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-   -   Warm up problems 305E (https://6066gmcclub.com/showthread.php?t=50571)

AZKen March 22nd, 2019 01:52 AM

Warm up problems 305E
 
It's in the 60's here during the day. I don't call that cold. My truck takes a long time to warm/run good. It does finally run good. Choke has to stay on for a few miles. Runs really good after that. Been doing that for months. A little worse when it was colder here. I did leave off the heat riser.
Read here that many leave it off with no problems in much colder states. So do I need it or is this some fuel delivery problem? Been thinking that because I don't start it much that the bowl dries out, but should not take that long to refill? New pump and lines and filters and tank. So what do you think this could be? It was 66 today when I ran it. How long does everyone's motor take to warm up? Are these motors so well designed for cooling that this is normal? Thermostat is 180 I think. Can't remember.

LEWISMATKIN March 22nd, 2019 02:04 AM

Re: Warm up problems 305E
 
My first 305 was cold-natured for 2 reasons. (1) I increased the size of the radiator from 2 row core to a 4 row core, and (2) I ran Kendall SD3 SAE 40 engine oil in it. Also, winter time in Cullman could get below 0'F occasionally and hang at a consistant 32'F during dec.-mar. My fix- Install 2 engine heaters in the block, and cut a piece of cardboard to cover part of the radiator. Hope this helps.

Cordially,
Lewis Ellis Matkin, Jr.

ilvracn March 22nd, 2019 03:09 PM

Re: Warm up problems 305E
 
v-6 engine has alot of iron to warm up, they weigh more than a big block chevy. i would say it should take more time to warm up. mine has a manual choke, i can usually push it clear in after a short drive.

James March 22nd, 2019 04:21 PM

Re: Warm up problems 305E
 
1 Attachment(s)
I have my heat riser valve wired open. I am using a 195° F thermostat. My truck take about 5-6 miles of driving 45 mph to reach the normal (N) mark, at 30-40°F OAT. I have a stock 3 rows radiator. The truck takes 8 gallons of coolant, with that much cooling capacity it takes a while to warm up. On my other 1979 Chevy truck with a V-8 it only hold 4 gallons 1.5 quarts of coolant. It only takes a couple of miles to warm up. My minivan only take 1 mile to warm up. The only non-stock thing I did was to find a air breather (don't know what it originally fit) the fit the Stromberg carburetor with a hot air duct. Made an adapter from a short piece of tail pipe and attached it to the right exhaust manifold with a worm clamp (see picture). Inside the breather there is a thermostatically controlled valve that run on vacuum. It regulate the temperature going into the carburetor.

AZKen March 22nd, 2019 09:40 PM

Re: Warm up problems 305E
 
Thank you very much everybody. Keep the info coming. I have the original rad. Everything original. I can't figure 66 degree outside temp would cause this. I know that on straight 6 that the exhaust is right under the carb and the heat riser would be super efficient. I don't see how one manifold, on one side, could heat the manifold/carb very efficiently on a V6 or V8. That may be the answer...it doesn't work so well especially as ilvracn says, lots of iron to heat up. That's why the internal cooling passages are so robust. It's also a lot of iron to cool back down.
James, you say it takes 4-5 miles to reach temp on gauge. My questing is about how it runs in that 4-5 miles.
Maybe I will just have to keep using the choke until I install the heat riser. If that does not give results, I will start thinking other things....... Like what?
I tested my heat riser yesterday with a heat gun and it worked really well. Next time I test it, I will use my laser temp gun to see what temps it operates at.

James March 22nd, 2019 10:51 PM

Re: Warm up problems 305E
 
I have to use the choke for the first half mile or so. Before I installed the hot air pipe I had to use the choke for about a mile or two. The exhaust heat up the incoming air through the hot air pipe making the engine see 70° air, better fuel atomization.


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