rsandhoff

I am putting together my first Olds rebuild and need some advice on the the valve train. I know this engine has non-adjustable rockers. I have looked on this forum and others, but could not find an exact match to my question. This is a stock 69 400 which has had the head and block surfaced. I am using Fel-Pro blue head gaskets. When I installed the lifters, rockers, and pushrods, the lifter preload measured .045. I measured this by tightening the pedestal bolts until the pushrod just contacted the lifter. The .045 was the clearance between the pedestal and the head.

I have seen measurements from .025 to .060 as being OK on different forums, but not for sure what the factory setting was.

Is .045 within the acceptable range?
If not, should I shim the pedestals or get different size pushrods? As a hobbyist I have rebuilt all of the engines for my projects, but I am no expert. This is my first Olds (69 442) and my first non-adjustable rockers.

Any help or recommendations would be appreciated. I know you can by the adjustable set-up, but I was wanting to go back as stock.

Ross (Waco, Tx)

Yellowstatue

Normally what you do with non adjustable rockers is run the bolt down till it stops and tighten a bit more (torque) and you are done...what pre-load??

cutlassefi

"what pre-load", Huh?

rsandhoff- you are correct. A figure of .030 to .060 is normally o.k. If you do have .045, then that should be fine. One more thing to check, when everything is tightened down make sure you still have a bit of travel left in the lifter. If you do then you're good to go.

jensenracing77

i always thought the measurement was taken at the lifter under the clip. is this way as accurate.

rsandhoff

Thanks for the quick replies. If all of the components are new and untouched, then all you have to do is just bolt everything up and torque the bolts down and pre-load should be correct. However in my case, the block and head were both surfaced (metal removed) and I am using a thicker head gasket. I was hoping that these two things would offset each other. Also, the head was compleely rebuilt with all new components. Valve stem height was checked with a OLDS gauge and is perfect. Anytime things change from the factory clearances, the valve pre-load could be affected.

Cutlassfi thinks .030 to .060 is accepable so I am feeling good about the .045clearance. I know the valve height is correct, and I am using stock push rods, so with the surfacing of the head and block offset by the thicker head gasket, I think I am fairly close to stock as far as pre-load. I just could never find in my manuals what is should be.

Jensenracing77, yes that would be the more accurate method, I just did not have a way (tool) to measure that clearance. Is there a method or tool?

FYI, just observing the travel (which is scary) it looks like the piston moves a little less than halfway down the bore when everythig is bolted down. I may be a little over cautious, but I do not want to open this engine up after completion. Did that once, no fun!!!!.

I know from research that Joe Padavano has a lot of Olds Tech knowledge. Is there a way to get his opinion on this topic. I'm a little new to forum protocol.

Thanks again

citcapp

If you want Joe's input, send him a pm

My442

Is the cam stock?

Most aftermarket cams have smaller base circles.

Bring #1 cylinder to TDC compression. Both valves should be closed, and the cam at base circle.

Slowly tighten the rocker bolt while spinning the pushron back and forth between your fingers. When you feel some drag - stop.

Put a dial indicator on the tip of the rocker over the push rod, and set to zero. Tighten the rocker bolt to 25 foot pounds, and take a reading.

.025" to .060" is fine.

If the reading is below .025", the pushrods are too long. You can buy a shim kit for the rockers.

If the reading is greater than .060", the pushrods are too short. You can mill down the pedistals or get longer pushrods.

joe_padavano

Coming in late, but it sounds like you have done everything correctly. As noted, 0.030-0.060 is acceptable, as there is some accommodation in the lifters. The shim kits for the rocker stands are available from the usual Olds specialty houses. Cam base circle diameter is obviously a factor in addition to the milled heads, compressed gasket thickness, valve stem height, pushrod length, and production tolerances.

Assuming the lifters are full of oil (you can do this by submerging new lifters in a coffee can of oil and pressing on the top - I use an old pushrod chucked in the drill press to press on the top of the lifter) and on the base circle of the cam, tighten the rocker bridge bolts until either the bridge touches the head or the pushrod touches the rocker. If the bridge hits the head first, the pushrods are too short. You can mill the bridges but that will alter the rocker geometry slightly. Longer pushrods are the better solution. If the pushrods hit first, check the gap between the bridges and the head with a feeler gauge. If it's within the 0.030-0.060 range just tighten the bolts. If it's more, shim to achieve 0.045. If it's less than 0.030, you can surface the bottoms of the bridges. Wet/dry sandpaper on a sheet of glass works well to achieve a flat bottom on the bridges.

rsandhoff

Thanks for the replies and the information. I got what I need and will get back on the engine soon. This is a great site for OLDS info and especially for those of us that are first time Olds restorers. I think the 69 Olds Cutlass was one of the most beautiful cars ever produced and hope to have mine (69 442 Trophy Blue w/Blue int. and White top) on the road before too long. The economy has slowed me up a little bit.

Thanks again.