I Guess This Could Be A Problem Huh?

[04lbram]

Well looks like I found out what part of my problem of not pulling in enough air during cruising is I have a small block radiator for a big block.   I never realized it until I started looking at other cars and wondering why this this thing wasn't pulling enough air around town other than the electric fan which will be getting replaced. So, would a small block radiator cause a problem cooling a much bigger motor? Just curious anyways.

[MoparYoungGun]

Definitely .

[golden73]

 

[cudaken]

 Why do you think it is for a small block? My 68 Runner came with a small 2 row when Mon and Dad bought her new in 68. What is the part number on it and what year is the car?

                                  Cuda Ken

                         

[04lbram]

Thing is my Challenger was originally a small block car and later that little 318 got replaced by a slightly larger 383 out of a 69 Road Runner. I found out by looking at a diagram of a big block and small block radiators. I can get a part number but, the radiator is in a 71 Challenger.

[Wakko]

My car is an original big block car and has a tiny radiator that's stock as far as I can tell.  Keeps it cool too, when it's not leaking.

[04lbram]

Mine doesn't leak. Just has a small electric fan from the previous owner. 

[Wakko]

Electric fans can be more trouble than they're worth.  12" fans can be rated anywhere from 800-900 CFM all the way to 1800 or more.  If someone that knows more about this can chime in here, I'm going to guess that anything under 2500 CFM or so would be inadequate for your car.  Again, that's me GUESSING, so if I'm wrong, don't jump on me.     I had twin 12" cheapie fans on a small block Chevy and it wouldn't keep it cool at all.  So either dump the single fan in favor of a pair of shrouded 12"s or put on a clutch fan/shroud.

[Ghoste]

There are many things that could make a difference.  Your locale and usual temps, driving conditions, that fan as Wakko mentioned.  What is the condition of that rad?  If you have the original smallblock rad the car has always had and you have a warmed over big block and you are driving more aggressively, it could be a combination of cooling system inadequacies.  Find out how small that rad really is and how much air that fan pulls first.

[04lbram]

I don't drive hard at all. In fact I baby it I just have a lot of stop and go around town but, once I'm on the highway I'm fine. The radiator I know is a Chrysler and not a reproduction as far as I can tell. I would say shape wise it's alright but, I think changing the fan would help probably more. I was thinking a universal fan would be better and bigger than the one I have now. I'm not sure how big the electrical fan I have is but, I would say it pulls 1200-1500 cfm.

[Steve P.]

Everything matters to cooling. You must give us a better picture to even begin to help..

Things to check:

1) with the engine off, pull the coil wire and the rad. cap.. Have someone else turn the engine over while you watch inside the rad. for air bubbles... YOU DO NOT WANT TO SEE BUBBLES!!  If no bubbles after cranking it over for a few 15 second intervals  replace rad. cap and coil wire and go to check #2.

2) While the engine is hot and the hood is open, moderately rev. the engine while watching the hoses. If either calapse you will need to replace them with a spring loaded hose or hard wall police option hoses..

3) Check rad. cap. If it's old just go ahead and replace it.. An open cooling system will never maintain it's cool. Water boils at 212* if not under pressure. Under pressure it will go higher. (I forget how high).  Sorry!!


There is much more but without knowing what you have it's like throwing darts in the dark..

Engine? How long since it was tanked?? Punched or not??
Water pump? Is it up to the job??
Belts?? Slipping??
Radiator?? How new or old?? Roded?? 2-3-4 row?? Volume?? Condition?? Cap condition?? Cap pressure???
Hoses?? Soft? Hard? Collapsing??
Shroud??
Correct fan?? Enough fan??
T-Stat?? What temp? How old?


If you stay cool on the highway you probably don't have a problem with heads or gaskets..

[04lbram]

Thanks guys. It's fine on the highway like I said. Heck even as long as I run 30-35 mph around town I'm fine.

[Afflyer]

04lbram-

My advice do you would be to take that 22" radiator and have it recored with a new 4 ROW for about $300.  I presume it's a "bucket top" (stock) radiator.  That's EXACTLY what I did and I couldn't be any happier!  I'm tellin you, I can't get my engine temp higher than 168 when I'm runnin down the road.  For a 440 with a 22" radiator, the four rows are far-and-away, much better than two rows.  You won't even need a shroud!

Bradley