VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 1934 Master Block Cleaning and Valve Questions

I finally got around to removing the head from my 34 Master to clean the rust and crud out of the block. A good amount came out but not as much as I suspected. I used a air blow gun converted to connect to a garden hose on the inlet end and a long piece of 3/16" brake tubing on the outlet end. By bending the tubing I was able to scratch and inject a stream of water through all of the passages in the block. It took a while but the water finally flowed clean. The radiator is being tanked and the head is being checked for cracks.





Now the bad news. Upon removing the head I found the lifter springs and brackets had been removed by a previous owner. All six exhaust valves burned. As a result I’m doing a complete valve job with new valves and springs etc. Here are my questions:

… From previous posts I understand I need to use later valve springs. Do I need to look for original 38-53 springs or are the current aftermarket springs listed for 216 and 235 acceptable. I read in an earlier post they should be but I’m concerned about bending a push rod with too heavy a spring.

… The brass coupler between the front and rear rocker arm shaft has an orifice that points towards the rear. There is no orifice controlling flow towards the front rocker shaft. Is this correct? All rocker arms had a good flow of oil prior to disassembly. The manual is silent on this.



… Lastly take a look at the crimp in the overflow tubing on the rocker shaft. The crimp shown in the picture is actually all the way through wall allowing oil to squirt up against the valve cover. Should I be concerned? Should I repair this?

Thanks Mike

there is only one way to do things, the right way or not at all!

the crimped pipe and hole in it are enough to tell you SOME FOOLS have been playing with your engine !!!!!!!!!

to be on the safe side , pull the motor and take the block assembly to your rebuilder and have it professionally hot tanked, reverse pressure flushed. New bearings, HONE it for new rings. Check camshaft for wear plus the timing gears. USE RODS TO GET DOWN THE WATER JACKETS AND CHIP AT THE RUST

In order to make sure the radiator is clear, have the top and bottom tanks removed and have the tubes rodded to make sure no obstructions, then have them re-installed by the rad shop.

There has been many posts and threads on 33--36 chevys overheating in this 33-36 section.. Find them and read them.

mike lynch..................

Yes my 1936 has only one orifice to the rear. The idea was to keep oil from flowing to the rear of the shaft when taking off as the vehicle is moving forwards. I think that the oil needs a restriction to help push more oil forward. The hole you are looking at in the top of the tube is an overflow vent. Mine is made the same. This allows oil to not build up to much pressure. After you clean and re-assemble...run the engine with the valve cover off. Observe the flow of oil coming out and down the rocker arms. There should not be a squirt of oil going against the valve cover from the hole in the tubing. It should be a weak overflow. There should be enough pressure on the main to force oil out and onto the rocker arms. It should be a light flow, more of a oozing farther onto the push rods. This will not occur right a way but may take several minutes running time before everything is lubing. Pre-lube everything before starting the engine. That way you don't get excited when it takes a long time for the oil to start flowing. Hope this helps you.

My 47 engine has a shield that clips on the tube over the hole which prevents the oil from squirting up against valve cover yet lets excess run out. I suspect the crimp in the subjects tube was someone's method of trying to force more oil out the rocker shafts. Most likely the shafts were partially plugged up with sludge.

dick

45 years ago I removed the valve helper springs and brackets (retainers) from my 1934 Master. I used the 1938 and up 216 valve springs. The later 235 valve springs are stronger and would be safe to use if the valve seats have been ground deeper into the head as the result of several valve grindings. I, and the present owner have driven the car over 40,000 miles and no problems have arisen. The other thing is at that time is replaced all the valves with the later improved valves Chevrolet offered for 1934 Masters. These valves use the "modern" split key valve keepers rather than the single bar type. This is a stronger, better method than the bar type which makes breaking of the retainer cap possible.
Crimping the rocker arm overflow pipe was a common fix for forcing more oil pressure to the rocker arms. If the rocker arms are oiling OK I would not worry about it. And yes, it (the oiling system), was designed to prevent excessive oil from flowing to the back of the head and leaking out of thee back of the cover.

I appreciate everyone's feedback and the answers to my questions. Thanks again for your input. Mike

One last question.

I assume as long as the valve guides are within specifications there is no need to replace them when upgrading to the later valves and springs. Correct?

correct