Hey forum, I'm hoping to get some help with this 96 RT/10 that was brought to me from a local body shop. A little history on the car, if I may. It was built for Domenick Rossi back in 1996. It has been wrecked pretty bad a few times. A local body shop purchased this last year at auction (in a box) and brought it to me after the body was complete. After days of repairing an electrical disaster we our now attempting to repair significant valve clatter. I've personally never seen a rocker shaft set up like this that utilizes u bolt style locks to retain valve adjustment (I'm happy to post a picture for anyone that has not seen this set up). That being said we have a few problems here. We have a few u bolts with stripped threads that need to be replaced inorder to retain proper adjustment. I called Hennessy on the phone to inquire about parts availability and proper valve adjustment on this set up and they were really not much help. I have searched and read some really good article on T&D adjustment but have found nothing on a Hennessy. Acquiring zero lash is not that difficult IMO, however how much past zero should you go w/ the hydraulic lifter that they use? Reccomended adjustment to be done hot or cold?? I read the T&D easy valve adjustment article (great explanation and simplification) and am still a little unsure on what the purpose of going an 1/8" to 1/4" past TDC when setting up valve lash is. With that being said, any info that could be passed on would be GREATLY appreciated. Thanks for taking the time to read this.
Hennessy Valve Adjustment (no info at my disposal)??
- Thread starter Scott183
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I was hoping you would chime in on this Jack. During my morning search and read, I found a lot of great valvetrain info you had posted including that made easy TDC chart.
Exactly what did you mean by 1/8" to 1/4" past TDC ,are you referring to crank movement or piston travel? As far as zero lash, not to hard to acheive, however with this setup, is it reccomended to go 1/2 turn past, full turn past?? We already set up at zero lash plus 90 degrees when cold, and it's still a clatter box. I just hate wasting my time doing this multiple times and guessing. I know Hennessy doesn't get much love around here, I'm not a fan so far myself. However the customer should not have to replace an entire valvetrain just to get accurate setup info. I think I may pull out and inspect each lifter and pushrod tomorrow, take some rod measurements, and get a baseline of what I have to work with. Thanks for the info, any more to offer is much appreciated.
Exactly what did you mean by 1/8" to 1/4" past TDC ,are you referring to crank movement or piston travel? As far as zero lash, not to hard to acheive, however with this setup, is it reccomended to go 1/2 turn past, full turn past?? We already set up at zero lash plus 90 degrees when cold, and it's still a clatter box. I just hate wasting my time doing this multiple times and guessing. I know Hennessy doesn't get much love around here, I'm not a fan so far myself. However the customer should not have to replace an entire valvetrain just to get accurate setup info. I think I may pull out and inspect each lifter and pushrod tomorrow, take some rod measurements, and get a baseline of what I have to work with. Thanks for the info, any more to offer is much appreciated.MTGTS
Enthusiast
Post some pics, I don't think Hennessey made their own RR's. They prob just used another brands for the Venom kit.
Thanks guys. I really have my back against the wall on this one with the lack of info available. Thanks Hennessy!! Yes, agreed zero lash, is zero lash, however each manufacture has a reccomended setting PAST zero lash, and that's really what I'm looking for. I just took the covers back off this thing and even when these things are snug, you can push down on what feels to be spongey lifters. I don't think that hydraulic lifters should feel this spongey. I'm setting up cyl #1 and going to remove the push rod and lifter to get a better idea of what they used here. The more info I gather, the better my chances of getting accurate info. Here are the pics, and thanks again!!
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Never seen anything like that before. That's either THE most ghetto rocker setup or the most genius one. If it were me...I'd ditch that rocker setup and go with Harland Sharp or T&D.steve911
Enthusiast
Its called a stud girdle. With any stud type rocker systems in racing engines, valve lift, rpm, spring pressure can raise havoc on the rocker arm studs. The girdle helps to spread the stress along the entire head. They actually work well.
These are predominantly used by the drag racers.
