Hey guys,
I recently rebuilt the 327 SB in my 69' El Camino and just got it back in and running. The rebuilt was just to replace replace the main and rod bearings and put in new rings. The heads were resurfaced but the block was not and did not need to be honed either. I did not make any performance upgrades or even replace any other parts (The engine was already recently built up before I acquired the car. An unnoticed oil leak forced the rebuild after ruining the bearings).

After I got the engine back in the car, running, and the timing set, I noticed that the temperatures of the header pipes were unusual. I used an inferred thermometer to take the temperature of each header pipe with the engine at normal temperature. On the passenger side header all the pipes were between 375-415 degrees F, which seems normal to me although I don't know what exhaust temp is usually like. On the driver side header though, the #1 cylinder only read around 110 degrees, the #3 cylinder around 130-140, the #5 around 230 degrees, and the #7 cylinder around 330-340 degrees.

I'm not sure what could cause this problem or what it really even means but I'm guessing that with exhaust as low as 100 degrees I must be losing a big chunk of performance. I have triple checked the timing and also reset the valve lash for both heads and had no change. Does any one have any ideas about what could be causing this problem or how to fix it?  One person suggested that the hydraulic flat-tappet lifters may be shot and need replacing. Could this be the Cause?

Thanks for any help,
Kevin  

Very poor mixture distribution possibly could be the culprit - but that is an awfully large temp drop across several cylinders.

I would imagine something is inhibiting the valves but you would notice it elsewhere. Is the engine running fine otherwise?  

Welcome to the forums, and I hope you solve the issue with your motor.  

Hey Guy, I know this might be a stupid question, but when they just done the refresh did they strip the block and take it and have it flushed and new cam bearings installed. Also sound like you have a solid lift cam with it have been starving for oil when it spun the bearings you may have cam lobs going down.{note} do not replace the lifters on a solid lift cam with out replacing cam !! Also when the refresh was done the lifters should have been put back in the same hole where they came out of, it can cause problems if not done so. Pull the  valve cover off the driver side and disable ignition by coil wire or b+ wire off of dis cap, spin engine over and see if by looking across the rocker arms if they all are moving the same amount of distance, I know this is not a exact science but it will give you a ideal maybe if a lobe is down!

p.s. I was a GM tech for 22yrs before coming disabled this keep me from going crazy sometimes but if someone does not agree with me or I'm wrong I'm not to old to learn or admit when I'm wrong!!!

thanks
Lee  

Hey guys, thanks for the replies. The cam bearings were replaced during the rebuild but the cam and lifters were not. I made sure to keep the lifters in order and put them back into the same holes they came out of. I don't know too much about cams so it could have been that the lobes are worn and I just did not notice it. I will check the travel of each rocker and see how they compare.
Thanks for the advice,
Kevin  

hey guy, please keep us posted what you find.

thanks
Lee  

not so sure this is or isn't the cam? have seen worn cam lobes befor and this caused over heating not drop in different temps. over all the pistons. the psgr. header temps. sound normal, yes try a new set of lifters. hopr this helps, piston head.