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Changing valve guides
by
rabbitman
on 21 Feb, 2011 20:04
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I'm putting together my golf and measured the valve guide "rock" like in the bentley. Seven of the valves were .025-.030" (the bentley doesn't give a new spec). One guide, the #2 intake is at .055ish..........the wear limit is .051"
I'm having problems finding a shop that will touch this head so I'm trying to decide if I should, 1) put it together and run it, and in the meantime collect valves, guides and the tools to change them myself if I can't find a shop that will do it.
2) Leave the guide alone and put new valves in (they have slight scratch marks, I can't feel 'em but they're visible),
3) or get new valves and guides. I really want to get this done and out of the shop though.
So will I even notice oil burnage? Can anything bad happen to the engine? What's your opinions?
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#1
by
CRSMP5
on 21 Feb, 2011 20:28
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you cannot just do that...
if you had the "proper tools" go for it.. but i doubt you do...
when you install new guids they will need a reamer run thru them.. no reamer you stand the chance of the valves locking open when warmed up..
you need to cut the valve seats.. this means also shortining the valves a titch (new or used).. having enough valve shims/tools to maybe take it apart a couple times to get the shims in proper tolerance.. you do not want the shims to be thin.. want them to be in the middle..
send it to a shop and just get them done right.. yea shipping will blow from alaska.. but the tools to do it right is far more expensive..
if you 100% trust your head.. aka no cracks or issues talk to myke_w get his head shop info and ship it there..
id ship it with cam removed and have it shipped back with cam removed.. do not ever ship a head with a cam in it.. too easy to tweek a valve which will let the head pop off in a bad moment of life..
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#2
by
rabbitman
on 21 Feb, 2011 20:50
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I should've specified that this is a hydro motor.
I do have access to a valve grinder, I doubt I have a seat grinder though.
I don't have a press or the proper uninstall/install tool.
I'm thinkin' I'll just run it. The only thing that can go wrong is it might burn oil right?
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#3
by
truckinwagen
on 21 Feb, 2011 20:52
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if the guide is too loose you could drop a valve.
not something I would risk with these motors.
I did not have a chance to look the head over really good, I thought it was in much better shape than that...
-Owen
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#4
by
rabbitman
on 21 Feb, 2011 20:54
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#5
by
rdezsofi
on 21 Feb, 2011 22:38
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I have that same tool. Works just fine. Install a valve guide, and test fit a valve. If it's too tight, try another valve. I have about 120,000 on a head where I did the valve guides with no problem. The head originally had around 100,000 on it when I worked it over. I had a machine shop press new valve seats in, and I hand lapped the new valves. Much easier on a hydraulic head, as you don't have to mess with the shims. I have a collection of about 200 shims, and it's time consuming compared to the hydro heads.
If the shop doesn't want to mess with your head.....try disassembling the whole head and see if they will at least do the valve seats to a 45 degree angle. (Or preferably, press in some new ones.) Order yourself some new valves....they are not expensive....so buy quality ones.
Meanwhile, you'll probably just use some oil. Try not to go over 2800-3000 rpm with that loose valve, though. Baby it. As a side note, if it's using some oil and you get some blue smoke, it will take quite a while to clear up after you get the head done, due to the oil residue in the exhaust that will slowly burn off.While you have the head off, it's easy to pull the pan, change out the rod and main bearings and maybe a fresh oil pump. If you do that, it's worth measuring the bore while each piston is down.....often there's minimal cylinder wear, still within specs. If thats the case, you can pull the pistons, hon ethe cylinders and install some Goetz piston rings. You'll be good for 200,000 more.....
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#6
by
rabbitman
on 21 Feb, 2011 22:49
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I have that same tool. Works just fine. Install a valve guide, and test fit a valve. If it's too tight, try another valve. I have about 120,000 on a head where I did the valve guides with no problem. The head originally had around 100,000 on it when I worked it over. I had a machine shop press new valve seats in, and I hand lapped the new valves.
try disassembling the whole head and see if they will at least do the valve seats to a 45 degree angle. (Or preferably, press in some new ones.) Order yourself some new valves....they are not expensive....so buy quality ones.
You'll be good for 200,000 more.....
You did this on a diesel?
This shop was afraid heating the head to loosen the guides would make the seats would fall out and after that it's too iffy to run (he said). I'm sure he wouldn't want to install new seats.
This engine only has 63,000 miles and this whole issue is from the two-owners-agoz friend putting the t-belt tensioner on backwards and smoking the new belt.
Now that I think about it, I bet we do have the right valve grinding stuff for this engine, if the sizes are anything like the aircooled vdubs.
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#7
by
Mark(The Miser)UK
on 22 Feb, 2011 04:12
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I'm putting together my golf and measured the valve guide "rock" like in the bentley. Seven of the valves were .025-.030" (the bentley doesn't give a new spec). One guide, the #2 intake is at .055ish..........the wear limit is .051"
I'm having problems finding a shop that will touch this head so I'm trying to decide if I should, 1) put it together and run it, and in the meantime collect valves, guides and the tools to change them myself if I can't find a shop that will do it.
