Time to build the 455 ive always wanted

About the only thing you can do is put shim stock between the pedestals and the rocker shaft if the preload is too high. I've seen motors break OEM rocker shafts when the preload was too high. 0.030 of shim stock solved that problem on most.

 

Definitely not adjustable pushrods. They look like a stock set. I scribed the marks as you instructed but all I had to measure was a set of feeler gauges. I only measured the five pushrods with lifters that weren't collapsed. There was a huge variance in my measurements. I need a better system to track the information as my feeler gauges allowed for inaccuracies. Either way, there was a difference of about double the space from the widest gap (#1 in/ex) to the smallest (#3 in). Something is definitely wrong here. What's the best tool to measure these distances? I used a pencil to scribe marks on the pushrods. Either way, new adjustable pushrods will be ordered! At the end of the day, it's surprising to see this cam in good shape like it is. No gouges or scoring at all.

 

I just reread your instructions and have done my measurements incorrectly. I never ensured that I was at the base of the lobe. I will redo it and let you know. They should all be the same right? As in the preload on all the good lifters?

 

Absolutely Larry! Seems to me like adjustable pushrods is a no Brainerd for setups like mine using the stock rocker assembly. I wish I had known all this before but hey, hindsight is always 20/20. I will have another conversation with my builder today. Seems to me he should have known to measure and order proper pushrods being that he cleaned up the deck as well as the face of the heads. Combined, probably ~.020 of material was removed and I have my original pushrods still in place and all this on top of a cam swap. Sure, the 284-88h is no monster lift cam but it's more than stock for sure. These pushrods were bound to cause an issue if you ask me. Dang, tough lesson learned here.

 

Ordered a set of lifters and a set of adjustable pushrods (5/16 O.D.) today. Hopefully this fixes the issue. My understanding is that once I install the pushrods and torque the rocker arm assembly down, I adjust the pushrod length to 0 lash (flush with the center of the lifter as well as flush with the rocker arm?) And then another 1/2 a turn on the adjustment knob for proper lifter preload. This procedure is done when the lifter is on the bottom side (opposite the lobe peak) of the cam for each valve. Am I on track here?

 

Larry posted thios procedure from the GSXtra years ago...

It allows you to adjust 4 valves at a time. To adjust the pushrod on a valve, the lifter must be on the heel of the that particular cam lobe. This procedure does that for 4 valves at a time. To follow it, you need to mark your balancer at 180*(1/2 way around). Position the timing mark at TDC #1 firing) Then adjust Intake valves for #2 and #7 cylinders, and exhaust valves #4 and #8. Then turn the crank(with 1/2" drive socket) 180*. Now adjust #1 and #8 intake valves, and #3 and #6 exhaust. Rotate crank 180*. Now adjust #3 and #4 intake valves, and #5 and #7 exhaust. Rotate the crank 180*. Now adjust #5 and #6 intake valves, and #1 and #2 exhaust. Make a diagram of the engine to illustrate valve position so you don't get confused. Drivers side cylinders are 1,3,5,7 and passenger side is 2,4,6,8. From the front of the engine to the rear, the valve arrangement is Ex-In-In-Ex-Ex-In-In-Ex. This is the same for both sides. You want to adjust the pushrod 1/2-3/4 of a turn past 0 lash. Just go slow and you should be fine. Hope that helps.

 

Did I miss what you discovered when checking the tops of the valve stems for variation? As noted, some is ok, ideally all the same.

I wouldn't think the cam you have would necessitate shorter than stock pushrod lengths unless between the block and heads +/-.050" was taken off. Do you know how much was taken off each?

 

I only got to measure the passenger side before I left for vacation. All were the same except the #1 exhaust valve which was significantly lower than the others. I didn't get the feeler gauges in there to see how much, but I would bet a out .035 or more. It was a lot. I will investigate more once thanksgiving/deer hunting is done. Priority for now is to fill this freezer! :Brow: But I did order the adjustable pushrods and lifters before I left. I definitely want to have that ability to size them for each valve individually. A roller setup isn't in the cards right now.

 

Thanks for posting this! :TU:

 

any update?

 

I got my parts delivered but haven't gotten them installed yet. Plan is to work on it this weekend.

 

Finally got the lifters and adjustable pushrods in today. Should get it fired up tomorrow evening after work. I figured it was best to wait for the rtv to set on the intake manifold, not to mention breaking in a cam at 9 pm on a Sunday night probably wouldn't win me any favors with the neighborhood. Hopefully this fixes my issues. I followed the procedure that was posted, ensuring to be on the base circle of each cam lobe and I adjusted each pushrod 1/2 turn from 0 lash then locked down the fastener nut. We shall see...

 

Sounds good, and as for those adjustable pushrods, you can't tighten those lock nuts enough..crank them like you want to break them. If they are not stupid tight, you'll be back in there tightening them back up...

 

No dice for tonight. Attempted to start and found out my RTV job on the intake manifold end seals was lackluster. I didn't use the black rubber end seals, only tried to seal it with RTV. Didn't work out at all. So I ordered another gasket kit and will reinstall it tomorrow. What is the best technique for ensuring the intake seals properly? As I turned the motor over, I could hear the weezing sound of a vacuum leak which lead me to believe the intake wasn't sealed. It was clear when I removed the intake.

 

I usually put a tall enough bead of Ultra Grey on the block and be sure the corners have a good blob. Let cure then razor blade trim any unsisghlty spewage...

 

You don't use the black rubber end seals?

 

The end seals are junk scrap'm, this is one of the few cases IMHO where u can go overboard with RTV and the outcone will be positive. With my old setup I had to lay down beads that were easily 3/8" thick since the bulldog heads pushed the intake up so high, that was even after a 1/4" aluminum spacer was made to get the corners right. I really like the powershot or caulk gun style tubes for ease of application. Makes the thicker beads easier to lay down uniformly. As a side note, a little gasgacinch around the water jackets holes is good practice to ensure a leak free seal.