valve covers and problem solved.

[ViperTony]

I hope this information helps. It was a culmination of my experience, experiences of fellow Viper owners and great advice from folks like JackB, Greg Good, Dan Lesser, Tator and many others. It's not THE definitive guide but hopefully with some team effort we can turn this into a quality how to here. I never got around to writing one up. I have so many half-finished how to's and not enough time to do them proper justice.

[Sybil TF]

Very nice write up! I'll pass it on to my man slave.

[slitherv10]

Just curious but, what would a shop charge to install these?

Not saying that is an option as I realize some of us like to get our hands dirty and enjoy DIY jobs.

[Sybil TF]

Just curious but, what would a shop charge to install these?

Not saying that is an option as I realize some of us like to get our hands dirty and enjoy DIY jobs. I read someone paid a $1,000 somewhere.

[slitherv10]

I read someone paid a $1,000 somewhere.

1000?!! Wow, why does that seam like too much..or is it..not sure to be honest. To put together a built motor it is around 2500-3500. That includes putting the rockers in. So for 1000 just for the rockers would seem too much in my opinion anyways.
Don't know really though as I have not done any work on my engine yet to compare. That is why I am asking.

[Sybil TF]

Viper Tony, A little recap, just follow your instructions and go in the firing order? And did you turn the engine over with one of those push button start switches that clips on the starter or did you turn it over by hand with a socket wrench?

[ViperTony]

Viper Tony, A little recap, just follow your instructions and go in the firing order? And did you turn the engine over with one of those push button start switches that clips on the starter or did you turn it over by hand with a socket wrench?

I just worked my way through each cylinder. I started with the driver's side then went over to the passenger side. I did one cylinder/valve at a time.

I rotated the crank by wrench/socket using the harmonic balancer bolt. This allowed me to get the precise opening/closing of the valves. I think the bump start works well if you're using the TDC method. I did the TDC at the beginning but after my build I've used the valve opening/closing procedure ever since. When several reputable and credible folks like Greg tells you this is the best way...I listen. The bump start, for me, was a PITA to get to the proper opening/closing of the valves. Easier for TDC using the straw or tool I posted. You can do a combination of both.....bump the engine over until you get close to TDC or when the valve you're working on is in motion and then use turn over the crank by hand to get it to where you want it.

This is one of those things whereby if you're new at it you need to go through the learning process to understand it. Do it by hand then do it by bump start. Do it by TDC then do it via the valve opening/closing procedure. Become one with your valve train. :D

[Sybil TF]

Did you remove the spark plugs and serpentine belt?

[ViperTony]

Yes, all spark plugs out. I didn't remove the serpentine belt. Just make certain you're in neutral and key in the off position.

[Sybil TF]

Yes, all spark plugs out. I didn't remove the serpentine belt. Just make certain you're in neutral and key in the off position.

How long or miles do they need to be rechecked? Or do they?

[ViperTony]

How long or miles do they need to be rechecked? Or do they?

No need to check them if the installation was done properly. For peace of mind, you can recheck them at some point. I had Tator check mine sometime later to make certain I did everything correctly. The key is proper rocker geometry, correct length push rods, zero lash and the correct (no more than 2 turns in) turns of the T&D rocker adjustment screw. Oil flow can become restricted if the rockers are adjusted beyond 2 turns of the screw.

Also, feel free to call someone like Chuck Tator for more advice. The nice thing about our community is that we have knowledgeable and helpful owners/techs. Besides, Chuck loves it when pretty blondes call him for advice. :D

[ZZ SRT]

Thanks for the write-up Tony! Very helpful as I am about to do this.

One question, I am changing out the valve spring seals and valve springs at the same time. I have read the stock retainers are heavy and can contribute to valve float. Is this true and does anyone sell a better aftermarket version?

[ZZ SRT]

Hey, I bought some T&D's used from another Viper owner. Do they typically come with 12 point hardware to mount the rails to the head, or just the 12 point bolts to mount each rocker to the rail??

I only received hardware for the rockers to the rail and need to know whether I should call T&D to order some hardware, or buy some shorter 3/8-16 bolts online.

[ZZ SRT]

Thanks for all the help guys! Where do I put my money to join this extremely helpful group of owners??

