[Fot] TR4 valve guide clearance

[Greg Solow]

For stock cast iron guides the clearances listed in the shop manual are 
fine. .0015 to .002" inlet and ..002 to .0025" on the exhaust. The engine 
should run ok sith up to .0015" additional clearance on each valve.  The 
problem that we have found with the iron guides is when using a high lift, 
fast acting racing cam, with additional spring pressure, The guides tend to 
wear very fast. We found up to .004" wear in 4 or 5 race weekends. Then the 
valves stop sealing as well and the engine looses power.
    It does not sound like you have a setup that required a better quality 
guide. Don't use valve stem seals and keep an eye on the wear as time 
passes.
                                                                             
                                        Greg Solow
----- Original Message ----- 
From: "Tim Murphy" <timmurph at fastbytes.com>
To: <fot at autox.team.net>
Cc: <rpm724 at att.net>; <ryan.murphy at fdlco.wi.gov>
Sent: Monday, April 02, 2012 2:59 PM
Subject: [Fot] TR4 valve guide clearance


>I took our head up to a machine shop in Appleton, WI to have it checked for
> cracks and primarily to get the valves ground.  Here is what the machinist
> has reported to me:
>
>
>
> Intake valve guides a little loose                Intake valve stems okay
>
>
>
> Exhaust valve guides okay                           Exhaust valves about
> 0.001 wear on the stem
>
>
>
> The intake valves are a nice fit into the exhaust guides.  This is not the
> usual type of wear he sees on the more common (Chevy and Ford V-8's) that 
> he
> works on.
>
>
>
> Question:  What is the "normal" clearance valve stem to valve guide for 
> the
> TR4 engine when used for racing?  To put it another way, can we run the
> engine with the intake guides loose and the 0.001 wear on the exhaust 
> valve
> stems?  And, is this the usual wear pattern on the TR4 engine?
>
>
>
> We are running a stock crank with stock rods, all balanced, and forged
> WISECO pistons with 87 mm liners from Ken Gilanders.  We try to keep to a
> 5500 RPM redline with occasional use of 6000 for overtaking.  For what 
> it's
> worth we have a 4.3 rear end and overdrive.
>
>
>
> I recall a discussion on the list some time ago regarding different
> materials being used for guides and a problem with getting the proper
> clearance.  As I recall, a number of folks were using these guides and
> unfortunately had valves get stuck with somewhat disastrous results.  I
> think the guides were bronze or some alloy with bronze in it.  I don't
> recall any discussion on clearance for stock valves and stock guides.  My
> gut feel is that I'd rather have the guides/valves a little loose than 
> have
> a valve stick and destroy the head and maybe the rest of the engine.
>
>
>
> Thanks for your help,
>
>
>
> Tim & Ryan Murphy
>
> 1961 TR4  #317
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