This my story on the smaller pulley. First, engine is a stock 292 in a 1956 Victoria. Bought the car with less than 50 miles on total frame off restoration Engine and auto trans included. It ran hot when idling in traffic from the start. Stock 160 thermostat and 6 blade fan. Tune was on specs. Radiator was first even thou it appeared new. Went to 4 core, just took longer to get hot. Added bypass with 1/8" hole, same result. Added Chrysler high flow thermostat, same result. Sealed slot in front of radiator at the top of the framing forcing/sucking all air thru radiator by the fan. First thing that actually helped but waiting at a long signal temp went up. Soon after found the stock seal over the radiator and framing heat up got slightly better. Always had to put the trans in nuetral as raise idle while waiting at signals
Started the engine one day with rad cap off. Ran until I knew the thermostat was open. Saw little to no water movement in the radiator. Raised idle and there was movement. Light bulb went on-----speed up the pump like Greenbird said on this site and I read. Bought a 5+" Mustang pulley and shorter belt and the problem was gone. After thermostat open, plenty of water movement at idle My car is a cruser mostly in town and on the freeways of SoCal I drive no more than 65. That's 10 mph over the limit when the car was new. Thinking of putting back the standard flow thermostat maybe even going to a 180*.
That's it and what worked for me. The dual quads changed nothing but the cool factor and a little mpg. A/C is next and I have no fear of heating up with it......Good Luck

56 Vic, B'Ville 200 MPH Club Member, So Cal.

On a Thunderbird there are two primary design problems - the 1 inch open spacer behind the pump removes any chance of the impeller being efficient - and the radiator is much smaller than a passenger car of the same year. You can also hurt yourself by fitting a thermostat with too small of a passage (restricting the already poor flow) and allowing a poorly operating distributor to retard the spark. You get all or a combination of these in effect - the birds overheat, especially at idle. The bypass - being a "rapid warm up" feature, doesn't help a Thunderbird - especially when it just keeps on warming it up as the day goes by...... 

I think Ted's advice about removing the one inch spacer - especially if you aren't demanding a "perfect restoration" - is good approach to the efficiency situation. In a standard block (with no spacer), the design of the impeller is still so crude as to prevent any chance of "cavitation" until reaching some astronomical RPM - and certainly not the way we drive our street cars. Fitting the engine with a smaller pulley - like the 289/302 part - had a very favorable immediate effect.

 

 
 Steve Metzger       Tucson, Arizona

Steve:  THANKS for pinpointing the early 'Birds' two cooling system design shortcomings, identifying how the cooling system's cooling problem can be exacerbated by the flow restriction posed by some replacement thermostats, and drawing attention to how a malfunctioning distributor's ignition advance curve can potentially result in retarded ignition timing and subsequent engine overheating.

THANKS, too, for reviewing the merits of Ted's suggestion of eliminating the one inch water pump spacer from the 'Bird timing chain cover for those of us that are not dedicated to 'originality' in assembling our 'Bird engines, for your suggestions of using a restriction in the water pump bypass hose, and a different diameter water pump pulley which in conjunction with a more efficient radiator will likely resolve the potential cooling system issues most 'Bird engines can experience in street or highway use.

Regards,

NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

re green birds talk of wp cavitation. ony time a waterpump can not move water ther is cavitation. in my case both birds had the spacer between the pump and front cover,tho i agree the spacer cuts punp eficencey some what but as long as the by pass is as desighened it woud be ok ,but more prone to cavitate if rad not adequet.remember 220 with a 15psi cap is not harmfull .lastly my examples wher std trans 

DryLakesRacer:  Kudos for your informative recounting of the steps you took to resolve the overheating issue you were experiencing with your 292 '56 Vic.  What you have related is like a case study.  Those who read your road-map-of-efforts-taken have a guide that will likely reduce the time, effort, frustration, and expense they have to expend in trouble shooting their overheating issue.

What you have done in submitting your entry to this thread is emblematic of how helpful one Forum participant can be to others who have a y-block technical problem.  Thanks to you and all our other members who make the time to relate their hands-on experiences of what they did and how they did it. 

Regards, 


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

The 1" spacer on the T-Bird is a long known issue. There has been a stainless steel baffle available from the T-Bird parts people for years to fix that problem. I installed one years ago and noticed no difference. Installed a new Ford radiator years back when they still had them and noticed no difference. Going with the bypass restrictor, 6 blade fan, and an electric fan in front of the radiator on a manual switch. If this does not work may try a smaller pulley. On the T-Bird the low hood is also part of the problem. Simple high school physics. A smaller space is easier to heat than a larger space. Problem is we don't want more heat in the engine compartment. Car has  always been fine on the highway and tended to heat up in traffic ever since I bought it in '65. A work in progress.

Interesting comments by all! it appears the the running hot issue is primarily with the T-Birds?  I never had a problem with running hot, only changed my stock rad to aluminum one because the original brass tank was becoming annealed and prone to cracking from expansion. I run an electric fan on a 190 deg F switch. It would only ever come on if I got stuck in traffic for long periods of time or when I shut the car down.

This being said, I may be perfectly fine, even with the higher compression in my new motor? I will say that if it does tend to run hot, I like the idea of going to the smaller Mustang pulley over the bypass restriction! Can anyone specify what year Mustang / size of pulley would be a good fit? 

I love the smell of burning rubber in the morning!

All i can add is and not y block for a change, is when i ran 351 cleveland in 72 ford here at tthe drags and with no fan but a reduced diameter water pump pulley and never ! ran hot or got hot. Works for me.



  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia

Rob - On a T-bird there is some forward room to work with, so I put on a Hayden fan clutch - and they show a 10% loss in speed - so a "speed up" pulley is a good idea. I also used a '69 Pontiac 7 blade aluminum fan matched to the T-bird shroud - so you can see "originality" wasn't my goal. In looking for a foxy aluminum pulley to drive all of that shiny stuff, I found CVF Racing ........ and they had a selection of pulleys, four bolt mount - for small block Fords. Call them about mounting dimensions and centerlines - on mine, I bought a two groove and cut one off to net the "right" position. Not the cheap way to go - but made a nice looking custom installation that looks (and is) properly engineered. Photos are in my album over on the HAMB.

Getting rid of the inherent underhood heat of the 'Birds is a pain - and I'm running the iron exhaust manifolds - so I had them "JetHot" coated and that was very effective. Your sedan may need to have the headers wrapped. I have also sealed my carb to the hoodscoop with an air pan so the engine runs on outside air. None of this stuff looks (or works) like a factory 'Bird.

 
 Steve Metzger       Tucson, Arizona

Canadian.. My smaller pulley is a Transdapt chrome single belt for a 56/66 Mustang 289. It is 5 7/8" diameter. I painted it black. Transdapt and Spectre list them with 1, 2 or 3 belts. For some reason the single is listed at 6.125 diameter which probably would have been better. Suprise to me that the 2 belt is smaller than the 1 and the 3 is smaller than the 2.
Remember to buy a shim kit also, add until the pulley lines up with crank pulley. With the radiator out you could probably adjust the snout with a puller. I believe the belt was 1" shorter. Good Luck

56 Vic, B'Ville 200 MPH Club Member, So Cal.