I read a couple of threads on here about engine temp, but I'm still not sure if I'm too rich or if the problem is more complicated than that. I have a small block 350 with way too much cam and I think too much carb. I don't know what heads I have, but they are iron and probably nothing special. The car is pretty gutless, and my temp rarely goes over 125 degrees. I read that I shouldn't trust the gauge in the car too much so I'll try to pick up an infrared thermostat and check the engine against that. My question is this, does running that cool indicate that I'm too rich? The car bogs down especially starting in first gear and generally makes very little power. My brother has a 69 with a 4 bolt camaro 350 that pulls a lot harder than my car and I don't think it's a really hot motor or anything. I have dual quads, I think edelbrock 500cfm, it is setup so that at part throttle only one carb opens and one remains closed but I'm wondering if this setup is part or all of my problem. I'm considering a 650 holley double pumper, I already have an edelbrock performer manifold and I'm thinking this would help the situation. The cam is a comp cams solid lifter, I think .525 lift, car does seem to suffer from low vacuum, my headlights work but are slow and the passenger side always moves last, usually have to rev the engine a little to get it to close or open. What do you think, will a smaller single carb setup work better? Should I try leaning the carbs I have? I also have an 70s LT-1 cam, would this be a better match for my engine?

 

Forgot to mention, I think I'm getting about 10mpg right now mixed in town and on highway if my fuel gauge is accurate. My brother's car seems to use less gas, not sure how much but enough to be noticeable at least by looking at the gauge while driving around.

 

it's hard to say if oversized carburetion is THE problem, but on a relatively stockish 350, dual 50cfm carbs are A problem for sure

 

Did you say your temperature does not raise past 125? That is below normal operating temperatures. You always want to get up to operating temps quickly. That is the primary purpose of the thermostat.

 

Yeah, at least according to the gauge in the car it never goes over 125 or so. Didn't have any luck finding a thermometer to check the actual temp in town, I was hoping to find something like this http://www.professionalequipment.com...d-thermometer/ but I'm inclined to think that the gauge is right and the engine is way too rich.

Could the thermostat being wide open cause this if the carbs were not rich?

 

yes, but it's more likely that the thermostat is not installed usually, even an open thermostat will give you more than 125F. the carbs being adjusted to too rich a mixture will not cause operating temps to remain that low. the thermostat would still keep closed until the car got up to operating temp.

 

OK, well I will pick a new thermostat, what temperature do I need 160, 180? Thanks for your help.

 

doesnt matter *that* much which you choose. a lot of 'vette guys are of the school of thought that c3s were designed to run hotter than most cars, but i live in AZ and like to see the cars run as cool as possible, so we always run 160s. either way, you'll get the car up to a better operating temperature, where adjusting those carbs will be much more accurate.

 

Before anything, you need to check your timing. Its easier and cheaper to check it yourself, and you will know for sure where it is after that.

Sean

 

true story.

 

Unless you intend to drag race the car, a dual-quad setup is probably really way more than you're gonna need for the street. it sounds like the engine was built using the old "If some is good, then way too much should be just about right" method which doesn't work any better today than it did twenty (or thirty or forty) years ago. C3's frequently do have temperature issues but not the ones you're having- I agree that you're probably missing the thermostat completely, and a good quality 180 degree unit should get you the kind of operating temp that you ought to be running at. As mentioned by others, no amount of overrichness would cause an engine to run THAT cold unless you're in Minnesota this time of year. With your cam (assuming you don't want to change it) a 700 cfm Holley double pumper would probably be a better choice as the 650 would starve for air slightly at the upper rpm ranges. WITH ALL THAT SAID, methinks you still need to check some basics like ignition timing and if that's good I would then begin to suspect that the cam may have been installed one (or maybe even two) teeth off. I dunno if an SBC would even run with the cam that far out but by the way you describe it it sounds like something internal could be seriously out of whack.....

 

The valve lash and timing were adjusted by my brother's mechanic before I picked up the car, I can't say that it is right but the guy who did it works on corvettes all day and probably did a better job than I would. I will check this later, but I've never done it and will need to pick up a timing light and some instructions. I think I'll pick up a tstat tomorrow and put that in. To check the cam installation I need to take off the water pump and the timing chain cover?

Also, I have an edelbrock 750 that I was going to sell, I was thinking this was still more carb than I need and I was told that a holley double pumper would give better low end response. Any thoughts on using this carb or should I just find a holley 700?