HELP!!! Have rebuilt 455 with over heating problems. Had motor bored 30 over,new 10-1hypertetonics piston & rings, 113a poston cam, up graded valve springs,edelbrock performer intake, 1 inch carb. spacer,and ported heads. I have 2 1/4inch dual exaust with flow masters that I used on car last year, when I put stock 455 in 85 buick regal. This car did 14.245 in quarter mile till it spun bearings. Sinse rebuild I've taken it easy on motor to break it in. After 500 miles I decided to see what it would do. wow! Runs better than I thought it would. Problem is when I really get on it motor temp. jumps from 190 to 220 to 230 to boiling in about 10 minutes. With old combo never went above 190. Running same quadrajet carb. as last year,7042237 off 72 caddy 472. With improvements to engine,is this carb. to lean? Would this explain suden over heating problem? My rebuild book says to go up on jet size, but could a lean condition really make it get this hot that fast? I mean boiling in 10 minutes! If I cruise at 55 it stays arond 190. If it is too lean what size jets to I go to? any help you could give me would be greatly appreciated! I,ve already overheated to boiling point 4 times,and get sick thinking about the damage I'm doing to motor. Thanks Don DeVille
Hi Don. Let's get a little more info... You can cruise at 55 and stay cool. When you beat on it the temp goes up. Well, that part is normal. But when you beat on it are you stopping and starting? Like at the drags? Or are you tooling around town, beat on it, tool some more, beat on it, etc.? Reason I ask is because if you beat on it and get it hot, then immediatedly idle like in the pits, that could not allow sufficient cool down, especially if you have a bad fan clutch or an improper fan shroud. Are you running electric fans? Thanks.
I agree, i have similar .30 over with hypers, zero deck for 11 to 1 compession, those pistons run tight in the bore, and with mine it ran really hot the first 1000 miles, the three row wasnt enough, so i went to a 4 row at about 700 miles and then it would stay under 220 and would cruize at 210 on a hot day. now it has 1500 miles on it and will stay under 205, and will cruize at around 195 on a hot day, but it does jump up for a bit when i race but not over 215. i also had clutch ran problems, but that was a gitting hot at idle problem. i do think that know that the moter has loosend up that i could get by with a 3 row, but i would be just getting by. i dont think that running to lean on a water cooled moter would cause a over heating problem? hope this helps.
