Guest Posted August 28, 2001 Share Posted August 28, 2001 Hi I have just finished installing a rebuilt 455 into my 66 skylark<BR>it seems to be running hot the paint on the heads near the exhaust manifolds and on the intake in the center is turning dark this dosnt seem normal to me? engine specs are 9-1 comp mild crane cam stock intake and exhaust manifolds and a Q jet from a 350<BR>radiator is stock (car had 300 W/ac &st300)<BR>no shroud cant find one to fit yet Timing is set at 6 btc is this correct? seems to run cooler at 10btc but car runs worse<BR>any suggestions <BR>Thanks Jim Link to comment Share on other sites More sharing options...
Guest Posted August 28, 2001 Share Posted August 28, 2001 If your using a Qjet from a 350 maybe you have a lean condition and that would cause it to run hotter.<P> Pat Sweeney Link to comment Share on other sites More sharing options...
Guest Posted August 28, 2001 Share Posted August 28, 2001 I agrre with that last one. If you are using a carb from the 350 I would think you would for sure have a lean mix!<P>What size radiator? 3 or 4 row? What size fan?<P>Duane Link to comment Share on other sites More sharing options...
Guest Posted August 28, 2001 Share Posted August 28, 2001 Hi I'm not sure of the radiator core think its a 3 core the fan is stock off the 300<BR>the paint discoloration really worries me I dont want to burn up a new motor The carb being lean my be the trouble I pulled some plugs and they are burning really clean<BR>Anybody know where the timing should be set<BR>I found a list on the net that says anywhere from 2 to 10 deg btdc any suggestions?<P>Thanks for all your help<BR>Jim Link to comment Share on other sites More sharing options...
Guest Posted August 28, 2001 Share Posted August 28, 2001 One more thing on carbs<BR>If I do replace this one what are yor thoughts on holley 4160 , edelbrock 750 preformer or a rebuilt Q jet from say NAPA auto parts anyone have experiance with any of these options<P>Jim Link to comment Share on other sites More sharing options...
Guest Posted August 28, 2001 Share Posted August 28, 2001 I'm not sure about changing carbs, so I won't address that.<P>You say that the engine runs cooler at 10 btc. Are you seeing that on a temp guage, or just guessing from the paint discoloration? If you have not already, I would put a temp guage on the engine so you really know if it is running hot or not. Maybe it was just bad paint?<P>Also, I think you're going to need a fan shroud on there.<P>Regarding timing, my '69 350 seems to like it at 10 degrees btc initial and 36 degrees total (in by 2500).<P>Ron* Link to comment Share on other sites More sharing options...
Guest Posted August 28, 2001 Share Posted August 28, 2001 The discoloration of the paint sounds normal.<P>I'll assume your reading engine temp. from a mechanical temp. gauge?<P>Using the radiator from a 300 to cool a 455, I think their might be an issue there. Check the size of the radiator core from the doner car (of the 455) and see how it compares to the 300. I could be wrong but the 455 one is probably larger and twice as thick as the 300.<P>Just something to consider<BR>Good luck. Link to comment Share on other sites More sharing options...
GSMAG Posted August 28, 2001 Share Posted August 28, 2001 The paint is going to discolor. That's not a good indicator of an engine running hot. A trusty temp guage is what you need. Link to comment Share on other sites More sharing options...
Guest Posted August 28, 2001 Share Posted August 28, 2001 Thanks for the input<BR>I have not installed a temp gauge yet<BR>will do this week end <BR> the radiator dose puke up some coolent after running for a little bit maybe 4 times around the block temp light dosnt come on unles I shut engine off and turn key back on<BR> I dont have the rad from doner car so I cant compare it <BR>I will update on actual temp after gauge is installed also thinking of a coolent recovery tank ?<BR>again thanks for the replies I hope to get this figured out soon the car has been idle for to long<P>Jim Link to comment Share on other sites More sharing options...
GSMAG Posted August 29, 2001 Share Posted August 29, 2001 The rebuilds I've done all were a little on the warm side to begin with. After break in, it should run a little cooler. The fact that it pukes after 4 trips around the block is a good indicator that it is really running pretty hot. Let us know what it looks like once you've hooked up the temp guage.<p>[ 08-29-2001: Message edited by: GSMAG ] Link to comment Share on other sites More sharing options...
Guest Posted August 29, 2001 Share Posted August 29, 2001 Ok I put a gauge on it today <BR>this time it took a bit longer to get hot <BR>went up to 215 after a 15min or so drive<BR>around town it didnt puke but I heard some hissing around rad cap (new 13lb) I also disconected the vacume adv line and the car runs better still surges a little at idle<BR>timing is set at 10 deg I think springs a re worn on dist Is there a fan shroud the will fit this combo? I'm sure it would help<BR>all your help is appriciated<P>Jim Link to comment Share on other sites More sharing options...
GSMAG Posted August 30, 2001 Share Posted August 30, 2001 A fan shroud will make a substantial difference. Not sure about your application. Anyone else? Link to comment Share on other sites More sharing options...
Steve B Posted August 30, 2001 Share Posted August 30, 2001 You can use the the shroud from a 67 GS 400 in that application. Poston has a glass reproduction for around $115. Link to comment Share on other sites More sharing options...
Guest Posted August 31, 2001 Share Posted August 31, 2001 Today I made the stock shroud fit (alot of cutting) took it out for a drive temp went to 180 thermostat opened went to 160<BR>slowly climed up to 215 on the highway<BR>by the time I got back it was at 225<BR>turned it off didnt puke temp light never came on but when I went to start back up it turned over real slow like it was out of time<BR>also with the shroud on I could really hear the fan wheeer what gives this thing is driving me nuts!<P>Jim Link to comment Share on other sites More sharing options...
Guest Posted August 31, 2001 Share Posted August 31, 2001 From what you discribe I see only three possibilities as long as the thermostat is fully opening)<BR>Coolant circulating to fast.<BR>" " " slow.<BR>Radiator to small.<P>The first two are easy, do you have the original waterpump and crank pullies still on the 455? If yes, then OK. If no, then circulation could be a problem.<BR>The last one is self-explanatory. Link to comment Share on other sites More sharing options...
Guest Posted August 31, 2001 Share Posted August 31, 2001 Dale the pullys are stock 455<BR>thermostat and water pump are new<BR>I think I'll take the radiator out this weekend and have it checked<BR>I may just be to small<BR> Dose anyone know if a (dare I say it)<BR>Chevelle big block radiator will fit <BR>Chevy parts are so much easier to find <BR>Thanks for all the help<BR>Jim Link to comment Share on other sites More sharing options...
Guest Posted September 2, 2001 Share Posted September 2, 2001 Also, the stock 300 fan is a small 4 blade, upgrade to a larger flax fan with more blades. Every bit helps.. Link to comment Share on other sites More sharing options...
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