norvalwilhelm
Well-known member
I got a request today to talk someone through a bigblock cylinder head assemly. While not an expert I have done this many times and while it sounds like alot of work it takes only an evening to install the valves and springs right.
Thought I would share this with anyone would wants to try it themselves. I would certainly help anyone who needs advice or someone jump in if I overlooked anything.
I can certainly talk you through it but you will need a few tools. The big one is the spring compressor. Do you have one? If not you will have to rent one.
You will have to make a little tool. The card with the cam will tell the installed height. It is probably 1 7/8th or 1.875. I take a piece of bronze welding rod and make a piece with radiuses ends or rounded ends exactly this length. Then I take the lift say .580 add .060 for safety for a total of .640. Now subtract the .640 from the 1.875 and you get 1.235. This is the length of the second rod. I then join the 2 rods together with another piece about 3 inches long. Join the 2 rods in the middle roughly on a 45 degree angle with the 2 precise lengths paralled. All this is rough but the rods are exact. Solder them together to form a tool in the shape of a Z but the joining rod not touching the ends but connected near the middle. One end has the installed height and the other the open plus saftey value.
Now take a spring and retainer and put it in a vise and squeeze the spring totally closed. Measure from the end of the spring to under the retainer. This is the collapsed size of the spring. Again add .060 to it for safety. This value must be under the 1.235 height you got for the open value of your gage.
Also get a collection of shims from a speed shop and try to make an agreement to take back any un-used shims.
Now install a valve in the head with the valve seal in place. Be sure to use the plastic cap on the valve to protect the seal. Install the retainer with keepers and pull up on the retainer and insert the large end of the gage you just made. It should fit. If too loose add shims until it is just a snug fit. If the gage is too long you are in trouble and need a higher installed height. Look into different keepers or retainers.
Now that you have the installed height properly set remove the gage and push down on the retainer until it bottoms on the seal. Try the gage now and it should not fit. It should be too long. Another way is put the smaller gage in place while pushing down and there should still be clearance between the seal and the top of the retainer.
If anything doesn't work as I have said please get back to me so we can discuss the problem.
I might have overlooked something or you need to adjust something,
Do this for every valve, don't skip any. I have seen all but one valve have the necessary clearance but one was out and it dropped a valve.
Good luck
Norval
Thought I would share this with anyone would wants to try it themselves. I would certainly help anyone who needs advice or someone jump in if I overlooked anything.
I can certainly talk you through it but you will need a few tools. The big one is the spring compressor. Do you have one? If not you will have to rent one.
You will have to make a little tool. The card with the cam will tell the installed height. It is probably 1 7/8th or 1.875. I take a piece of bronze welding rod and make a piece with radiuses ends or rounded ends exactly this length. Then I take the lift say .580 add .060 for safety for a total of .640. Now subtract the .640 from the 1.875 and you get 1.235. This is the length of the second rod. I then join the 2 rods together with another piece about 3 inches long. Join the 2 rods in the middle roughly on a 45 degree angle with the 2 precise lengths paralled. All this is rough but the rods are exact. Solder them together to form a tool in the shape of a Z but the joining rod not touching the ends but connected near the middle. One end has the installed height and the other the open plus saftey value.
Now take a spring and retainer and put it in a vise and squeeze the spring totally closed. Measure from the end of the spring to under the retainer. This is the collapsed size of the spring. Again add .060 to it for safety. This value must be under the 1.235 height you got for the open value of your gage.
Also get a collection of shims from a speed shop and try to make an agreement to take back any un-used shims.
Now install a valve in the head with the valve seal in place. Be sure to use the plastic cap on the valve to protect the seal. Install the retainer with keepers and pull up on the retainer and insert the large end of the gage you just made. It should fit. If too loose add shims until it is just a snug fit. If the gage is too long you are in trouble and need a higher installed height. Look into different keepers or retainers.
Now that you have the installed height properly set remove the gage and push down on the retainer until it bottoms on the seal. Try the gage now and it should not fit. It should be too long. Another way is put the smaller gage in place while pushing down and there should still be clearance between the seal and the top of the retainer.
If anything doesn't work as I have said please get back to me so we can discuss the problem.
I might have overlooked something or you need to adjust something,
Do this for every valve, don't skip any. I have seen all but one valve have the necessary clearance but one was out and it dropped a valve.
Good luck
Norval
