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| | | | Joined: Mar 2003 Posts: 93 'Bolter | | 'Bolter Joined: Mar 2003 Posts: 93 | Hello world...do ya think that a '47 chev (with a '57 235 transplant) has a pressurised coolant system? If so, what pressure rad cap is advisable? Cheers! | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | 47 chev,
I understand that the recommended pressure caps for '54 and later 235 engines were 4 psi in a truck engine and 7 psi in a car engine. I think that earlier truck engines (216 and 235) both had 0 (zero) pressure radiator caps.
Maybe someone else knows if pressures greater than 0 psi were safe with other '47 parts (specifically, radiator and water pump).
Someone will correct me on this, if I'm wrong.
Tim | | | | | Joined: Aug 2000 Posts: 587 Shop Shark | | Shop Shark Joined: Aug 2000 Posts: 587 | Probably 4 pound, but get a shop manual for it to be sure, the manual will come in handy for a lot information and help. | | | | | Joined: Oct 2002 Posts: 4,066 Bolter | | Bolter Joined: Oct 2002 Posts: 4,066 | I have a 7# on my 54eng 235,works fine for me, in fact I go in a lot of stop and go on the interstate today, and it was also a very warm day about 93, the truck never got pass 185..good luck..Fred
Redryder pixMy HotrodA veteran - whether active duty, retired, national guard, or reserve - is someone who, at one point in his or her life, wrote a blank check made payable to The 'United States of America', for an amount of "up to and including my life."I am fighting cancer and I am winning the fight | Pain is part of life; misery is an option. | | | | | Joined: Oct 2001 Posts: 3,458 Extreme Gabster | | Extreme Gabster Joined: Oct 2001 Posts: 3,458 | I would start with 4 and only go up if you have overheating problems. A pressure system allows more heat transfer because it allows the water to be hotter before it boils over. If it doesn't boil over at 4 then leave it alone, it will be easier on the seals. 7 may be safe but I wouldn't go there unless you need to.
Paint & Body Shop moderator
A lone amateur built the Ark. A large group of professionals built the Titanic. | | | | | Joined: Dec 2001 Posts: 1,745 Member | | Member Joined: Dec 2001 Posts: 1,745 | Mine came with a 7 and I changed it to a 4 and it runs at the same temp in hot weather. So, I figure it is safer on my old radiator.
54 3100 with 235
62 flatbed dump C60 with 261
| | | | | Joined: Nov 2000 Posts: 1,966 'Bolter | | 'Bolter Joined: Nov 2000 Posts: 1,966 | My 50 3/4 ton had a 0 lb. cap on the original radiator and a transplanted 307 V8. Worked great summer and winter. I tried a 4 lb. cap and my radiator started leaking. Good luck
Professional Novice
| | | | | Joined: Jun 2001 Posts: 169 'Bolter | | 'Bolter Joined: Jun 2001 Posts: 169 | My 52 year old radiator leaked with 0# cap....really leaked with 4# cap  New radiator solved everything at 4#. PRW | | |
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