set valves on 300 I6
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set valves on 300 I6
Howdy,
I have an, 87 f150 with 300 I6 and EFI. I had a cracked head, so I bought one in a junk yard. Did thorough cleanup and lapped in the valves by hand. Everything looked good. Installed and when I went to fire it up I had low compression and no compression in most cylinders. I understand (Now!) that you have to grind the valves to a certain length so the rocker fulcrums bottom out in the right place. Thus, I removed material lapping the valves and some are hanging open when the bolts are tightened down. Can I do anything about this without removing the head again? Is it possible to shim the fulcrums individually up? Could I Install studs with locking nuts instead of the 5/16" bolts? Can somebody please help me? Also, is there supposed to be an load at all applied to the lifters or ideally do the valves just sit on the rocker arms and no force is applied? Thanks for your time.
-Greg Beaman
I have an, 87 f150 with 300 I6 and EFI. I had a cracked head, so I bought one in a junk yard. Did thorough cleanup and lapped in the valves by hand. Everything looked good. Installed and when I went to fire it up I had low compression and no compression in most cylinders. I understand (Now!) that you have to grind the valves to a certain length so the rocker fulcrums bottom out in the right place. Thus, I removed material lapping the valves and some are hanging open when the bolts are tightened down. Can I do anything about this without removing the head again? Is it possible to shim the fulcrums individually up? Could I Install studs with locking nuts instead of the 5/16" bolts? Can somebody please help me? Also, is there supposed to be an load at all applied to the lifters or ideally do the valves just sit on the rocker arms and no force is applied? Thanks for your time.
-Greg Beaman
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set valves on 300 I6
I was wondering if I could install studs and buy some locking nuts, similar to a chevrolet (I know that is a bad word here) set-up and have a full range of adjustment without having to remove the head. Anyone have any comments? Has anyone done this sort of thing before? Thanks. You guys seem to be very knowledgeable. Hope someone can help me.
-Greg Beaman
-Greg Beaman
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set valves on 300 I6
Just in case anybody cares about this...I did find some excellent info on this sort of procedure. The link is as follows:
http://www.cranecams.com/master/adjustvt.htm
For any other cheap skates (or just plain poor like me) out there. These people sell a shim set made just for adjusting a valve train without having to cut the valves to length. It also explains the reasons and procedure for such an adjustment. I would be wary of putting studs in the head like I discussed earlier, due to the rocker alignment pieces. they are designed to align the rockers only for assembly but are then bolted down and supposed to carry no load. The shim solutiong compensates for this problem and is probably cheaper too. The set is only about $10. I will keep you posted on the results of the actual installation. Thanks again to those who replied with help.
-Greg Beaman
http://www.cranecams.com/master/adjustvt.htm
For any other cheap skates (or just plain poor like me) out there. These people sell a shim set made just for adjusting a valve train without having to cut the valves to length. It also explains the reasons and procedure for such an adjustment. I would be wary of putting studs in the head like I discussed earlier, due to the rocker alignment pieces. they are designed to align the rockers only for assembly but are then bolted down and supposed to carry no load. The shim solutiong compensates for this problem and is probably cheaper too. The set is only about $10. I will keep you posted on the results of the actual installation. Thanks again to those who replied with help.
-Greg Beaman
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From: Northeast Wisconsin
set valves on 300 I6
I have the exact same '87 300CID inline 6 you have, and just did a valve job also. I encountered the exact same problem. I thought the push rods had magically grown about 3/4" while I had the head off. When re-installing, both valves on each cylinder would open when I tightened down the rocker arm. I thought I had gone nuts ... couldn't figure it out. Checked around with "knowledgeable" friends, and they also suggested the machine shop had either planed the head or forgot to compensate for the valve grind by not removing enough from the valve stems. Turns out none of this was true.
I know it sounds strange, but here's how you fix the problem:
1. Remove all 6 spark plugs, to take the compressive load off the pistons.
2. Crank over the engine with the starter for about 45 - 60 seconds. Have a friend put their hand close to one of the plug holes while you crank. At first they'll feel no or very littly air coming out, but it'll increase as you continue to crank the engine.
3. After the 45 - 60 seconds, stick the plugs back in and start the engine.
I know this sounds VERY strange, but go to the other forum that covers the '87 F-150s (I can't remember the exact range of years it's listed under ...87 - '96, I think) and look for a recent posting (Tuesday, 03/11) entitled "'87 F150 300cid inline 6 valve grind problem" I posted). The last post explains what happens and why the steps above work. The valves were working right before you took the head off, and nothing else changed in the lifter system, so it HAS to work when you put it back together. You don't need to add any shims, re-grind anything, or jump through any hoola-hoops. You're almost there, believe it or not!!
I had occasion to verify my logic today when I looked at a Mitchell book on how a hydraulic lifter is constructed.
I know it sounds strange, but here's how you fix the problem:
1. Remove all 6 spark plugs, to take the compressive load off the pistons.
2. Crank over the engine with the starter for about 45 - 60 seconds. Have a friend put their hand close to one of the plug holes while you crank. At first they'll feel no or very littly air coming out, but it'll increase as you continue to crank the engine.
3. After the 45 - 60 seconds, stick the plugs back in and start the engine.
I know this sounds VERY strange, but go to the other forum that covers the '87 F-150s (I can't remember the exact range of years it's listed under ...87 - '96, I think) and look for a recent posting (Tuesday, 03/11) entitled "'87 F150 300cid inline 6 valve grind problem" I posted). The last post explains what happens and why the steps above work. The valves were working right before you took the head off, and nothing else changed in the lifter system, so it HAS to work when you put it back together. You don't need to add any shims, re-grind anything, or jump through any hoola-hoops. You're almost there, believe it or not!!
I had occasion to verify my logic today when I looked at a Mitchell book on how a hydraulic lifter is constructed.
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From: Keweenaw Bay, MI
set valves on 300 I6
Them lifters were probably still charged with oil from prior to you doing your valves. After your valves were done, the height of that lifter has to be less because the grind on the head and on the valve removed metal. The last post is accurate on what to do. The oil is kept in these lifters by a check valve that is internal to the lifter and the lifter has to bleed the excess oil out in order for it to get to the desired height.
