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  #21  
Old 04-20-2017, 07:10 AM
Witsend Witsend is offline
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Seems cheaper and probably last longer to just get all new ones for $7-$12 ea than to bother with a valve job.
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  #22  
Old 04-20-2017, 06:15 PM
Crusty Crusty is offline
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Exhaust valves get a lot of heat on the stems. Replacing the exhaust valves isn't a bad idea.
Intake valves are a different story though. They don't get the same heat and drop the valve head like exhaust valves can. After refacing the intake valves, if they're too "sharp", THEN replace them.
Regardless, new valves and NOT cleaning up the valve seats is kinda like taking a shower and putting dirty socks back on. Same as refacing the valves and not trimming up the seats.....only half a job. New valves or refaced intake valves......
Even the position of the valve/seat mating lines is important once you're in that far. Just lapping them in may not get the position of the seal in the optimum position. (nevermind three angle valve jobs that all the hot-rodders used to brag about. Sometimes we would cut 5 angles to get things just right-!!) (taught by OLD SCHOOL machinists before the apprenticeship started back in the day....)
Why not take the heads to a machine shop and let them do the heads completely and properly-?? Sometimes heads can be machined and only take 3 to 7 thou off if the machine shop knows what they're doing. The head gaskets will thank you.
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  #23  
Old 04-20-2017, 10:01 PM
Witsend Witsend is offline
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It's a Lap Dog that I don't want to toss any more bones at I believe the valves and seats get cut, the metal may not be quite as hard and durable any more.
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  #24  
Old 04-21-2017, 07:13 PM
Glide Glide is offline
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As much as I don't like to agree with Crusty,I've yet to see any reason to replace any valves in these engines,even those with 400,000 km on them.
New aftermarket valves won't last near as long as a properly ground set of factory ones.
I grind my own,always have.Lapping destroys the interference angle and shortens the life of your valve job.
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  #25  
Old 04-24-2017, 07:22 PM
STURNER STURNER is offline
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I feel this may be an a lot of hours and money spent just to be on the hook for the warranty when it's all over. I won't say that a reman unit would be better than the work you have performed but it would have been gone a long time ago with minimal worry.
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  #26  
Old 04-24-2017, 09:37 PM
Witsend Witsend is offline
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Quote:
I feel this may be an a lot of hours and money spent just to be on the hook for the warranty when it's all over. I won't say that a reman unit would be better than the work you have performed but it would have been gone a long time ago with minimal worry.
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Man, I sure hope it doesn't work out badly. Just pre lubed and got the short block bolted up, Still waiting on the 8 new exhaust valves. (Melling), same brand as the regular roller lifters I put in. Installed AC/ Delco AFM lifters. Also Changed the 4L60E front pump seal and turbine shaft seal on the transmission, drained the converter overnight and the trans filter, so hoping both the trans and engine won't mess up together.
Thought it was pretty interesting that when the AFM solenoids are Not energized , oil doesn't flow to the AFM lifters as far as I could tell.

Last edited by Witsend; 04-25-2017 at 08:33 PM..
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  #27  
Old 04-25-2017, 05:22 AM
Crusty Crusty is offline
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Quote:
Originally Posted by Glide View Post
As much as I don't like to agree with Crusty,I've yet to see any reason to replace any valves in these engines,even those with 400,000 km on them.
New aftermarket valves won't last near as long as a properly ground set of factory ones.
I grind my own,always have.Lapping destroys the interference angle and shortens the life of your valve job.
Hey Glide. Polite agreements and dis-agreements are what makes this site much better than others.
As for aftermarket valves, there are some that are quite acceptable, others not quite so acceptable.
Sure, re-use the original valves and face them yourself, but, even factory valves have a limit and can be faced and still have too thin a "lip" which will "tulip" up so replacement may be appropriate. It depends on how much metal is remaining after re-facing.
The valve stems can also become worn and before we wasted time re-facing any intake valves, they were inspected. Anything more than one or two thou were tossed aside.
As for the EXHAUST valves, my mentors taught us that the stems could have taken too much heat and weakened the metal at the thinnest point (just where the valve head tapers down to the stem) and re-facing the intakes (where enough metal remains) and replacing the exhaust valves (with quality components) resulted in fewer problems.
Oh, you're absolutely correct about the lapping. We would lap every valve in place simply enough (VERY little) to get the witness line showing exactly where, and how wide, the contact between the face and the seat was.
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  #28  
Old 04-25-2017, 08:31 AM
Witsend Witsend is offline
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Thought I recall back in the Nineties , Ford training class telling us that valve and seat refacing should no longer be done in Stone Age Fashion with grinding stones, and specified using equipment that cuts the valves and seats. Absolutely no more Knurling of Valve guides.
I also seem to remember the expensive on car brake lathes that they wanted the brake rotors machined with , and the expensive Road Force Wheel Balancers. These ingenious ideas worked to save on new car warranty expenses, changing rotors hubs , bearings, tires and wheels that weren't manufactured perfectly true.Not popular with flat rate techs , for saving time and making money though
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  #29  
Old 04-25-2017, 05:42 PM
Crusty Crusty is offline
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Quote:
Originally Posted by Witsend View Post
Thought I recall back in the Nineties , Ford training class telling us that valve and seat refacing should no longer be done in Stone Age Fashion with grinding stones, and specified using equipment that cuts the valves and seats. Absolutely no more Knurling of Valve guides.
I also seem to remember the expensive on car brake lathes that they wanted the brake rotors machined with , and the expensive Road Force Wheel Balancers. These ingenious ideas worked to save on new car warranty expenses, changing rotors hubs , bearings, tires and wheels that weren't manufactured perfectly true.Not popular with flat rate techs , for saving time and making money though
Whether one uses stones or cutters, it's the end result that really matters-!! As for knurling valve guides, that was NEVER a "proper" repair. Back in the 70's there was the capability to drill out worn guides, then press in NEW guides. Done correctly they would outlast the original guides.
On-Car brake lathes simply MASKED the ROOT CAUSE of the brake vibrations, but you're correct....it was an attempt to save the manufacturer warranty money for sub-quality OE components. Had one recently where the customer and I both knew the hub had a bit of an issue, and we decided to have the dealer trim the rotor to true on-the-car. Later, when the bearing eventually needed to be replaced, THEN we also replaced the hub with the bearing.
Road force balancing has its place, but it's usually only necessary when the tire name-brand isn't one of the top-shelf brands. Good tires don't need the fudging....
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  #30  
Old 04-27-2017, 11:21 AM
Witsend Witsend is offline
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Unhappy Transmission dipstick tube, any trick to install it?

From messing with the dipstick tube bracket, bending bracket away from the bell housing stud bolt in order to remove bell housing bolt the dipstick tube seal showed leakage, so after the engine was out I decided to change the cooler lines, trans front seal and a new trans dipstick tube seal. Not wanting anything in my way torquing down the heads , I left the trans dipstick tube removed, but now I can't figure out how to get the trans dipstick tube installed because the head , rear heat tube, AC accumulator are in the way. There has got to be a trick to get the turd in without beating the living f@ck out of the dipstick tube in order to get it to get past , but it will likely crack it or slice the seal grommet. GM had a recall on the trans dipstick tubes, so what did all the Bushers do to get them in and out? Unbolt the trans mount and Jack up the transfer case and back of trans I wish I had installed the trans dipstick tube before installing and torquing down the right cylinder head
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