70 Still getting hot, what else to look for?

340dart.812 said
the main thing that could be tight are the pistons to the clyinder walls and or the ring gap. what is the piston to wall clearance? what is the ring gap? If you used standard rings they are high tension and it will run hot untill they seat in alt least that is what i came up with after tearing my engine apart after around 600 very light miles on it due to overheating and its real close to what your engine is except I rebuilt the bottom end too and I just wanted to check and make sure I didnt mess something up building it. Upon dissasembly I noticed the pistons seemed to have exsessive friction comming from them I checked the crank and it turned really free so I rechecked the piston clearances I have kb hyperneumatic pistons so I set the piston to wall a little tighter cuz they dont expand as much as forged and I set the ring gap to what I thought was the reccomended clearance at .010 and .012 and my machinist said that they may be binding but the cylinder walls wernt scuffed so we decided to set the ring gap alot looser and it acually ended up with more cranking compression and it still ran hot for only about 350 or so miles and it only got hot at idle then it went away I acually switched to a alum rad during this also before tearing it apart and it made it a little better but didnt fix it this is just a thought if you have covered all the regular cooling basics like you mentioned. good luck

I honestly couldn't say, I could call the machinst, but its been so long I doubt he remembers. I am running KB hypers also, KB116CP IIRC. Maybe I just need to drive it more??

demon seed said
Have you got the coil spring inside the lower rad hose. Being left out could cause overheating on the highway when engine is reving.

Terry

360scamp said
Thats what I was thinking, maybe it is sucking it self shut. I had that happen on my old 73 scamp. Also have you "burped" the cooling system?

System is burped, they don't seem to make the springs anymore, so I cut down and coiled up a coat hanger.

70Duster440 said
You might try bumping the timing up 3-4 degrees.

Will do, I need to check it anyway cause I'm not %100 sure on what the timing is set at anyway.

demon seed said
He also said it got up to 240 in traffic and I guess I should have asked how long it was idling in front of his shop to get up to 210 deg.

Terry

Took about 10 minutes to hit that temp.

kanders said
Lars, you said you had a clutched fan, is it operating correctly? Do you have a fan shroud whick fits the fan correctly (far enough into the shroud and a correct diameter. Kev

I assume its working, I can't hear it working, it only has about 300 miles on it (like everything else). I had to fab the shroud, its pretty ugly, it has about 1/2 to 3/4 of an inch all the way around (I couldn't get it perfectly round).