Valve Job/Adjustment: Tipping vs. Shim Replacement (1 Viewer)

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This topic is mentioned a bunch, but I couldn't find a definitive thread comparing the two.

To be short, my head gasket blew, the head is off and I'm ready to bring it to the machine shop to get a valve job (regrinding valves/seats and installing new seals/guides). I called two shops in my area that came well recommended.

Shop A: Adjusts valves by "tipping" them; grinding a bit off the stem.

Shop B: Adjust valves by replacing shims.

I'm trying to decide which way to go and am looking for pros and cons for each. I'll start; from what I understand...

VALVE TIPPING****************************

+ Pro 1: Cheaper.
+ Pro 2: Faster turn-around time.

- Con 1: Grinding can remove the hardened coating of the stem to expose the non-hardened metal; thus introducing premature wear.


VALVE SHIM REPLACEMENT********************

+ Pro 1: Wear surface at cam/shim interface is renewed.

- Con 1: Shims are hard to find.
- Con 2: Shop charges are higher due to increased time and materials.
 
Last edited:
Joined
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I have heard of shops that grind the shims as well. If it were my engine torn down - I would want the new proper shims in it for reassembly. Do it right and you will probably never revisit it for the rest of the trucks life.
 
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Shop A: Adjusts valves by "tipping" them; grinding a bit off the stem.

Shop B: Adjust valves by replacing shims.

I'm trying to decide which way to go and am looking for pros and cons for each. I'll start; from what I understand...

VALVE TIPPING****************************

+ Pro 1: Cheaper.
+ Pro 2: Faster turn-around time.

- Con 1: Grinding can remove the hardened coating of the stem to expose the non-hardened metal; thus introducing premature wear.


VALVE SHIM REPLACEMENT********************

+ Pro 1: Wear surface at cam/shim interface is renewed.

- Con 1: Shims are hard to find.
- Con 2: Shop charges are higher due to increased time and materials.
When I had my heads overhauled my valves were tipped (80 and 3.0 4runner). You're talking a few thousandths of an inch, it's SOP during an overhaul.

Grab your FSM and look through the section on the cylinder head and you'll find the specs on the valves and process to tip the valves. In the '94 manual it is on pages EG-55 & 56. If after the grind and tipping they are below spec they must be replaced. If the OEM shows the practice in the manual it is accepted.

That said save yourself the $$ and reuse all of your existing shims.
 
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If it were my engine torn down - I would want the new proper shims in it for reassembly. Do it right and you will probably never revisit it for the rest of the trucks life.
Per the '97 FSM (page EM-5 "Adjust Valve Clearance"), the way to adjust valve clearance is to replace shims; plain and simple.

Grab your FSM and look through the section on the cylinder head and you'll find the specs on the valves and process to tip the valves.
Per the '97 FSM (page EM-29 "Inspect and Grind Valves"), the only mention of grinding the valve stems is: "Check the surface of the valve for wear. If the valve stem tip is worn, resurface the tip with a grinder or replace the valve. NOTICE: Do not grind off more than minimum."

If you had intake and exhaust valves that fall on the lower end of "standard length", then it would permissible to grind off:

0.012" from the intake stems

0.011" from the exhaust stems

So, the FSM only calls out grinding valve stems for resurfacing; not for adjusting valves. But, this advice to grind the stems, even a bit, could be interpretted that it is permissilbe to adjust the valves in this manner as well.

Taking off 11 or 12 thou from the valve is a bit sketchy as the depth of the hardened heat treated layer may be 0.010" or less.

So, in regard to "To Tip" or "Not To Tip", if the material removed during grinding did not cause the stem to fall below the minimum length, there should be no problem as far as Mr. T is concerned.

I have no idea how much the machine shops grind off of the stems to adjust the valves. If it's usually only a few thou, I'd feel pretty comfortable with the procedure. If it approaches 0.010", I'd be weary.

Does anyone know?

.
 
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Canyon Lake, TX
 
 
I just finished putting my cruiser back together from a valve job and the machine shop tipped the valves. I ask about the valve adjusting and was told that the shim kits would cost him $250 + the last time he checked and that he just doesn't do enough Land cruisers to justify the capital expense. I was then told that Land cruiser heads use a bigger puck than any of the other toyota engines/heads so he can't use them on other engines. He timed himself and said it took every bit of 2.5 hours to set the valves.

I have only had to do a valve job on my Land cruiser so my experience is limited, but I look at it this way. Toyota wants you to replace the head if it has to be milled down at all. That is setting a very high standard. My guess is that the same standard is carried through to tipping the valves. The head on my cruiser had to be milled .008 in order to remove the impressions caused by the firing rings of the old head gasket. It was good and straight to start with.

