MoparFins

Please login or register.

Login with username, password and session length
Advanced search  

News:

We changed servers, which is good, and lost all passwords, which is bad. See above.

Pages: [1] 2   Go Down

Author Topic: Worn Valve Guides  (Read 1267 times)

Dan Cluley

  • Hero Member
  • *****
  • Karma: +0/-0
  • Posts: 532
    • View Profile
Worn Valve Guides
« on: April 14, 2010, 11:38:56 PM »

Next question in the Dart head swap:
 
My mechanic friend Kenny has got the '85 heads apart and says the valves look ok, but the guides are worn.
 
His first suggestion was to knurl the guides, but he doesn't have the right size tool(he's a Ford guy).  Doing a little looking online, I'm seeing suggestions that this isn't a good permanent fix, and that the tools are not cheap.
 
FSM says to ream the guides, and use oversize valves.  Kenny thinks .005 would be enough.   Looks like a new set of vavles would cost more than the knurling tool, but not a lot. 
 
So, I'm not sure which way to go, and am not sure what tool is needed.  Since Kenny doesn't have much Mopar experience I want to double check what size reamer is needed. 
 
Thanks,
CBarge2010-04-15 14:12:26
Logged
1965 300 Convertible
1974 Dart Sedan

Steve

  • Administrator
  • Hero Member
  • *****
  • Karma: +1/-0
  • Posts: 8653
    • View Profile
Worn Valve Guides
« Reply #1 on: April 15, 2010, 07:17:25 AM »

Tough call Dan
 
It depends on how bad the guides are.
Logged
Favorite Expression. . . Damned Kids.  Lots of projects.  Donations accepted

Stewart Van Petten

  • Jr. Member
  • **
  • Karma: +0/-0
  • Posts: 85
    • View Profile
Worn Valve Guides
« Reply #2 on: April 15, 2010, 08:04:37 AM »

Why can't you install some new bronze guides? If the only choices are larger valves or knurling I would go with larger valves. New valves will last longer than knurling the guides.
Logged
Polaraco made me do it

Steve

  • Administrator
  • Hero Member
  • *****
  • Karma: +1/-0
  • Posts: 8653
    • View Profile
Worn Valve Guides
« Reply #3 on: April 15, 2010, 08:57:22 AM »

That is true. . .But Dan isn't a walking money factory.  Looking for a way out Stu.  LOL
 
I've run on bad guides for years. . .
Logged
Favorite Expression. . . Damned Kids.  Lots of projects.  Donations accepted

Guests

  • Guest
Worn Valve Guides
« Reply #4 on: April 15, 2010, 07:23:48 PM »

Knurled guides is a short term fix at best, maybe a couple years out of it and you have wasted all the time and energy just to do it again.  1985 should have those really good PC seals on the stems, are in the gasket sets to start with, and are pretty good at keeping oil out of where it isn't supposed to be. Oversized valve stems, as you noted, doesn't fix the problem, just puts new parts on old parts (both ways actually), so the question to help with the decision is, were the guides worn to the point that the faces of the valves themselves were not the proper colors (light exhaust, darker intakes), because if they were OK sealing, PC/Viton seals will probably save a whole lot of money for now, as a set of yard heads with proper colored valve faces would be about the same cost of new oversized valves.
Logged

Dan Cluley

  • Hero Member
  • *****
  • Karma: +0/-0
  • Posts: 532
    • View Profile
Worn Valve Guides
« Reply #5 on: April 15, 2010, 09:37:19 PM »

Ok, knurling is definitely out. 
 
Assuming I can get the oversized vavles (haven't talked to anyone locally, but looking online I see intake, but no exhaust yet) that seems like it would be about half the cost of replacing the guides.  Is there a real advantage to new guides that would make it worth the difference.
 
Digging a little deeper in the '74 FSM it looks like the reamer should be .002 bigger than the valve stem.  but they say the total allowable play is .017  That seems like quite a range?
 
