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Author Topic: Need radiator advice with a MCI 5A  (Read 721 times)
napamikey
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« on: May 23, 2013, 09:22:33 AM »

Hey Guys

I've got a 67 5a with an 8v71. A few years back the top of one of the radiators started leaking.  I plugged it up with some JB weld and forgot about it.

I figured now was the time to clean it up and fix it properly so I pulled the radiator, cleaned it up and noticed the leak was coming from a gasket for the spout which was riveted on the top.  Way over my head to I sent it to a shop, they cleaned it out and said the core was junk and wanted $900 to re-core it.

I've gone over the Sierras (San Francisco to Reno) multiple times and it always stayed below 200 with the misters on. I also have tested them with a temp gun and they were dropping 20-30 degrees. 

Now for my questions:

Is $900 for a core realistic?
Do I need to replace both? (There goes the gas money!)
Should I adjust or change the system, get different radiators or something while I'm at it?

Thanks a lot guys for your advice.

Mike
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1967 MCI 5a 8v71
San Francisco, CA
Lin
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1965 MC-5a




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« Reply #1 on: May 23, 2013, 10:41:52 AM »

I don't know if the price is right, but radiator cores are expensive.  You can check around and get comparisons.  There are more efficient designs than the original core that will fit--different fins and even another row of tubes.  Someone here will know what they're called or you can talk to shops about it.  Although changing both radiators would be great, I would tend to put the money where it was needed and deal with the other radiator when it called for it.
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You don't have to believe everything you think.
napamikey
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« Reply #2 on: May 23, 2013, 11:47:10 AM »

Thanks for the info. 

The reason I think both radiators may need to be redone as I think they each service their own bank of 4 cylinders on the 8v71.  Probably will not be wise to have each bank different temps but that may not be a big deal as well.
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1967 MCI 5a 8v71
San Francisco, CA
TomC
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« Reply #3 on: May 23, 2013, 11:49:15 AM »

When I turbo'd my 8V-71, I had the radiator redone. Went from a 5 row straight fin to a 6 row serpentine fin. Works better but still have to use misters on long pulls in the summer. The radiator is as large as I can put in the space. The recore on my single large radiator was $1,500 4yrs ago. Yes each of the 2 radiators is fed from the individual head, but joins together on the cool side going into the engine. Good Luck, TomC
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Tom & Donna Christman. '77 AMGeneral 10240B; 8V-71TATAIC V730.
wg4t50
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« Reply #4 on: May 23, 2013, 12:03:52 PM »

Correct, My MC7 original set up had a common junction box between the radiators this used the left radiator doing most of the cooling, noticed the later models had each thermostat going to a radiator with a smaller balance hose between the radiators, this had each radiator doing its share, not a perfect solution but a large improvement.
Other ideas, use smaller pulley on fan gear box to speed up fans, MCI   Is the place I got it and shorter V-Belt, another idea, open up the fan discharge opening to a square opening same size as the width.
Gave it all up when went with the 12V-71 setups.
Dave M
« Last Edit: May 23, 2013, 12:09:17 PM by wg4t50 » Logged

MCI7 20+ Yrs
Foretravel w/ISM500
WG4T CW for over 50 wpm for ever.
Central Virginia
bevans6
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« Reply #5 on: May 23, 2013, 12:22:37 PM »

The water flow on the MCI is basically from the bottom of the water pump inlet upwards.  Coolant is mixed and shared between the two radiators at the water pump inlet and the engine then sends water into the block water jacket.  That means that both sides of the engine see the average temp of the returned coolant.  From there as you say it goes out the two sides and up.  It's also shared in the common coolant expansion tank in the middle between the radiators, so while there are two radiators they share the load rather than act independently to each cool half the engine.  It makes no difference if one side is cooling more than the other side if the overall system performance is adequate, with that said there is no reason not to have them both working well.  I've done setups similar on race cars where one rad was quite large and did 80% of the cooling, the other was small and just added to the cooling, as long as their outputs were merged together going back into the engine it was fine.

Brian
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1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
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1978 Lola T440 Formula Ford
1972 NTM MK-4 B/SR
wg4t50
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« Reply #6 on: May 23, 2013, 12:58:11 PM »

Once you realize the length of the routing, the longer line ( curb side ) slows the flow, if it makes zero difference, it is amazing that MCI would spend the time & money to change the design.  From my early experience it helps.YMMV
Dave M
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MCI7 20+ Yrs
Foretravel w/ISM500
WG4T CW for over 50 wpm for ever.
Central Virginia
napamikey
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« Reply #7 on: May 23, 2013, 09:55:59 PM »

Thanks for your advice.  At least it is a $900 job and not double!  I can wait to do that next year Smiley
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1967 MCI 5a 8v71
San Francisco, CA
Ed Hackenbruch
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« Reply #8 on: May 24, 2013, 03:55:40 AM »

Mike, i just sent you a personal message. Smiley  Ed
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1968 MCI 5A with 8V71 and Allison MT644 transmission.  Western USA
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