I think the design of later cruisers (cam on puck) makes the chance of a problem minimal. The pucks only push down directly on top of the valve. Compare this to the older valve trains that have a rocker arm which hits the top of the actual valve. The rocker arm moves in a slight arc when it pushes down on the top of the valve introducing a lateral force causing more wear. It would seem that the condition of the top of the valve is more important in the older engines.
 
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when i had my head rebuilt i checked all the valve tolerences before taking the head to the shop. after the valve seats were resurfaced i oked the shop to "tip" the valves slightly to bring all back to spec. i made the shop hold reassebly of the head untill i personally took a feeler guage to the valves and confirm they were to spec. only then did i let the shop reassemble the head. pucks vs tips is not as important as the tolerances themselves.

one adnvantage to tipping the valves is that you can be very specific as to where you want the valves. the fsm gives an acceptable range for valve clearance. with tipping you can ask a good machinest to stay to the tight or loose side of that range and get the valves right where you want them. cant do easily by shuffling pucs

also the pucs themselves have tolerances within their holes. you get new pucks and they may be out of spec

the sad thing is that my motor ran perfect before I PMed the head gasket which turned out to be perfect. but now at leaste my motor doesn't smoke because of the new valve seals
 
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When I had my heads overhauled my valves were tipped (80 and 3.0 4runner). You're talking a few thousandths of an inch, it's SOP during an overhaul.

Grab your FSM and look through the section on the cylinder head and you'll find the specs on the valves and process to tip the valves. In the '94 manual it is on pages EG-55 & 56. If after the grind and tipping they are below spec they must be replaced. If the OEM shows the practice in the manual it is accepted.

That said save yourself the $$ and reuse all of your existing shims.
If I had it to do over, I would do this, no questions asked. My motor is back together with one shim slightly out of spec loose because I got tired of waiting for the last shim. It seems at least one size of shim is always made of unobtanium.
 
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I have no idea how much the machine shops grind off of the stems to adjust the valves. If it's usually only a few thou, I'd feel pretty comfortable with the procedure. If it approaches 0.010", I'd be weary. Does anyone know?.
Well, I just called "Shop A" and asked, on average, how much they grind off when they tip the valve stems. Obviously, it's hard to deliver an "average", but the shop owner conveyed that it's usually in the range of 3 to 7 thou.

I asked him if it ever approached something like 0.010" and he said "Jesus, no! If the valve is that bad, we'd put in a new one."

So, at least at this shop, it seems like valve tipping would not remove ALL of the hardened heat treated material.
 

cruiserdan

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The ammout of material removed from the end of the stem will be equal to the amount of material removed from the valve margin and the seat in the head, assuming that the clearance was in spec before the valve and seat were ground. Nipping a bit off of the end of the stem is not at all a problem. If the valve had to be ground enough that the stem would have too much material removed the valve margin would also be insufficent and the valve would get tossed in the dustbin.
 
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As indicated there is no major drama to adjust valve clearances by grinding the tips as long as the specs noted in the FSM are upheld. Save yourself the headaches and more importantly $$ and consider this when having your head overhauled.
 

Onur

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If I had it to do over, I would do this, no questions asked. My motor is back together with one shim slightly out of spec loose because I got tired of waiting for the last shim. It seems at least one size of shim is always made of unobtanium.
Where did you try to get the shim from? I've never had any issues geting shims from Toyota. They might take a while depending on supply and if they are on the slow boat from the islands.

Also, what size do you need?

Thanks.
-o-
 
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FJ80 Head/Valves

I had my '95 FJ80's engine completely rebuilt. When I got it back everything ran perfect except for the apparently popular 'smoke at startup'. It also used much more oil than I was willing to accept. I returned the truck and the engine was pulled again and all block machining specs were verified. The head was checked again and I was told all was correct. Well... it isn't. Smoke at startup and too much oil consumed. Thanks much in part to this site, I believe the shop was not prepared to handle the head correctly. Sorry for the long message, but here is my question. Who around Greenville, SC really knows how to rebuild the head and make sure the valves are right? Is there anyone from Atlanta to Charlotte that comes with a recommendation. Thanks in advance, Ray
 

Onur

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In the ATL area I would definitely recommend Michael and his crew at ACC (Atlanta Custom Creations). They are very well-regarded in the LC world and do top-notch work.

They are vendors here and support the Land Cruiser community.

Good luck.
-o-
 

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