[ViperTony]

Sorry I missed your posts ZZ. Yes the T&Ds come with bolts to mounts the stand to the cylinder head. I'd call T&D to get the right bolts. They can send you the shims too in case you need them. I have no idea if the stock retainers facilitate valve float.

[ZZ SRT]

Sorry I missed your posts ZZ. Yes the T&Ds come with bolts to mounts the stand to the cylinder head. I'd call T&D to get the right bolts. They can send you the shims too in case you need them. I have no idea if the stock retainers facilitate valve float.

Thanks Tony. Talked to Greg Good and he said to definitely ditch the stock retainers because they are soft. I also can see a few cracks in mine.

As for the missing hardware, I bought some ARP Moly 12 point 3/8-16 bolts. Hopefully the bolt heads won't be too tall to fit underneath the rockers. If I have an interference, I'll give T&D a call and get the originals. As for shims, I already checked rocker geometry and I think I'm okay.

[ACR_VP]

No need to check them if the installation was done properly. For peace of mind, you can recheck them at some point. I had Tator check mine sometime later to make certain I did everything correctly. The key is proper rocker geometry, correct length push rods, zero lash and the correct (no more than 2 turns in) turns of the T&D rocker adjustment screw. Oil flow can become restricted if the rockers are adjusted beyond 2 turns of the screw.

Also, feel free to call someone like Chuck Tator for more advice. The nice thing about our community is that we have knowledgeable and helpful owners/techs. Besides, Chuck loves it when pretty blondes call him for advice. :D

Figured I would reply in this thread in case someone in the future has the same situation as myself...

I am finishing up swapping in ported heads and t&d roller rockers in my '99. Kept the stock 708 cam and lifters. Anyway, I went through and got the proper geometry and measured the pushrods... My stock one's were 7.6" I believe and they seem to be correct to me (I used an adjustable pushrod, and 7.55 they are too short and 7.65 too long). Also all the valves were replaced on the heads with bigger ones, and I verified with a straight edge that they are all exactly the same height.

Still I'm having trouble finding zero lash / adjusting preload... On some of the rockers I can tell that the pushrods a few thousands from touching the rocker the adjustment screw is all the way out. I can shake them side to side slightly. By your steps above this is correct, I can tighten down 3/4 a turn and they make contact (which is where I believe it's zero lash), and then one additional turn for the pre-load.

My problem is that some rockers feel like they are at zero lash with the adjustment screw all the way up... I can't shake them left/right, but they feel like they are resting in the rocker and lifter already, and are easy to rotate. Rotating the adjustment screw down, I can't pin-point the definitive spot where the pushrods resist being rotated. And even at 2 full turns down from all the way out, I can still rotate the pushrods (though of course its harder to). I can still rotate the adjuster down more, to where the pushrods can't rotate and it's clear that they are putting pressure on the lifter, but this is obviously past 2 full turns down.

Where I landed at last night was treating zero lash as where the pushrods started to slightly resist being rotated, and then went one full rotation down for lifter preload. Without the lifters pumped up (and when the lifters are on the base of the cam of course), I can push down on the rocker/pushrods, depressing the lifter, and the rocker will come off the top of the valve by a fair bit.

I just don't know if I'm doing everything right.. And I'm also intrigued as to the slight difference given that I know the valves are all the exact same height.

[Troublemaker]

I am just throwing this out there from a complete lack of experience stand point, but can the non uniform issue that you are running into be caused by slight variances in the mounting surfaces on the head. I have not done this type of modification yet, but when looking for unusual results the root cause sometimes is something you didn't change. It's more about added new to old that you find these results, like putting new doors in an old house(which sucks).

[ACR_VP]

I am just throwing this out there from a complete lack of experience stand point, but can the non uniform issue that you are running into be caused by slight variances in the mounting surfaces on the head. I have not done this type of modification yet, but when looking for unusual results the root cause sometimes is something you didn't change. It's more about added new to old that you find these results, like putting new doors in an old house(which sucks).

not sure... I didn't think to take a straight edge to the mounting surfaces, but all of the rockers are the correct geometry with the same number of shims added under the t&d stands (I use the tape/marker method).

