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Re[2]: Anti-cavitation Water Pump

To: tigers@autox.team.net,
Subject: Re[2]: Anti-cavitation Water Pump
From: LeBrun@hii.hitachi.com
Date: Tue, 04 Jun 96 09:54:43 PST
     Steve;
           -Years ago I had a "HIPO" 289 stuffed into a '66 
     ECONOLINE...with the engine between the front seats. There was a floor 
     pan about 4' square under the front to force the air in & up to the
     radiator. I would run a max 160 thermostat in winter & drop down to 
     140 in summer. I had a flex fan and heavy duty radiator too. One area
     that helped me was plugs. "Stock" callout was BF-42 (Autolite) I ran
     BF-32's in winter and put in BF-22's in summer as a normal change.
     
     I could have slight ping with the BF-32's when it got hot & going to 
     the BF-22's it quit, even under heavy acceleration and no other 
     changes to timing, carb, etc. 
     
     I worked as an automotive machinist many moons ago, and only when we 
     did "hipo" stuff at the shop such as balancing & degreeing we almost
     always ran into a serious problem. Even on assembly, the timing marks
     can be off from the factory, E.G. what's marked as TDC, say, is way 
     off when the engine is built up with a degree wheel. Also, on 
     rebuilds, sometimes the rubber insulator INSIDE the harmonic balancer 
     is softened enough when the engine is "hot-tanked" for cleaning. It 
     can soften enough to twist a little but not break completely away from 
     the front pulley. This will then throw off your timing marks also. My 
     289 was off by around 25-30 degrees after the engine was put back into 
     the car. When set at the 6-12 initial on the pulley, it would die. 
     Check your marks, and if off, make new ones. Get a bottle of the INK 
     used at a wrecking yard to mark parts and make new marks. This is 
     especially good for setting timing under bright sun, like at a track. 
     Also, I've found that if your distributor is off by even 1 TOOTH in 
     relation to your cam/crank timing, everything is off and cannot be 
     dialed in. When your timing is set where you like it after a tune up,
     use the same ink to mark your dist. & housing.

     Have you put your engine on a scope?...it almost sounds like you're running
     the ignition timing more retarded than it should be.

                               Phil 

______________________________ Reply Separator _________________________________
Subject: Re: Anti-cavitation  Water Pump
Author:  "STEPHEN SALATA                   USAET(UTC -04:00)" 
<usfmdgbj@ibmmail.com> at ~INTERNET
Date:    6/4/96 6:26 AM


The water pump was purchased from a local (Detroit area) "accumulator" of       
Sunbeam parts 14 years ago.  I believe he had them rebuilt locally.             
But, the basics should be covered.  The condition exists on both this           
low mileage engine, and a similar previous low mileage 302, but not a           
rebuilt 260.  Even though I am running a Holley electric pump (in spare         
tire well) and a pressure regulator near the carb, it can vapor lock when       
the HOT engine is dropped to under 1500 RPM.  It sometimes also boils the       
gas in the carb after the engine is turned off!  To date, I have installed:     
a high density 3 row radiator core, wide 6 blade stainless flex fan (with       
original shroud), electric pusher fan, blocked off horn holes in radiator       
support, sealed bottom of shroud to crossmember to prevent hot air              
recirculation, and tried 160 deg thermostats and plain thermostat restrictor    
plates with various hole diameters.  The engine won't actually boil over if     
the electric fan (thermostatically controlled) is working, but will run to      
230 deg after maybe 1/2 hour of running at all speeds.  Engine RPM at 65 MPH    
is about 2700 RPM.  The cooling changes were put in place one at at time.       
     
To help stop vapor lock, all the lines from the pump have been carefully routed 
away from the exhaust and covered in a high tech insulating wrap.  The carb     
(Holly 4 bbl) has a 1/2" phenolic spacer under it, along with a GM carb heat    
shield under it.  The hood is a LAT with the exhaust vent in back.  Also,       
the heat crossover in the intake is blocked off.                                
     
Engine timing is set at 12 deg BTDC, with 36 degrees total.  The only things    
that I can guess that may still be causing the problem are that the flex fan    
is actually flattening out at speed and blocking air flow, or that the rebuilt  
radiator is defective or just plain inefficient.  The questions about the       
anti-cavitation water pump were a result of my trying to figure out what may    
be different on my car as opposed to 95% of the other Tigers out there.         
..... ANY IDEAS?                                                                
     
*** Forwarding note from I1922283--IBMMAIL  06/04/96 02:25 ***                  
Date: Mon, 3 Jun 1996 23:23:14 -0700 (PDT)                                      
To: "STEPHEN SALATA                   USAET(UTC -04:00)" <usfmdgbj@ibmmail.com> 
From: Tom Hall <Modtiger@engravers.com>                                         
Subject: Re: Anti-cavitation  Water Pump                                        
Cc: tigers@autox.team.net                                                       
     
At 09:42 AM 6/3/96 EDT, you wrote:                                              
>Does anyone have any experience with running the so called                     
"anti-cavitation"                                                               
>style water pump?  It was used on the 302 Boss engine (among others).  It      
has                                                                             
>curved impeller blades instead of the common straight blades.  I'm running     
     
>this pump on my 302 Mk.1, along with every cooling trick I can think of,       
and                                                                             
>it still runs 230 degrees and vapor locks the carburetor at 70 deg ambient     
     
>temperatures.  Maybe this style pump is contributing to this problem.          
     
     
Stephen,                                                                        
     
I've run this pump for years, and I'm curious, where did you find one to fit    
a Tiger.  I had to make mine from SVO parts, including pulling the old          
impeller, changing the seal, and pressing the new impeller on to the shaft.     
A lot of effort, but I consider it worth it to reduce the cavitation common     
to straight blade pumps.  This is particularly true with 3.54 and up gears.     
     
It frequently takes a lot of effort to pin down why your Tiger runs so hot.     
You must be sure that you have covered all of the basics to assure that your    
system is operating at full efficiency.  You also have to be sure that you      
don't have problems like combustion leakage into the cooling system.  The       
problems are frequently overlapping, and this makes them hard to pin down.      
We, on the net, may be able to help you if you can be specific, and tell us     
what youv'e done to date.                                                       
     
Because of the electric fuel pump, vapor locking is not a common problem.       
You will have to define your terms so that we can offer suggestions.            
     
     
Tom Hall                                                                        
     
     
---- End of mail text                                                           
     
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