2) Leave the guide alone and put new valves in (they have slight scratch marks, I can't feel 'em but they're visible),
3) or get new valves and guides. I really want to get this done and out of the shop though.
So will I even notice oil burnage? Can anything bad happen to the engine? What's your opinions?
So is this an n/a Golf?I would not change anything on the head.
The only valve out of spec is an inlet, and will have nothing travelling up the stem any how 
.
Any trivial scoring will serve to hold the lubricant.
A slack valve will still seat correctly/repeatedly.
I don't know why you would want to grind seats anyhow, as long as they seal:
Assemble head, and with head upsidedown pour kerosine on each valve head in turn when shut to check for sealing. Nothing else required other than:
Perhaps change the valve stem seals, if they are not gripping the valve stems, and be sure you assemble them[push them on ] correctly. I think its an 11 or 12mm 12point socket.
Why would the head drop a valve with a slack sleeve?
Give me the money you are going to throw away, and if you get a dropped valve from that intake within 18 months I'll give you double your money back 
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#8
by
maxfax
on 22 Feb, 2011 07:31
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I've run some pretty sad heads.. For quite long periods of time too... Other than maybe a touch more oil consumption (coulda been rings too) they actually ran quite well.. These were all NA's of course.. The exhaust valves were so bad on my last head they literally would just fall out with the seal removed.. Never measured so see how bad they actually were, there was no need..
I guess the real question would be, what are your intentions and expectations of this engine???
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#9
by
rdezsofi
on 22 Feb, 2011 08:05
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I have that same tool. Works just fine. Install a valve guide, and test fit a valve. If it's too tight, try another valve. I have about 120,000 on a head where I did the valve guides with no problem. The head originally had around 100,000 on it when I worked it over. I had a machine shop press new valve seats in, and I hand lapped the new valves.
try disassembling the whole head and see if they will at least do the valve seats to a 45 degree angle. (Or preferably, press in some new ones.) Order yourself some new valves....they are not expensive....so buy quality ones.
You'll be good for 200,000 more.....
You did this on a diesel?
Yes, a 1.6 NA. The seats, valve guides and prechambers are simply a press fit. The guides are quite tight....they probably won't fall out by only heating the head if you tried! A worn guide on the intake side will suck some oil in at higher rpms, but being either cylinder 2 or 3 the problem won't be as noticeable. Cylinders 1 and 4 will suck more oil in around sharp corners as the oil pools there, reesulting in a large cloud of smoke coming out of a long sharp corner taken at speed. The biggest concern is if the head is flat. Ant more than .004 and junk it. Remember that if the head is warped, the cam is being held in a bent position. Milling the head still leaves you with a problem with the cam bearings being in line.
You can mill the head .002 or .003, but you have to remove the prechambers and then they have to be milled down the same prior to being installed.
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#10
by
R.O.R-2.0
on 22 Feb, 2011 08:22
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some people knock the cups out, some people skim the heads with them in, some knock them out and fly cut the precup bore.
i dont think there is really a wrong way. but i would go with the fly cut precup bore personally..
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#11
by
RabbitJockey
on 22 Feb, 2011 18:20
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yeah i think the right way to do it is to remove the cups, surface the head then skim the same amount off the top of the cups or the top of their hole in the head, then reassemble the pre cups are supposed to stick out a small amount to account for heat expansion
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#12
by
rabbitman
on 22 Feb, 2011 19:35
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I guess the real question would be, what are your intentions and expectations of this engine
Some day I'd like to turbo it.......
, I have that euro vnt-15 that wouldn't boost on my rabbit that I'm gonna send out and get fixed (some day), and from what I've read the euro vnt shouldn't interfere with the rear mount.
I talked to the guy at aircooled engines plus about the guides and he said "just bang 'em out and bang the new ones in", haha. He also said heating the head to 200-220F would help loosen the guides without loosening the seats too much, 300F is the limit and after that things start getting loose.
I checked my available tools and found the guide reamer and all seat and valve grinding stuff in case I have to grind anything, then I ordered the guide tool on ebay.
I really hate putting a head on with stuff out of spec, I have the stuff and it's all apart so I guess I should do it right.
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#13
by
maxfax
on 22 Feb, 2011 19:51
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I really hate putting a head on with stuff out of spec, I have the stuff and it's all apart so I guess I should do it right.
That's typically how I feel about things, unless it's some POS beater that I'm just running into the ground... By the sounds of things this one doesn't fall under "POS beater".. You're this far into it, what's a little bit more??
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#14
by
rabbitman
on 22 Feb, 2011 20:01
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That's typically how I feel about things, unless it's some POS beater that I'm just running into the ground... By the sounds of things this one doesn't fall under "POS beater".. You're this far into it, what's a little bit more??
This car is supposed to get me out of the "he drives a beater" class without getting a car that I really hate haha, I'll get a cushy newer car when I'm old and boring
. I want to get the rabbit off the road for a while and do some rust repair, fix some oil leaks and quiet it down a lot and I need another car that I like during that time.......I'm not planning to sell the golf afterwards though.