Thread: Newbie question

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Ok, I have a 1979 Cutlass.
It has a 305, 4bbl and its giving me a headache(*what else is new*). lol. My question is.. What is the NORMAL oil pressure for a STOCK 305. And the fact temp.. This car came from New Mexico.. I am in Canada, I only drive it during july, aug. and sept. I'm not sure why but the previous owner had a 193 thermosat in there. If I put in a 160 is that to low? I was told that if the thermostat opens up to early, it can cause sludge and carbon build up.
I am running 10w30 and with the engine sittin at 190 it has about 20 PSI, Cold start 40-45. Here is what I cant figure out.. I just did the carb over.. It runs fine without bogging.. A little on the rich side by the smell of it.. It WAS surging when you hold it at a steady speed so I disconnected the vacuum to the EGR valve.. it stops surging.. However.. it now pings. Only under 1/4 throttle, and only when she gets past 150* Shoud I just advance my timing a degree or two to compensate for the EGR? or replace the egr before anything and see what happens.
ANy good results to switching to an HEI distributor on a factory 305?
I know thats alot of Q's... SOrry bout that.. I'll try to put them in different threads next time.
Thanks for the help

IMO, I would replace the EGR valve first and go from there.

no time to read the entire post, but 160 is way to low the engine has to reach 212 degrees F to evaporate all of the water and other crap in the engine, i have a 180 in mine and it will run at 175 -190 smoothely, its the same year but a 350, and about the other thing, why not change the timing 2 degreese, its free and it doesnt take long.

I was told that 212 was to high.. Usually 190-200 is running for me. a friend told me I would damage my heads if it got any hotter than 220. I'll give it a try it goes in storage next week so I'll keep posting till then, thanks for the help both of you!

I would run the 160 thermostat regardless....

What you have is a lean fuel condidtion....thats causing the surging....when you unplug the egr valve you are raising cylinder temps and that is causing the pinging...

First thing I would do is check the color of the plugs...You are probably going to have to jet it a little richer...

You may also have the 305 H.O model this can be noted by the use of and Aluminum hood (not steel) and and Aluminum deck lid too....

I had a 78 H.O. 305 and the whole dog house was aluminum as well as the deck lid....(magnet won't stick....just slides off)

Use a 190 thermostat at least, if its not boiling over it aint too hot. You do want your fuel to burn instead of condesing back into raw gas in the intake. Dont u? Plug off the egr for now and see how it runs when u adjust the timing. Then decide if u need a new egr. Or if u have the right octane for your compression ratio. If u dont know the comp. ratio, try raising the timing some and lowering the octane till u get a happy medium. Where it starts right, cold or hot and u get good accleration and smooth idle.

I disagree on the 190 temp....

The only reason to have one that hot is to pass an emissions test....

The hotter you run an engine the more fuel it needs to consume to make the same power....

If you run it at 160 it will take less fuel to make the same power and may also alleviate the lean condition.....my 2cents

If it's a stock motor then use whatever came in it for the Thermostat. I think it's 180. I am having problems with my truck running too rich right now and not starting very easily. One prob is that the Q Jet carb is old and needs rebuilt but then again there are millions of hoses and some aren't even hooked up and I can't find where they even go. I looked for places where hoses can go into and nothing to be found. I am going to keep up with this thread and see what you come up with because I have kind of the same problems.

I am quoting this from www.performanceunlimited.com website. Hope this clarifies things to some degree:

