trunion upgrade proplem
01-12-2011, 08:18 PM
#24
If you are still using the original DOD lifters, there will be 8 of them that are "normal" and 8 that are "special" collapsible lifters. The ECM commands the internal DOD oil flow valving to collapse these 8 "special" lifters which effectively turns your engine into a 4 cylinder for economy. These "special" lifters are pretty much junk for a HP engine with a high-lift cam. Most who do away with the DOD also swap to 16 "normal" lifters so as not to experience these spurious collapsing issues.
Not saying that's your problem, but it would be suspect - IF - you still have the original DOD lifters...
Not saying that's your problem, but it would be suspect - IF - you still have the original DOD lifters...
01-13-2011, 07:34 AM
#27
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Getting the balance between no side to side movement and no bind is the key to no noise with the trunion bearings/rockers. It's an extremely small window and I can guarantee that's where your noise is coming from. Guys will tell you that some side to side movement is ok... It's not. I did my own and went through the same thing.
01-13-2011, 08:31 AM
#29
The only thing I did was upgraded the rockers, installed a fast 102, and plugged my oiling towers under my intake. My setup is a stock shortblock ls2, t.e.a. Ported 317's stage 3 shaved to a 64cc chamber with 2.08/1.60 valves, the cam is stated in the first post 230/238 .600/.604 112+2, pushrods are 7.350, head gaskets are cometic .51. The cam was spec'd by pat g himself so I trust him.
01-13-2011, 08:47 AM
#30
speed inc.
i took a fast 90 off of the ls2 and swapped to the 102. i just came from my car and couldnt get it to tap again. reved for quite a few times and it never made a sound. all rockers are installed properly, all torqued down. best guess is it was somehow hitting the valve cover. because it hasnt done it since i put it back together and didnt tighten them down as much 
i heard the eps camshafts are ground on a smaller base than a regular camshaft? is this true or just another wrong intertnet fact? i have 7.350 pushrods. 
02-18-2011, 04:38 PM
#36
But why is my question. I have had no proplems out of these lifters before the trunion upgrade. Went home on my lunch tried to get it to make the noise and it didnt make it. I reved the motor pretty high quite a few times and no noise.
02-18-2011, 05:09 PM
#37
I've got no answer for that one. I can only tell you that past experience for intermittent ticking generally turns out to be a lifter. Based on my experience with my own trunion upgrade, I would pull them and make sure they all are silky smooth and rotate round and round completely free and smooth.
When I did mine, some of the rocker bodies required honing for smooth operation. If you are binding, perhaps it could be the problem.
When I did mine, some of the rocker bodies required honing for smooth operation. If you are binding, perhaps it could be the problem.
02-18-2011, 05:21 PM
#38
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Does the temp seem to make a difference ? Did You rebuild this engine ? Is the rear cover oil passage bored out larger ? If not , it may be a lack of oil getting to the passenger side lifters, push rods, rockers .
You're question about camshafts , the larger the lift the smaller the base circle . The stock 5.3 cams base circles are 1.483" and the lifts are .455 and .468 where as the LS2 and LS6 2002+ base circles are 1.519" with lifts of .521 or .525 . They have to do it this way because if they just kept increasing the lobe sizes the lobes would not fit through the bearings .
Does anyone know where I can get the spacer and longer bolts for using the older trannies with the ls gen3 engines for $50 . I've seen it in LS1-tech somewhere but I can't find it now ?
You're question about camshafts , the larger the lift the smaller the base circle . The stock 5.3 cams base circles are 1.483" and the lifts are .455 and .468 where as the LS2 and LS6 2002+ base circles are 1.519" with lifts of .521 or .525 . They have to do it this way because if they just kept increasing the lobe sizes the lobes would not fit through the bearings .
Does anyone know where I can get the spacer and longer bolts for using the older trannies with the ls gen3 engines for $50 . I've seen it in LS1-tech somewhere but I can't find it now ?
Last edited by chrisfrost; 02-18-2011 at 05:24 PM. Reason: forgot something
02-18-2011, 06:09 PM
#40
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Ok , this is what I suggest . The next time it is ticking , shut it down and remove the rocker cover , then start it back up and hopefully it will tick for You so You can pinpoint the noise .