Steve A.
These are predominantly used by the drag racers.
Steve A.
Now that I have this torn apart, I have a better idea of how it is supposed to work. The u-bolts are there for nothing more than to keep the adjuster from backing off. They do not hold any tension on the rocker stud at all. That being said we brought 1 up to TDC, pulled the rockers off for push rod and lifter inspection, much to my shagrin to find out the cylinder heads need to be removed for lifter extraction/ inspection. I went around to every cylinder to check the lifters and better than 1/2 feel pretty spongy (they don't require a ton of effort to move). I would think after the 100 miles I have put on this since it's long sit that they should all be pumped up by now. I'm basically down to two choices at this point. Either set them by ear, like I used to do, or bite the bullet and minimally replace the lifters , if not the entire valve train. I appreciate you guys that chimed in on this. Any other ideas or info is always welcome! Thanks
BTW it currently has Comp Camps 1.7 Roller Rockers and 8.050 push rods.
BTW it currently has Comp Camps 1.7 Roller Rockers and 8.050 push rods.
Greg Good Cylinder Heads
Enthusiast
That is an old rocker setup that was used before T&D or Jesel made rocker arms for the Viper. At the time, it was the only way to put roller rockers on a Viper. The u-bolts can be bought from Moroso. The pre-load should be set at least 1/2 turn, but 1 full turn will probably be better.
Just for information, the rocker arms fit a small block Chevy, the studs are from a big block Chevy (3/8" bottom, 7/16" top), the guide plates are Isky, and the pushrods are small block Chevy. The stud girdle maeks it all rigid so a rocker boss on the head does not break off, and it cuts down on valvetrain harmonics.
Just for information, the rocker arms fit a small block Chevy, the studs are from a big block Chevy (3/8" bottom, 7/16" top), the guide plates are Isky, and the pushrods are small block Chevy. The stud girdle maeks it all rigid so a rocker boss on the head does not break off, and it cuts down on valvetrain harmonics.
You know the system to a tee Greg. I had forgotten to mention the Isky pr guide plates. What about the adjuster setup with the center hex head. Should those be centered in the adjuster bore, and then locked down after valve adjustment? I talked to a local guy who builds performance engines around here and he said not to worry so much about spongy rockers quite yet. His suggestion was zero lash plus a half turn, I'll probably split it down the middle between you and him at 3/4 past and see what I got. If she's still noisey I think lifters are going to be a must!
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BTW are there any external ways to find TRUE cyl #1 TDC. Through my reading the only mark that is on these engine is at the timing gear. Now that I have Jack's cylinder adjustment chart I'd like to put my degree wheel on here and do it more accurately than a screwdiver in the hole.
Greg Good Cylinder Heads
Enthusiast
I would give it another try with one turn of preload before declaring the lifters bad. Also, that rocker setup has some *wiggle* and it will never be as quiet as a T&D/Jesel. As long as you can't hear it with the hood closed it's ok, IMHO.
You can actually toss the center lockdown screws. They're redundant. Once you tighten the stud girdle the poly-lock is not going to turn and change preload.
All hydraulic lifters that are on an open valve bleed down after a few minutes. Some more than others. Thats' why it is common for an engine with a *cam* to tick for a few seconds on cold start.
Several companies sell a tool that screws into the spark plug hole. It is spring loaded and extends down into the cylinder. As the piston moves up it contacts the tool and the external part of the tool (which is graduated) also moves up. You just have to get close, this is not like degreeing a cam, the base circle on the cam is fairly wide.
Greg may want to add to this, but, if these are newer lifters, they are notorious for leaking down and clacking.
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NI-KA
Enthusiast
Jack B do you know if summit racing carries the tool you describe? If so do you know what keyword I can search for it under?