"However, there is a "middle ground" where both optimum performance as well as minimal wear share similar characteristics. That "magic" number lies in the 175-180 degree range, which requires a 180 degree thermostat. The all too commonly used 160 degree thermostat is way too low to be considered for performance or engine longevity. As the chart illustrates, engine wear increased by double at 160, than at 185 degrees. So then, why do the 160's exist in the first place? The 160's were commonly used in older, open loop cooling systems where only 6 pound radiator caps were used, and low 212 degree boiling points were experienced. In contrast, modern cooling systems can see upwards of 260 degrees in coolant temperature with radiator pressures exceeding 45 pounds. Many early hot rodders found the 160's to be better performing than the 190's, however, the in between "180" appears to satisfy both ends of the spectrum. The correct water temperature is required for the cylinders to achieve a minimum specific temperature in order to allow a fully homogenized Air/Fuel mixture to combust efficiently. Guess what the minimum number is… right! 180 degrees. Even so, you might see some still recommending the lower 160's, for no other reason than to possibly get that last drop of horsepower out, at the high price of dramatically reducing the life of the engine and it's internal components."

trying to think back, but the best i can remember surging was a big problem out of the show room. i dont think it was no way to get it out with the smog set up they had on them. seems like to me a lot of it was in the trans. lock up, and unpluging the lock up on the trans fixed a lot of it. you need to run a stock thermostate anyway. sounds like the egr is doing what its suppose to. check the trans. idea out.

im not 100% sure when they started the trans. lock up and this is assuming that it has it.

Good bit of info rumrumm thanks, I just learned something new.

Originally posted by FMXhellraiser
If it's a stock motor then use whatever came in it for the Thermostat. I think it's 180. I am having problems with my truck running too rich right now and not starting very easily. One prob is that the Q Jet carb is old and needs rebuilt but then again there are millions of hoses and some aren't even hooked up and I can't find where they even go. I looked for places where hoses can go into and nothing to be found. I am going to keep up with this thread and see what you come up with because I have kind of the same problems.

make shure your choke is working properly. I'v heard of numerouse accounts of 80's 305's hard starting due to malfunctioning chokes on the carbs( which is the first thing I would suspect on a hard starting carb'd engine anyway )., clean the choke and grease up the butterfly with some white spray grease, so it will unstick if it is stuck

Also FMX....look for an emissions manual...Autozone used to carry them...

They have the emissions hose routing for a lot of vehicles.....

So I have to wonder....My last 350 I built I got 210,000 on the rebuild and I used a 160 thermostat.... I also had 4.56 rear gears and 38in tall tires (1ton van) it got 18mpg in town and 24highway with a 350 turbo.....

So....If had I used a 180 thermostat I may have gotten 420,000 miles out of it..... Hell it'd still be running if I hadn't checked the oil and not ran it low and toasted the cam which in turn impregnated the bearings with crap....

any argument....

Originally posted by dr_bowtie
Also FMX....look for an emissions manual...Autozone used to carry them...

They have the emissions hose routing for a lot of vehicles.....

So I have to wonder....My last 350 I built I got 210,000 on the rebuild and I used a 160 thermostat.... I also had 4.56 rear gears and 38in tall tires (1ton van) it got 18mpg in town and 24highway with a 350 turbo.....

So....If had I used a 180 thermostat I may have gotten 420,000 miles out of it..... Hell it'd still be running if I hadn't checked the oil and not ran it low and toasted the cam which in turn impregnated the bearings with crap....

any argument....

A 1 ton van that gets 24 m.p.g. with out an overdrive and a 4.56 gear.All I can say is WOW.Are you an engineer for G.M.?

Erik, Notice the 38 inch tall tires too? Gotta take that into concideration.
Matt, your right I think that is the problem. My father said that he bets it is and keeps telling me that he thinks that is what it is. I greased everything up because the throttle stuck on me when I opened it up and stayed stuck until I beat the crap out of the gas pedal basically. I am going to just get a new Holley carb and Edelbrock intake manifold and hopefully that helps out. I may be able to get a guy to tune the Q Jet up and rebuild it for free. A friend of mine knows the guy and said that a Q Jet can get tuned and run just as good as a Holley. I have a Hot Rod or Chevy Performance mag SOMEWHERE that says the EXACT same thing. My dad thinks that we should just buy a nice Holley one instead, especially since we will be putting on the manifold and headers too. We will see.
dr_bowtie, Thanks for that bit of info man, I will check at auto zone and see what I can find.