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View Full Version : Cooling problems with a 400 sbc


Jeep Victim
04-06-2008, 05:32 PM
I have been informed that the 400 has cooling issues.I was going to pick one and a set of Vortec heads,does anyone know about the cooling problems and or how to get around them?

Always broke
04-06-2008, 09:52 PM
No problems Barry just make sure you run the proper sized rad for it thats all
Alot of people put them in small cars and don't upgrade the rad

pumpkin
04-06-2008, 10:50 PM
No cooling problems whatsoever. I have one in my blazer, and my son has one with vortec heads in his pu. You'ld be better of and cheeper with aftermarket aluminium heads though.

kootenaycat
04-06-2008, 11:11 PM
Don't the 400 heads have different steam holes? There was something about that I remember reading when swapping heads onto the 400. I guess the aftermarket heads would already be made specific?

Kingblazer84
04-06-2008, 11:16 PM
the stock 400 heads have steam port holes drilled in the heads if you swap heads thats when you need to have a machine shop drill the steam port holes in the heads so the 400 doesnt overheat like a biatch also a good 4 core rad is a must along with a flex fan works well

pumpkin
04-07-2008, 07:23 AM
Yes 400's have to have steem holes in the heads. In order to fit a high lift cam in the vortec heads, my son ended up spending $1200 on them. I ordered a set of aluminium heads fro ebay and got them for $1000 delivered. That included 2.05 intake valves, 7/16 screw in studs, guiud plates and having the steam holes drilled. Again as far as any heating isues, it is no different than a 350.

Nutbar
04-07-2008, 11:17 AM
Yes 400's have to have steem holes in the heads. In order to fit a high lift cam in the vortec heads, my son ended up spending $1200 on them. I ordered a set of aluminium heads fro ebay and got them for $1000 delivered. That included 2.05 intake valves, 7/16 screw in studs, guiud plates and having the steam holes drilled. Again as far as any heating isues, it is no different than a 350.

[iagree] The 400s have steam holes in the block deck that need to be drilled in to any other head you put on them, you shouldn't need a machine shop to do it I carefully did my own using an old set of head gaskets as a guide.

With what is available in the aftermarket now the Vortech heads are a waste of money, as Bob said, it is cheaper to buy new aftermarket heads than to modify Vortechs to work and the aftermarkets will perform better as well.

As far as heating issues, if the cooling system is up to snuff then there should be no heating issues, the 400 I ran in my CJ stayed cool better than the 350 that I am running now.

Bent Black
04-09-2008, 12:04 AM
i run a 400 in my 64 lowrider never gets hot ideling in trafic i also drilled my own steam holes using the gasget. fan shrouds are very important as well! and if u do mud bogging flex fans suck! sitting in one spot reving 5+ the blades go flat causing les airflow through the rad.[cheers]

Jeep Victim
04-09-2008, 08:03 AM
Won't be much mud bogging in this truck,it's gonna be about 3 inches off the ground.Thank you for all the good and informative input,it is appreciated.

godtool
04-09-2008, 08:28 AM
I ran a 400 in my 81 Jimmy but doing a slow very steep hill climb (big huge rocks to navigate) for 6 k in 40 degrees+ heat I got vapor lock. I had a new 3 core rad, a long tranny cooler. I think I made a mistake of using a 3 bladed fan when I should have used a 5-6 bladed fan. BUT I'm certain there is other good pointers.

pumpkin
04-09-2008, 01:55 PM
I ran a 400 in my 81 Jimmy but doing a slow very steep hill climb (big huge rocks to navigate) for 6 k in 40 degrees+ heat I got vapor lock. I had a new 3 core rad, a long tranny cooler. I think I made a mistake of using a 3 bladed fan when I should have used a 5-6 bladed fan. BUT I'm certain there is other good pointers.


The 400 had nothing to do with the problem,,,,,,,, it would have done the same thing with a 305.

godtool
04-10-2008, 11:14 AM
Me understand! I'd still have the 400 but a rod bearing went, I had to move so I gave the 400 away for a $100 to Fortins in Chilliwack. I know, I know,. stupid move, should have kept it to rebuild one day.... As for an engine now I got a 305 again but have a 454 to go in one day.... but darn gas prices... once I buy a tandem trlr for it, I'll put in the 454. I have stock engine oil cooler for 454 too!

godtool
04-10-2008, 11:17 AM
My 400 also ran hotter then the 305. Great on those really cold days! Too make certain my cooling was better I put a 5 or 6 bladed fan on the 305, the one that came with the 454. But my temp gauge reads no different with more blades on fan. My 305 never got vapor lock until I put in the 400. But I guess the 5-6 bladed fan would have been better on the 400 on that hill climb rather a 3 bladed 305 fan??

godtool
04-10-2008, 11:21 AM
Better yet re-route the fuel lines away from the timing cover. I weas told but never did: put heat shielding around fuel line especially where exhaust pipe runs by fuel line on frame rail. Put electrical fuel pump in which again would remove fuel lines away from engine. I saw a guy with a coil of copper wire in a coffee can filled with dry ice when he was doing some kind of wheelin' at the fraser river. Really can't remember the details. I guess the dry ice would not last long?