Do you guys think i will over heat ?

The 302 I got last week is bored 40 over.and I have the stock radiator for a v8 maverick. it's going to be a weekend car so what do you guy think?

 

my brother has the stock 2 row radiator and he over heats in traffic

 

.040 over shouldn't give you any problems with over heating

 

If u have other mods besides the .40 over; my guess is it will overheat in summer if/when u get stuck in traffic jams. Time will tell!

 

if it is a pretty stock 302+.040 and you have a v8 radiator you should be fine as long as you still have the shroud and the radiator is clean. Make sure you use anti freeze.

 

Thank you guys for the fast help I will put some pics up soon of the engine in the car

 

So does someone want to explain how overboring a engine causes over heating??? Most of the heat is in the heads, not in the block...

Only overbored engines that I've see that overheated were assembled with too tight of clearances, had a radiator that was partially clogged or had other cooling system issues...

 

Uh I'm gonna take a stab at how one could think this could result in overheating. A larger combustion area allows for more combustion which could lead one to think there is more heat.

The reality is though that the area and intensity of a combustion is if I recall correctly inversely proportional to the heat creation. Like a 10 foot flash fireball has less residual heat dissipation than a 5 foot flash fireball for example. Even with more fuel being involved that would probably result in a longer burn rather than a hotter burn, since once combustion occurs it's pretty hard to get the heat up.

I suppose though they could also be thinking that because there is less material in the block it will be able to sink less heat; but again the reality is that it would actually sink slightly more heat because less material will transfer heat faster. So while the block would get hotter faster, it still would be unlikely to get any hotter than it did before.

I'm not exactly an expert in this area though.

 

I fully agree with this statement...

I'm in the opinion over heating issues are more of a build error than anything else, and as long as the cooling system is up to par(40+ years ago, many were borderline when new) actual overheating is rare...

 

Make sure the head gaskets are installed in the right direction and there shouldn't be any overheating with +040, assuming the cooling system is functioning properly.

A friend of mine has a +040 302 (308) in his Maverick with a stock cooling system (3-row, A/C car) and he's never had any cooling issues. Of course it's not in Georgia in the middle of summer either.

 

that prior statement does have some merit. That's why they say that larger overbores(.060-.080 on these little thin-bore engines) can cuase additional strains on cooling systems.

From everything I've learned.. it has much more to do with the horsepower more than bore size/thickness. That's also why many aftermarket radiators are rated by power level regardless of the engine they're used on. That's why a 350 horse motor will tax a cooling system far more than any stock rebuilt .060 over 302 ever would.

For additional cooling in hotter weather.. my advice to the OP is this.. and also in this order of importance.

1. A good thorough cleaning/flush. A quick warning here though.. sometimes older system can start to leak/weep after heavy cleanings.

2. Low temp t-stat(160-170 max rating). Preferably of a balanced design.

3. Watter wetter.. or equivelant brand of surface tension reduction agent. Using none or substantially less anti-freeze and higher concentrations of these products(up to a point) will improve temp reductions even further.

4. Electirc fans(preferably thermostatically controlled) will aid low rpm cooling where mechanical fan speeds may not be sufficient enough to keep temps from spiking in heavy stopped/slow moving traffic.

Using all of the above tricks will easily let you get away with running what is considered to be a tiny radiator by most standards. Yet my 500+ horse 383 Chevy gets by just fine with a STOCK single core rad from a 4cyl model S-10.

 

If using a mechanical fan, make sure the blade is as close to the rad as possible and has a good shroud Also a good, lightweight multi-blade fan...Of course everything depends on outside ambient temp when sitting in traffic....Big difference between 80 and 100 degrees....Too far advanced timing will also cause it to run hotter

 

Mine is .040 over. It did overheat. But not so much because of the .040 as much as adding more cam, heads, and all the other power additions.

It did so on my stock engine, as well. The more power I added, the hotter the car ran.

The single best way to cool it down (it, being my car) was a new aluminum radiator. Since then, I have cooled it further using a 160 thermostat, and water wetter really did bring it down another 5-10 degrees in hot driving conditions. I was very surprised by that little bottle.

My cooling fan is electric and set to come on at 190 degrees (and turn of at 165 or 175, I don't remember which), and it seldom comes on at all anymore. It has to be a really hot summer day for it to even cycle.

So, if it is a pretty stock engine I would not worry about it. If it starts to heat up, swap in a new radiator, and you should be in good condition.

If it runs hot, DO NOT FIGHT IT!

I spent many years and hundreds of posts on here trying to cool mine down, and until I spent a couple hundred for the radiator, it was all a waste of time and money.

And mine did not heat right up, or even run dangerously hot. But as I drove, it would slowly creep up to 200, 210, 220, then I would pull over and let it cool, stopping about every 40-50 miles. It never spewed, it never blew a head gasket. Just made me start to get nervous.

Now it runs 180-185, very rarely reaching the 190, then quickly dropping when the fan comes on.

 

Some of the things I tried to make it run cool before I swapped radiators.

various sizes, brands, and quality thermostats.
using no thermostat
various water-to-antifreeze ratios
various cooling tubes, including the one with the spring inside, and flexible aluminum tubes
filling stock radiator with muriatic acid to burn out the calcium buildup (not while installed in car)
having a radiator shop cut the top off and ream out the radiator, weld back up, repaint
variations in timing advance
electric fan with thermostatic switch
a different electric fan with better pull and shroud coverage

so you can see that the list above includes many hours of work, and several hundred dollars spent, with little, if any, improvement.

The aluminum radiator fixed it.

 

wow guys i cant thank you guys enough i hope to have it up and running some time in may im getting there

you guys jump right in help me when im in need THANK YOU