[Troublemaker]

not sure... I didn't think to take a straight edge to the mounting surfaces, but all of the rockers are the correct geometry with the same number of shims added under the t&d stands (I use the tape/marker method).

I was just throwing out a question, I try to analyze crap from its simplest form. And the fact that I have considered this as a future modification I am just following along for the knowledge, but have no advice to offer.

[ViperTony]

Figured I would reply in this thread in case someone in the future has the same situation as myself...

I am finishing up swapping in ported heads and t&d roller rockers in my '99. Kept the stock 708 cam and lifters. Anyway, I went through and got the proper geometry and measured the pushrods... My stock one's were 7.6" I believe and they seem to be correct to me (I used an adjustable pushrod, and 7.55 they are too short and 7.65 too long). Also all the valves were replaced on the heads with bigger ones, and I verified with a straight edge that they are all exactly the same height.

Are you sure they're the same height? When laying the straight edge across the tips of the valve stems did you use a feeler gauge underneath the straight edge/tip to determine if there's any gaps?



My problem is that some rockers feel like they are at zero lash with the adjustment screw all the way up... I can't shake them left/right, but they feel like they are resting in the rocker and lifter already, and are easy to rotate. Rotating the adjustment screw down, I can't pin-point the definitive spot where the pushrods resist being rotated. And even at 2 full turns down from all the way out, I can still rotate the pushrods (though of course its harder to). I can still rotate the adjuster down more, to where the pushrods can't rotate and it's clear that they are putting pressure on the lifter, but this is obviously past 2 full turns down.

You may not achieve zero resistance but you need to take up the play or slack between the adjuster and push rod. If the lifters have bled down (very likely) you won't get much resistance. Some will feel more spongy than others. That's OK. When the lifters pump up with oil they will be fine. You don't want to go past two turns of the adjuster on the T&D's.

Likewise, if the lifter is pumped up then you'll feel the opposite you noted in the first sentence above.


Where I landed at last night was treating zero lash as where the pushrods started to slightly resist being rotated, and then went one full rotation down for lifter preload. Without the lifters pumped up (and when the lifters are on the base of the cam of course), I can push down on the rocker/pushrods, depressing the lifter, and the rocker will come off the top of the valve by a fair bit.

You found it. That's it. If the lifters are bled down then yes you'll be able to depress the rocker as you mentioned. That's OK. When the lifters are pumped up with oil it'll be fine. If you kept adjusting the rockers down too much then when your lifters pump up with oil it may hold the valve open because you went too far. You don't want to adjust the shit out of the rockers. Sounds like you did the right thing!


I just don't know if I'm doing everything right.. And I'm also intrigued as to the slight difference given that I know the valves are all the exact same height.

As long as you're on the base circle and your rocker geometry is good and you have the correct length pushrods and there are no other issues such as excessive cam lobe wear, etc....you should be ok. I think that what you're experiencing is the bleed down nature of the lifters. The low-bleed lifters are better than the quick bleed lifters but they all bleed down. I was talking with an engineer at Johnson lifters and he gave me the bleed-down times of the Mopar lifters. It was seconds. Literally seconds after the engine is shut off they start bleeding down. As you're adjusting the rockers they will bleed down to nothing, most of them. When you start your engine they will pump back up.

I've been through what you described when adjusting lifters and it was the bleed-down nature that caused me the anxiety.

Which lifters did you end up using? If you've upgraded your heads using higher spring pressures don't use the cream-puff lifters.

[ACR_VP]

I actually JUST got done adjusting them again and I'm certain I got everything right this time...

I did a bit of troubleshooting and moved pushrods and rockers around between cylinders. This lead me where to look, and it seems that there was a tiny amount of difference height of the studs. Yay, so I had to ensure I had the right geometry on all the valves using a sharpy on the top of the valves. Dead center actually had a wider wear mark than just a hair above dead center, so I went with the spot with the thinnest wear mark (the thinnest wear mark will yield the most valve travel, least amount that the rocker has to roll on the top of the valve).

On the one's that had slack, zero lash was found in between 1/4 and 1/2 turn from the top. From there I turned a full revolution for the preload. Using this as a guide, the other rockers that were basically at zero lash with the adjuster screw all the way out, I gave them 1/2 to 3/4 of a turn from full out. So I'm confent now that the right amount of preload is set, and that I'm in the right zone on the rockers to ensure proper oil flow. Also verified that smaller pushrods would have put me more than 2 turns in on the rockers.

