Valves for 243 heads / Suggestions?
Valves for 243 heads / Suggestions? I recently purchased a set of heads from a member here, and I'm getting ready to install them on my truck. I sat down with my uncle who has experience rebuilding heads, and he pointed out a few small issues that I want to take care of before slapping them on the truck (this is my daily driver). All of the sealing surfaces of the heads are in great shape, and the straight edge backs that up. The valves however look like they have lost the hardened tips, and they are starting to flake. For safe measure I'm going to put new valves in. We're also going to cut new seats, and adjust the valve heights. Does anyone have any recommendations on what valves I should purchase? Also when adjusting valve heights, how much material can be removed from the tip of the valves safely? Thanks for reading this. Any and all info is much appreciated.
243 heads.
Valves that are flaking.
Heads after a good soaking in the hot tank.
243 heads.
Valves that are flaking.
Heads after a good soaking in the hot tank.
I'm crossing my fingers that the seats won't be in bad shape, and we can just lap the valves, drop the new valves in, and the heights won't need to be adjusted. I would just like the information before we get started, if possible. With my luck I know that won't happen, but I can dream right. I'll be taking the heads apart tonight after work and checking everything before ordering parts. We'll also be measuring the valve guides to see if the valve guides need to be replaced as well. I really don't want to have to pull the heads again for a while if I don't have to.
What are all of the measurements I need to be aware of while rebuilding these as well guys? I'm sure my uncle will fill me in, but for my own information I would really like to know. So far I've gathered that the following are important measurements.
Cylinder Head Deck Flatness - .004"
Installed Valve Spring Height - 1.800"
Valve Spring Shims - 1.250" O.D.
Valve Stem Height - ???? (I'm planning on measuring what the valve stem height on my 317 heads are currently, taking an average, using the average height I get and using that number on the new valves) (I can't seem to find an installed valve stem height listed anywhere)
Valve stem diameter - .313"-.314"
Valve guide installed height - .682"
Valve face angle - 45 degree
Valve seat angle - 46 degree
If I'm missing anything, or my numbers are wrong, I would really appreciate some guidance/help. Thanks.
Cylinder Head Deck Flatness - .004"
Installed Valve Spring Height - 1.800"
Valve Spring Shims - 1.250" O.D.
Valve Stem Height - ???? (I'm planning on measuring what the valve stem height on my 317 heads are currently, taking an average, using the average height I get and using that number on the new valves) (I can't seem to find an installed valve stem height listed anywhere)
Valve stem diameter - .313"-.314"
Valve guide installed height - .682"
Valve face angle - 45 degree
Valve seat angle - 46 degree
If I'm missing anything, or my numbers are wrong, I would really appreciate some guidance/help. Thanks.
Last edited by PowellSixO; Feb 6, 2017 at 11:32 AM.
Well, I guess I'll post my findings later after I tear the heads apart. I've looked all day for an answer on the installed valve stem height and only found one guy who claimed 2.000". I'll measure tonight and post back tomorrow probably.
The stock heads have hardened exhaust valve tips welded on as I recall. So if you grind them down, you will no longer have a hardened tip. You could run caps or replace the valves. Some of the head shops (e.g., Livernois) used to keep sets of the lightweight LS6 valve stems when they were upping valve size and you could but a set used from them and others. I would try that first so you get GM valves of the proper length. I always laps valves before installation into the heads as a final last step and to verify the sealing surface.
The stock heads have hardened exhaust valve tips welded on as I recall. So if you grind them down, you will no longer have a hardened tip. You could run caps or replace the valves. Some of the head shops (e.g., Livernois) used to keep sets of the lightweight LS6 valve stems when they were upping valve size and you could but a set used from them and others. I would try that first so you get GM valves of the proper length. I always laps valves before installation into the heads as a final last step and to verify the sealing surface.
We took my 317 heads apart last night, and the 243 heads and took some measurements. The installed spring height was 1.800", which is what I had set my PAC 1218's to when I did my cam. And the valve stem height was indeed 2.000" +-.005". We check the valve guides, and they were still good. We ordered a set of valves from his supplier (not sure who that is honestly, but I'll find out). The new valves will be here today. The valve seats looked pretty good, minus a little carbon on the exhaust valves. I'm going to hot tank the heads one more time today, and then we'll see exactly where we are with the valve seats. I'm thinking we'll only have to lap the new valves in, and not have to cut any new seats. But we'll see this evening.
I didn't have a lot of luck tanking the heads. I used a bamboo chopstick that I filed down to look like a chisel and used that to remove heavy deposits and then cleaned the heads. The bamboo won't damage the aluminum and it works well for removing deposits.
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Good tip. I'll try that.
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Well I got the heads back together last night. I hot tanked them all day, and they came out pretty damn clean. The intake seats looked pretty good, but the exhaust seats looked a little rough. The exhaust seats ended up just having carbon on them. We were able to clean the seats, lap the new valves to the seats, and tested them with some sort of liquid (can't remember the name of it). The seats were in good enough shape still, that we didn't have to shave any of the new valves. They all installed right at 2.000" with a few going 2.005". We then put the new valve stem seals in, my PAC 1218 springs, and retainers and clips back in. We checked the installed spring height which came out to 1.810-1.815" on all of the springs. Since I have my rev limiter set at 5900 in my truck I don't think this will be a problem. Any who, they're back together and I'll start the process of putting them back in the truck tonight.
Carbon on exhaust valves seats before cleaning them up.
New valves.
Heads back together. I forgot to take pictures of the valve seats after they were cleaned and lapped.
Carbon on exhaust valves seats before cleaning them up.
New valves.
Heads back together. I forgot to take pictures of the valve seats after they were cleaned and lapped.
Summit for example:
https://www.summitracing.com/oh/sear...mounted-steps/
Well it's finally finished. Getting the bolts torqued was a pain in the butt! I need to get a longer 1/2" ratchet. Lol.
Bolts finally torqued.
New knock sensors and wiring harness just because.
Ready for the intake.
Ready to start and check for leaks.
It's official. I've got 243 heads on the truck finally.
First start up.
Bolts finally torqued.
New knock sensors and wiring harness just because.
Ready for the intake.
Ready to start and check for leaks.
It's official. I've got 243 heads on the truck finally.
First start up.