thank you. i may just order a set of those
valves for small block 587 heads
- Thread starter texas360
- Start date
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i dont plan on running 2.02 valves.. im trying to build these heads on a budget and limit as much machine shop money as possible
I like just using brand new valves, feel like it is one half of the valve job having them ready to go. Then they stand up higher in the chamber because they have not been ground sitting in lower like a used valve. Standing up higher adds to better compression ratio.
Then new valves have the new stems so they fit tighter in your existing valve guides, unlike used valves being worn down making the guides looser. Not to mention not having to clean all the carbon off a used valve and grind the face to fit the seat.
Check your valve seats in the head, maybe a light grind if needed, lightly lap the valves in with some compound, new seals and you are good to go.
how do i check and make sure guides dont show too much wear,,
Without being particular enough to measure, I stick the valves in almost seated and wiggle the head back and forth in a few directions. You shouldn't have much if any play.
There is another little trick. With the valve springs and seals off run the valve open about 1". Then put a finger over the top of the valve guide. With the tip of the valve stem right at your finger, pull the valve out real quick. If you hear a pop sound then you know your guides are pretty good. No pop means your guides are getting looser because air is getting around the loose valve in the guide. Mike's wiggle the valve test is good to do too.
Can try again with the new valves they should fit tighter than the used ones. Sometimes the end of the used valve stem gets hammered over enough by the rocker arms that they are hard to push back out through the guides.
So stop right there and take some 180 grit emery paper, sand the tip of the valve stem while rotating the valve with your other hand to get the burr off the end so it will easily slide out. Otherwise you will damage the valve guide trying to push the valve out with the burr on the end.
The exhaust valve has a greater tolerance for the expansion due to the hot gasses so they will not "Pop" as loud as the intake valves and guides.
And yes there is a few thousands difference between the intake and exhaust valve stem diameters to deal with the extra heat on the exhaust side.
Most of the times the exhaust guides will wear out first from the extra heat associated with them. Can try the new valves and see if they tighten up within reason.
If not then there is the knurling process that can be done to save the existing guide and get it to tighten up again.
Have done all the exhaust guides by knurling on some heads and all the intake guides were good yet. Just have to see what you have there.
Can try again with the new valves they should fit tighter than the used ones. Sometimes the end of the used valve stem gets hammered over enough by the rocker arms that they are hard to push back out through the guides.
So stop right there and take some 180 grit emery paper, sand the tip of the valve stem while rotating the valve with your other hand to get the burr off the end so it will easily slide out. Otherwise you will damage the valve guide trying to push the valve out with the burr on the end.
The exhaust valve has a greater tolerance for the expansion due to the hot gasses so they will not "Pop" as loud as the intake valves and guides.
And yes there is a few thousands difference between the intake and exhaust valve stem diameters to deal with the extra heat on the exhaust side.
Most of the times the exhaust guides will wear out first from the extra heat associated with them. Can try the new valves and see if they tighten up within reason.
If not then there is the knurling process that can be done to save the existing guide and get it to tighten up again.
Have done all the exhaust guides by knurling on some heads and all the intake guides were good yet. Just have to see what you have there.
i was looking at the knurling process and thats pretty neat process, but wow the kits to perform are almost $500. wowza... i think my intake guides are fine for sure.. i get a good suction and pop, but my exhaust valves not so much.. but im also checking with worn out valves so they may not exactly be correct stem size from wear
how much clearance should i have? i have a dial gauge and could check play that way, i dont have any small measuring tools with micrometers
Lisle tools had a inexpensive knurling tool back when. I saw one on E bay for sale. Not a permanent fix but it does "tune up" the guides and takes some of the slop out. Bronze guides or guide inserts seem to be the way to go.
Can try the wiggle test with the exhaust valve put in upside down, less wear on the valve stem on the top vs the bottom by the head. Then you can try the wiggle test in the valve seat area with the top of the valve stem coming through there for your test. If it tightens up enough without clicking while wiggling, then the new valves should take care of it.
Otherwise take the heads into a machine shop to have the exhaust guides knurled, simple task for them. Bring your new valves with so they can get the fit right.
These are some nice stock style umbrella valve seals, for intake and exhaust with stock style springs.
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