Quote:
Originally Posted by Cliff R
A couple of observations.
You don't need an operable downshift solenoid in the TH400 with a well thought out Pontiac build. As a matter of fact, I unhook them in my vehicles. Instead, I use my right hand to select lower gears if/as needed plus full control of the upshift points as well. Using the solenoid would for sure destroy the car or get me killed or seriously injured anyhow. If I were cruising along at 30 mph or so and went to full throttle the engine would try to rip the tires right off the rims if it shifted to low gear and I'd likely lose control of it and end up wrapped around a telephone pole.
I'd also add here the using Rhoads lifters on a RAIV cam has absolutely NOTHING to do with racing the car or not. They are used to help offset the 80 something degrees of overlap and improve idle quality, vacuum production at idle speed and for improved throttle response and engine power right off idle and low RPM's. They work as advertised and take these somewhat "antiquated" engine designs to give them variable valve timing, like modern engines. The downside is that they make noise while doing it, which some folks can tolerate and others simply cannot.
Advancing the cam has really nothing to do with engine noise unless you went so far, the valves are smacking the pistons. In that event it would have bent them and you'd be walking anyhow. I've found that the RAIV cam likes to be at 109-110 ICL in a 455 build with moderate compression. Never used one in a 428 but I still wouldn't advance it very far, maybe 108-109ICL and run with it..........FWIW.....
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" I'd also add here the using Rhoads lifters on a RAIV cam has absolutely NOTHING to do with racing the car, or not. They are used to help offset the 80 something degrees of overlap and improve idle quality, vacuum production at idle speed, and improved throttle response and engine power right off idle and low RPM's. They work as advertised and take these somewhat "antiquated" engine designs and give them variable valve timing like modern engines. The downside is that they make noise doing it, which some folks can tolerate and others simply cannot".
What you said in the above quote concerns me at this time. I have successfully completed a rebuild on my 1967 TH 400 Trans. and after testing and tuning I replaced the vacuum Modulator and procured a rebuilt Valve body and we ran into a different issue. The car has been off the road for the past 2 years dealing with the Trans, so I went through the Tri-power Carbs. because they too have been sitting.
Prier too rebuilding the Trans. we installed the "041" Cam and then we advanced it 6 degrees at the Crank and so 3 degrees at the Cam, without ever degreeing the Motor. Currently as we test and tune seem to have a vibration that did not exist - ever. We took a hose and listened with our ears all around the Engine to isolate where the vibration/noise was coming from, and came up with some theories. First, we looked at the Torque converter to Fly wheel and the bolts were tight. Then we checked the Drive shaft and found no problem there. Then I remembered we had advanced the Cam timing and are currently reversing that procedure installing the Cam with zero advance. I plan on purchasing a degreeing wheel kit. We just removed the intake Manifold to inspect the pushrods and Lifters, then we spun each Pushrod when the Cam lobe circle was on top to check the Valve lash on these Johnson almost new Lifters. The almost new Chrome Moly HD Pushrods to Rocker Arm to top of Valves looks well and to spec. and no Metal is on top of the Vally area. The only thing wrong is the crossover exhaust in the Heads are missing 25% material and need to be replaced. We spun the Motor using our push button to starter tool and no noise or ad-moralities noted. While I order the Gaskets, I will need to reassemble this HO 428 ci Pontiac Motor, I will pull the Oil pan to inspect the inner pan for Metal and plan to cut open the remote Oil filter looking for metal too. Perhaps the noise/ Vibration went away by zeroing the Cam chain Gears? I won't know until I run the Motor so, I best check all while I am this deep into this Engine. Once I inspect the lower half of the Block, then we will spin the motor once again.
If anybody (friend or foe) has any input here, please advise me.
P.S. I am so tempted to remove these Heads, ones that I have never removed since owning this project vehicle.