[Supras] Head Gasket Choice For N/A

[Christian, Skip]

Hi Jim,

	Appreciate the info.  If bolts were stretched, when they heated
up, they would become longer & leak would be worse.  But, who knows; I
just know I've been driving it like this for three years.
	The "possible" bent valve story is interesting.  I replaced the
timing belt, water pump, etc.  Turned the engine over by hand two
revolutions - everything was fine.  I finished buttoning it up and tried
to start it.  No start - when cranking it sounded wrong (like the
injector timing signal wasn't there).  So I stopped & tried to turn it
by hand to TDC to check the valve timing.  Crank wouldn't turn past 10
BTDC.  I turned it the other way and it stopped at approx 10 ATDC.  My
assumption is #3 intake valve bent - although I don't know how.....

Thanks, Skip

-----Original Message-----
From: Jim Jobe [mailto:jjobe2 at supratech.org] 
Sent: Friday, March 02, 2007 10:03
To: Christian, Skip
Cc: Bob Schultz; supras at supras.com
Subject: Re: [Supras] Head Gasket Choice For N/A


Sounds like you overstretched the head bolts and they have lost tension
and elasticity.  72ft-lbs is the proper spec.

You likely need to resurface the block deck as well as the head - enough
damage and nothing will seal.  Unless you have plans to turbocharge it,
put a stock gasket on with new stock bolts at 72ft-lbs and ensure the
rest of the cooling system is in proper working order.

It's suprising that you bent a valve - in stock form the 7MGTE is a
non-interference motor.  If this is what your dealer is telling you I'd
look elsewhere.

On Fri, Mar 02, 2007 at 08:38:57AM -0500, Christian, Skip wrote:
> Bob,
> 
> 	Thanks. I've done the head gasket once already.  Stuck on a
stock 
> gasket, torqued to 54/58 (?) ft-lbs (from TSRM).  Lasted two weeks & I

> started hearing the tell tale bubbles in the heater.  I figured the 
> engine was trash, so I got out the torque wrench and torqued all of 
> them to 85 ft-lbs.  FYI - Block deck is trashed from acid damage.  
> After the
> 85 ft-lbs, as long as the car was COMPLETELY warmed up before touching

> the accelerator pedal, the car used NO coolant no matter how hard it 
> was driven.  But, touch the gas before and gurgling from the heater.  
> Gasket would seal with head expansion at 85 ft-lbs !
> 	Unfortunately, I used a "Gates" timing belt....... Because I was
in a 
> hurry...  It shredded itself at 82K miles and I ended up with bent 
> valves.  Intakes were set at .0004 because dealer had no shims and cam

> timing was changed to increase overlap (big power difference - more 
> than all the aftermarket parts combined & still passed emissions).
> 	So, here I am.  Planning to buy a "rebuilt head" & install.
> Maybe, I just don't learn :-)
> 
> Thanks, Skip
> 
> P.S.  Wonder if those 85 ft-lbs stock bolts are going to come off.  My
> '88 had one of the Allen heads crack...
> 
> -----Original Message-----
> From: Bob Schultz [mailto:bob_schultz at bellsouth.net]
> Sent: Friday, March 02, 2007 8:23
> To: Christian, Skip
> Subject: RE: [Supras] Head Gasket Choice For N/A
> 
> Unless you find major problems with the deck don't worry about the 
> block
> 
> Except for guys trying to hit 1000 hp or the errant engineer out there

> shops just clean up the block and install the gasket.
> 
> Check the head and resurface if necessary.
> 
> Torque to the higher head bolt pressure and pray...
> 
> It should last
> 
> Bob
> 89 with oem gasket
> 
> --Original Message-----
> From: supras-bounces at supras.com [mailto:supras-bounces at supras.com] On 
> Behalf Of Christian, Skip
> Sent: Friday, March 02, 2007 7:35 AM
> To: supras at supras.com
> Subject: [Supras] Head Gasket Chioce For N/A
> 
> Hey Guys,
> 	I have an '86.5 N/A with a BHG.  Haven't got the time to pull
the 
> engine, but need to replace the head gasket.  Question - what is the 
> best head gasket choice for a less than perfect block deck.  Sorry, 
> but I need to get this car back on the road.
> 
> Appreciate The Help, Skip
> 
> _______________________________________________
> Supras mailing list
> Supras at supras.com
> http://supras.com/mailman/listinfo/supras_supras.com
> 
> 
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.5.446 / Virus Database: 268.18.5/707 - Release Date: 
> 3/1/2007
> 2:43 PM
> 
> 
> _______________________________________________
> Supras mailing list
> Supras at supras.com
> http://supras.com/mailman/listinfo/supras_supras.com