Kept lifters stock since I have a '99 and they are the better one's.

[Sybil TF]

You know you are getting old when you are at home on a Saturday night installing RR's. Well, the stockers are off...

[Sybil TF]

Getting closer lol

[Sybil TF]

My push rod length ended up being 7.650. No shims were needed. Did the tape method and geometry was dead on. Checked several for the hell of it. It seems that 7.650 is commonly used by those who have the 708 cam from my previous research. Went with the stronger 3/8ths pr's.

Now the lash needs to be set and hopefully it will run...

[Greg Good]

Glad you went with 3/8" pushrods. It makes a difference.

[ViperTony]

Greg spent many an hour on the phone with me to help me get this process right. I didn't hang up on him over it though! :witless:

[Sybil TF]

Thanks to JackB several years ago he found a way to speed up the adjustment of the rockers. I hope he doesn't mind me sharing this here but here it is:

"I just had some head work done and before I adjusted the rockers I looked at making the process a bit easier. I have adjusted rockers multiple times and it has never been easy. Everyone has had to come back more than one time to get it right. The key is to manually rotate the engine by hand, via the harmonic balancer bolt head. Using the following sequence you only have to rotate the crank two revolutions. This method also assures that the lifters are on the base circle. Taking my time it took me 30 minutes to adjust the rockers, plus, I did not have to come back and adjust them a second time. There is also no need to warm the engine.

One of the keys to proper geometry is the correct pushrod length. With the T&D's you must measure/size the pushrod with the rocker adjusting nut one turn down. You then turn/preload the adjuster down one further turn, that is ideal. Each full turn of the adjuster equals .050"."

3110Just curious, where do you get a 31mm and a 12 point 5/16 socket? No one seems to have these at all lol

used a 8mm 12 point for the rockers and the 1 1/4 for the HB bolt which is a little sloppy...

[ViperTony]

Just curious, where do you get a 31mm and a 12 point 5/16 socket? No one seems to have these at all lol

McMaster-Carr.com

[Sybil TF]

McMaster-Carr.comThanks! Got them ordered. Thankfully the 8mm and the 1 1/4 got the job done but will have these just in case. Probably going to replace the harmonic balancer so the 31mm will come in handy...

[Sybil TF]

:dancingman:Finally wrapped this up today. Car did not blow up so all is good. Sounds well and seems a little more responsive when you mash the gas.

Thanks to ViperTony for the instructions and everyone else for your advice!

[Sybil TF]

I forgot to mention that my rockers do not hit the baffles inside:dancingman:

[RTTTTed]

Excellent. Your manslave did a great job. Now you need to reward him.

Probably about 12 - 15whp from those rockers

[Sybil TF]

Excellent. Your manslave did a great job. Now you need to reward him.

Probably about 12 - 15whp from those rockersI'm the reward lol

[Sybil TF]

These were about $1,600. A good set aof RR's is not $2,000 to $3,000. Just saying....

[Ttillots]

Viper Tony.... I’m in the middle of figuring out my T&D Roller Rockers right now. With the Hydraulic lifter pressurized, do you only find zero lash or do you find zero lash then 1 full turn to set preload with the adjustment screw?

[ViperTony]

Viper Tony.... I’m in the middle of figuring out my T&D Roller Rockers right now. With the Hydraulic lifter pressurized, do you only find zero lash or do you find zero lash then 1 full turn to set preload with the adjustment screw?

Find zero lash than 1 full turn to set pre-load. Did you check your geometry? For stock Gen2 heads it shouldn't be an issue with T&D's. I don't know if I detailed here or not but I used the gauge supplied T&D as well as a sharpie and tape method. Put a piece of tap over a few of the valves tips, marked up the rocker roller ball with the sharpie and cranked the engine over a few times. I then checked the line left on the tape by the roller. It should be slightly forward of centerline. The geometry is more of an issue for Jessel rockers which do require the rocker bosses to me machined. I believe Greg did something with longer valves since he decked my heads, I forget. It's been awhile. :) But when my heads were stock I had no issues with the geometry.