 
-----
 
Dana44:
 
I'm not sure I'm following all of your post.  Are you suggesting that if the guides are only worn a little to just put new seals on and ignore it?   Unfortunately my friend and the heads are 40 minutes away, so that's been part of the problem with this project.  Here are pics of what they looked like when I pulled them.  (I would guess that the car was junked because of an accident, so was probably running, but I don't know for sure)
 
 

 
 

 
 
 
Logged
1965 300 Convertible
1974 Dart Sedan

Steve

  • Administrator
  • Hero Member
  • *****
  • Karma: +1/-0
  • Posts: 8653
    • View Profile
Worn Valve Guides
« Reply #6 on: April 16, 2010, 07:55:06 AM »

It is and it's normal.  They are allowing for wear and for expansion.  Was that .017 for both exhaust and intake?  Maybe  you are not as bad as you thought.
 
If memory serves me correct, those are high alloy heads like the later blocks.  They shouldn't be worn that bad.  If you can scrounge up a dial indicator see how much side play you have.  Those heads don't look bad at all.  Maybe a bit light on the maintiance, but the combustion chambers look good.
Logged
Favorite Expression. . . Damned Kids.  Lots of projects.  Donations accepted

Steve

  • Administrator
  • Hero Member
  • *****
  • Karma: +1/-0
  • Posts: 8653
    • View Profile
Worn Valve Guides
« Reply #7 on: April 16, 2010, 07:55:56 AM »

Hey Ed
 
Let's show Dan the art of porting. 
Logged
Favorite Expression. . . Damned Kids.  Lots of projects.  Donations accepted

Guests

  • Guest
Worn Valve Guides
« Reply #8 on: April 16, 2010, 06:56:42 PM »

Quote from: D Cluley
Ok, knurling is definitely out. 
 
Assuming I can get the oversized vavles (haven't talked to anyone locally, but looking online I see intake, but no exhaust yet) that seems like it would be about half the cost of replacing the guides.  Is there a real advantage to new guides that would make it worth the difference.
 
Digging a little deeper in the '74 FSM it looks like the reamer should be .002 bigger than the valve stem.  but they say the total allowable play is .017  That seems like quite a range?
 
 
-----
 
Dana44:
 
I'm not sure I'm following all of your post.  Are you suggesting that if the guides are only worn a little to just put new seals on and ignore it?   Unfortunately my friend and the heads are 40 minutes away, so that's been part of the problem with this project.  Here are pics of what they looked like when I pulled them.  (I would guess that the car was junked because of an accident, so was probably running, but I don't know for sure)
 
 

 
 

 
 

D Cluley, in looking at the valves and combustion chambers, under the circumstances, valve grind and seals should be good. Bad guides will crust up on the backs of the bad valves and grease up the cylinders because compression is being lost. Your cylinders are clean, the valve grind looks to be pretty weak, but I have seen much worse (gotta love good stem seals).  I think the worse one is the bottom far right cylinder, probably number 8 originally, but you could get just as much out of a regular one angle valve job and new seals in the rebuild gasket set to start with. Valve stem/guide wear is measured by opening the valve to a set height and measuring its side play. This distance can be anywhere from .350inch to 1.00 inch, then a dial indicator measures the amount of play you can get from the edge of the valve both directions, and it would be a FSM that would tell for sure how far the valve is to be raised open. Don't waste the money on the oversize valves, guides themselves will have the same problem later after reamed, and then you have funky sized valve stems requiring extra work later (and the cost of the current ones being properly reamed to fit the new oversize valves, not much money saved after all this).
 
The two heads, number three is the semi-bad one, but not horrible, bottom head number one and four, number four being the worst, but in comparison, even worst would be if oil was dripping from the chamber after sitting the head on its side. Money an issue, grind and seal and you will get 50K or more out of them and save the most money overall. The best cylinder I would say is bottom head number three. Pretty even color on the exhaust valve, looks to be burning very well.
 
