I swapped in a new heater core, and the temp, at least according to the stock guage, is up some, though not significantly. The point at which the t-stat opens also seems higher. Why would this occur?

JamesC

 

What was wrong with the heater core you replaced?

What else did you do when you replaced the core (like flush the radiator, perhaps)?

 

The old core was leaking sufficiently enough to pond the pass side floor board. I topped off with fresh coolant a couple of times after running the engine to operating temps and letting it cool.

JamesC

 

Reason I asked is increased flow through the new core, assuming the old core was partially clogged, would increase the bypass flow, which may increase coolant temp slightly. Flushing can have interesting effects, too.

Sounds like the system just shifted slightly. Doubt you've got anything to worry about.

 

While I have your ear, I've been considering an underdriven crank pulley. Would that cause any significant problems with engine temp?

JamesC

 

the power gain from an underdrive crank pulley is minimal at best, and the less out put from your accessories is not worth it.

save your money and spend it on exhaust, between the cherrybomb yohave which u is robbing performance, and sounds like ***. and the exhaust manifolds, there is a lot of power to found.

get some headers, and a cat back, you will be more than impressed with the results

 

I'm sure what you have to say is true, but I'm content with what I have for the moment. Any insight into the question?

JamesC

 

The underdrive will cause your alt. to spin slower, primarily at idle. That reduces it's ability to easily put out the amount of current it needs to produce to keep all accessories working properly, including the ignition system. This will cause it to wear out faster. How much? No idea.

Turning the water pump at a lower RPM will reduce the amount of GPM that's flowing through the cooling system. It's been argued time and time again, but the truth is, the more fluid you can flow per minute will cool better.

I don't know of any other pulleys that come with those kits since I've never even looked into buying them. Maybe the power steering? If so..... again, why would you want to slow down the pump at low RPM/slow speeds? That's when you need power assist the most.

The HP increase is usually minimal. I'm guessing ~5HP, maybe 10 at high RPMs on higher HP engines (350 or more), but the things I mentioned above aren't outweighed, IMHO.

Don't fall victim to the "UP to 20 HP increase". Remember... that's UP TO 20HP. That doesn't mean you'll gain that much.