Here ya go bud, I was gonna ask the same question.
http://www.summitracing.com/parts/POW-POW101330/?rtype=10
I would guess they do, especially since they have gone tool crazy. I looked at mine and it does not have a manufacturers name. I think I bought it from Gratiots Garage, but, I have not seen it lately in their catalog. I know Snap-On had it, but, I don't see it in their catalog either.
This is the tool and I bought in 2008 from Eastwood. But I can no longer find it in their catalog:
I think you're one state over from me. I can mail it to you if it helps, just need it back when you're done. If I find online I'll let you know. - tony
I think you're one state over from me. I can mail it to you if it helps, just need it back when you're done. If I find online I'll let you know. - tony
NI-KA
Enthusiast
This is the tool and I bought in 2008 from Eastwood. But I can no longer find it in their catalog:
I think you're one state over from me. I can mail it to you if it helps, just need it back when you're done. If I find online I'll let you know. - tony
Great offer ! I might take you up on it.
I am not sure about the summit racing tool posted above. I think I will take the picture of the above tool and head up to summit racing and see if they can find it in their catalog.
I can also look at the summit tool that is posted and see how it works just to make sure it is the right tool.
Thanks for the feed back guys. Using the tools will be easier than trying to peer down into the spark plug hole.
The other tool is a piston stop. I have it in my cam degree kit from Powerhouse products. It came with two types of piston stops one for the heads off and one for the heads on (pictured). I can send you that one too.
Here's a pic of a pointer I made to show TDC on the Viper. You'll notice that I also marked the dampner as well. I set this up when I had the engine apart, but you could do the same with once you determine TDC with one of the tools shown in the earlier posts.
Thanks for all the suggestions, ideads, and offers!! I am probably going to do it the old fashion way with a thin screwdriver in the hole and just find each piston tdc like that. I hope to get some time on this in the next few days and wrap this up. I will report back after she's up and running again. Thanks again!!
Just a quick update. Set every valve to 1 full turn past zero lash and still have a moderate valve clatter. After every valve was set, you could still feel the "sponginess" in 1/2 of the lifters. The customer and I have decided to drive it for 500 miles and see if any of the lifters recover. If not we have no choice but to replace them. Thanks for all the info you guys passed on to me.
Viper Wizard
Enthusiast
My Tech Session last year for the club was on 1.7 rockers and I had a 96 RT/10 hennless Viper in my shop to show everyone what goes wrong when they use the wrong parts! Scott183 if you'd like, give me a call and I can tell you all about them.
http://forums.viperclub.org/forums/269-Vendor-Review-Tator-s-Garage
http://forums.viperclub.org/forums/269-Vendor-Review-Tator-s-Garage
After you set the lash, some are going to be spongy, my 97 does the same thing. The reason is, you have rotated the engine several revolutions without building oil pressure at the lifters. That should not affect the setting accuracy, you are setting the rockers against the spring preload of the lifter. If the lifters are good they will pump right back up after you start.
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dam thats a clean engine!!!!!
Here's a pic of a pointer I made to show TDC on the Viper. You'll notice that I also marked the dampner as well. I set this up when I had the engine apart, but you could do the same with once you determine TDC with one of the tools shown in the earlier posts.
Man I would have liked to attend that class. I did not see your ph# in your sig. I'll send you a pm so I can give you a call.
Red Snake, if this were my car (wishing it was), I would have already yanked the heads and changed them out. the customer is upside down on this thing. It's for his wife, so who knows how long she'll keep it?? He probably should have bought her a running car, then he would have known what he was getting!
JackB, I am clearly aware that the sponginess will be there until oil pressure builds up. Unfortunately they are not quieting down after the pressure has come up, which is almost instantaneous. They don't sound bad for the first ten minutes of run time, however after the engine is fully warmed up, and you get out and work this engine, the clatter comes in pretty decent. Per customer request we are running 5w-30 Mobil 1. I'm not a big fan of synthetic motor oil, and have debated switching this over to a petroleum based oil to see what happens.
Sort of a side bar, the 2013 viper is going to use Penzoil Ultra full synthetic.
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