Porting? Would love to port these heads, lots of potential as a closed combustion chamber powerhouse head.
Logged

Dan Cluley

  • Hero Member
  • *****
  • Karma: +0/-0
  • Posts: 532
    • View Profile
Worn Valve Guides
« Reply #9 on: April 16, 2010, 09:42:59 PM »

Ok, I will be talking to Kenny this weekend, and will see if he's got actual numbers on the play.    It would be nice if we could put this back together without spending any more, but I'm not holding my breath.
Logged
1965 300 Convertible
1974 Dart Sedan

Guests

  • Guest
Worn Valve Guides
« Reply #10 on: April 17, 2010, 09:27:30 PM »

Quote from: D Cluley
Ok, I will be talking to Kenny this weekend, and will see if he's got actual numbers on the play.    It would be nice if we could put this back together without spending any more, but I'm not holding my breath.
The issue is not correct, it is lack of money, and since things don't look burned or overly greasy/grimy worn, it would give you several years of simply worn heads and parts until you can save the money for a new set of heads, or guides. Aeroheads has new heads for around $400 if not mistaken, junkyard heads are hit and miss, but these are pretty tough designed heads, and if money is this tight (understood in this economy), valve grind and new seals will suffice under the circumstances.
Logged

Dan Cluley

  • Hero Member
  • *****
  • Karma: +0/-0
  • Posts: 532
    • View Profile
Worn Valve Guides
« Reply #11 on: April 19, 2010, 11:17:14 PM »

I get what you are saying.
 
At this point I really need to get some more info from Kenny (he was sick this weekend :( )
All I know is that he said they were worn, but sometimes being a bit of a perfectionist, that could be anything from worn but still in spec, worn to spec, or the valves are about to fall out.  ;)
 
If it REALLY needs new guides, I will spend the money, but of course, that means other projects don't get done, so I'm just triple checking everything.
 
Thanks again,
 
Dan
Logged
1965 300 Convertible
1974 Dart Sedan

Steve

  • Administrator
  • Hero Member
  • *****
  • Karma: +1/-0
  • Posts: 8653
    • View Profile
Worn Valve Guides
« Reply #12 on: April 20, 2010, 06:16:37 AM »

yeah. . but this one had to be done too.  This is your daily.  Think of all that new found power and economy you'll be getting
Logged
Favorite Expression. . . Damned Kids.  Lots of projects.  Donations accepted

Leaburn Patey

  • Hero Member
  • *****
  • Karma: +0/-0
  • Posts: 4606
    • View Profile
Worn Valve Guides
« Reply #13 on: April 20, 2010, 08:07:09 AM »

Quote from: POLARACO
yeah. . but this one had to be done too.  This is your daily.  Think of all that new found power and economy you'll be getting
I agree.
Dan,getting the heads done  and the Dart will be able to pass the POS pontiac with the half flat tire and no sidewindow on I 75! LOL!!
 
Logged
1968 Newport Custom project BOAB
1973 Satelitte wagon
1983 Dodge 400
2006 300C HEMI!!

Steve

  • Administrator
  • Hero Member
  • *****
  • Karma: +1/-0
  • Posts: 8653
    • View Profile
Worn Valve Guides
« Reply #14 on: April 20, 2010, 09:20:20 AM »

Quote from: CBarge
Quote from: POLARACO
yeah. . but this one had to be done too.  This is your daily.  Think of all that new found power and economy you'll be getting
I agree.
Dan,getting the heads done  and the Dart will be able to pass the POS pontiac with the half flat tire and no sidewindow on I 75! LOL!!


 
I REMEMBER THAT!  AND I SQUEEZED THE GUY WITH MY TRAILER!     Too bad I didn't have the car on the trailer.  They're as nuts up there as they are in Boston. . .
Logged
Favorite Expression. . . Damned Kids.  Lots of projects.  Donations accepted
Pages: [1] 2   Go Up
 

© 2008-2014 Steve Hobby • © 2015 Allpar, LLC